A recent global study warns that millions of people in India and around the world may be at danger of developing chronic health problems as a result of chikungunya, a mosquito-borne virus that causes high fever and severe joint pain. Researchers from the London School of Hygiene & Tropical Medicine (LSHTM), Nagasaki University, and the International Vaccine Institute in Seoul have created the most detailed map of chikungunya risk ever. 

According to the study, some 14.4 million people worldwide may be at risk of infection each year, including 5.1 million in India. If the virus spreads beyond the existing at-risk areas, the global total could reach 34.9 million, with India alone accounting for 12.1 million cases. 

Chikungunya is a major long-term threat to millions of people globally, with almost half of survivors enduring permanent joint discomfort and mobility issues. The load is not uniformly distributed across ages: individuals aged 40 to 60 are more likely to experience chronic symptoms, but children under 10 and seniors over 80 are at a larger risk of severe acute sickness. Geographically, the impact is concentrated in India, Brazil, and Indonesia, which together account for about half of the worldwide load on healthcare systems and affected individuals, emphasising the critical need for targeted prevention and support efforts. The primary researcher, Hyolim Kang, stated, "Even the healthiest people can be infected and left with lifelong handicaps." Prevention is essential." 

Chikungunya is a virus spread predominantly by Aedes aegypti (yellow fever mosquito) and Aedes albopictus (tiger mosquito). Infected people often have a high fever of over 39°C, severe joint and muscular discomfort, and, in rare cases, life-threatening consequences. Currently, there is no specific therapy for the illness, and care is primarily focused on symptom management. However, two vaccinations have been approved in several countries, providing a prophylactic measure against the disease. 

The researchers used powerful machine learning models to predict chikungunya risk by combining several characteristics. They took into account the availability and appropriateness of Aedes mosquitoes, the virus's major carriers, as well as climate variables such as temperature and rainfall, which influence mosquito reproduction and viral transmission. The models also included population density and country GDP, which show how human concentration and economic factors influence disease spread and healthcare capability. Finally, historical chikungunya data served as a foundation for calibrating the projections, allowing the team to estimate current and future infection risks more accurately. 

This method enabled them to estimate both short-term infections and long-term effects, surpassing typical monitoring data, which frequently underestimates instances. 

Sushant Sahastrabuddhe of the International Vaccine Institute stated, "Our models provide real-time insights to help public health professionals manage outbreaks and plan vaccination strategies effectively." 

The study emphasises the urgent need for countries to increase their prevention, vaccination, and public awareness efforts, particularly in areas where the chikungunya risk may have been underestimated. Public health officials are recommended to prioritise vaccination for high-risk age groups, constantly monitor mosquito populations, and adopt effective breeding control measures, as well as provide assistance to patients experiencing long-term symptoms following infection. Together, these methods can slow the virus's transmission and mitigate its long-term impact on impacted communities. 

Senior author Kaja Abbas stated, "Prioritising regions that conventional surveillance might miss can save millions from long-term disability."