Decreased Sensitivity of Schistosoma sp. Egg Microscopy in Women and HIV-Infected Individuals

Abstract

It has been postulated that impaired host immunity due to HIV infection reduces parasite egg excretion. /HIV interactions have also been shown to differ by sex. We hypothesized that egg excretion would vary based on both HIV status and sex. We examined data from more than 1,700 participants in eight studies conducted in northwest Tanzania between 2010 and 2016. infection was defined by circulating anodic antigen (CAA) serum levels ≥ 30 pg/mL and/or egg positivity in either stool by Kato Katz method or urine by filtration. We used multivariable analyses to determine the impact of confounding factors such as sex, age, previous praziquantel treatment, and worm burden as measured by serum CAA level, on the relationship between egg excretion and HIV status. HIV-infected individuals were significantly less likely to excrete schistosome eggs than HIV-uninfected individuals, even after controlling for worm burden and sex (OR = 0.6 [0.4, 0.9], = 0.005). Furthermore, after controlling for worm burden and HIV status, women had lower odds of egg excretion than men (OR = 0.4 [0.3, 0.5], < 0.001). Sensitivity of egg microscopy was lower in HIV-infected women than HIV-uninfected men (41% versus 61%, < 0.001), whereas sensitivity in women remained low in both groups (33% versus 37%, = 0.664). Our study is the first to report that women with infection excrete fewer eggs than men for a given worm burden, regardless of HIV the status. These findings suggest that guidelines for use of microscopy to diagnose infections in HIV-infected individuals and in women merit reconsideration.

Urogenital Schistosomiasis and Sexually Transmitted Coinfections among Pregnant Women in a Schistosome-Endemic Region of the Democratic Republic of Congo

“…37 Finally, women with schistosomiasis were recently shown to be less likely than men to excrete eggs during active infection. 45 Hence, it is likely that nondifferential misclassification (under-detection) of schistosomiasis occurred in our cohort, downwardly biasing estimates of disease prevalence. Selection bias is also of potential concern because women with symptomatic schistosomiasis or STI may be more likely to visit antenatal clinics than uninfected or asymptomatically infected women.…”

Impact of schistosome infection on long-term HIV/AIDS outcomes

“…It is surprising that sex was not significantly associated with HIV/AIDS progression given that studies demonstrate higher HIV-1 viral load set-points in men than in women [ 48 – 50 ]. It is possible that other variables were so strongly associated with the outcome that the sex effect became relatively inconsequential, that sex differences in linkage to care were small in our study, or that the complexities of interactions between host sex and schistosome infection [ 51 ] make detection of a simple relationship difficult.…”

A systematic review and meta-analysis to assess the association between urogenital schistosomiasis and HIV/AIDS infection

“…Though these are all recommended tests for diagnosing UGS, this highlights the lack of a gold standard testing for S. haematobium [40]. Furthermore, women have been shown to have lower odds of egg secretion than men (OR = 0.4 (0.3,0.5), P<0.001) which could possibly have affected the results [41]. For HIV infection, all the eight studies used serological diagnostic tests, in line with WHO recommendations of HIV laboratory diagnosis.…”