Factors Associated With Cryptosporidium Infection Among Adult HIV Positive Population in Contact With Livestock in Namwala District, Zambia

Asymptomatic carriage of intestinal protists is common in children in Lusaka Province, Zambia

BACKGROUND

PCR-based screenings on the presence of diarrhoea-causing intestinal protist species are limited in Zambia, resulting in inaccurate current prevalence and epidemiological data. Sensitive PCR-based methods are particularly well suited for detecting subclinical infections in apparently healthy carriers.

METHODOLOGY

In this prospective cross-sectional study, we investigated the occurrence of the most common intestinal protists in an apparently healthy paediatric population (5-18 years) in Lusaka Province, Zambia. We collected single stool samples (n = 256) and epidemiological questionnaires on demographics, behavioural habits, drinking water and toilet access from participating children. We used PCR for the initial screening of samples for the presence of intestinal protist species and Sanger and next-generation sequencing for genotyping. We conducted statistical analyses to assess the association of the gathered variables with an increased likelihood of the investigated pathogens.

PRINCIPAL FINDINGS

Blastocystis sp. was the most prevalent intestinal protist found (37.9%, 97/256; 95% CI: 31.9-44.1), followed by Giardia duodenalis (30.9%, 79/256; 95% CI: 25.3-36.90), Entamoeba dispar (13.3%, 34/256; 95% CI: 9.4-18.1), and Cryptosporidium spp. (4.3%, 11/256, 95% CI: 2.2-7.6). Entamoeba histolytica was not detected. Based on Sanger sequencing results, subtypes ST2 (44.3%, 43/97), ST1 (35.1%, 34/97), and ST3 (20.6%, 20/97) were identified within Blastocystis sp. and assemblages B (71.0%), A+B (16.1%), and A (12.9%) within G. duodenalis. Cryptosporidium parvum (81.8%) and C. hominis (18.2%) were the only two Cryptosporidium species found. Living in the Kafue District was positively associated with higher infection rates by G. duodenalis and Blastocystis sp. Schoolchildren living in Chongwe District were more likely to be infected by Cryptosporidium spp.

CONCLUSIONS/SIGNIFICANCE

Intestinal protist infection/colonization is a common finding in apparently healthy children in Lusaka Province, Zambia. Asymptomatic carriers may play an underestimated role as spreaders of gastrointestinal parasitic infections. This study improves our current understanding of the epidemiology of diarrhoea-causing protists in Zambia and sub-Saharan Africa and indicates that the role of asymptomatic carriers of gastrointestinal parasites in transmission should be further explored.

Cryptosporidium Species Infections Detected from Fecal Samples of Animal and Human Hosts in South Africa: Systematic Review and Meta-Analysis

This study presents a systematic review and meta-analysis approach of Cryptosporidium species prevalence studies in animal and human hosts published between 1980 and 2020 in South Africa. Extensive searches were conducted on three electronic databases including PubMed, ScienceDirect and Google Scholar. The findings indicated an overall pooled prevalence estimate (PPE) of Cryptosporidium spp. infections in animals and humans at 21.5% and 18.1%, respectively. The PCR-RFLP appeared to be the most sensitive diagnostic method with a PPE of 77.8% for the detection of Cryptosporidium spp. infections followed by ELISA (66.7%); LAMP (45.4%); PCR (25.3%); qPCR (20.7%); microscopy (10.1%); IFAT (8.4%); and RDT (7.9%). In animal hosts, C. parvum had the highest PPE of 3.7%, followed by C. andersoni (1.5%), C. ubiquitum (1.4%) and C. bovis (1.0%), while in humans, C. parvum also had the highest PPE of 18.3% followed by C. meleagridis at 0.4%. The data generated in this study indicated that Cryptosporidium spp. infections were highly prevalent in both animals and humans in South Africa, especially in the KwaZulu-Natal and North West provinces. However, we further observed that there was a lack of prevalence studies for both animals and humans in some of the provinces. This study highlights the necessity for a "One Health" strategic approach promoting public hygiene, animal husbandry and regular screening for Cryptosporidium spp. infections in both animals and humans.

High Clinical Burden of Cryptosporidium spp. in Adult Patients with Acquired Immunodeficiency in Ghana

There is a paucity of information on the prevalence, risk factors, and clinical correlates of people living with HIV (PLWH) who are co-infected with Cryptosporidium spp. in the post-combined antiretroviral therapy era in Ghana. To provide such data, in this observational study, stool samples of 640 HIV-positive and 83 HIV-negative individuals in Ghana were screened for Cryptosporidium spp. Additionally, sociodemographic parameters, clinical symptoms, medication intake, and immunological parameters were assessed. The prevalence of Cryptosporidium spp. was 11.8% (n = 73) in HIV-positive and 1.2% (n = 1) in HIV-negative participants (p < 0.001). Within the group of HIV-positive participants, the prevalence reached 26.0% in patients with CD4+ T cell counts below 200 cells/µL and 46.2% in the subgroup with CD4+ T cell counts below 50 cells/µL. The frequencies of the clinical manifestation of weight loss and gastrointestinal symptoms were significantly higher in patients with Cryptosporidium spp. compared to those without co-infection (45.8% vs. 21.4%, p < 0.001 and 22.2% vs. 12.2%, p = 0.031, respectively). In the modern post-cART era, the acquisition of Cryptosporidium spp. among PLWH in Ghana is driven largely by the degree of immunosuppression. Access to cART and screening for Cryptosporidium spp. as part of routine care might help control and reduce the burden of the infection.

Parasitological, Molecular, and Epidemiological Investigation of Cryptosporidium Infection Among Cattle and Buffalo Calves From Assiut Governorate, Upper Egypt: Current Status and Zoonotic Implications

Details about the epidemiological patterns and real contributions of different reservoir animals in maintaining the transmission cycle of Cryptosporidium spp. in Upper Egypt remain lacking. This study was designed to investigate the occurrence of Cryptosporidium spp. in cattle and buffalo (n = 608) from Upper Egypt. The parasite for the resulting positive samples by fecal examination was molecularly identified using nested PCR targeting the small subunit rRNA. Moreover, several explanatory variables, including animals' age, sex, condition, seasonal variations, were examined to describe the epidemiological pattern of the disease. Interestingly, the fecal examination revealed that 33.55% (204/608) of the animals under study were infected with Cryptosporidium, including 38.27% among cattle and 28.16% among buffalo. The parasite was molecularly identified using nested PCR, and their amplicons were identified in almost all fecal samples using microscopy (202/204). According to age as an individual variable factor, the infection rates of Cryptosporidium spp. in cattle calves with ages of <1, 1–3, and >3 months were 39.13, 34.04, and 54.54%, respectively. Meanwhile, in buffalo calves, the occurrence rates were 28.57, 27.27, and 29.41%, respectively. Regarding sex, female cattle calves were more susceptible to Cryptosporidium infection (51.28%) than males (26.19%) (p < 0.05), whereas male buffalo calves had a higher infection rate (32.25%) than females (25%). According to seasonal variations, the infection rates of Cryptosporidium spp. in cattle calves during spring, summer, autumn, and winter were 42.11, 30.43, 30, and 52.63%, respectively. In contrast, lower infection rates of 30, 21.42, 23.52, and 35% were reported in buffalo calves during spring, summer, autumn, and winter, respectively. The rate of infection was 45.16% in diarrheic cattle calves and 15.78% in non-diarrheic ones (p < 0.05). Meanwhile, the infection rate was 33.96% in diarrheic buffalo calves and 11.11% in non-diarrheic ones (p < 0.05). This study reported a higher occurrence of Cryptosporidium infection among the animals under study and revealed that buffalos and cattle can contribute to maintaining the transmission cycle of this zoonotic parasite in Upper Egypt.

A meta-analysis of Cryptosporidium species in humans from southern Africa (2000-2020)

Abstract

The epidemiology of cryptosporidiosis in southern Africa is largely unknown. The disease is associated with diarrhea and nutritional deficiencies, leading to severe morbidity and mortality among immune-compromised patients. This study aimed to assess the pooled prevalence of Cryptosporidium spp. infection among immune-compromised humans in southern Africa over the past 20 years. Reports of Cryptosporidium spp. infection in humans published between 2000 and 2020 using Google Scholar, PubMed, Ovid Medline, African Journal Online (AJOL), and Web of Science literature databases were obtained. Inclusion criteria of sorted articles for Cryptosporidium spp. infection were standardized using preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist. A total of 22 eligible studies were sorted for meta-analysis. Overall prevalence of Cryptosporidium spp. infection in southern African countries with reports was 16.8% (95% CI 9.7-25.3). Sub-group analysis showed a pooled prevalence of 25.2, 20.5, and 17.9% among HIV/AIDS patients, children, and diarrhoeic individuals, respectively. Pooled prevalence was highest in South Africa and lowest in Zimbabwe across examined individuals. The pooled prevalence of Cryptosporidium spp. infections in diarrhoeic patients was highest in individuals from Botswana (17.6%) which is significantly different (Χ ² = 9.337; P = 0.002) from South Africans (12.7%). South African individuals with HIV/AIDS showed the highest pooled prevalence of Cryptosporidium infections than other countries. The high prevalence of Cryptosporidium spp. infections among immune-compromised patients in southern Africa showed that the pathogen is of significant importance in this region. Continuous studies on the genetic characterization of Cryptosporidium spp. isolates and associated risk factors are needed across southern Africa to identify the predominant subtypes in humans.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-021-01436-4.

Prevalence, risk factors and impact of cellular immunity on intestinal parasitosis among people living with HIV at Auchi, Edo State, Nigeria

This study was sought to determine the impact of CD4⁺ T-cell count and associated risk factors with intestinal parasitosis in people living with HIV (PLHIV) in Central Hospital, Auchi, Edo State, Nigeria. One hundred and seventy (170) HIV-seropositive subjects were enrolled in the study from 24 August 2015 to 22 January 2016. Sociodemographic data were assessed using structured questionnaires. Blood and stool samples were collected from every participant. CD4⁺ T-cell count and stool parasitology were performed. The prevalence of intestinal parasites was 44.7%. Helminthiasis (67%) was a predominant infection in the study, while 32.9% had protozoasis. Specifically, Ancylostoma duodenale (33.3%) was the most common helminth, and Trichuris trichiura (7.8%), the least. However, Strongyloides stercoralis, Ascaris lumbricoides and Hymenolepis nana were 13.7%, 31.5% and 13.7%, respectively. Cryptosporidium spp. (25.0%) was the only protozoan. Lower CD4⁺ T-cell count, ART naivety (OR = 2.62 p < 0.05), residence in a rural setting (OR = 0.89, p < 0.05), and farming occupation (OR = 1.70, p < 0.05) were associated with the prevalence of intestinal parasitosis among PLHIV. This study revealed a significantly high prevalence of intestinal parasitosis in ART naive PLHIV with reduced CD4⁺ count. Hence, it is recommended to frequently test for intestinal parasitosis and commencement of ART in all PLHIV to improve their health and longevity.

Molecular Epidemiology of Human Cryptosporidiosis in Low- and Middle-Income Countries

Cryptosporidiosis is one of the most important causes of moderate to severe diarrhea and diarrhea-related mortality in children under 2 years of age in low- and middle-income countries. In recent decades, genotyping and subtyping tools have been used in epidemiological studies of human cryptosporidiosis. Results of these studies suggest that higher genetic diversity of Cryptosporidium spp. is present in humans in these countries at both species and subtype levels and that anthroponotic transmission plays a major role in human cryptosporidiosis. Cryptosporidium hominis is the most common Cryptosporidium species in humans in almost all the low- and middle-income countries examined, with five subtype families (namely, Ia, Ib, Id, Ie, and If) being commonly found in most regions. In addition, most Cryptosporidium parvum infections in these areas are caused by the anthroponotic IIc subtype family rather than the zoonotic IIa subtype family. There is geographic segregation in Cryptosporidium hominis subtypes, as revealed by multilocus subtyping. Concurrent and sequential infections with different Cryptosporidium species and subtypes are common, as immunity against reinfection and cross protection against different Cryptosporidium species are partial. Differences in clinical presentations have been observed among Cryptosporidium species and C. hominis subtypes. These observations suggest that WASH (water, sanitation, and hygiene)-based interventions should be implemented to prevent and control human cryptosporidiosis in low- and middle-income countries.