Male genitourinary schistosomiasis-related symptoms among long-term Western African migrants in Spain: a prospective population-based screening study

Abstract

Background: Schistosomiasis is highly endemic in sub-Saharan Africa and frequently imported to Europe. Male urogenital manifestations are often neglected. We aimed to ascertain the prevalence of genitourinary clinical signs and symptoms among long-term African migrants in a non-endemic European country using a serology test.

Methods: We carried out a prospective, community-based cross-sectional study of adult male migrants from sub-Saharan Africa living in Spain. Schistosoma serology tests and microscopic urine examinations were carried out, and clinical data were obtained from an electronic medical record search and a structured questionnaire.

Results: We included 388 adult males, mean age 43.5 years [Standard Deviation (SD) = 12.0, range: 18-76]. The median time since migration to the European Union was 17 [Interquartile range (IQR): 11-21] years. The most frequent country of origin was Senegal (N = 179, 46.1%). Of the 338, 147 (37.6%) tested positive for Schistosoma. Parasite eggs were present in the urine of only 1.3%. Nine genitourinary clinical items were significantly associated with positive Schistosoma serology results: pelvic pain (45.2%; OR = 1.57, 95% CI: 1.0-2.4), pain on ejaculation (14.5%; OR = 1.85, 95% CI: 1.0-3.5), dyspareunia (12.4%; OR = 2.45, 95% CI: 1.2-5.2), erectile dysfunction (9.5%; OR = 3.10, 95% CI: 1.3-7.6), self-reported episodes of infertility (32.1%; OR = 1.69, 95% CI: 1.0-2.8), haematuria (55.2%; OR = 2.37, 95% CI: 1.5-3.6), dysuria (52.1%; OR = 2.01, 95% CI: 1.3-3.1), undiagnosed syndromic STIs (5.4%), and orchitis (20.7%; OR = 1.81, 95% CI: 1.0-3.1). Clinical signs tended to cluster.

Conclusions: Urogenital clinical signs and symptoms are prevalent among male African long-term migrants with a positive Schistosoma serology results. Genital involvement can be frequent even among those with long periods of non-residence in their sub-Saharan African countries of origin. Further research is needed to develop diagnostic tools and validate therapeutic approaches to chronic schistosomiasis.

Keywords: Chronic schistosomiasis; Long-term migrant; Male genital schistosomiasis; Schistosomiasis; Urogenital schistosomiasis.

Fig. 1

Box plot of number of genitourinary symptoms broken down by schistosomiasis serology test result. N: Number

Fig. 2

Prevalence of genitourinary signs and symptoms assessed in the study broken down by schistosomiasis serology test results¹. ¹We considered cumulative history of signs and symptoms obtained from both a directed questionnaire and clinical records. *P value < 0.05; **P value between 0.05 and 0.1. Add the abbreviations in this figure

Fig. 3

Accumulation of urogenital and reproductive system signs and symptoms among every participant in the study with a positive schistosomiasis serology test result (N = 147)¹. ¹Each column represents an individual with a positive schistosomiasis serology test result. The graphic representation has been ordered according to the cumulative number of clinical items in every case from box A (11 to 4), box B (4 to 2) to box C (2 to 0). The overall cumulative prevalence of each clinical item in decreasing order was: haematuria (N = 80, 55.2%), dysuria (N = 76; 52.1%), pelvic pain (N = 66, 45.2%), infertility (N = 48, 33.6%), orchitis (N = 30, 20.7%), pain on ejaculation (N = 21, 14.5%), dyspareunia (N = 18, 12.4%), erectile dysfunction (N = 14, 9.5%), haematospermia (N = 12, 8.3%), syndromic STI (N = 8, 5.4%), prostatitis (N = 5, 3.4%), and hydrocele (N = 3, 2.0%). Shaded squares indicates missing or unavailable data

Fig. 4

Network analysis of the signs and symptoms identified in the study sample*^1–3. *Every clinical sign or symptom is a node. The size of the node correlates with the number of individuals presenting the given condition. An edge between nodes (variables) indicates a statistically significant association between them. The thickness of the edges indicates the strength of the association, which correlates with the number of times that both items appear together in the data set. A more central location of the node indicates a higher centrality score, which can be interpreted as a higher influence (higher density of connections) over the network. In Figure S1 we show the centrality scores of the network calculations for each of the variables examined. Briefly, the network suggests the existence of clusters of signs and symptoms around the case definition of genitourinary schistosomiasis used for this analysis (Schisto +). Note that the working case definition should not be considered a diagnostic criteria for MGS because it cannot be performed in the absence of reliable microbiological methods to identify parasites. ¹UTI: Urinary tract infections; ²STI: Sexually Transmitted Infections. ³We considered for this analysis the cumulative history of signs and symptoms collected by means of both a directed questionnaire and a review of digitalized medical histories