Dengue History

History of Dengue

2011-09-21T03:23:00.001-07:00

History of Dengue

The first reported epidemics of dengue fever occurred in 1779-1780 in Asia, Africa, and North America; the near simultaneous occurrence of outbreaks on three continents indicates that these viruses and their mosquito vector have had a worldwide distribution in the tropics for more than 200 years. During most of this time, dengue fever was considered a benign, nonfatal disease of visitors to the tropics. Generally, there were long intervals (10-40 years) between major epidemics, mainly because the viruses and their mosquito vector could only be transported between population centers by sailing vessels.

A global pandemic of dengue began in Southeast Asia after World War II and has intensified during the last 15 years. Epidemics caused by multiple serotypes (hyperendemicity) are more frequent, the geographic distribution of dengue viruses and their mosquito vectors has expanded, and DHF has emerged in the Pacific region and the Americas. In Southeast Asia, epidemic DHF first appeared in the 1950s, but by 1975 it had become a leading cause of hospitalization and death among children in many countries in that region.

Current Trends

In the 1980s, DHF began a second expansion into Asia when Sri Lanka, India, and the Maldive Islands had their first major DHF epidemics; Pakistan first reported an epidemic of dengue fever in 1994. The recent epidemics in Sri Lanka and India were associated with multiple dengue virus serotypes, but DEN-3 (one of the subtype of Dengue viruses) was predominant and was genetically distinct from DEN-3 viruses previously isolated from infected persons in those countries. After an absence of 35 years, epidemic dengue fever occurred in both Taiwan and the People's Republic of China in the 1980's. The People's Republic of China had a series of epidemics caused by all four serotypes, and its first major epidemic of DHF, caused by DEN-2, was reported on Hainan Island in 1985. Singapore also had a resurgence of dengue/DHF from 1990 to 1994 after a successful control program had prevented significant transmission for over 20 years. In other countries of Asia where DHF is endemic, the epidemics have become progressively larger in the last 15 years.

In the Pacific, dengue viruses were reintroduced in the early 1970s after an absence of more than 25 years. Epidemic activity caused by all four serotypes has intensified in recent years with major epidemics of DHF on several islands.

Despite poor surveillance for dengue in Africa, epidemic dengue fever caused by all four serotypes has increased dramatically since 1980. Most activity has occurred in East Africa, and major epidemics were reported for the first time in the Seychelles (1977), Kenya (1982, DEN-2), Mozambique (1985, DEN-3), Djibouti (1991-92, DEN-2), Somalia (1982, 1993, DEN-2), and Saudi Arabia (1994, DEN-2). Epidemic DHF has been reported in neither Africa nor the Middle East, but sporadic cases clinically compatible with DHF have been reported from Mozambique, Djibouti, and Saudi Arabia.

The emergence of dengue/DHF as a major public health problem has been most dramatic in the American region. In an effort to prevent urban yellow fever, which is also transmitted by Aedes aegypti, the Pan American Health Organization (PAHO) organized a campaign that eradicated Ae. aegypti from most Central and South American countries in the 1950s and 1960s. As a result, epidemic dengue occurred only sporadically in some Caribbean islands during this period. The Ae. aegypti eradication program, which was officially discontinued in the United States in 1970, gradually eroded elsewhere, and this species began to reinfest countries from which it had been eradicated. In 1997, the geographic distribution of Ae. aegypti is wider than its distribution before the eradication program (see Figure 1 below).

Figure 1. Distribution of Aedes aegypti (red)
in the Americas in 1970 and in 1997.

In 1970, only DEN-2 virus was present in the Americas, although DEN-3 may have had a focal distribution in Colombia and Puerto Rico. In 1977, DEN-1 was introduced and caused major epidemics throughout the region over a 16-year period. DEN-4 was introduced in 1981 and caused similar widespread epidemics. Also in 1981, a new strain of DEN-2 from Southeast Asia caused the first major DHF epidemic in the Americas (Cuba). This strain has spread rapidly throughout the region and has caused outbreaks of DHF in Venezuela, Colombia, Brazil, French Guiana, Suriname, and Puerto Rico. By 1997, 18 countries in the American region had reported confirmed DHF cases (Figure 2), and DHF is now endemic in many of these countries.

Figure 2. American countries with DHF cases (red), before 1981

and from 1981 to 1997.

DEN-3 virus recently reappeared in the Americas after an absence of 16 years. This serotype was first detected in association with a 1994 dengue/DHF epidemic in Nicaragua. Almost simultaneously, DEN-3 was confirmed in Panama and, in early 1995, in Costa Rica. In Nicaragua, considerable numbers of DHF cases were associated with the epidemic, which was apparently caused by DEN-3. In Panama and Costa Rica, the cases were classic dengue fever.

Viral envelope gene sequence data from the DEN-3 strains isolated from Panama and Nicaragua have shown that this new American DEN-3 virus strain was likely a recent introduction from Asia since it is genetically distinct from the DEN-3 strain found previously in the Americas, but is identical to the DEN-3 virus serotype that caused major DHF epidemics in Sri Lanka and India in the 1980s. As suggested by the finding of a new DEN-3 strain, and the susceptibility of the population in the American tropics to it DEN-3 spread rapidly throughout the region caused major epidemics of dengue/DHF in Central America in 1995.

In 1997, dengue is the most important mosquito-borne viral disease affecting humans; its global distribution is comparable to that of malaria, and an estimated 2.5 billion people live in areas at risk for epidemic transmission (please click HERE to see map). Each year, tens of millions of cases of dengue fever occur and, depending on the year, up to hundreds of thousands of cases of DHF. The case-fatality rate of DHF in most countries is about 5%; most fatal cases are among children and young adults.

There is a small, but significant, risk for dengue outbreaks in the continental United States. Two competent mosquito vectors, Ae. aegypti and Aedes albopictus, are present and, under certain circumstances, each could transmit dengue viruses. This type of transmission has been detected three in the last 16 years in south Texas (1980, 1986, and 1995) and has been associated with dengue epidemics in northern Mexico. Moreover, numerous viruses are introduced annually by travelers returning from tropical areas where dengue viruses are endemic. From 1977 to 1994, a total of 2,248 suspected cases of imported dengue were reported in the United States. Although some specimens collected were not adequate for laboratory diagnosis, 481(21%) cases were confirmed as dengue. Many more cases probably go unreported each year because surveillance in the United States is passive and relies on physicians to recognize the disease, inquire about the patient's travel history, obtain proper diagnostic samples, and report the case. These data suggest that southern Texas and the southeastern United States, where Ae. aegypti is found, are at risk for dengue transmission and sporadic outbreaks.

The reasons for this dramatic global emergence of dengue/DHF as a major public health problem are complex and not well understood. However, several important factors can be identified.

First, effective mosquito control is virtually nonexistent in most dengue-endemic countries. Considerable emphasis for the past 20 years has been placed on ultra-low-volume insecticide space sprays for adult mosquito control, a relatively ineffective approach for controlling Ae. aegypti.

Second, major global demographic changes have occurred, the most important of which have been uncontrolled urbanization and concurrent population growth. These demographic changes have resulted in substandard housing and inadequate water, sewer, and waste management systems, all of which increase Ae. aegypti population densities and facilitate transmission of Ae. aegypti-borne disease.

Third, increased travel by airplane provides the ideal mechanism for transporting dengue viruses between population centers of the tropics, resulting in a constant exchange of dengue viruses and other pathogens.

Lastly, in most countries the public health infrastructure has deteriorated. Limited financial and human resources and competing priorities have resulted in a "crisis mentality" with emphasis on implementing so-called emergency control methods in response to epidemics rather than on developing programs to prevent epidemic transmission. This approach has been particularly detrimental to dengue control because, in most countries, surveillance is (just as in the U.S.) very inadequate; the system to detect increased transmission normally relies on reports by local physicians who often do not consider dengue in their differential diagnoses. As a result, an epidemic has often reached or passed transmission before it is detected.

Future Outlook

No dengue vaccine is available. Recently, however, attenuated candidate vaccine viruses have been developed in Thailand. These vaccines are safe and immunogenic when given in various formulations, including a quadrivalent vaccine for all four dengue virus serotypes. Efficacy trials in human volunteers have yet to be initiated. Research is also being conducted to develop second-generation recombinant vaccine viruses; the Thailand attenuated viruses are used as a template. Therefore, an effective dengue vaccine for public use will not be available for 5 to 10 years.

Prospects for reversing the recent trend of increased epidemic activity and geographic expansion of dengue are not promising. New dengue virus strains and serotypes will likely continue to be introduced into many areas where the population densities of Ae. aegypti are at high levels. With no new mosquito control technology available, in recent years public health authorities have emphasized disease prevention and mosquito control through community efforts to reduce larval breeding sources. Although this approach will probably be effective in the long run, it is unlikely to impact disease transmission in the near future. We must, therefore, develop improved, proactive, laboratory-based surveillance systems that can provide early warning of an impending dengue epidemic. At the very least, surveillance results can alert the public to take action and physicians to diagnose and properly treat dengue/DHF cases.

Dengue fever

2011-09-21T03:22:00.001-07:00

Dengue Fever

O'nyong-nyong fever; Dengue-like disease; Breakbone fever

Last reviewed: August 28, 2009.

Dengue fever is a virus-based disease spread by mosquitoes.

Dengue hemorrhagic fever

Hemorrhagic dengue; Dengue shock syndrome; Philippine hemorrhagic fever; Thai hemorrhagic fever; Singapore hemorrhagic fever

Last reviewed: December 7, 2010.

Dengue hemorrhagic fever is a severe, potentially deadly infection spread by certain species of mosquitoes (Aedes aegypti).

What is dengue fever?

Dengue fever is a disease caused by a family of viruses that are transmitted by mosquitoes. It is an acute illness of sudden onset that usually follows a benign course with symptoms such as headache, fever, exhaustion, severe muscle and joint pain, swollen glands (lymphadenopathy), and rash. The presence (the "dengue triad") of fever, rash, and headache (and other pains) is particularly characteristic of dengue. Other signs of dengue fever include bleeding gums, severe pain behind the eyes, and red palms and soles.
Dengue (pronounced DENG-gay) can affect anyone but tends to be more severe in people with compromised immune systems. Because it is caused by one of four serotypes of virus, it is possible to get dengue fever multiple times. However, an attack of dengue produces immunity for a lifetime to that particular serotype to which the patient was exposed.
Dengue goes by other names, including "breakbone" or "dandy fever." Victims of dengue often have contortions due to the intense joint and muscle pain, hence the name breakbone fever. Slaves in the West Indies who contracted dengue were said to have dandy fever because of their postures and gait.
Dengue hemorrhagic fever is a more severe form of the viral illness. Symptoms include headache, fever, rash, and evidence of hemorrhage in the body. Petechiae (small red or purple splotches or blisters under the skin), bleeding in the nose or gums, black stools, or easy bruising are all possible signs of hemorrhage. This form of dengue fever can be life-threatening and can progress to the most severe form of the illness, dengue shock syndrome.

Dengue fever facts

2011-09-21T03:21:00.001-07:00

Dengue fever facts

Dengue fever is a disease caused by a family of viruses that are transmitted by mosquitoes.
Symptoms such as headache, fever, exhaustion, severe joint and muscle pain, swollen glands (lymphadenopathy), and rash. The presence (the "dengue triad") of fever, rash, and headache (and other pains) is particularly characteristic of dengue fever.

Dengue is prevalent throughout the tropics and subtropics. Outbreaks have occurred recently in the Caribbean, including Puerto Rico, the U.S. Virgin Islands, Cuba, and in Paraguay in South America, and Costa Rica in Central America.
Because dengue fever is caused by a virus, there is no specific medicine or antibiotic to treat it. For typical dengue fever, the treatment is purely concerned with relief of the symptoms (symptomatic).
The acute phase of the illness with fever and myalgias lasts about one to two weeks.
Dengue hemorrhagic fever (DHF) is a specific syndrome that tends to affect children under 10 years of age. It causes abdominal pain, hemorrhage (bleeding), and circulatory collapse (shock).
The prevention of dengue fever requires control or eradication of the mosquitoes carrying the virus that causes dengue.
There is currently no vaccine available for dengue fever.

Dengue fever symptoms

2011-09-21T03:20:00.001-07:00

Dengue fever is a very common disease in many tropical countries, especially South America, sub-Saharan Africa, India and Southeast Asia. It is caused by a virus that is transmitted by mosquitoes of the Aedes genus. After 1-2 days of incubation the next dengue fever symptoms appear: high fever, joint pain, reddish spots on the skin. Other dengue fever symptoms are headache and muscle pain. In some cases the patient also feels loss of appetite or a vomiting sensation.
Dengue fever may be complicated and result in Dengue hemorrhagic fever. This complication usually occurs in people who have previously suffered from this disease. Initially it produces more bleeding in various places in the body and there are some small red spots (petechiae) in the skin that occur because of small blood vessels rupture in the skin. Then may also occur disseminated intravascular coagulation, or blood coagulates in blood vessels. This is a body reaction to lack of oxygen due to blood loss.
Dengue fever symptoms usually appear after 4 to 7 days. These are usually symptoms similar to influenza, such as high fever or pain behind the eyes. Dengue fever is also called breakbone fever because of the joint pain. Some people show no symptoms. In more severe cases, infected people (about 1%) may suffer from dengue haemorrhagic fever. Dengue hemorrhagic fever can possibly cause a shock. With adequate medical care, death occurs in only 1% of cases.

Clinical dengue fever symptoms

Generally mild, dengue fever usually heals spontaneously within a week without sequelae. In some sever case it can be fatal. The incubation period of dengue virus lasts 48 hours to 7 days but more rarely up to 15 days. After this incubation period, the early physical symptoms caused by the disease are felt.
Dengue fever symptoms in fact reflect the immune response of our body:

High fever (39 ° - 40 °)
Asthenia
Severe headache
Intense muscle pain and joint pain (arthralgia)
Macular erythematous rash
Generalized lymphadenopathy
Moderate hepatomegaly.

Typically fever reappears a few days later. In most cases the dengue fever symptoms have short life. But sometimes, there is a severe worsening of the condition with an increase of dengue fever symptoms, and clinical signs indicate a coagulation disorder (level tasks purpuric skin bleeding from the nose or gums). This transformation of the disease between the second and the fifth day guide to the more severe form of hemorrhagic dengue especially if one is in a context of strong epidemiological prevalence of this form.
Recovery time is usually very long.

Dengue is an acute, febrile infectious disease caused by a virus of Flaviridae family and is transmitted through the mosquito Aedes aegypti. Currently, dengue fever is considered a major public health problems world wide.
Worldwide, there are four types of dengue fever since the virus causing the disease has four serotypes: DEN-1, DEN-2, DEN-3 and DEN-4.

Dengue fever symptoms

Dengue can present clinically in four different ways: silent infection, dengue fever, Dengue hemorrhagic fever and dengue shock syndrome. Among them stand out classical dengue fever and dengue hemorrhagic fever.
...read a complete description of dengue fever symptoms: Dengue fever symptoms

Dengue fever treatment

If you have fever and headache you should take paracetamol and you should avoid as much as possible aspirin because it can cause bleeding. There is no specific treatment and the patient should treat symptoms.

Dengue fever vaccine

There is no dengue fever vaccine but exists some possible vaccines. Specialists work hard in order to establish which is the most indicated.

Silent infection

The person is infected with the virus but shows no symptoms. The vast majority of dengue infections have no symptoms.

Classic dengue fever

Dengue fever lasts for 5-7 days. The infected person has high fever (39 ° to 40 ° C), headache, tiredness, muscle aches and joint pain, malaise, nausea, vomiting, red spots on the skin, abdominal pain (especially in children).
The dengue fever symptoms are lasting up to one week. After this period, the person may still feel tired and unwell.

Dengue Hemorrhagic

Dengue hemorrhagic fever is a serious disease and is characterized by changes in blood coagulation of the infected person. Initially is resembling dengue classic, but after the third or fourth day of the disease arise bleeding because of the bleeding of small vessels and in the internal organs. Among dengue hemorrhagic fever symptoms are nosebleeds, gingival, urinary, gastrointestinal or uterine bleeds. In dengue hemorrhagic fever, the patient's blood pressure drops, which can cause dizziness, collapse and shock. If the disease is not treated quickly, can lead to death.
...read a complete description of dengue hemorrhagic fever symptoms: Dengue hemorrhagic fever symptoms.

Dengue shock syndrome

This is the most serious presentation of dengue fever and is characterized by a large drop or absence of blood pressure. The person affected by the disease has an almost imperceptible pulse, restlessness, pallor and loss of consciousness. In this type of presentation of the disease, there are records of various complications such as neurological, cardio respiratory problems, liver failure, gastrointestinal bleeding and pleural effusion.
Among the main neurological manifestations, are: delirium, drowsiness, depression, coma, extreme irritability, psychosis, dementia, amnesia, paralysis and signs of meningitis. If the disease is not treated quickly, can lead to death.
Dengue fever is an infectious disease transmitted by mosquitoes. It is causing a severe flu-like illness and sometimes potentially lethal complication called dengue hemorrhagic fever. Globally, the incidence of dengue has grown dramatically in recent decades. About two-fifths of the world's population are now at risk. Dengue is found in the tropics and subtropics of the world, with a predilection for urban and semi-urban areas. Dengue hemorrhagic fever is a major cause of illness and death among children in some Asian countries. There is no specific treatment, but medical care is frequently adapted to the life of patients suffering from dengue hemorrhagic fever. The only way to prevent transmission of dengue hemorrhagic fever is to fight against the mosquito vectors.
Dengue hemorrhagic fever, was recognized for the first time in 50 years during epidemics in the Philippines and Thailand, but today is found in most Asian countries and in many of them, it is now a major cause of hospitalization and mortality for children.
The four dengue viruses are very closely related. Infection with a second virus, increases the risk of more serious disease with bleeding complication. The global impact of dengue has grown dramatically in recent decades. Approximately 2.5 billion people, two fifths of the world population, are now at risk. In 2007 alone, over 890,000 cases were reported in the Americas, including 26,000 cases of dengue hemorrhagic fever. In 2007, Venezuela reported over 80,000 cases, including at least 6,000 cases of dengue hemorrhagic fever.

Other statistics:

It is estimated that each year are 500,000 cases of dengue hemorrhagic fever, including a very high proportion of children which require hospitalization. Death occurs in at least 2.5% of cases.
Without proper treatment, the fatality rate of dengue hemorrhagic fever can exceed 20%. Doctors and nurses who know how to recognize symptoms and treat the effects, can reduce death rates to less than 1%. Dengue hemorrhagic fever is a serious illness, with an increased risk of mortality. It is caused by Marburg virus, which is part of the same family as Ebola hemorrhagic fever virus producing. These are some of the most virulent pathogens known.

The disease has a sudden onset with severe headache, located mainly at frontal and occipital bones. The early symptoms are not specific and therefore clinical diagnosis is made difficult. Acute phase is characterized by fever, abdominal pain and cramps, severe diarrhea, nausea.
Dengue hemorrhagic fever (DHF), is a potentially fatal disease, and it is characterized by loss of appetite, vomiting, abdominal pain, symptoms of shock and bleeding from the nose or under the skin. The occurrence of DHF may be associated with those who suffer a second infection or immunodeficiency, or who are under 15 years. DHF can be fatal.

Dengue fever prevention

Even if it doesn't exist any vaccine there are some personal measures that everyone can take in order to avoid dengue. The most important thing is to avoid areas where the mosquitoes are present. People should cover up and use an insect repellent. You should take care because the repellent can be dangerous if you don't wash your hands after you used it.Take care with kids because their skin is more sensitive. It is very well if you can sleep under a net treated with insecticide.

Dengue hemorrhagic fever

2011-09-21T03:19:00.001-07:00

It is known that four dengue virus causes dengue hemorrhagic fever. This condition appears when one gets two different viruses that cause dengue. Worldwide appear millions of cases of dengue fever each year and a small percentage transform into dengue hemorrhagic fever.

Dengue hemorrhagic fever symptoms

Initial symptoms include the following:

Decreased appetite
Fever
Headache
Joint pain
Muscle aches
Vomiting

Symptoms of acute phase

ecchymosis
generalized rash
petechiae
worsening of initial symptoms
restlessness
shock
chills
sweating

A physical examination may indicate the following:

Liver enlargement (hepatomegaly)
Hypotension
Rash
Bloodshot eyes
Red throat
Lymphadenopathy
Rapid and weak pulse

Tests include the following:

Arterial blood gas
Coagulation studies
Electrolytes
Hematocrit
Liver enzymes
Platelet count
Serologic studies
Tourniquet test
Chest x-ray (may demonstrate pleural effusion)

Treatment

Only symptoms may be treated, as dengue hemorrhagic fever is triggered by a virus that yet does not have a specific cure.

Electrolyte imbalances is corrected by electrolytes and Intravenous fluids
Fresh blood transfusion help in correcting any bleeding troubles
Blood oxygen levels must be treated as they tend to get very low. Oxygen therapy is usually necessary

Dengue hemorrhagic fever prognosis

Most patients with dengue hemorrhagic fever recover with early intense care. The patients that usually do not survive are those who go into shock.

Dengue hemorrhagic fever complications

Encephalopathy
Residual brain damage
Liver damage
Seizures
Shock

Dengue fever treatment

2011-09-21T03:18:00.001-07:00

Dengue fever usually presents no complications, but there are some severe and rare hemorrhagic forms, which involves a doctor. And avoid self-medication, including taking aspirin-cons who is formally specified, because it will increase the risk of bleeding.
There are no specific dengue fever treatment. In order to keep under control dengue fever the patient should take some measures. For example platelet transfusions are often used or the patient can lower temperature or pain using the usual forms which dependend on the patient. If the patient has nausea intravenuos hydration is required. Non steroidal anti -inflammatory drugs are also prohibited. In case of myalgia or headache the patient is allowed to take acetaminophen or codeine who will treat dengue fever symptomatic. A very important part of dengue fever treatment is the rest but also to drink a lot of liquids. The patient is fully recovered after 2 weeks. There are cases when the patient have to deal with complications and need close doctor monitoring.

Symptomatic dengue fever treatment only for simple, uncomplicated dengue

There is currently no completely effective therapy for treating infections caused by dengue virus. To reduce fever is the only course of action. There is no vaccine effective against dengue. A cross-protection with the vaccine against yellow fever have been reported. Vaccination remains still in the realm of research. But since the precautions listed above are taken, the risk of contracting the disease is low for people traveling in countries where malaria is endemic.

Antibiotics

They only address to the complications of dengue, they are powerless against the virus.

Treatment of dengue hemorrhagic fever

A hospitalization is urgently needed. This absence of any specific treatment makes prevention crucial. Any measures that reduce exposure to this type of mosquitoes during the period when they feed also reduces the risk of dengue.
These include the following:

Staying in rooms completely enclosed air-conditioned or whose openings are protected by nets.
Wearing trousers and long sleeved top, light-colored.

It is recommended that travelers stay in a country where most effective. The dengue is endemic to protect himself with insect repellent before going outside. Repellents containing DEET(N,N-Diethyl-meta-toluamide) are concentration of DEET varies from one product to another and the higher it is, the greater the protection lasts. DEET concentrations higher than 35% are not indicated in children (risk of convulsions). Products containing 35% DEET protect from 4 to 6 hours, with those containing 95% DEET, protection lasts for 10 to 12 hours. The travelers in the tropics and particularly in Southeast Asia and South America are at risk of contracting dengue. As there is currently no vaccine against dengue fever, travelers should avoid being bitten by mosquitoes to avoid contracting the infection.
Any person suspected to be infected by dengue fever, especially when it can be a form of bleeding, should immediately consult a doctor and must refrain from taking aspirin in all its forms (or other salicylates) because of the high risk of bleeding or gastric bleeding (erosive gastritis or ulcer). The high fever of an episode of dengue fever is managed by the use of paracetamol and usual means of thermolysis (dressing, warm shower, ventilation body).

Dengue fever vaccine and dengue fever prevention

2011-09-21T03:17:00.000-07:00

Dengue fever is a viral disease caused by viruses of the genus alphaviruses (thus an arbovirus) and transmitted to humans by many arthropod vectors such as mosquitoes (Aedes aegypti and Haemagogus Sabethes). Viruses (four strains of flaviviruses) of dengue are transmitted to humans by mosquitoes and in particular by Aedes aegypti female, a specie well adapted to urban life, especially in tropical environments. Another feature of this type of transmission, unlike most of the vectors of malaria, mosquito feeds preferably on its human host during the day. It often enters houses to rest and feed and breed in water bodies or tanks located near homes. Consequently, Aedes aegypti has invaded urban, suburban and rural areas of many tropical regions.
In present there is no dengue fever vaccine but exist a lot of projects developing. If for other diseases there are vaccines, a dengue fever vaccine is more difficult to obtain because it has to have a tetravalent composition. Specialists are now working at five possible vaccines in order to obtain the best dengue fever vaccine. So if there is no dengue fever vaccine people should do something to cure the disease and the first step is knowing something about the dengue fever prevention.
Dengue fever prevention is very important in order to avoid the disease. So you should:

Cover up: wear long-sleeved shirt tucked into light colored pants, shoes (not slippers) and a hat.
Apply insect repellent to exposed skin:

Repellents containing DEET are most effective.
Follow the manufacturer's instructions.
Do not apply on irritated skin, cuts or scratches.
Do not spray directly on face.
Wash your hands after application to avoid contact with lips and eyes.
It is not recommended to use products that combine DEET and sunscreen.
However, if you want to use these two products, apply sunscreen first and let it soak into the skin for 20 minutes before applying insect repellent containing DEET.
After you return indoors, wash to remove the repellent.

Sleep under a net, preferably insecticide-treated:

Make sure the net is intact.
Tuck net under the mattress.
Make sure the screen does not affect you (or you might get bitten through the net).

Consider your accommodations: Stay in a place where all openings are screened or completely enclosed air-conditioned.
For added protection, apply a repellent containing permethrin on your tents, clothes and other travel accessory:

Treatment with permethrin is effective for up to two weeks or six washings.
Permethrin is not sold in Canada, but travel clinics can tell you how to buy permethrin and pretreated material before or during your trip.

The simplest action for dengue fever prevention is to prevent the birth of a mosquito, since there are no vaccines or medicines that fight infection. For this, we must eliminate the places they choose to play. The basic rule is to not leave water, even it is clean beceuse they stop in any container. As the proliferation of mosquito is fast, in addition to government initiatives, it is important that the population will also collaborate to break the cycle of transmission and contamination. To get an idea in 45 days of life, a single mosquito may infect up to 300 people.
So the trick is to keep containers such as water tanks, barrels, drums, tanks properly closed. And do not leave standing water in places such as glasses, pots, dishes and pots of plants or flowers, bottles, cans, tires, cooking pots, roof gutters, trays, bowls, drains, drainage, gutters, cement blocks, cemetery urns , leaves of plants, and bamboo stumps, tree holes, and other places where rainwater is collected or stored.
Remember that the egg of the mosquito can survive up to 450 days, even if the place where the egg was deposited is dry. If the area receives water again, the egg will become active and can reach adulthood in a time between 2 and 3 days. Therefore it is important to remove and wash the containers with soap and water.

Dengue Fever Pictures

2011-09-21T03:14:00.001-07:00

Dengue Fever Pictures

Most common in areas of south east Asia and some parts of Africa, Dengue fever is a virus that is spread by mosquitoes. It has been known to cause very high fever as well as intense rashes that can sometimes grow into lesions if not treated properly. The problem is, this disease often strikes in impoverished areas where the proper care isn't always readily available, and people suffering from a simple fever aren't properly treated. This can result in serious complications or even in death in a lot of cases. If you believe that your or someone you know is suffering from Dengue fever, contact a medical professional right away to get more information. As we've already mentioned, symptoms include a very high fever, itchy and discolored rashes over large parts of your body, skin lesions, as well as painful or achy joints and muscles, and headaches. Below, we've included some photos of patients who are suffering from Dengue fever so that you can have a point of reference to understand this viral disease and what it looks like when people have it.

As was mentioned before, Dengue fever is transmitted almost exclusively through mosquitoes in areas of Asia and Africa. Simple things like mosquito nets can make a huge difference in people's lives in terms of keeping them happy and healthy. Unfortunately, in many of those areas, even the most basic elements for disease control aren't available and it takes a constant and sustained effort from concerned people to work to educate the public on the causes of diseases like Dengue fever, as well as to secure and distribute the means to reduce the occurrence of this disease. This is a mosquito transmitting the disease from one person to another through sucking the blood of its victim.

Although Dengue fever normally presents as a slightly discolored area (could be a very large area of skin) covered in an ichy rash, it can also sometimes present in more extreme ways. The skin lesion here is painful and also potentially dangerous because of a lot of bleeding underneath the skin. This sort of reaction is rare, but also can happen a lot if the rashes and disease in general go untreated. Also, a lot of scratching or skin aggravation can lead to a lot of problems, though in this particular case, it was probably a combination of all three.

In some patients, people with Dengue fever can become really sick and experience a lot of bleeding, even into eye cavities like in this case. Broken capillaries and blood vessels in the eyes can cause serious problems for people and it can cause vision problems. This patient has experienced these bleeding symptoms and run into some very serious problems. This type of bleeding can be corrected and cured with the proper treatment, but hurry. Often, these types of more serious symptoms are indications that the disease has reached a pretty advanced phase and can mean that treatment needs to be administered very soon in order to prevent more permanent damage.

Perhaps the most common symptom of Dengue fever is the slightly discolored itchy rash. Usually, it begins in a small area around where the initial infection took place from the bug bite, but it can spread very quickly. This is a particularly bad case where the rash has spread completely over the person's skin all along their back, neck, and arms. The rash is extremely itchy and as you can see, slightly discolored red and also slightly raised above the skin. This patient will need to receive treatment right away both for the uncomfortable symptoms of the rash as well as for the fever itself as the rash progressing this far indicates that the disease has moved to a pretty advanced stage. Again, medical care at this stage is very, very important.

Here is a summary of all the symptoms we've talked about associated with Dengue fever. Take note of the headache, eye pain, and muscle aches along with the rash which is the most common symptom, along with fever. Back pain is another common symptom which usually accompanies the joint and muscle pain associated with the disease. This viral infection is very serious and we can't stress enough how important it is that you seek medical help immediately if you or someone you know has this disease, because although it is typically only found in parts of Asia and Africa, it can occur anywhere and all over the world in any person.

We hope this guide to information concerning Dengue fever has been helpful, and we hope these photos have provided valuable inisght into what some of these symptoms actually look like. All the photos and information are meant to be helpful to you, but bear in mind that although the information on this site comes from medical research, it is not written by or with the consultation of a doctor, and therefore should not be taken as medical fact. Instead, use the information and photos as a guideline to understanding some of the symptoms of Dengue fever so you are more informed about when you should call a doctor and what to tell him or her when you talk.

Dengue Fever Prevention

2011-09-21T03:13:00.001-07:00

Neither vaccine nor drugs for preventing infection are available. The bite of one infected mosquito can result in infection. The risk of being bitten is highest during the early morning, several hours after daybreak, and in the late afternoon before sunset. However, mosquitoes may feed at any time during the day. Aedes mosquitoes typically live indoors and are often found in dark, cool places such as in closets, under beds, behind curtains, and in bathrooms. Travelers should be advised to use insecticides to get rid of mosquitoes in these areas and to select accommodations with well-screened windows or air conditioning when possible. Additionally, travelers should take measures to avoid being bitten by mosquitoes. Long-term travelers and expatriates can take extra precautions to reduce mosquito-breeding sites around their accommodations by emptying and cleaning or covering any standing water (such as in water storage tanks and flowerpot trays).

How can dengue fever be prevented?

The transmission of the virus to mosquitoes must be interrupted to prevent the illness. To this end, patients are kept under mosquito netting until the second bout of fever is over and they are no longer contagious.
The prevention of dengue requires control or eradication of the mosquitoes carrying the virus that causes dengue. In nations plagued by dengue fever, people are urged to empty stagnant water from old tires, trash cans, and flower pots. Governmental initiatives to decrease mosquitoes also help to keep the disease in check but have been poorly effective.
To prevent mosquito bites, wear long pants and long sleeves. For personal protection, use mosquito repellant sprays that contain DEET when visiting places where dengue is endemic. There are no specific risk factors for contracting dengue fever, except living in or traveling to an area where the mosquitoes and virus are endemic. Limiting exposure to mosquitoes by avoiding standing water and staying indoors two hours after sunrise and before sunset will help. The Aedes aegypti mosquito is a daytime biter with peak periods of biting around sunrise and sunset. It may bite at any time of the day and is often hidden inside homes or other dwellings, especially in urban areas.
There is currently no vaccination available for dengue fever. There is a vaccine undergoing clinical trials, but it is too early to tell if it will be safe or effective. Early results of clinical trials show that a vaccine may be available by 2015.

Mosquito Life-Cycle

2011-09-21T03:12:00.000-07:00

Mosquito Life-Cycle

Aedes aegypti and other mosquitoes have a complex life-cycle with dramatic changes in shape, function, and habitat. Female mosquitoes lay their eggs on the inner, wet walls of containers with water. Larvae hatch (picture 1, inset) when water inundates the eggs as a result of rains or the addition of water by people. In the following days, the larvae (picture 2) will feed on microorganisms and particulate organic matter, shedding their skins three times to be able to grow from first to fourth instars. When the larva has acquired enough energy and size and is in the fourth instar, metamorphosis is triggered, changing the larva into a pupa (picture 3). Pupae do not feed; they just change in form until the body of the adult, flying mosquito is formed. Then, the newly formed adult emerges from the water after breaking the pupal skin (picture 4, inset). The entire life cycle lasts 8-10 days at room temperature, depending on the level of feeding. Thus, there is an aquatic phase (larvae, pupae) and a terrestrial phase (eggs, adults) in the Ae. aegypti life-cycle.
It is this life-cycle complexity that makes it rather difficult to understand where the mosquitoes come from. Similar complex life-cycles with aquatic and terrestrial forms are observed in amphibians. For educational and training purposes, it is rather useful to make life-cycle kits, so people have an opportunity to watch how the aquatic stages turn into terrestrial ones.

There is a very important adaptation of Ae. aegypti and other dengue vectors that makes controlling their populations a difficult task. Their eggs can withstand desiccation for several months, which means that even if all larvae, pupae, and adults were eliminated at some point in time, repopulation will occur as soon as the eggs in the containers are flooded with water. Unfortunately, there is no effective way to control the eggs in containers.

Sri Lankan experts give serious advice on dengue

2011-09-21T03:10:00.001-07:00

Sri Lankan experts give serious advice on dengue

ISLAMABAD: Amid mounting deaths caused by dengue fever, a team of Sri Lankan experts, specialized in treating and controlling the disease, says fumigation, being done officially or unofficially, can help overcome the spread of ailment by just 15 per cent while preventive measures taken by the community at homes can defeat it by 85 per cent.
They have told worried Chief Minister Shahbaz Sharif that the dengue fever was basically a "domestic problem" that citizens would have to deal with. "If clean water is kept uncovered at homes, the disease cannot be curbed," one of them said.
The team comprises doctors, clinical experts, epidemiologist, physicians and communication specialists that is visiting Pakistan on the invitation of the Punjab government to make suggestions on treating and controlling the dengue fever as Sri Lanka has an excellent experience of defeating it.
The experts said Sri Lanka has successfully grappled with the disease over the past thirty years mainly by creating 100% public awareness. Additionally, it has introduced legislation that penalizes citizens who do not implement precautionary measures in their homes.
They said that the incidence of tremendous drop of platelets in patients struck by the dengue fever is highly negligible, just 0.12 %, and prompt making up of the deficiency is at times counter-productive. The experts said that Sri Lanka treated at least 35,000 dengue fever patients in 2009. Of them, there were only 350 deaths.
They explained that patients were afflicted by dengue fever or dengue hemorrhage fever. They said that the panic created in Pakistan has led to most deaths because some affected who are already suffering from diabetes or heart problems can't physically and psychologically bear the pressure of the disease and collapse having cardiac arrest. The experts said that the ratio of those hit by dengue hemorrhage fever, which was very serious disease, was just 0.1 percent. They said that the best treatment for the dengue fever patient was to keep checking his or her temperature for three days and then treat him by the use of only Paracetamol in the next ten days to make him recover from the disease.
The experts said that last year Sri Lanka had 3,500 such patients but only one died. They said that hospitals were meant to treat many more serious patients, who deserved immediate attention.
They said fumigation could not be very helpful because the disease spreads from homes. He said that in Sri Lanka public awareness has been achieved by 95 % and the rest of the 5 % are prosecuted and jailed for not adhering to the law.
The experts said that even if a small minority of citizens did not take precautionary measures at their residence, several others living in the neighbourhood are affected. The Sri Lanka team told the chief minister that it would stay in Pakistan till the time the problem was overcome. It said that it would carry out tests of all water triggering dengue fever. An official, who was present in the briefing, said that the Sri Lanka experts were also taking preventive measures to avoid the disease because they were tremendously exposed.
End.

Your Guide to Dengue Fever

Dengue Fever is a major global health threat and a leading cause of mortality in the tropics and subtropics. It is caused by infection with any one of four serotypes of dengue virus transmitted by the bite of the Aedes mosquito. This mosquito species breeds around habitations and feeds during the day. As many as 100 million people are infected annually, of which about 25,000 die of the disease.

Presentation

Once inoculated into the human body, dengue has an incubation period (during which the virus multiplies) of 3-14 days. Thereafter, in the typical form of the disease, a five- to seven-day acute fever ensues. Recovery is usually complete by 7-10 days.
It is important to appreciate that about half of all dengue infections go completely unnoticed. Some patients have isolated fever while others may produce the typical symptom complex of classic dengue fever (DF). Fever may be as high as 106°F. The fever presents in a nonspecific manner and may not be distinguishable from other infectious illnesses. The fever in DF is often preceded by chills, red speckles on the skin, and facial flushing. It typically begins on the third day of symptoms and lasts five to seven days. The other symptoms associated with DF include headache, which is usually generalised, pain in the back of the eye, nausea or vomiting and a rash that begins on day three and persists for about three days. DF can also be associated with muscle aches, joint pains and generalised fatigue. Abdominal pain when present can be a heralding sign of a more serious form of the disease, known as dengue hemorrhagic fever (DHF).
DHF is characterised by bleeding. This may be as mild as small amounts of oozing from the nose or gums or serious enough to present with copious bloody vomiting, an abnormally heavy period or excessive blood in the stool. Abdominal pain, excessive restlessness, confusion, decrease in body temperature, and a drop in the platelet count are indicators of imminent DHF.
Patients who have previously had DF (over half of which go unnoticed) are specifically at risk for development of DHF. It is also important to keep in mind that it is at the time when the fever is receding that DF patients are at greatest risk for DHF. This is the time to watch for the warning signs mentioned above and seek emergency care. If not properly taken care of, DHF complications (particularly gastrointestinal bleeding) can worsen and induce shock. This most severe and fatal form of dengue is known as Dengue Shock Syndrome (DSS). DSS is characterised by cold-clammy skin, a fast heart rate, decreased blood pressure, delirium, difficulty breathing and damage to the internal organs specifically the liver and kidney. DSS can lead to multiorgan failure and death.

Outcome

Most patients achieve a complete recovery from dengue. Even patients with DHF and DSS usually recover with proper resuscitation. Infection with one dengue serotype confers lifelong immunity against that particular serotype, but still leaves the individual susceptible to the other three serotypes. As mentioned above, a subsequent infection by a different serotype is a major risk factor for the development of DHF and, as a result, DSS.

Prevention

No vaccine is currently available to prevent contracting the dengue virus. Consequently, the most effective protective measures are those that avoid mosquito bites. Repellants and protective clothing are simple effective measures to take. Even better, eliminate mosquito breeding grounds: ensure no water is left standing in flower vases, old tires, etc. Since the Aedes is a day-biting mosquito, mosquito nets are not useful. (Read about some alternative solutions to protecting your home here.)

Diagnosis

DF is diagnosed clinically, based on the patient’s presenting symptoms and signs. A complete blood count might reveal a low white cell and platelet count. Serological testing and PCR are not only very costly but are unhelpful in the initial stages of the disease.

Treatment

Dengue fever is usually a self-limited illness, and only supportive care is required. No specific antiviral medication currently is available to treat dengue infections. Paracetamol should be used to manage the fever. Other agents including aspirin should be avoided, especially in children.
Patients may become dehydrated from fever, vomiting or lack of adequate dietary intake. Patients who are able to tolerate oral fluids should be encouraged to drink oral rehydration solution, fruit juice or water to prevent dehydration. Patients should also have their blood counts measured daily from the third day of illness until one to two days after the fever abates.
Patients who improve can continue to be monitored in an outpatient setting. Patients who do not improve should be admitted to specialised camps or a hospital for hydration. Patients with dengue shock syndrome are treated in intensive care units.
No specific diet is necessary for patients with dengue fever. Bed rest is advised.
When the patient’s fever is going away, watch for the warning signs mentioned above (taken from the CDC site here). If any of them appear, take the patient to the Emergency department of your nearest hospital immediately.

US Research About dengue

2011-09-21T03:08:00.000-07:00

US Research About dengue

We have some very exciting leads on different types of vaccines that are in various stages of clinical trial that hopefully can be implemented with a reasonable period of time," said Anthony Fauci, director of the infectious diseases division of the US National Institutes of Health (NIH).
Regional health researchers met Thursday in the Puerto Rican capital to discuss progress and treatment of dengue, which is transmitted to humans by the female Aedes mosquitoes.
Dengue causes a severe flu-like illness for most victims that lasts about a week. There are four strains, one of which is a potentially lethal type.
Dengue has reemerged in recent years as a serious public health threat in tropical regions.
It killed 1,167 people in Latin America last year. Puerto Rico recorded the largest outbreak in its history with 21,000 cases last year, according to the US Centers for Disease Control. There were 69 cases in the Key West section of the US state of Florida in 2010.
The Philippines recorded more than 730 deaths and Malaysia 134 in 2010, according to figures from the World Health Organization, while India experienced a 20-year high in infections.
Harold Margolis, director of the CDC's dengue center, said he's hopeful that a vaccine would soon be available.
"There's been tremendous progress," he said. "There are a number of vaccines that are now in clinical trials and there's now very exciting information there, so we are finally getting (into the last process) but it can take a while."
Fauci, from the NIH, added: "We need a better understanding of the relationship between the dengue virus and the vector, mainly the mosquito."
Meanwhile, surveillance is vital.
"The important factor is how good our surveillance is to pick up the disease," Margolis said. "I think right now we know where it is and now we need to be creative with the new tools and research to try to make sure that doesn't go any further."
The infectious diseases division of the NIH spent $45 million in dengue research last year, up from $5 million in 2000.
One theory for the resurgence is global warming, allowing the mosquitoes, and hence dengue fever, to spread.
Drought conditions in some areas also have worsened the outbreak because people have stored water in and near their living areas, creating breeding grounds for mosquitoes that harbor the virus.
Authorities in Sri Lanka were so concerned about dengue last year that they introduced heavy fines for people with standing water on their property, and deployed troops to clean up public places.
The three-day summit in Puerto Rico was hosted by NIH, CDC and the Pan American Health Organization.

Residence of dengue insect

2011-09-21T03:06:00.001-07:00

The New Delhi Municipal Council has started spraying
and fogging to sanitise and control mosquito-breeding in the New Delhi area after the insects were found breeding near the Prime Minister’s residence last week.
While P K Sharma, a health official, NDMC claims it is just a precautionary step, sources in the civic body’s Health department have informed that NDMC personnel had spotted mosquitoes breeding in the nallah near 7, Race Course Road during a routine check on June 10.
Aedes Aegypti mosquitoes were also seen breeding near Assam Bhawan, Punjab Bhawan and in the coolers at various shops in A block, Connaught Place, they said.
The civic body has now deployed around 170 personnel to carry out fogging and spraying operations.
“Keeping in mind last year’s dengue outbreak in the Capital, we have already initiated steps to sanitise these areas. If needed, we will deploy more people to bring the situation under control,” a health official said.

Lame mosquitoes to stop dengue

2011-09-21T03:04:00.000-07:00

Scientists are breeding a genetically altered strain of mosquito in an effort to curb the spread of dengue fever.

The dengue virus is spread by the bite of infected female mosquitoes and there is no vaccine or treatment.
Experts say the illness affects up to 100 million people a year and threatens over a third of the world's population.
Scientists hope their genetically altered males will mate with females to create female offspring that will inherit a gene limiting wing growth.
The study is published in Proceedings of the National Academy of Sciences.
The scientists say their approach offers a safe, efficient alternative to harmful insecticides and could be used to stop other diseases spread by mosquitoes, like malaria.
They estimate that if released, the new breed could sustainably suppress the native mosquito population in six to nine months.
Researcher Professor Anthony James, of the University of California, Irvine, said: "Current dengue control methods are not sufficiently effective, and new ones are urgently needed.
"Controlling the mosquito that transmits this virus could significantly reduce human morbidity and mortality."

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