Central America is currently experiencing its worst dengue fever epidemic of the decade, with more than one million people affected by this painful and often debilitating disease. In 2019, more than 400 deaths have been reported in Central America due to dengue. Honduras accounted for 180 of these deaths, markedly higher than the three dengue-related deaths reported in Honduras in 2018). In addition to Central America’s highest number of dengue-related deaths, Honduras also reported the highest number of overall cases (112,708) in the region and the region’s highest proportion of severe dengue (at about 20 percent of cases).
Dengue fever is caused by one of the four dengue viruses spread through the bite of the Aedes species of mosquito, which thrives in tropical and subtropical regions across the world. According to the U.S. Centers for Disease Control and Prevention (CDC), 40 percent of the world’s population is at risk of dengue virus infection.
Weather conditions and other circumstances in Honduras produced conditions ripe for dengue. In 2019, the country experienced a severe drought as well as periods of unexpected and intense rainfall. Flooding can create more breeding sites for mosquitoes to lay their eggs. During droughts, people often store water in their homes, and if improperly stored, these containers provide additional places for mosquitoes to breed. Without effective disease surveillance, vector control measures, and education campaigns in place, dengue can quickly spread.
The Pan-American Health Organization (PAHO) recommends several measures for countries to take to combat dengue, including strengthening surveillance and laboratory diagnosis, strengthening vector surveillance and control, and training healthcare professionals to properly diagnose and manage dengue patients.
However, surveillance and control of dengue is often challenging, as it is in Honduras, where surveillance data to detect mosquito-borne disease were limited and the Ministry of Health faced resource constraints especially affecting vector surveillance. Through funding from the CDC, TEPHINET consultants Dr. Norma Padilla and Dr. Juan Carlos Lol are working with the Ministry of Health to implement stronger entomological surveillance and laboratory systems to improve preparedness and response to mosquito-borne outbreaks.
Padilla and Lol, both from the Universidad del Valle de Guatemala, are supporting the development, design, and implementation of a national entomological surveillance system. Padilla, an entomologist, is an assistant professor as well as the chief of the malaria and vector biology unit at the university’s Center for Health Studies. Lol is a biochemist who has been working on insecticide resistance in mosquitoes of genus Anopheles and Aedes. They spend half of their time in Honduras as part of a multidisciplinary team to stand up a functional National Reference Entomology Laboratory near Tegucigalpa and to strengthen the capacities of five regional entomological laboratories. Strengthening capacity includes improving entomology surveillance including insecticide resistance, standard operating procedures and training plans. In addition, Dr. Padilla and Dr. Lol are collaborating with Emory University in spatial mapping of temporal risk to improve dengue prevention and control measures.
“With this support from CDC and TEPHINET, national entomological activities will be strengthened in the areas of laboratory and surveillance in order to more effectively control this outbreak and future outbreaks in Honduras,” says Dr. Emily Zielinski-Gutierrez, the director of the CDC Regional Office for Central America.
Biochemist Dr. Juan Carlos Lol examines ovitraps (devices which consist of a dark container containing water where mosquitoes can lay their eggs) for the presence of Aedes mosquito eggs in November 2019.