By Jamie Hansen, Global Health Communications Manager
As the risk of several mosquito-borne diseases increases in Sub-Saharan Africa, it is critical to understand key risk factors for each disease, in addition to how they interact with one another, in order to inform local prevention strategies and policies
A new study by a team of Stanford researchers and their Kenyan colleagues, published recently in Nature Scientific Reports, sheds light on the magnitude of lifetime and recent co-exposure (being exposed to two or more of them at once) to three disease of high concern: malaria, dengue virus and chikungunya virus. They also investgiated the risk factors associated with co-exposure to these infections
Researchers followed 4,534 participants of varied ages in two urban settings in Kenya for 27 months. They found no evidence of acute infection with more than one disease at a time. However, participants showed a risk of contracting two or more of the illnesses over their lifetime ranging between 0.75-9%
Just under 9 % of participants had suffered prior dengue and chikungunya infections in their lifetimes, and just under 1% were sickened with one of these illnesses during the study. The researchers found that key risk factors included crowded homes and water collection containers near the home (which can serve as mosquito breeding grounds)
These findings are important because, while malaria remains a more common disease risk in these communities, with 15.5 percent of participants testing positive, dengue and chikungunya are also significant threats and are often under-diagnosed. Additionally, they are caused by a different mosquito species with different breeding and biting patterns, which requires distinct preventive strategies from malaria
“The similar initial symptoms for all three infections complicate clinicians’ ability to identify cases of co-infection and co-exposure, which underscores the need for additional laboratory diagnostics,” said Amna Tariq, MPH, PhD, the study’s lead author and a Global Health Emerging Scholar supported by the Stanford Center for Innovation in Global Health. “Understanding the burden of co-exposure and the co-circulating burden of these diseases can help local policymakers strategize control policies such as providing mosquito nets, applying mosquito repellents, and draining water containers during peak transmission seasons.”
Desiree LaBeaud, MD, MS, associate dean of the Stanford Center for Innovation in Global Health, was senior author
