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

Economic impact assessment of small ruminant fasciolosis in Nigeria using pooled prevalence obtained from literature and field epidemiological data.

Small ruminant fasciolosis (SRF) is a snail - borne disease, transmitted by tropical freshwater snail, Lymnaea (Radix) natalensis in Nigeria. Fasciolosis in small ruminants is often neglected and information on the prevalence and economic losses are scarce. The aim of this study was to evaluate the prevalence of SRF and provide estimated annual economic losses associated with the disease. Meta-analysis revealed pooled prevalence of 2.1% (95%CI: 0.0-5.8) in studies across Nigeria, while the distribution of L. natalensis was 13.2% (95%CI: 11.6-14.1) among collected snails. Approximately 29.4% livestock owners disagree with veterinary inspectors on the liver condemnation of their slaughtered animals in the abattoir during meat inspection. No significant difference (P > 0.05) was observed between SRF in sheep and goats. Mortality cost was estimated at US$ 55,671,620, while total liver condemnation was US$ 552,448. Direct losses were estimated at US$ 60,132,318 and indirect losses at US$ 17,807,706. The overall economic losses attributable to SRF in Nigeria was estimated at US$ 77,940,024 / annum (equivalent to 28.06 billion naira). Fasciolosis in small ruminant remains a major concern for Nigerian livestock industry. The present and future impact of the disease was further discussed. Considering the high economic burden of fasciolosis in small ruminants, improved disease surveillance and meat inspection, regular treatment and control campaigns are important to reduce infection rates and economic losses.

Financial losses estimation of African animal trypanosomosis in Nigeria: field reality-based model.

INTRODUCTION: Theoretical and modelling approaches were undertaken on Nigerian livestock industry to estimate financial losses due to African animal trypanosomosis. METHODS: Surveys were conducted between March 2018 and February 2019 to include focus group interactions, in-depth household engagements concerning livestock practices in relation to AAT. Financial losses estimation on livestock were targeted to provide ways to regain cost and maximize household livelihoods. Mathematical equation was developed to project the effects of intervention strategies. Important variables such as mean AAT prevalence, incidence rate, birth rate, morbidity and mortality were estimated and inserted in the model. RESULTS: Mean total income per capita was US$ 1.31 / person / day among livestock producers in Nigeria. A total of US$ 518. 9 million were estimated from direct losses, while US$ 58.8 million as indirect losses. Annual estimated losses to AAT from cattle, sheep, goat and pigs in Nigeria is US$ 577.7 million. This is equivalent to 207.98 billion Nigerian naira and represents 6.93% of annual livestock GDP in the country. This could increase to 85% in the next 50 years if there are no proper control interventions. Control efforts could reduce the losses to US$ 16.7 million at the rate of 0.2% during the same period. DISCUSSIONS: AAT has severe socioeconomic impact on producer's livelihood and urgent improved control intervention strategies should be instituted to reduce the losses attributed to the disease.

Economic model of bovine fasciolosis in Nigeria: an update.

Bovine fasciolosis is a zoonotic infection transmitted by infected freshwater snail-Lymnaea (Radix) natalensis-in tropical regions. The prevalence of bovine fasciolosis in Nigeria is overwhelming with huge financial cost. In the chronic form of the disease, hyperplastic cholangitis and calcification of bile ducts occur with severe liver damage. The aim of the study was to estimate annual economic losses of bovine fasciolosis in Nigeria. Disease prevalence was estimated at 18.3% (8.5-30.6), average annual disease incidence is maintained at 2.5%, an estimated mortality rate of 1.5%, a total liver condemnation rate of 11.1% were estimated from affected liver due to fasciolosis, annual slaughter rate of 10.5% and a total cattle population of 20 million. A total of 7.3% livestock owners consider fasciolosis as a threat, while only 4.3% have ever used molluscicide. Treatment cost of controlling fasciolosis is estimated at US$375,000, which puts the total annual loss due to fasciolosis at US$26.02 million. Both direct and indirect sources of production losses have an impact on the livestock industry in Nigeria. Bovine fasciolosis threatens food security in Nigeria; therefore, further awareness among livestock owners is needed on control strategies to improve the income base for small-scale livestock farmers.

Risk factors associated with seropositivity for Toxoplasma gondii in population-based studies among immunocompromised patients (pregnant women, HIV patients and children) in West African countries, Cameroon and Gabon: a meta-analysis.

Toxoplasmosis in immunocompromised individuals can be life threatening. The information needed for proper control and management strategies in endemic West African countries is lacking, hence a systematic review and meta-analysis were performed. This study aimed to determine the seroprevalence of anti-Toxoplasma gondii among pregnant women, HIV/AIDs and children in West Africa, Cameroon and Gabon. The epidemiology of the disease published between 1984 and 2019 using PubMed, Web of Science, Ovid MEDLINE, AJOL and Google Scholar databases were identified. Studies that met the inclusion criteria of Toxoplasma gondii infections under the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist were analysed. A total of 58 eligible studies were selected for meta-analysis. These studies considered 18,674 hosts and an overall pooled seroprevalence of anti-T. gondii antibodies were 45.4, 39.0 and 29.5% for pregnant women, HIV/AIDS patients and children, respectively. Pooled seroprevalence was highest in Gabon and lowest in Mali for pregnant women while highest levels of seropositivity for anti-T. gondii antibodies for HIV/AIDS individuals and children were both observed in Ghana. The major risk factors associated with anti-T. gondii seropositivity were gravida status, contact with cats, consumption of raw vegetables and /fruits, age and CD4 counts. More studies are needed to determine seroconversion rate. Improved sensitization among immunocompromised patients on T. gondii and its risk factors will be an efficient method to reducing the prevalence of the disease. One Health interventions involving transdisciplinary, integrative research and capacity building are necessary to address the problem of toxoplasmosis in West Africa.

Epidemiological dynamics and associated risk factors of S. haematobium in humans and its snail vectors in Nigeria: a meta-analysis (1983-2018).

Schistosoma haematobium, a major pathogen of urogenital schistosomiasis, has been reported to be affecting an estimated 30 million people in Nigeria. Current national estimates of S. haematobium and its cercariae, in humans and snail vectors respectively, are lacking in Nigeria, hence systematic meta-analyses were conducted to understand the disease dynamics in the endemic country over a period of 35 years based on publications from five databases (AJOL, Ovid MEDLINE, Google Scholar, PubMed and Web of Science). The preferred reporting items for systematic reviews and meta-analyses (PRIMSA) checklist were used as the standard guide for the analyses. The prevalence of S. haematobium in human hosts in Nigeria using quality effects model was 32.1% (27.3-37.2), while schistosome cercariae were observed at 3.5% (0.0-11.9), 18.2% (4.7-36.8) and 18.7% (0.0-46.1) and for B. forskalii, Bulinus globosus and B. truncatus, respectively. The high report of schistosome cercariae indicates the continuous transmission of S. haematobium in humans especially with individuals who have frequent contact with freshwater. Heterogeneity of subgroup analyses (regions, zones, sex, age groups, diagnostic techniques) and risk factors (pathological signs, occupation, water sources, anthropogenic activities, treatment) were determined. The result showed prevalence of an endemic moderate class infection that has been linked to several risk factors. Therefore, there is need for increased awareness on the prevalence, transmission routes and treatment strategies to mitigate the disease in this endemic area.

A meta-analysis of Toxoplasma gondii seroprevalence, genotypes and risk factors among food animals in West African countries from public health perspectives.

Toxoplasma gondii has been incriminated as an important opportunistic zoonotic protozoan parasite in food animals. A West African meta-analysis was conducted to assess the seroprevalence, genotypes and risk factors of T. gondii infection in food animals. Databases were searched electronically, considering T. gondii infection in cattle, goats, sheep, pigs and chickens. These were conducted to estimate overall pooled seroprevalence, confidence intervals at 95 % (CI) and heterogeneity using quality effects model. Qualitative data on risk factors to determine effects on human populace and possible control strategies were evaluated. Pooled seroprevalence of anti-T. gondii antibodies for food animals was 25.5 % (18.9-32.8); and for each animal namely cattle, sheep, goats, pigs and chickens were 16.3, 29.1, 18.1, 35.9 and 36.0 %, respectively. Most studied food animals were observed in Nigeria, while the highest seroprevalence was observed in examined goats from Republic of Benin, the lowest was in cattle from the same country. Substantial variability (Q = 2759.5; I2 = 98.3; Qi = 17.3; df = 48) among studies and lack of publication bias (LFK index = -0.08) in overall assessment was observed. In spite of the high seroprevalence in food animals, awareness and research activities in most endemic West African countries is low. Failure to associate the common risk factors have limited the reliable estimation of T. gondii infection. Therefore, more efforts are needed in awareness campaign, management practises, careful treatment of contaminated environment with cat faeces, among other measures to assist in the prevention of T. gondii in food animals.