LIMA, Peru - Scientists from the Virology Surveillance Program at U.S. Naval Medical Research Unit (NAMRU) SOUTH recently published findings from a study of samples processed from a recent dengue outbreak, in collaboration with the Health Ministry of Peru and Naval Medical Research Command (NMRC).
Dengue fever is a viral mosquito-borne disease that is transmitted through the bite of an infected Aedes mosquito. Symptoms such as fever, tiredness, aches and pains, and headaches usually begin four to 10 days after infection, and are similar to influenza, COVID-19 and malaria. The Pan American Health Organization (PAHO) reports that Peru has the highest fatality rate for the disease in South America.
Researchers saw an increase in Dengue cases across regions of Peru, beginning in April 2023 and continuing until March 2024. The outbreak prompted a coordinated response to inform and support the Peruvian Ministry of Health.
“The main issue is that dengue cases began extending to other regions of Peru, where cases were previously uncommon,” said Dr. Julia Ampuero, Febrile/Dengue surveillance division lead for NAMRU SOUTH. “However, in 2023, the virus was spreading to the central coast, including Lima, the Peruvian capital. In the past, cases were mainly found in the Amazon region and on the northern coast near Ecuador.”
The Peruvian Health Ministry has reported a 262% rise in dengue fever cases in 2024, compared to 2023; the increase in cases has been attributed to high temperatures and excessive rainfall since 2023, due to the El Nino weather pattern.
Ampuero and the surveillance team have implemented a network to detect when an outbreak occurs and monitor the rise in cases; the network notifies the Peruvian Ministry of Health, which can then raise the alarm in different regions of Central and South America.
“NAMRU SOUTH strengthens the country’s surveillance by covering more sites around the region,” Ampuero said. “Assisting with cold chain technology to preserve samples for a longer period, and reporting any increase in cases of febrile, dengue or other pathogens strengthens the capabilities of the Peruvian Ministry of Health.”
The program assists the Peruvian government in their own extensive research, helping them apply findings to clinical diagnostics and mitigation efforts.
“The longer period of febrile illnesses opens opportunities for more research, and for designing better protocols to differentiate between other febrile illnesses” explained Lt. Cmdr. William Graham, department head for the Virology Surveillance program. “We are seeing an evolution of a different illness that causes similar symptoms which last for a longer period of time, and we need to know which illnesses are which to not waste resources.”
In the U.S. Southern Command (SOUTHCOM) area of responsibility (AOR), there are threats of dengue, COVID-19, influenza and hantavirus, requiring robust systems of surveillance and monitoring.
“Having designed regions centralized around lab hub locations provides additional analytical testing, which in turn ensures proper execution of additional protocol directives and diagnostic requirements,” Graham said.
Within 24 to 48 hours, the program provides data from each consolidated region around the SOUTHCOM AOR into one report for the Ministry of Health and the Global Emerging Infections Surveillance Branch. The program informs fleet and terrestrial movement decision-making, and its design reduces the strain on central lab processing times.
“The disease detection and alert pathways we have implemented have been designed to monitor known threats and identify unknown threats over time, said Graham. “The laboratory assets and resources have been positioned in a modular platform allowing them to be deployed based on pathogen detection and operational requirements.”
NAMRU SOUTH collaborates with NMRC’s Biological Defense Research Directorate (based out of Frederick, Maryland) in these processing efforts, sending samples for sequencing and further long-term research, with the aim of developing better vaccines and treatments.
“By analyzing Dengue virus genomes and other virus genomes to see what genetic variations they encode, we can evaluate whether they contain new mutations that might require detection assays to be revised,” explained Dr. Kimberly Bishop-Lilly, the head of NMRC’s Genomics and Bioinformatics Department. “Data from the samples will inform force health protection decision-making and potentially reveal what other acute febrile illness pathogens are co-circulating in the population at the same time as Dengue virus are occurring.”
“This collaboration between multiple labs brings out each other’s’ strengths,” Bishop-Lilly added. “From my experience, it is always better to have multiple eyes on a problem.”
In July, the Peruvian news agency Andina released a story about the cooperative efforts between the U.S. and Peru in bridging scientific cooperation for early detection of diseases such as Dengue, malaria and anti-microbial resistant infections.
The U.S. Ambassador to Peru, Stephanie Syptak-Ramnath, visited NAMRU SOUTH on July 9. She thanked the command for their “exceptional medical and public health research,” and added, “I thank the entire team for their dedication and effort to improve health in our region.”
NAMRU SOUTH, part of the Navy Medicine Research & Development enterprise, conducts research on a wide range of infectious diseases of military and public health significance, and supports Global Health Engagement through surveillance of those diseases, including dengue fever, malaria, diarrheal diseases and antimicrobial-resistant infections.
The Navy Medicine Research & Development enterprise, led by NMRC, is engaged in a broad spectrum of activity from basic science in the laboratory to field studies in austere and remote areas of the world to investigations in operational environments. In support of the Navy, Marine Corps, and joint U.S. warfighters, enterprise researchers study infectious diseases, biological warfare detection and defense, combat casualty care, environmental health concerns, aerospace and undersea medicine, medical modeling, simulation, operational mission support, epidemiology and behavioral sciences.
Story originally posted on DVIDS:
NAMRU South Virology Surveillance Efforts Against Dengue