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Countries of the World Health Organization (WHO) African Region have experienced a wide range of coronavirus disease 2019 (COVID-19) epidemics. This study aimed to identify predictors of the timing of the first COVID-19 case and the per capita mortality in WHO African Region countries during the first and second pandemic waves and to test for associations with the preparedness of health systems and government pandemic responses. Using a region-wide, country-based observational study, we found that the first case was detected earlier in countries with more urban populations, higher international connectivity and greater COVID-19 test capacity but later in island nations. Predictors of a high first wave per capita mortality rate included a more urban population, higher pre-pandemic international connectivity and a higher prevalence of HIV. Countries rated as better prepared and having more resilient health systems were worst affected by the disease, the imposition of restrictions or both, making any benefit of more stringent countermeasures difficult to detect. Predictors for the second wave were similar to the first. Second wave per capita mortality could be predicted from that of the first wave. The COVID-19 pandemic highlights unanticipated vulnerabilities to infectious disease in Africa that should be taken into account in future pandemic preparedness planning., (© 2021. The Author(s).)

Background: Schistosomiasis is known to induce inflammatory immune responses. C-reactive protein (CRP), resistin and P-selectin are serological inflammatory markers that rise during the acute stages of infection. Here, we propose such inflammatory biomarkers have a potential for use in urogenital schistosomiasis diagnostic screening for exposure and infection in preschool-aged children., Methods: As part of a larger study on urogenital schistosomiasis, 299 preschool children aged 1-5 years were included in this cross-sectional study. Parasitological diagnosis was conducted using urine filtration for Schistosoma haemtobium infection, and Kato Katz for S. mansoni infection. Serum levels of P-selectin, resistin, CRP, and antibodies against S. haematobium cercarial antigen preparation (CAP) and soluble worm antigen preparation (SWAP) were measured by ELISA., Results: Of the 299 participants, 14% were egg positive for S. haematobium. Serology showed 46 and 9% of the participants to have been exposed to S. haematobium cercarial antigens and adult worm antigens, respectively. Levels of P-selectin were significantly higher in participants infected with S. haematobium (egg-positive) than in uninfected participants (p = 0.001). Levels of P-selectin were also higher in those exposed to cercarial antigen than in unexposed participants (p = 0.019). There was a positive correlation between P-selectin and infection intensity (r = 0.172; p = 0.002), as well as with IgM responses to CAP and SWAP (r = 0.183; p = 0.001); (r = 0.333; p < 0.0001) respectively. CRP significantly correlated with IgM responses to CAP (r = 0.133; p = 0.029) while resistin correlated with IgM responses to CAP and SWAP (r = 0.127; p = 0.016); (r = 0.197; p = 0.0004). CRP levels were higher in those exposed to cercarial and adult worm antigens than unexposed participants (p = 0.035); (p = 0.002) respectively, while resistin was higher in participants exposed to cercarial antigen than unexposed participants (p = 0.024)., Conclusion: In this preschool population, P-selectin is significantly associated with urogenital schistosome infection and intensity; hence a potential biomarker for infection diagnosis and disease monitoring. The inflammatory biomarkers (P-selectin, Resistin and CRP) were significantly higher in participants exposed to cercarial antigens than unexposed individuals indicating an underlying inflammatory environment.

Praziquantel (PZQ) is an anthelminthic human and veterinary drug used to treat trematode and cestode worms. Changes in immune responses have been demonstrated in humans following curative PZQ treatment of schistosome infections. These changes have been attributed to the removal of immunosupressive worms and immune responses to parasite antigens exposed from dying worms. To date, there has been no study investigating the potential direct effect of PZQ on the host immune cells. Herein, we analyzed the effect of PZQ on human CD4 + T cells classically costimulated by CD3/CD28 or costimulated by the complement regulator CD46 to induce Type 1 regulatory T cells (Tr1). Our results show that PZQ enhanced T-cell proliferation, increased secretion of IL-17 and IL-10 but had no effect on secretion of GM-CSF or IFNγ. Moreover, PZQ increased the coexpression of CD49b and LAG-3, a hallmark of Tr1 cells, suggesting increased Tr1 differentiation. Indeed, supernatants from PZQ-treated cells were able to decrease bystander T-cell activation, and this was partly reduced when blocking IL-10. Hence, our study demonstrates that PZQ directly modulates human T-cell activation and promotes Tr1 differentiation, suggesting that PZQ may have immunomodulatory functions in parasite-unrelated human inflammatory diseases., (© 2019 Australasian Society for Immunology Inc.)