Schistosomiasis in the Military-A Narrative Review

Abstract

Schistosomiasis is a parasitosis caused by trematodes of the genus Schistosoma. Humans are infected when coming into contact with freshwater containing the parasites' infective stages, which are amplified through freshwater-dwelling snails acting as intermediate hosts. Schistosomiasis has posed significant problems for troops exposed to freshwater in endemic regions ever since the Napoleonic wars. Schistosomiasis has substantial differences in clinical presentation, depending on the type of parasite, intensity of infection and reinfection, clinical form, and disease stage. It can remain undiagnosed for long periods of time, with well-known long-term morbidity and mortality risks. The diagnosis of schistosomiasis depends on its stage and relays on several tests, all with limitations in sensitivity and specificity. The diagnostic gold standard is the detection of eggs in urine, feces, or tissue biopsies, but this can raise problems in patients such as military personnel, in which the worm burden is usually low. Praziquantel is the drug of choice for schistosomiasis. Currently, there is no available commercial vaccine against any Schistosoma parasite. Avoiding freshwater exposure is the best prevention. Herein, we review the clinical presentation, diagnosis, treatment, and prevention of schistosomiasis in the military. This information may decrease the impact of schistosomiasis on this particular professional group.

Keywords: Schistosoma spp.; imported disease; military; neglected tropical disease; schistosomiasis; travel medicine; tropical deployment; tropical medicine; veterans.

Figure 1

Flowchart showing the selection of publications on schistosomiasis in military personnel.

Figure 2

Schistosoma life cycle. A: eggs (left to right: S. japonicum, S. haematobium, S. mansoni); B: miracidium; C: sporocysts; D: cercariae; E: schistosomulum; F: a pair of adult worms. : asexual reproduction stage (inside the intermediate hosts).