In February 2024, Mombasa experienced a sudden outbreak of acute hemorrhagic conjunctivitis (AHC), commonly known as “red eye” disease. Many residents rushed to hospitals with complaints of bloodshot, painful eyes that appeared overnight. Scientists have now identified the cause of the outbreak: a strain of an old virus called coxsackievirus A24 variant (CA24v), which may have originated from the Indian Ocean island of Mayotte.
AHC is a highly contagious infection that spreads through direct contact with infected secretions. It causes sudden eye redness, itching, blurred vision, and swollen eyelids. In some cases, people may also experience fever, body aches, and a runny nose. Crowded areas like schools and public transport hubs are prime locations for its rapid transmission. While AHC is often self-limiting and resolves on its own, outbreaks can lead to economic losses as individuals miss work or school. Mismanagement, such as self-medication and the use of traditional remedies, can also worsen symptoms.
To determine the exact cause of the outbreak, scientists collected eye swab samples from 13 patients at a clinic in Mombasa. Initial tests for bacterial infections detected only non-pathogenic bacteria, ruling out a bacterial cause. They then screened for adenovirus, another common cause of AHC, but all samples tested negative.
The breakthrough came when researchers used metagenomic sequencing, a powerful technique that scans for all possible pathogens in a sample. This analysis detected coxsackievirus A24 variant (CA24v) in three of the 13 samples. Further genetic analysis confirmed the findings, showing that the strain found in Kenya closely resembled one identified in Mayotte earlier in the year. This suggests the virus may have spread across regions through human travel and trade.
CA24v is a type of enterovirus known to cause various infections, including hand-foot-and-mouth disease and respiratory illnesses. It was first isolated in Singapore in 1970 and has since been linked to multiple AHC outbreaks worldwide. Although the virus has been detected in East Africa before, this is the first time it has been confirmed as the cause of an outbreak in Kenya. Previous detections of CA24v in the region include Uganda and South Sudan in 2010, as well as Tanzania, Burundi, Malawi, and South Africa in 2023.
The identification of CA24v in Kenya has significant public health implications. Since the disease spreads easily through contact, hygiene measures such as frequent handwashing, avoiding touching the face, and disinfecting shared surfaces are crucial for prevention. Schools and public institutions may need to implement temporary closures or exclude infected individuals to control transmission.
Although AHC is rarely life-threatening, experts warn against the overuse of antibiotics to treat the condition. Most outbreaks are caused by viruses rather than bacteria, making antibiotics ineffective. Unnecessary antibiotic use can contribute to antibiotic resistance, posing long-term health risks.
The findings were shared with health authorities to aid in public health response efforts. Understanding the specific cause of such outbreaks allows for better management and prevention strategies, ensuring that appropriate measures are taken to reduce the spread of infections in the future.
