Vectors and Vector-borne Illness
Vector-borne diseases are infections spread by insects, rodents and other animals and include some of the most dangerous diseases to both public health and deployed Service Members including malaria, dengue, Zika, tick-borne encephalitis and others, causing millions of infections each year. AFRIMS works with regional partners to identify, characterize and overcome vector-borne disease by developing pharmacological and public health strategies. These activities include developing and testing novel vaccines, diagnostics and drugs to prevent and treat disease as well as vector control strategies to prevent virus-carrying animals from proliferating. With a changing climate that makes more areas of the world more favorable to vectors of disease for more months of the year, these diseases will continue to be a significant threat to force health protection.


Chiggers are tiny, six-legged wingless larvae that mature to become a type of mite. Chiggers are typically found in tall grass, weeds and the edges of woodlands. Their bite causes severe itching and red pimple-like bumps or hives. Chigger bites can transmit the bacteria Orientia tsutsugamushi, which causes scrub typhus, a disease without a vaccine. AFRIMS conducts surveillance for chiggers and scrub typhus across Southeast Asia.


Chikungunya is an emerging disease spread by Aedes aegypti and Aedes albopictus mosquitoes found across Africa, Asia and the Americas. Currently there are three genotypes of chikungunya virus: West African, East-Central-South African and Asian. Each genotype has contributed to outbreaks over time but in 2004, the ECSA and Asian genotypes began to expand significantly leading to increased cases worldwide. In acute disease, chikungunya infection can lead to high fever, profound joint pain and a rash similar to dengue virus. A key difference to dengue is the chronic, debilitating arthritis that can develop in up to 30-40% of cases and can lead to severe morbidity. It's global distribution, potentially severe consequences and lack of preventive vaccines make it a significant threat to deployed Service Members in endemic areas. 
Entomology | Virology


Infecting over 390 million individuals worldwide, dengue remains a persistent threat to deploying Service Members. As a mosquito-borne disease, spread by the same vector as chikungunya and Zika, increased global temperatures combined with continued urbanization and travel serve to increase the likelihood of exposure to dengue's four serotypes. Dengue is particularly dangerous, due to the potential for ADE and severe dengue (previously termed dengue shock syndrome or dengue hemorrhagic fever by the World Health Organization's 1997) which can be associated with mortality rates of 1% with proper care but up to 26% without. Current treatments address symptoms and disease management primarily focuses on prevention through vector control. However, vector control is increasingly complicated by insecticide-resistance in mosquitoes and the lack of a safe vaccine.
Entomology | Veterinary Medicine | Virology 


Malaria remains the most significant parasitic disease in the world. Transmitted through the bite of an infected Anopheles mosquito, nearly half of the global population is at risk, with an estimated 216 million cases per year in 91 countries. While progress has been made to reduce the burden of malaria around the world, rising resistance to existing malaria drugs and insecticides, geopolitical instability and increasingly inaccurate rapid diagnostic tests threaten these accomplishments. As such, it is a significant threat to both public health and deployed U.S. military forces, the majority of whom lack immunity to the parasite. Addressing the threat of malaria to military and global populations is of critical concern to health diplomacy and international security and a challenge that requires sustained commitment to research and developing effective scientific, clinical, political and social solutions.
Bacterial and Parasitic Diseases | Entomology | Veterinary Medicine


Mosquito-borne pathogens are among the most prevalent and dangerous threats to deployed Service Members, public health and regional stability. Diseases like dengue, malaria and Zika exist cyclically, where an infected mosquito spreads the disease to a human or vertebrate host who then spreads the disease back to a new mosquito when bitten again. While public health strategies using bite prevention technologies (bed nets, treated clothing, etc), repellents and preventive drugs and vaccines have made some progress in mitigating the burden, their efficacy is limited by rising resistance amongst pathogens and their vectors. Furthermore, as the climate changes and mosquitos are able to survive in more areas of the world for more months out of the year, new regions are threatened by the diseases they carry. These dangers underscore the importance of active surveillance of both mosquitoes and the diseases they carry to inform public health efforts and responsive drug and vaccine development. 


Rodents such as rats and mice are associated with a number of health risks and are known to spread more than 35 diseases. These diseases can be spread to humans directly through bites, handling of live or dead rodents and contact with rodent feces, urine or saliva. Diseases carried by rodents can also be spread to humans indirectly through fleas, ticks or mites that have fed on an infected rodent.

Scrub Typhus

Scrub typhus, also known as bush typhus, is a disease caused by a bacteria called Orientia tsutsugamushi. Scrub typhus is spread to people through bites of infected chiggers (larval mites). The most common symptoms of scrub typhus include fever, headache, body aches and sometimes rash. Most cases of scrub typhus occur in rural areas of Southeast Asia, Indonesia, China, Japan, India and northern Australia. Anyone living in or traveling to areas where scrub typhus is found could get infected and there is no vaccine to prevent this disease. AFRIMS scientists work across Southeast Asia to track the incidence of this disease. 
Entomology | Veterinary Medicine


Tick-borne diseases, which afflict humans and other animals, are caused by infectious agents transmitted by tick bites. They are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses and protozoa. Because individual ticks can harbor more than one disease-causing agent, patients can be infected with more than one pathogen at the same time, compounding the difficulty in diagnosis and treatment. 16 tick-borne diseases of humans are known, of which four have been discovered since 2013. As the incidence of tick-borne illnesses increases and the geographic areas in which they are found expand, health workers increasingly must be able to distinguish the diverse, and often overlapping, clinical presentations of these diseases. 


Zika virus is a mosquito-borne disease found around the world. Spread by Aedes mosquitoes, it is frequently found in urban environments and is likely to spread as humans expand into more areas. Distinguishing it from other flaviviruses, Zika has a relatively high rate of asymptomatic infection, can be spread through blood or sexual contact and can be found in bodily fluids for weeks to months after initial infection. Currently there is no treatment for Zika and disease management is primarily focused on symptoms with particular care required for pregnant patients due to the risk of transmission to the baby and ensuing severe morbidities. As such, AFRIMS conducts surveillance and countermeasure development work to detect and combat Zika to maintain force health protection for both Service Members and their families when they return home from deployment to an endemic region. 
Entomology | Retrovirology | Veterinary Medicine | Virology