Respiratory morbidity in Schistosoma mansoni infection: a rapid review of literature

Ther Adv Infect Dis. 2023 Dec 25:10:20499361231220152. doi: 10.1177/20499361231220152. eCollection 2023 Jan-Dec.

Abstract

Background: Schistosomiasis contributes to 2.5 million disability-adjusted life years globally. Acute and chronic respiratory morbidity of Schistosoma mansoni (S. mansoni) is poorly documented in the literature. We conducted a rapid literature review of the burden of respiratory symptoms and lung function abnormalities among patients with S. mansoni. We also report the immunologic and lung imaging findings from the studies reviewed.

Methods: We carried out a comprehensive literature search in Embase and MEDLINE from the inception of the databases to 13th March 2023.

Results: A total of 2243 patients with S. mansoni were reported from 24 case reports, 11 cross-sectional studies, 7 case series, 2 cohort studies and 2 randomized controlled trials. The prevalence of any respiratory symptom was 13.3-63.3% (total number of patients studied, n = 149). The prevalence of the individual symptoms among patients with S. mansoni in whom respiratory symptoms were sought for was as follows: cough (8.3-80.6%, n = 338), dyspnea (1.7-100.0%, n = 200), chest pain (9.0-57.1%, n = 86), sputum production (20.0-23.3%, n = 30) and wheezing (0.0 - 20.0%, n = 1396). The frequency of the symptoms tended to be higher in acute schistosomiasis. Restrictive lung disease was prevalent in 29.0% (9/31). The commonest chest imaging findings reported were nodules (20-90%, n = 103) and interstitial infiltrates (12.5-23.0%, n = 89). Peripheral blood eosinophilia was prevalent in 72.0-100.0% of patients (n = 130) with acute schistosomiasis and correlated with symptoms and imaging abnormalities. Three case reports in chronic S. mansoni reported elevated C-reactive protein, leucocyte, neutrophil and absolute eosinophil counts, eosinophil percentage, IgE and IgG4.

Conclusion: There is a high prevalence of respiratory morbidity among patients with S. mansoni, particularly in the acute stage of the infection, although the studies are relatively small. Larger studies are needed to characterize respiratory morbidity in chronic schistosomiasis and determine the underlying clinical and immunological mechanisms.

Keywords: Schistosoma mansoni; cough; dyspnea; eosinophils; lung function; respiratory symptoms.

Plain language summary

Respiratory problems in people with bilharzia Bilharzia causes significant health problems among those affected. However, little is known about respiratory problems associated with bilharzia. We systematically searched for studies published on bilharzia and respiratory problems in literature. We found that a high proportion of people with bilharzia report cough, difficulty in breathing, chest pain, sputum production and wheezing. Also, a good number have lung function impairment and abnormalities on X-ray imaging. Blood eosinophils tended to be associated with the respiratory symptoms and imaging abnormalities which suggests that eosinophils may be involved in causing respiratory problems. We conclude that lung problems are common among people with bilharzia although the studies reviewed were small and mostly among people with acute infection. Larger studies are needed to further characterise lung problems in Bilharzia.

Publication types

  • Review