Chikungunya Surge in East Africa: WHO’s Global Alert Sparks Urgent Action

By Defraise Enosh MUHINDO

On July 22, 2025, the World Health Organization issued a global alert warning of a rapidly spreading chikungunya epidemic, originating in the Indian Ocean islands and now threatening East Africa, including Kenya, Somalia, Uganda, the Democratic Republic of Congo, Rwanda, and Tanzania. With over 220,000 cases reported across 14 countries and 80 deaths since January 2025, the WHO fears a repeat of the 2004–2005 outbreak that infected nearly half a million people globally. In East Africa, fragile health systems, climate-driven mosquito proliferation, and urban challenges amplify the crisis.

The Chikungunya, first identified in Tanzania in 1952, is a mosquito-borne virus causing sudden fever, severe joint pain, headaches, nausea, and rashes. While rarely fatal (mortality rate below 1%), its chronic joint pain can disable victims for months, disrupting livelihoods. The WHO reports that the current epidemic, driven by Aedes aegypti and Aedes albopictus mosquitoes, has infected approximately 300,000 people in Réunion alone, with Mayotte declaring an epidemic on May 27, 2025, recording 1,170 cases by June 18. In East Africa, Kenya, Somalia, and the DRC are confirmed hotspots, while Rwanda, Tanzania, and Uganda face significant risks due to historical and ongoing viral circulation.

A 2024 meta-analysis in the Journal of Medical Virology estimates chikungunya’s prevalence in East Africa at 20.6%, with Rwanda reporting an alarming 63%, the DRC 10%, Tanzania 6.6%, and Uganda included in the regional burden. The WHO attributes the surge to climate change, which extends warm, wet conditions favoring mosquito breeding, and the E1:A226V viral mutation, enhancing transmission by Aedes albopictus.

Country-Specific Impacts: A Region Under Strain 

Kenya: Outbreaks in Mandera (2016, roughly 1,792 cases, 80% attack rate) and Mombasa (2017–2018, 453 cases, 32 confirmed) underscore Kenya’s vulnerability. In 2025, the WHO confirms epidemic transmission, with urban areas like Mombasa at risk due to open landfills and stagnant water. A 2014–2018 Kilifi study found 12.7% of childhood fevers linked to chikungunya, signaling endemicity. The Ministry of Health distributed 30,000 insecticide-treated nets in Mandera in 2016, but current response details are scarce.

Somalia: Confirmed cases emerged in 2016 near the Kenyan border, marking improved diagnostics. The WHO notes ongoing transmission in 2025, exacerbated by insecurity and poor sanitation in camps. Cross-border coordination with Kenya in 2016 aimed to enhance surveillance, but underreporting persists due to limited laboratory capacity.

Democratic Republic of Congo (DRC): A 1999–2000 Kinshasa outbreak infected some 50,000 people, and 2018–2019 flare-ups reported over 11,000 suspected cases. The 2024 meta-analysis confirms a 10% prevalence. The WHO highlights urban risks in 2025, worsened by 7.3 million internally displaced people living in crowded camps. Conflicts, including M23 clashes, hamper response efforts.

Rwanda: The 2024 meta-analysis reports a 63% prevalence, the highest in the region, based on a single study. The WHO includes Rwanda in its 2025 alert, citing risks from population mobility and mosquito-friendly climates. No specific 2025 case counts are available, but high prevalence suggests active circulation.

Tanzania: As the virus’s 1952 discovery site, Tanzania has documented cases since 2007–2008. A 2016 study in the northeast detected chikungunya in febrile patients, and the 2024 meta-analysis estimates a 6.6% prevalence. The WHO confirms endemicity in 2025, with urban breeding sites driving transmission.

Uganda: Historical outbreaks (1960, 1982) and a 2019 study showing IgG antibodies in blood donors confirm chikungunya’s presence. The 2024 meta-analysis includes Uganda in the 20.6% regional prevalence. While no 2025 outbreak is explicitly reported, the WHO’s alert flags Uganda due to refugee camps and cross-border trade.

Challenges and WHO’s Urgent Recommendations

The WHO warns that misdiagnosis is rampant, as chikungunya mimics dengue and Zika, and testing (RT-PCR, serology) is scarce in rural East Africa. In Somalia and Uganda, underreporting is likely due to weak laboratory networks. In the DRC, 50% of Mandera’s health workers were infected in 2016, crippling services. No specific antiviral exists, and treatment remains symptomatic. Two vaccines are approved globally, but access in Africa is limited.

The WHO’s July 2025 alert urges immediate action:

Vector control: Eliminate stagnant water (e.g., buckets, tires) and deploy insecticides, as seen in Kenya’s 2016 campaigns.

Public awareness: Promote repellents and long clothing, since Aedes mosquitoes bite during the day.

Surveillance: Enhance diagnostics to track cases, with projects like ACHIEVE (2025–2028) testing febrile patients in Kenya, Tanzania, and Uganda.

The $10.3 million ACHIEVE study, funded by the Coalition for Epidemic Preparedness Innovations, aims to quantify chikungunya’s burden, especially in children, and prepare vaccine trials. “We’re likely underestimating chikungunya’s impact, particularly in kids,” says Professor George Warimwe of Oxford University.

The WHO’s alert underscores chikungunya’s threat to East Africa, where climate change, urbanization, and conflict fuel its spread. With 220,000 cases globally in 2025, the region risks a prolonged crisis without swift intervention. In Kenya’s Mombasa, Somalia’s camps, and the DRC’s Kinshasa, residents face a daily battle against mosquitoes. Rwanda’s high prevalence and Tanzania’s endemicity demand vigilance, while Uganda’s historical burden signals latent risk.“We cannot let this become another 2004,” a WHO spokesperson stated, referencing the half-million-case epidemic. East Africa’s response bolstered by research, vector control, and global support will determine whether this alert sparks action or fades into another underfunded crisis.