Dengue Fever 101
Dengue fever is the fastest spreading vector-borne disease in the world and causes many attendant health complications, as well as death. It was first recognized during the dengue fever epidemics in the Philippines and Thailand in the 1950s.
There are roughly 400 million dengue fever infections worldwide each year, of which 96 million leads to illness. It is common in more than 100 countries in the world, and Asia accounts for about 70 percent of the global burden. According to data from the World Health Organization (WHO), from January 1 to July 18, 2020, there were 55,160 cases of dengue fever and 200 deaths in the Philippines. This is significantly lower compared to the number of cases reported in the same period in 2019. However, for a tropical country like the Philippines, the threat of a dengue outbreak is omnipresent, and transmission is continuous.
Transmission
Dengue fever virus (DENV) is transmitted to humans through a bite from an infected female mosquito, primarily the Aedes aegypti or “yellow fever” mosquito. When an uninfected mosquito bites an infected person, it can spread the virus to the next person it bites, thus signaling the start of a potential public health crisis. The Aedes aegypti mosquito is the leading carrier of the Chikungunya and Zika viruses as well.
There are four distinct but related DENV serotypes. The first infection of any serotype is usually benign or asymptomatic. As it is possible to get an infection from any of the four serotypes, a second infection may lead to a lethal complication. Dengue fever can affect adults, young children and in some cases, infants. Pregnant women infected with DENV may affect the health of their newborns. Although rare, it is also possible to spread dengue fever through blood transfusion or organ transplantation.
Symptoms
Symptoms of dengue fever typically appear four to 10 days after exposure to DENV and last for two to seven days. Fever is the primary symptom of DENV, but it can be confused with other diseases. To address this dilemma, the WHO classified dengue fever into two categories, namely: dengue fever with or without warning signs, and severe dengue fever. The former allows medical professionals to triage patients in hospitals.
Dengue fever with or without signs may develop a high fever of 40 degrees Celsius, accompanied by any of the following: nausea, rashes, pain behind the eyes, muscle or joint pain, and vomiting. The symptoms of severe dengue can manifest about three to seven days after the onset of illness, as the fever is dropping. Some visible signs of severe dengue are fatigue, restlessness, rapid breathing, severe abdominal pain and persistent vomiting, often accompanied by blood. When these symptoms appear, getting medical assistance is essential to prevent shock, internal bleeding and death.
Treatment
Dengue fever patients can take fever reducers and pain relievers such as acetaminophen or paracetamol. Infected people cannot take non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin as these drugs act by thinning the blood, which may bring about hemorrhage.
Most people will recover after a week of rest and staying hydrated. However, for severe dengue fever, proper medical care is imperative within 24 to 48 hours after its first indication. Under the close monitoring and care of health practitioners, a patient’s risk of increased severity can be lowered. There is currently no specific treatment for dengue fever, but the symptoms are manageable through proper medication.
Prevention
The most effective way to prevent dengue fever is to focus on the vector that causes it. Aedes aegypti mosquitoes reproduce in surfaces and containers that hold water: from tin cans, buckets and discarded tires to untended pools and clogged rain gutters. Get rid of water in these containers and keep them tightly closed to deter mosquitoes from laying eggs in them.
Door and window screens can keep the home free from mosquitoes, along with insect repellent products such as coils and evaporators. Keep in mind that Aedes aegypti is a day-time feeder, which is mostly active during sunrise and sunset. Minimize skin exposure by wearing loose-fitting, long-sleeve clothing and applying insect repellent during peak times.
In some countries, dengue vaccine is available for people between nine and 45 years old. However, it is only indicated for those who have had a previous diagnosis of dengue fever. Administering dengue vaccine to an individual who has not been previously infected may only increase the risk of developing a severe form of the disease.
Dealing with dengue is a continuing battle, but with increased awareness and education about the disease and how to prevent it, communities and individuals may be better prepared to eventually eradicate it.
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References:
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Dengue and severe dengue [Internet]. World Health Organization. 2020 [cited 2021 Jan 6]. Available from: https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue
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Dengue Situation Update Number 601 [Internet]. World Health Organization. 2020 [cited 2021 Jan 6]. Available from: https://www.who.int/docs/default-source/wpro---documents/emergency/surveillance/dengue/dengue-20200813.pdf?sfvrsn=fc80101d_38
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Dengue [Internet]. 2020 [cited 2021 Jan 6]. Available from: https://www.cdc.gov/dengue/index.html