Dengue fever, a potentially deadly viral disease transmitted by mosquitoes, has resurfaced in Kenya after a long absence, raising serious public health concerns. A recent confirmed case in Kilifi County highlights the re-emergence of this neglected disease, which shares symptoms similar to malaria and typhoid fever, making early diagnosis challenging.
Dengue fever is spread primarily by two types of mosquitoes: Aedes aegypti and Aedes albopictus. These mosquitoes are commonly found in regions such as the lake areas, northeastern parts of the country, and along the coast. The disease is caused by four distinct virus types, with type two being the most prevalent locally. Globally, the World Health Organization estimates that about 40 percent of the population lives in dengue-prone areas, with up to 100 million infections occurring annually. While many infections may show no or mild symptoms, dengue is responsible for approximately 22,000 deaths worldwide each year.
In Kenya, dengue fever outbreaks have been sporadic but recurrent. The last significant wave before the current case was recorded in 2011, particularly in the Rift Valley and coastal regions such as Mombasa. The disease was first identified in Malindi back in 1982. Since its resurgence, multiple outbreaks involving different virus serotypes have occurred, mostly along the coast and northeastern areas. However, the true extent of the disease’s spread may be underestimated due to frequent misdiagnosis, as symptoms often mimic those of other common febrile illnesses.
Typical symptoms of dengue fever include high fever sometimes reaching 40 degrees Celsius—headache, nausea, vomiting, rash, and pain behind the eyes, in the joints, and muscles. In more severe cases, individuals may experience intense abdominal pain, repeated vomiting, bleeding from the nose or gums, and dangerously low blood pressure that impairs circulation. The incubation period can range from a few days up to two weeks after the bite of an infected mosquito. While recovery usually grants lifetime immunity against that specific serotype, subsequent infections with different serotypes increase the risk of severe complications.
Kenya currently does not have access to dengue vaccines like Dengvaxia or Qdenga, which have been approved elsewhere since around 2016. Without vaccination, prevention and management rely heavily on early detection, prompt medical attention, and vector control strategies. Health professionals recommend regular screening, especially in endemic areas, since delayed or missed diagnosis can lead to fatal outcomes.
Preventing dengue largely depends on avoiding mosquito bites, particularly because the Aedes mosquitoes bite during the day, with peak activity at dawn and dusk. Protective measures include wearing long-sleeved clothing, applying mosquito repellents, and using insecticide-treated nets. Environmental management is also critical: these mosquitoes breed in stagnant water found in common household items such as water storage containers, discarded tires, and any other places where water collects.
Several factors increase the risk of dengue infection. Older adults are more vulnerable, partly because they spend more time at home where day-biting mosquitoes are prevalent. Urban living conditions, inadequate mosquito control, poor environmental sanitation, certain jobs, recent travel to affected areas, and limited public awareness also contribute to transmission.
Currently, treatment options for dengue are primarily supportive. There is no specific antiviral drug for the disease. Management focuses on controlling fever and pain, avoiding medications like non-steroidal anti-inflammatory drugs that may exacerbate bleeding risks. Severe cases may require hospitalization for intravenous fluids, oxygen therapy, and blood transfusions.
To combat dengue, Kenya employs integrated vector management strategies. These include entomological surveillance by both governmental and non-governmental organizations, pesticide application, indoor residual spraying, and the promotion of insecticide-treated nets. Such measures aim to reduce mosquito populations and limit human contact with vectors.
Given the potential severity of dengue fever and the absence of vaccines in the country, continuous monitoring, improved diagnosis, public education, and sustained vector control are critical to prevent further outbreaks and protect public health. The resurgence of dengue is a reminder that neglected diseases can swiftly become major threats without proper attention and resources.
