The best way to fight chikungunya transmission is to protect yourself individually against mosquito bites and slow down their reproduction.
During the month of August 2023, a chikungunya epidemic was identified in Senegal, affecting the Kedougou region, in the south of the country. The three departments of this region reported 112 confirmed cases of this viral disease. Although chikungunya is relatively rare in Senegal, health authorities are seeking to allay concerns by pointing out that no serious cases have been reported so far.
The chikungunya virus originated in Africa but has spread around the world over the years. At over the past 20 years, increasing numbers of chikungunya infections have been reported in African countries, but the general picture of its circulation remains underestimated, with the disease being underdiagnosed and underreported.
The chikungunya virus was first identified time in Tanzania in 1952. Chikungunya is an infectious disease caused by a virus transmitted to humans by mosquitoes of the genus Aedes (tiger mosquito). The name of the disease means “one who walks bent over”, because the infection not only causes high fever, but also joint and muscle pain. This name is derived from a word from the kimakonde language – spoken in southeastern Tanzania and northeastern Mozambique – and meaning “to warp”.
According to the WHO, since 2004, urban outbreaks of chikungunya have been reported in more than 110 Asian countries, Africa, Europe and the Americas. These outbreaks have become more frequent and widespread where populations ofAedes aegypti orAedes albopictus are well established. In these regions, local transmission by mosquitoes is now known.
Month recherches relate mainly to pathogen epidemiology vector-borne diseases responsible for febrile illnesses in West Africa. In this article, I explain the symptoms, treatment, diagnosis and prevention of this infection.
Symptoms, treatment and vaccines
In cases with symptoms, the disease appears after an incubation period of 4 to 8 days on average, following the bite of an infected tiger mosquito. A high fever (above 38,5°C) appears suddenly, accompanied by headaches, aches or joint pains, which can be intense, mainly affecting the wrists, ankles and phalanges and which are often very disabling.
These symptoms usually last a few days, but may persist for weeks or months. The evolution can be rapidly favorable, if the patient responds well to symptomatic treatment. After recovery, patients are likely to have acquired immunity against future infections.
Clinical management focuses on relieving fever and joint pain with antipyretics, appropriate analgesics, good fluid intake and patient rest. There is no specific antiviral drug for chikungunya infection.
Many vaccines are under development, but they are not yet approved. This is why the WHO encourages countries to improve patient care and implement social communication strategies aimed at reducing the presence of vector mosquitoes.
The chikungunya virus can be detected directly in blood samples taken from the patient during the first week of illness by PCR (DNA amplification technique or RNA of the carrier of the disease). Other tests can detect a person's immune response to chikungunya virus infection.
These tests are typically used to look for the presence of antibodies to the virus, which are usually detectable within the first week after illness onset and can still be detected for about two months.
This is why WHO encourages countries to build and maintain the necessary capacity for case detection and confirmation.
Prevention and control
During a bite, the tiger mosquito takes the virus from an infected person, and during another bite, it transmits it to a healthy person. This is why the best way to fight against the transmission of chikungunya is to protect yourself individually against mosquito bites (long clothes, skin repellents, mosquito nets), and to destroy the most accessible breeding sites.
This requires mobilizing communities who play a vital role in reducing mosquito breeding sites by regularly emptying and cleaning water containers, disposing of waste and supporting local mosquito control programs .
During outbreaks, insecticides can be sprayed to kill adult mosquitoes. Window and door screens can also prevent mosquitoes from entering homes. Insecticide-treated bed nets should be used (day and night) against biting mosquitoes, especially young children and the sick or elderly.
All these measures can also be taken on an emergency basis by the health authorities to control mosquitoes.