In February 2024, Mombasa witnessed a surge in cases of acute hemorrhagic conjunctivitis (AHC), commonly known as “red eye” disease. Thousands of residents reported waking up with bloodshot, swollen eyes, leading to a wave of concern as hospitals became overwhelmed. Scientists have now identified the virus responsible for the outbreak, marking a major breakthrough in understanding the disease in Kenya.
A team of researchers at the KEMRI-Wellcome Trust Research Programme worked for months to pinpoint the cause of the outbreak. While AHC can be triggered by bacterial infections, allergens, or viruses, the specific agent is rarely investigated in Kenya. However, the latest study confirms that the outbreak was caused by coxsackievirus A24 variant (CA24v), a highly contagious enterovirus known to cause AHC outbreaks worldwide.
The study, published in the Wellcome Open Research journal, titled “Identification of coxsackievirus A24 variant during an acute hemorrhagic conjunctivitis outbreak in coastal Kenya, 2024,” provides crucial insights into the disease’s origins. Researchers discovered that the virus strain detected in Kenya closely resembles a strain found in Mayotte, an island in the Indian Ocean.
CA24v has a long history of triggering epidemics of “red eye” across various continents. First identified in Singapore in 1970, it has since been linked to multiple outbreaks in Asia and Africa. The virus is highly transmissible through direct contact with infected secretions, making crowded environments such as schools, public transport, and workplaces particularly vulnerable to its spread.
In East Africa, previous detections of CA24v occurred in Uganda and South Sudan in 2010, while cases were reported in Tanzania, Burundi, Malawi, and South Africa in 2023. This suggests that international travel and trade may play a role in the virus’s movement across regions.
The outbreak in Mombasa was characterized by sudden-onset symptoms, including:
- Red, bloodshot eyes
- Eye swelling and irritation
- Itching and blurred vision
- Fever, body aches, and a runny nose in some cases
While AHC typically resolves on its own, the rapid spread of the disease led to significant disruptions in daily life, with affected individuals missing work and school.
To identify the virus, researchers collected eye swab samples from 13 patients at a Mombasa clinic. Initial tests ruled out bacterial infections and adenoviruses—previously thought to be the leading cause of AHC. However, using metagenomic sequencing, a cutting-edge technique that scans for all possible pathogens, scientists detected CA24v in three of the samples.
Additional genetic analysis confirmed that the strain in Kenya was closely related to the one detected in Mayotte earlier in 2024. This revelation underscores the need for improved surveillance of viral diseases in Kenya and East Africa.
The confirmation of CA24v as the cause of the 2024 outbreak has significant public health implications. Because AHC spreads through direct contact, health officials recommend the following measures to prevent further outbreaks:
- Frequent handwashing to reduce the risk of infection
- Avoiding touching the eyes and sharing personal items like towels and makeup
- Disinfecting commonly touched surfaces in public places and households
- Seeking medical advice instead of self-medicating, as improper treatment can worsen symptoms
Public health officials also warn against the misuse of antibiotics, as AHC is primarily viral, not bacterial. Overprescription of antibiotics for viral infections contributes to antibiotic resistance, posing a broader public health challenge.
The KEMRI researchers, in collaboration with the Ministry of Health, emphasize the need for continued monitoring and genetic sequencing of viruses responsible for outbreaks in Kenya. Future research will focus on whole genome sequencing of CA24v to track its evolution and spread more effectively.
With the increasing frequency of viral outbreaks in Kenya and the region, enhanced surveillance and timely public health interventions will be key to preventing future epidemics of “red eye” disease and other emerging infectious diseases.
