A Cross-Sectional Study of Seroprevalence of Strongyloidiasis in Pregnant Women (Peruvian Amazon Basin)

Abstract

Strongyloidiasis is a soil-transmitted helminthiasis with a high global prevalence. Objectives: We aimed to evaluate the prevalence of Strongyloides stercoralis infection and assess strongyloidiasis serology as a screening technique in the Peruvian Amazon. Material and Methods: We performed a cross-sectional study of strongyloidiasis in 300 pregnant women in Iquitos (Peru) from 1 May 2019 to 15 June 2019. Women were tested using serology (Strongyloides IgG IVD-ELISA kit) as an index test and the modified Baermann technique and/or charcoal fecal culture as the parasitological reference standard. Results: The reference tests showed S. stercoralis in the stool of 30 women (prevalence: 10%; 95% confidence interval [CI] 7.1% to 13.9%), while 101 women tested positive on the blood test (prevalence: 33.7%; 95% CI 28.6% to 39.4%). Fourteen of the 15 women (93.3%) with positive results according to the modified Baermann technique, and 14 of the 23 women (56.5%) with positive charcoal cultures also had positive serological results. Serology showed a sensitivity of 63.3% and a negative predictive value of 94.4%. Conclusion: In Iquitos, pregnant women have a high prevalence of S stercoralis. S. stercoralis ELISA could be an excellent tool for population-based screening, as it has a high negative predictive value that can help to rule out the presence of active infection.

Prevalence of Strongyloidiasis in Peru: Systematic Review

“…Regarding sample collection, most studies collected a single stool sample; four studies used more than one (9,13,18,20). Investigators in four studies also collected blood samples, in two cases for performing S. stercoralis serology (8,11), in two for assessing anemia (11,24), and in one for evaluating eosinophilia (17). Table 1 presents a summary of the characteristics of included studies .…”

“…Among those designed speci cally to study S. stercoralis, 10 used the Baermann technique for diagnosis (7-11, 16, 19, 21, 22, 26). Seven studies used agar, Dancescu or charcoal cultures (7,8,11,16,19,22,26); two performed speci c serological tests (8,11); and one employed a string capsule/enterotest (27). Other diagnostic techniques used to detect the presence of larvae in stool samples included direct smear of feces in saline-Lugol iodine stain, spontaneous tube sedimentation, formalin-ethyl acetate concentration, and Harada-Mori lter paper culture.…”

“…The ELISA was positive in 72% of the blood samples, and the negative predictive value of the serology was 98%. In another study from the same region (11), the prevalence of S. stercoralis infection was 10% using the Baermann method, charcoal culture and ELISA for diagnosis. In this case, the sensitivity of the serology was 63.3% and the negative predictive value, 94.4%.…”

Prevalence of strongyloidiasis in Peru: systematic review and meta-analysis

“…The study populations were very heterogeneous: three papers included the adult population (over 15 years old) [ 15 – 17 ], eight were in children [ 8 , 9 , 18 – 23 ], and nine studied both adults and children [ 7 , 10 , 11 , 24 – 29 ]. One study included only people infected with HIV [ 15 ] and another only pregnant women [ 17 ].…”

Chagas Disease in Pregnant Women in the Peruvian Amazon Basin. Cross-Sectional Study

“…We obtained a blood sample for serological detection of T. cruzi antibodies, S. stercoralis IgG antibodies, and HTLV antibodies, and a stool sample to test for parasitic infections. Our group published results on the prevalence of strongyloidiasis and other intestinal parasites in a parallel report (8).…”