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Cryptosporidium is a major etiological agent of diarrhoeal diseases among children and immune-compromised individuals in sub-Saharan African countries. We conducted a study to determine the prevalence and genetic characteristics of Cryptosporidium spp. in stool samples from patients with diarrhoea who presented at the University Teaching Hospital in Lusaka, Zambia. Cryptosporidium species and subtypes from 71 microscopically confirmed cryptosporidiosis stool samples collected between 2017 and 2019 were determined by polymerase chain reaction followed by partial sequencing of the small subunit rRNA and 60-kDa glycoprotein (gp60) gene. Additionally, data for the period between 2014 and 2019 were reviewed and analysed for cryptosporidiosis seasonal and age distribution. Cryptosporidium was more prevalent in the rainy season. The highest number of cases was reported among the 1–4 year age group. By sequence analysis of the 71 positive isolates, Cryptosporidium hominis (n = 42; 59.2%), C. parvum (n = 27; 38%), C. felis (n = 1; 1.4%), and C. meleagridis (n = 1; 1.4%) were identified. Four C. hominis subtype families (Ia, Ib, Id, and Ie) and three C. parvum subtype families (IIc, IIe, and IIs) were identified. The most frequent subtypes were IeA11G3T3 (n = 20; 28.2%), IIcA5G3 (n = 12; 16.9%), IIeA12G1 (n = 11; 15.5%) and IaA30R3 (n = 10; 14.1%). The observed species/subtypes of C. hominis and C. parvum indicated that the infection was mainly transmitted through the anthroponotic route. The identification of C. felis and C. meleagridis suggests that an atypical zoonotic transmission cycle also exists.

Background: Schistosoma mansoni is hyperendemic in many rural areas of Zambia where up to 77% of people are positive for infection via serologic evaluation. Zambia also has a high prevalence of HIV infection. Individually, S. mansoni and HIV infection impair gastrointestinal barrier integrity and induce inflammation, but the effects of coinfection are not well understood. We set out to test the hypothesis that HIV would exacerbate intestinal barrier failure in patients with S. mansoni infection., Methods: Adults attending medical outpatient clinics in Kaoma, Western Province, Zambia, were enrolled in a case-control study to determine the relative contributions of schistosomiasis and HIV to microbial translocation (measured as soluble CD14 [sCD14] and lipopolysaccharide binding protein [LBP]) and inflammation (measured as CRP)., Results: Among 152 adults evaluated, 74 (49%) were HIV-seropositive, 45 (29%) were shedding schistosome ova (Kato-Katz), 120 (81%) were seropositive for schistosome antibodies (i.e. prior or current infection, with or without egg shedding) and 16 (11%) were HIV/schistosome coinfected (defined by Kato-Katz). HIV infection was associated with higher circulating sCD14 concentrations (p=0.003 by Kruskal-Wallis test), but schistosomiasis was not. HIV infection was associated with greater exposure to schistosomes assessed serologically (OR=2.48, 95% CI 1.05 to 5.86; p=0.03), but reduced likelihood of egg shedding (OR 0.47, 95% CI 0.21 to 1.01; p=0.03)., Conclusions: There was no evidence for a compounding or synergistic effect of coinfection on microbial translocation that appeared to be correlated with HIV infection. Further studies are needed to understand how the increase in LBP secondary to HIV infection may decrease schistosome egg excretion in coinfected individuals., (© The Author(s) 2021. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.)

All-trans retinoic acid (ATRA) up-regulates, in laboratory animals, the expression of the gut homing markers α4β7 integrin and CCR9 on lymphocytes, increasing their gut tropism. Here, we show that, in healthy adult volunteers, ATRA induced an increase of these gut homing markers on T cells in vivo in a time dependent manner. The coordinated increase of α4β7 and CCR9 by ATRA was seen in 57% (12/21) of volunteers and only when given together with an oral Vivotif vaccine. When this coordinated response to ATRA and Vivotif vaccine was present, it was strongly correlated with the gut immunoglobulin A (IgA) specific response to vaccine LPS (ρ = 0.82; P = 0.02). Using RNA-Seq analysis of whole blood transcription, patients receiving ATRA and Vivotif in conjunction showed transcriptomic changes in immune-related pathways, particularly including interferon α/β signaling pathway, membrane-ECM interactions and immune hubs. These results suggest that exogenous ATRA can be used to manipulate responses to a subclass of oral vaccines, so far limited to a live attenuated Vivotif vaccine., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)