Knowledge Exchange by ISID

Chikungunya is a mosquito transmitted alpha virus. Since its emergence in Africa, the global distribution is rapidly expanding, the disease has spread to most continents. The spread to new areas is possible due to the travel of infected persons and presence of mosquitoes in these new areas that are able to spread the disease. The spread has been found to be more in tropical and sub-tropical countries. Several data driven empirical approaches and spatiotemporal forecasting have been used to forecast chikungunya spread in places like the Americas. Some of these forecasting methods have been used to predict infected cases and locations based on machine learning. Although there is currently no specific treatment and vaccine in use, there are several vaccine candidates in different stages of clinical trials that have shown promising results.

Chikungunya is a mosquito borne viral disease caused by the Chikungunya virus (CHIKV), a Togaviridae virus, and is transmitted by Aedes mosquitoes. Clinical symptoms include acute onset of fever, debilitating joint and muscle pain, headache, nausea, and rash, potentially developing into long-term serious health impairments. Chikungunya virus causes clinical illness in 72 – 92% of infected human around 4 to 7 days after an infected mosquito bite. Complications resulting from the disease include visual, neurological, heart and gastrointestinal manifestations; fatalities have been reported in elderly people at higher risk.
 
Chikungunya outbreaks have been reported in Asia, Africa, the Americas and recently in Europe. Both the medical and economic burden are expected to grow as the CHIKV primary mosquito vectors continue their geographic spread Although there are some candidate vaccines in clinical trials none are licensed. Therefore, chikungunya shall remain a major public health threat.

According to the WHO, the incidence of dengue has increased considerably in recent decades. Dengue is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, Southeast Asia, and the Western Pacific. Asia bears about 70% of the global burden of dengue. There is no specific treatment for dengue. So far only one dengue vaccine CYD-TDV has been licensed for use. It is currently in use in about 20 countries globally. There are several candidate vaccines in different stages of development, some are currently in various stages of Clinical Trials. Several challenges have been faced in the development of the vaccines, some of which include the nature of the virus itself that has four serotypes and the immune response to the vaccine.

Dengue is the fastest spreading mosquito-borne viral disease; a distinction the WHO recognized when naming it a Top 10 threat to global health. Dengue is mainly spread by Aedes aegypti mosquitoes and, to a lesser extent, Aedes albopictus mosquitoes. It is caused by one of the four dengue serotypes, each of which can cause dengue fever or severe dengue. Dengue is pandemic-prone, and outbreaks are generally observed in tropical and subtropical areas. However, recent outbreaks have affected the continental United States and Europe. An estimated 40% of the world is at risk now lives with this threat. There has been a significant increase in number of dengue cases over the years, despite improvements in case management and a reduction in the Case Fatality Rate. Increased surveillance, better case management, innovative vector control, and diagnostics may improve control efforts globally.