Asymptomatic Visceral Leishmania infantum Infection in US Soldiers Deployed to Iraq. (20th September 2018)

• Record Type: Journal Article
• Authors: Mody, Rupal M; Lakhal-Naouar, Ines; Sherwood, Jeffrey E; Koles, Nancy L; Shaw, Dutchabong; Bigley, Daniel P; Co, Edgie-Mark A; Copeland, Nathanial K; Jagodzinski, Linda L; Mukbel, Rami M; Smiley, Rebecca A; Duncan, Robert C; Kamhawi, Shaden; Jeronimo, Selma M B; DeFraites, Robert F; Aronson, Naomi E
• Is Part Of: Clinical infectious diseases. Volume 68:Number 12(2019)
• Page Start: 2036
• Page End: 2044
• Publication Date: 2018-09-20
• Subjects: visceral leishmaniasis -- asymptomatic -- US soldiers -- deployed -- Iraq; Communicable diseases -- Periodicals; 616.905
• DOI: 10.1093/cid/ciy811
• Languages: English
• ISSNs: 1058-4838

Abstract

Abstract: Background: Visceral leishmaniasis (VL), due to Leishmania infantum, is a persistent intracellular parasitic infection transmitted by the bite of infected sand flies. Symptomatic VL has been reported in U.S. soldiers with Iraq deployment. Untreated symptomatic VL can be fatal; asymptomatic VL (AVL) may establish a lifelong risk of reactivation. We report prevalence and AVL risk factors in Operation Iraqi Freedom (OIF) deployers during 2002–11. Methods: Healthy soldiers exposed to VL endemic areas in Iraq and 50 controls who never traveled to endemic regions were recruited through military healthcare facilities (2015–17). Responses to a risk factor survey and blood samples were obtained. Leishmania research diagnostics utilized included enzyme-linked immunosorbent assay (ELISA), rk39 test strips, quantitative polymerase chain reaction (PCR), and interferon gamma release (IGRA) assays. Statistical analyses included Fisher exact test, Pearson χ 2 test, Mann-Whitney U test, and logistic regression. Results: 200 deployed subjects were enrolled, mostly males (84.0%), of white ethnicity (79.0%), and median age 41 (range 24–61) years. 64% were seropositive for Phlebotomus alexandri saliva antibodies. Prevalence of AVL (any positive test result) was 39/200 (19.5%, 95% confidence interval 14.4%–25.8%). Two (1.0%) PCR, 10 (5%) ELISA, and 28 (14%) IGRA samples were positive. Travel to Ninewa governorate increased risk for AVL ( P = .01). Conclusion: AVL was identified in 19.5% of OIF deployers; travel to northwest Iraq correlated with infection. Further studies are needed to inform risk for reactivation VL in US veterans and to target additional blood safety and surveillance measures. Abstract : Approximately 20% of US soldiers deployed to Iraq were found to be infected with Leishmania by blood assays performed at least a decade after deployment. This disease burden and risk for reactivation in US military personnel is underrecognized.