Prevalence of gastrointestinal pathogens in Sub-Saharan Africa: systematic review and meta-analysis

Identifying Potential Determinants of Faecal Contamination on Domestic Floors in Three Settings in Rural Kenya: A Mixed Methods Analysis

Observational evidence suggests that household floors may be an important domain for the transmission of enteric and parasitic infections. However, little work has been done to investigate how household floors can become contaminated with human and animal faeces. This study uses a mixed methods approach to postulate the proximal and distal determinants of household floor contamination with faeces in groups of rural villages in 3 counties in Kenya (Bungoma, Kwale and Narok). Quantitative data was collected through a household census and analysed descriptively and using mixed effects logistic regression models. Qualitative data was collected through unstructured observations of daily routines and in-depth interviews. These data were analysed thematically with case memos produced for routine activities that were hypothesised to be determinants of floor contamination. Possible proximal determinants of floor contamination included; (1) animal contact with floors; (2) child faeces disposal, and; (3) floor cleaning routines. Distal determinants are suggested to be rooted in the socioeconomic, environmental, and cultural context in which households were located and included; (1) the type and number of animals owned by households; (2) presence/absence of dedicated shelters for housing animals at night, which impacted whether sleeping or cooking areas were exposed to animals; (3) Accessibility of inside spaces to poultry and other roaming animals; (4) ownership of an improved floor; (5) ability of animals to access neighbours compounds; (6) seasonal changes in weather. These results will be of use in identifying the contexts in which faecal contamination of domestic floors may be contributing towards transmission of enteric and parasitic infections and in designing effective interventions to prevent this exposure.

Genomic Characterization of Multidrug-Resistant Pathogenic Enteric Bacteria from Healthy Children in Osun State, Nigeria

Antimicrobial resistance (AMR) is responsible for the spread and persistence of bacterial infections. Surveillance of AMR in healthy individuals is usually not considered, though these individuals serve as reservoirs for continuous disease transmission. Therefore, it is essential to conduct epidemiological surveillance of AMR in healthy individuals to fully understand the dynamics of AMR transmission in Nigeria. Thirteen multidrug-resistant Citrobacter spp., Enterobacter spp., Klebsiella pneumoniae, and Escherichia coli isolated from stool samples of healthy children were subjected to whole genome sequencing (WGS) using Illumina and Oxford nanopore sequencing platforms. A bioinformatics analysis revealed antimicrobial resistance genes such as the pmrB_Y358N gene responsible for colistin resistance detected in E. coli ST219, virulence genes such as senB, and ybtP&Q, and plasmids in the isolates sequenced. All isolates harbored more than three plasmid replicons of either the Col and/or Inc type. Plasmid reconstruction revealed an integrated tetA gene, a toxin production caa gene in two E. coli isolates, and a cusC gene in K. quasivariicola ST3879, which induces neonatal meningitis. The global spread of AMR pathogenic enteric bacteria is of concern, and surveillance should be extended to healthy individuals, especially children. WGS for epidemiological surveillance will improve the detection of AMR pathogens for management and control.

Genomic Characterisation of Multidrug-Resistant Pathogenic Enteric Bacteria from healthy children in Osun State, Nigeria

Antimicrobial resistance (AMR) has been established to be a significant driver for the persistence and spread of bacterial infections. It is, therefore, essential to conduct epidemiological surveillance of AMR in healthy individuals to understand the actual dynamics of AMR in Nigeria. Multi-drug resistant Klebsiella quasivariicola (n=1), Enterobacter hormaechei (n=1), and Escherichia coli (n=3) from stool samples of healthy children were subjected to whole genome sequencing using Illumina Nextseq1000/2000 and Oxford nanopore. Bioinformatics analysis reveals antimicrobial resistance, virulence genes, and plasmids. This pathogenic enteric bacteria harbored more than three plasmid replicons of either Col and/or Inc type associated with outbreaks and AMR resistant gene pmrB responsible for colistin resistance. Plasmid reconstruction revealed an integrated tetA gene responsible for tetracycline resistance, and caa gene responsible for toxin production in two of the E.coli isolates, and a cusC gene known to induce neonatal meningitis in the K. quasivariicola ST3879. The global spread of MDR pathogenic enteric bacteria is a worrying phenomenon, and close surveillance of healthy individuals, especially children, is strongly recommended to prevent the continuous spread and achieve the elimination and eradication of these infections. Molecular epidemiological surveillance using whole genome sequencing (WGS) will improve the detection of MDR pathogens in Nigeria.

Gastrointestinal parasites in Africa: A review

Data on human gastrointestinal parasites (GIP) infections in the african sub-regions and countries are mainly lacking in terms of prevalence and population stratification by afflicted age group, symptomatology, multi-parasitism, and diagnostic methods. This study aims to describe the GIP reported in african countries and discuss the extent of the burden in the african context. Only 68.42% (39/57) of african countries reported human cases of GIP with helminths (45%, CI: 40-50%, I²: 99.79%) as the predominant parasitic group infecting the african population. On a regional scale, Central Africa had the highest pooled prevalence for GIP (43%, CI: 32-54%, I²: 99.74%), while the Central African Republic led all countries with a pooled prevalence of 90% (CI: 89-92%, I²: 99.96%). The vulnerable population (patients who are minorities, children, old, poor, underfunded, or have particular medical conditions) was the most affected (50%, CI: 37-62%, I²: 99.33%), with the predominance of GIP in the 6 to <20 years age group (48%, CI: 43-54%, I²: 99.68%). Reports on multi-parasitism (44%, CI: 40-48%, I²: 99.73%) were almost double the reports of single infections (43%, CI: 27-59%, I²: 99.77%) with combined molecular and non-molecular techniques demonstrating the best performance for GIP identification. The current review spans more than 40 years of GIP reports from the african continent. Geographical characteristics, environmental factors, habits of its inhabitants, and their health status play a crucial role in GIP modulation and behaviour in its captive hosts. Strategies for regular and enhanced surveillance, policy formation, and high-level community awareness are necessary to identify the true incidence in Africa and the transmission of the pathogens via water and food.

Prevalence and antimicrobial resistance profiles of Campylobacter species in South Africa: a "One Health" approach using systematic review and meta-analysis

OBJECTIVES

This study investigated the prevalence and antibiotic resistance (AR) profiles of Campylobacter spp. isolated from animals, humans, and the environment in South Africa based on available published data.

METHODS

Original articles published from January 1, 1990 to January 1, 2021 were searched from PubMed, ScienceDirect, Google Scholar, Africa Index Medicus, Scopus, and African Journal Online databases. Data were analyzed with Comprehensive Meta-Analysis (version 3.0).

RESULTS

After screening, articles on animals (n = 25), humans (n = 7), environment (n = 3), animals/environment (n = 2), and a (n = 1) study on animals, humans, and the environment were included in this review. The pooled prevalence estimates (PPEs) were 28.8%, 16.4%, and 28.4% in animals, humans, and the environment, respectively. The Campylobacter jejuni and Campylobacter coli species were commonly isolated from humans, animals, and the environment in South Africa. The AR profiles were screened from 2032 Campylobacter spp., with the highest PPE of AR observed against clindamycin (76.9%) and clarithromycin (76.5%). Campylobacter isolates tested with the disk diffusion assay and minimum inhibitory concentration methods recorded an overall AR prevalence of 35.3% and 37.1%, respectively, whereas multidrug resistance PPE was 35.3%.

CONCLUSION

Regular surveillance of Campylobacter spp. prevalence and its antimicrobial resistance strains is recommended, as well as the formulation of a "One Health" approach for better management and control of Campylobacter spp. infection in South Africa.

Epidemiology and pre-vaccine burden of rotavirus diarrhea in Democratic Republic of Congo (DRC): Results of sentinel surveillance, 2009-2019

INTRODUCTION

Since August 2009, the Democratic Republic of Congo (DRC) has implemented sentinel site surveillance for rotavirus gastroenteritis. Limited hospital studies have been carried out, in DRC, describing the epidemiology of rotavirus diarrhea before rotavirus vaccine introduction in October 2019. This analysis describes the epidemiology of rotavirus gastroenteritis and characteristics of circulating viral strains from 2009 to 2019.

MATERIALS AND METHODS

We analyzed demographic and clinic data collected from children < 5 years old enrolled at three rotavirus sentinel surveillance sites in DRC during 2009-2019, prior to rotavirus vaccine introduction in 2019. Data have been described and presented as mean ± standard deviation for quantitative variables with normal distribution, or as median with an interquartile range [Q1-Q3] for quantitative variables with non-normal distribution, or as absolute value with percentage for qualitative variables.

RESULTS

Between August 2009 and December 2019, 4,928 children < 5 years old were admitted to sentinel surveillance sites for gastroenteritis in the DRC; the rotavirus positivity rate was 60 %. There was a slight male gender predominance (56 %), and the majority of children (79 %) were 0-11 months of age. Every year, the incidence was highest between May and September corresponding to the dry and cool season. Genotyping was performed for 50 % of confirmed rotavirus cases. The most common G genotypes were G1 (39 %) and G2 (24 %) and most common P genotypes were P[6] (49 %) and P[8] (37 %). The most common G-P genotype combinations were G1P[8] (22 %), G2P[6] (16 %) and G1P[6] (14 %). Genotype distribution varied by site, age group, and year.

CONCLUSION

From 2009 to 2019, rotavirus-associated gastroenteritis represented a significant burden among DRC children under 5 who were admitted to sentinel sites. G1P[8] was the most commonly identified genotype. Continued monitoring after the introduction of rotavirus vaccine will be essential to monitor any changes in epidemiology.

Global Burden of Cyclospora cayetanensis Infection and Associated Risk Factors in People Living with HIV and/or AIDS

Cyclospora cayetanensis infections remain one of the most common protozoan opportunistic causes of gastrointestinal diseases and diarrhea among people living with HIV and/or AIDS (PLWHA). This study was conducted to provide a summary of the evidence on the global burden of C. cayetanensis infection and associated risk factors among PLWHA. Scopus, PubMed, Science Direct, and EMBASE were searched up to February 2022. All original peer-reviewed original research articles were considered, including descriptive and cross-sectional studies describing C. cayetanensis in PLWHA. Incoherence and heterogeneity between studies were quantified by I index and Cochran’s Q test. Publication and population bias were assessed with funnel plots and Egger’s asymmetry regression test. All statistical analyses were performed using StatsDirect. The pooled prevalence of C. cayetanensis infection among PLWHA was 3.89% (95% CI, 2.62–5.40). The highest prevalence found in South America was 7.87% and the lowest in Asia 2.77%. In addition, the prevalence of C. cayetanensis was higher in PLWHA compared to healthy individuals. There was a relationship between a higher C. cayetanensis prevalence in PLWHA with a CD4 cell count below 200 cells/mL and people with diarrhea. The results show that PLWHA are more vulnerable to C. cayetanensis infection and emphasizes the need to implement the screening and prophylaxis tailored to the local context. Owing to the serious and significant clinical manifestations of the parasite, an early identification of seropositivity is recommended to initiate prophylaxis between PLWHA with a CD4 count ≤200 cells/mL and PLWHA who do not receive antiviral therapy.

Multidrug-resistant enteric bacteria in Nigeria and potential use of bacteriophages as biocontrol

Enteric bacterial pathogens have been implicated in many cases of gastroenteritis in Nigeria, a West African country. This situation is worsened by some reports of the high prevalence of multidrug-resistant enteric bacteria. To better prepare for situations in which even antibiotics of last resort would fail to treat infections caused by these pathogens, attention should be paid to alternative antimicrobial strategies. Here, we summarize existing reports of multidrug-resistant enteric bacterial infections in Nigeria, and importantly present the use of bacteriophages (viruses of bacteria) as an attractive antimicrobial alternative to combat these pathogens. It is hoped that this review will encourage research into the use of lytic bacteriophages against multidrug-resistant enteric bacteria in Nigeria.

One Health Perspective of Salmonella Serovars in South Africa Using Pooled Prevalence: Systematic Review and Meta-Analysis

Salmonella is a bacterium that is commonly associated with food-borne infections and is regarded as one of the most important pathogens in public health. Salmonella serovars, particularly Typhimurium and Enteritidis, which are widely distributed globally, mainly result in outbreaks commonly linked to the consumption of animal products. This study is a systematic review and meta-analysis of studies reporting the prevalence of Salmonella serovars from one health perspective that included human, environmental, and animal samples in South Africa. PubMed, ScienceDirect, African Journals Online, and Scopus databases were used to conduct extensive searches of articles which were ultimately included or excluded following the Systematic Reviews and Meta-Analysis (PRISMA) guidelines. According to the data obtained in this review, the overall pooled prevalence estimates (PPE) of Salmonella serovars detection were 79.6%, 61.6%, 56.5%, and 43.2% for human, environment, animal, and environment/animal samples in South Africa, respectively. The majority of the studies (50%) used the polymerase chain reaction (PCR) technique for the detection of Salmonella serovars, followed by culture methods (26.7%), while 20% used serotyping. The PPE for nontyphoidal Salmonellae (NTS) was 65.6% and 34.4% for Salmonella Typhimurium and Salmonella Enteritidis, respectively. Our data further shows that 3 serovars, namely, Salmonella Typhimurium, Salmonella Enteriditis, and Salmonella Hadar, have been isolated from animals, humans, and the environment in South Africa. Our results highlight the ongoing spread of Salmonella spp. especially on animals which might end up infecting humans via direct contact with infected animals or eating infected animal products. This calls for deliberate “One Health” epidemiological studies in order to document information on the transmission between humans, animals, and the environment. This will ultimately result in the formulation of a consolidated salmonellosis control policy by the environmental, human, and veterinary health sectors.

Acute gastroenteritis and the usage pattern of antibiotics and traditional herbal medications for its management in a Nigerian community

Acute gastroenteritis (AGE) is the highest cause of mortality worldwide in children under the age of 5 years, with the highest mortalities occurring in low-to-middle income countries. Treatment can involve use of unregulated herbal medication and antibiotics. A cross sectional study was carried out to investigate the use of antibiotics and traditional herbal medications in the management of AGE among Yòrùbá-speaking communities in Kwara State, Nigeria. Our findings suggest habitual use of antibiotics (54.6%) and herbal medication (42.5%) in the management of AGE with high levels of self-prescription of antibiotics (21.7%) and herbal medications (36.2%) within the community. Ethanolic extracts of selected herbal plants reported (i.e. Aristolochia ringens, Azadirachta indica, Chromolaena odorata, Etanda Africana, Ficus capensis, Ficus vogelii, Mangifera indica, Momordica charantia, Ocimum gratisimum, Senna alata, Sorghum bicolor and Vernonia amygdalina) were investigated for antibacterial properties, using bacteria known to be causative agents of AGE. Our findings showed that, with exception of Ficus vogelii, which enhanced bacterial growth, the plant extracts reported all showed some antibacterial activity. We further discuss our findings within a regulatory context, with the aim to guide the use of traditional and herbal medication in low-to medium income countries (LMICs) and reduce the potential risks associated with the development of antimicrobial resistance.

Prevalence of diarrhoeal pathogens among children under five years of age with and without diarrhoea in Guinea-Bissau

BACKGROUND

Childhood diarrhoea, a major cause of morbidity and mortality in low-income regions, remains scarcely studied in many countries, such as Guinea-Bissau. Stool sample drying enables later qPCR analyses of pathogens without concern about electricity shortages.

METHODS

Dried stool samples of children under five years treated at the Bandim Health Centre in Bissau, Guinea-Bissau were screened by qPCR for nine enteric bacteria, five viruses, and four parasites. The findings of children having and not having diarrhoea were compared in age groups 0-11 and 12-59 months.

RESULTS

Of the 429 children- 228 with and 201 without diarrhoea- 96.9% and 93.5% had bacterial, 62.7% and 44.3% viral, and 52.6% and 48.3% parasitic pathogen findings, respectively. Enteroaggregarive Escherichia coli (EAEC; 60.5% versus 66.7%), enteropathogenic E. coli (EPEC; 61.4% versus 62.7%), Campylobacter (53.2% versus 51.8%), and enterotoxigenic E. coli (ETEC; 54.4% versus 44.3%) were the most common bacterial pathogens. Diarrhoea was associated with enteroinvasive E. coli (EIEC)/Shigella (63.3%), ETEC (54.4%), astrovirus (75.0%), norovirus GII (72.6%) and Cryptosporidium (71.2%). The only pathogen associated with severe diarrhoea was EIEC/Shigella (p<0.001). EAEC was found more frequent among the infants, and EIEC/Shigella, Giardia duodenalis and Dientamoeba fragilis among the older children.

CONCLUSIONS

Stool pathogens proved common among all the children regardless of them having diarrhoea or not.

Reactivation of latent infections in solid organ transplant recipients from sub-Saharan Africa: What should be remembered?

International migration from Sub-Saharan African countries to the European Union and the United States has significantly increased over the past decades. Although the vast majority of these immigrants are young and healthy people, a minority can be affected by chronic conditions eventually leading to solid organ transplantation (SOT). Importantly, these candidates can bear geographically restricted fungal and parasitic latent infections that can reactivate after the procedure. An appropriate evaluation before transplantation followed by treatment, whenever necessary, is essential to minimize such risk, as covered in the present review. In short, infection due to helminths (Schistosoma spp. and Strongyloides stercoralis) and intestinal protozoa (Entamoeba histolytica, Giardia lamblia or Cyclospora cayetanensis) can be diagnosed by multiple direct stool examination, serological assays and stool antigen testing. Leishmaniasis can be assessed by means of serology, followed by nucleic acid amplification testing (NAAT) if the former test is positive. Submicroscopic malaria should be ruled out by NAAT. Screening for Histoplasma spp. or Cryptococcus spp. is not routinely indicated. Consultation with an Infectious Diseases specialist is recommended in order to adjust preemptive treatment among Sub-Saharan African SOT candidates and recipients.

Mortality in relation to profiles of clinical features in Ghanaian severely undernourished children aged 0-59 months: an observational study

Severe acute malnutrition (SAM) is associated with a complex pattern of various clinical conditions. We investigated how risk factors cluster in children with SAM, the relationship between clusters of risk factors and mortality as well as length of stay in children with SAM. A prospective observational study design was used. Data were extracted from medical records of 601 infants and children aged 0-59 months admitted and treated for SAM in three Ghanaian referral hospital between June 2013 and June 2018. Among the 601 medical records extracted, ninety-nine died. Three clusters of medical features clearly emerged from data analyses. Firstly, an association was defined by eye signs, pallor, diarrhoea and vomiting with gastrointestinal infections and malaria. In this cluster, pallor and eye signs were related to 2- to 5-fold increased mortality risk. Secondly, HIV, oedema, fast pulse, respiratory infections and tuberculosis; among those features, HIV increased child mortality risk by 2-fold. Thirdly, shock, convulsions, dermatitis, cold hands and feet, weak pulse, urinary tract infections and irritability were clustered. Among those features, cold hands and feet, dermatitis, convulsions and shock increased child mortality risk in a range of 2- to 9-fold. Medical conditions and clinical signs in children diagnosed with SAM associate in patterns and are related to clinical outcomes.

Physician Perception and Diagnosis of Intestinal Parasitic Infections among Patients with Gastrointestinal Symptoms in Ghana

This study evaluated physicians' perception and diagnosis of intestinal parasitic infections (IPI) in patients with gastrointestinal (GI) symptoms. This cross-sectional survey used a Google form questionnaire distributed online. Demographic and clinical practice information was solicited, including if “IPI was considered as a diagnosis in the last patient seen,” “if stool investigation was requested among the last patients seen,” and physicians' perception of the burden of IPI in the country. Using Pearson chi-square and multivariate logistic regression analysis, we tested the significance of the associations of the job cadre of the physicians and their perception of the IPI burden with consideration of IPI as a diagnosis in the last patient seen, request for stool investigation in the last patient seen, and overall frequency of the request for stool investigation. Ultimately, 184 physicians responded. The majority agreed to “often seeing patients with GI symptoms” (156, 84.7%), “not considering IPI among the last patient seen” (106, 57.6%), and “not requesting stool investigation among the last patient seen with symptoms” (136, 73.9%). House officers (81, 44.2%) constituted the highest proportion of physicians who considered IPI as a diagnosis among the last patient seen (39, 48.1%, p = 0.05). Most physicians (138, 75%) considered IPI as a burden in Ghana. They constituted significant proportions of the physicians who considered IPI as a diagnosis among their last patients seen (65, 83.3%, p = 0.02) and were twice more likely to consider IPI as a diagnosis among the last patients seen than their colleagues who did not consider IPI as a burden in Ghana (AOR 2.26, p = 0.04). The consideration of IPI as a diagnosis among patients with GI symptoms and request for stool investigations was low among physicians in this study. Further engagements with physicians in Ghana are needed to help improve their diagnosis of IPI in patients with GI symptoms.

A scoping review of the detection, epidemiology and control of Cyclospora cayetanensis with an emphasis on produce, water and soil

Cyclospora cayetanensis is a parasite causing cyclosporiasis (an illness in humans). Produce (fruits, vegetables, herbs), water and soil contaminated with C. cayetanensis have been implicated in human infection. The objective was to conduct a scoping review of primary research in English on the detection, epidemiology and control of C. cayetanensis with an emphasis on produce, water and soil. MEDLINE® (Web of ScienceTM), Agricola (ProQuest), CABI Global Health, and Food Science and Technology Abstracts (EBSCOhost) were searched from 1979 to February 2020. Of the 349 relevant primary research studies identified, there were 75 detection-method studies, 40 molecular characterisation studies, 38 studies of Cyclospora in the environment (33 prevalence studies, 10 studies of factors associated with environmental contamination), 246 human infection studies (212 prevalence/incidence studies, 32 outbreak studies, 60 studies of environmental factors associated with non-outbreak human infection) and eight control studies. There appears to be sufficient literature for a systematic review of prevalence and factors associated with human infection with C. cayetanensis. There is a dearth of publicly available detection-method studies in soil (n = 0) and water (n = 2), prevalence studies on soil (n = 1) and studies of the control of Cyclospora (particularly on produce prior to retail (n = 0)).

A systematic review and meta-analysis reveal that Campylobacter spp. and antibiotic resistance are widespread in humans in sub-Saharan Africa

INTRODUCTION

Campylobacter spp. are zoonotic bacteria that cause gastroenteritis in humans worldwide, whose main symptom is diarrhea. In certain cases, extra intestinal manifestations may occur, such as Guillain Barré syndrome. The bacteria cause severe diarrhea mostly in children and in immunocompromised individuals. This review aims to address the prevalence of Campylobacter spp. in humans in sub-Saharan Africa. It also aims to understand the impact of HIV in the prevalence, as well as to report data on antibiotic resistance and propose research priorities.

METHODS

We followed PRISMA guidelines to find studies on the occurrence of Campylobacter spp. in humans in all countries from sub-Saharan Africa. Studies published between 2000 and 2020 were searched in PubMed, Cochrane Library, CINAHL, African Index Medicus, African Journals Online, Google Scholar and Science Direct. We have conducted a random-effect meta-analysis and calculated the proportion of resistant isolates to different antibiotics.

RESULTS AND DISCUSSION

We found 77 studies that described such occurrence in humans in 20 out of 53 sub-Saharan African countries. Campylobacter jejuni was the most prevalent species. Pooled prevalence was 9.9% (CI: 8.4%-11.6%). No major variations within the different sub-regions were found. Most studies reported Campylobacter spp. as the cause of diarrhea, mainly in children. Some studies reported the bacteria as a possible etiologic agent of acute flaccid paralysis and urinary tract infection. Campylobacter spp. presented a higher pooled prevalence in HIV infected patients, although not statistically significant. High proportions of resistant strains were reported for many antibiotics, including erythromycin and tetracycline.

CONCLUSION

Campylobacter spp. occur in sub-Saharan Africa, although information is scarce or inexistent for many countries. Research priorities should include investigation of the understudied species; extra intestinal manifestations; the impact of HIV infection and associated risk factors. Control strategies should be reinforced to contain the spread of this pathogen and drug resistance.

Economic analysis for national immunization program planning: A case of rotavirus vaccines in Burundi

BACKGROUND

In Burundi, diarrhea is the third leading cause of mortality among children under five years of age. This study conducted an economic analysis of rotavirus vaccination program in Burundi.

METHODS

A Markov model was constructed to simulate clinical and economic outcomes for the 2019 birth cohort for a period of 5 years. Empirical costing data were collected. ICER per episode averted, ICER per death averted, ICER per DALY averted, net present value, and budget impact were estimated for 4 brands of WHO pre-qualified rotavirus vaccines. One-way and probabilistic sensitivity analysis as well as threshold analysis were performed.

RESULTS

For the base case, while all four WHO pre-qualified rotavirus vaccines were cost-effective (ICER < 3 GDP per capita), three of them (i.e. Rotarix, Rotavac and Rotasiil) were very cost-effective (ICER <1 GDP per capita) from both the provider and societal perspectives. The vaccines were still very cost-effective at a price increase of up to US$ 5.09, US$ 3.16, US$ 3.89, and US$ 2.69 for Rotarix, RotaTeq, Rotavac, and Rotasiil, respectively. Probabilistic sensitivity analysis indicated that vaccination programs with Rotarix, RotaTeq, Rotavac, and Rotasiil are cost-effective at a probability of 93.8%, 27%, 99.1%, and 92.7%, respectively. All vaccination programs were cost-beneficial with a net present value in the range of US$ 5,214,912 and US$ 11,135,997.The budget required to run the vaccination program, estimated with break-even prices, ranged between US$ 42,249,498 and US$ 53,487,935 for a 5-year time period. When compared to the GDP of Burundi in 2019, these are are less than 2%.

CONCLUSION

The rotavirus vaccine is good value for money. Findings from this study offer evidence on potential economic benefits as well as the required budget for different rotavirus vaccination programs, which could be useful for future planning related to rotavirus vaccine coverage in Burundi after graduation from GAVI.

Intestinal parasitic infections and associated factors among people living with HIV/AIDS in Ethiopia: A systematic review and meta-analysis

Background

Intestinal parasitic infections are major public health problems throughout the world, particularly in people living with HIV/AIDS. People living with HIV/AIDS are vulnerable groups for a variety of diseases, hence they are easily affected by opportunistic and non-opportunistic intestinal parasites due to the weakening of their immunity. Therefore, this study aimed to estimate the pooled prevalence and factors associated with intestinal parasitic infections among people living with HIV/AIDS in Ethiopia.

Methods

Articles were identified through search engines in the online electronic databases PubMed/MEDLINE, EMBASE, HINARI, CINAHL, Cochrane Library, Google Scholar, and reference lists of previous studies following the PRISMA Protocol. Studies conducted between 2003 and 2020 with English language were included in this study. This review included papers with having high-quality NOS scores. Meta-analysis was computed using STATA version 11 software. Heterogeneity was assessed using the Cochrane Q-test and I² test statistics. Subgroup and sensitivity analysis was employed with evidence of heterogeneity. Publication bias was determined using the funnel plot and Egger’s regression test statistic.

Results

This study included a total of twenty-two cross-sectional studies with 5,833 study participants. The mean age of the study participants was 35 years old. The pooled prevalence of intestinal parasitic infection among people living with HIV/AIDS in Ethiopia was 39.15% (95%CI: 32.34, 45.95). The pooled prevalence of intestinal parasitic infections among people living with HIV/AIDS who had taking ART and who had not to start ART was found to be 28.27% (95%CI 22.47, 34.06) and 41.63% (95%CI: 28.75, 54.52) respectively. Unavailability of latrine (AOR: 4.87, (95% CI: 2.39, 9.92)), CD4+ T cell count <200cells/μl ((AOR: 3.53, (95%CI: 1.98, 6.27)), and having a history of diarrhea (AOR: 4.79 (95%CI: 1.53, 14.99) were factors significantly associated with intestinal parasitic infections.

Conclusion

In this study, the overall pooled prevalence of intestinal parasitic infections among HIV/AIDS patients in Ethiopia was relatively high. CD4+ T-cell count <200cells/μl, unavailability of a latrine, and history of diarrhea were significantly associated with intestinal parasitic infections. Therefore, the policymakers and health care professionals could give special attention to the presence of latrines, early detection and treatment of intestinal parasitic infections, and early initiation of ART drugs.

The immunoglobulin G antibody response to malaria merozoite antigens in asymptomatic children co-infected with malaria and intestinal parasites

Background

Co-infection with malaria and intestinal parasites is common in children in Africa and may affect their immune response to a malaria parasite infection. Prior studies suggest that co-infections may lead to increased susceptibility to malaria infection and disease severity; however, other studies have shown the reverse. Knowledge on how co-morbidities specifically affect the immune response to malaria antigens is limited. Therefore, this study sought to determine the prevalence of co-infection of malaria and intestinal parasites and its association with antibody levels to malaria merozoite antigens.

Methods

A cross sectional study was carried out in two villages with high transmission of malaria in Cameroon (Ngali II and Mfou) where mass drug administration (MDA) had been administered at ~6-month intervals (generally with albendazole or mebendazole). Children aged 1–15 years were enrolled after obtaining parental consent. A malaria rapid diagnostic test was used on site. Four (4) ml of peripheral blood was collected from each participant to determine Plasmodium falciparum infections by microscopy, haemoglobin levels and serology. Fresh stool samples were collected and examined by wet mount, Kato-Katz method and modified Ritchie concentration techniques. A Multiplex Analyte Platform assay was used to measure antibody levels.

Results

A total of 320 children were enrolled. The prevalence of malaria by blood smear was 76.3% (244/320) and prevalence of malaria and intestinal parasites was 16.9% (54/320). Malaria prevalence was highest in young children; whereas, intestinal parasites (IP+) were not present until after 3 years of age. All children positive for malaria had antibodies to MSP1₄₂, MSP2, MSP3 and EBA175. No difference in antibody levels in children with malaria-co infections compared to malaria alone were found, except for antibody levels to EBA-175 were higher in children co-infected with intestinal protozoa (p = 0.018), especially those with Entamoeba histolytica infections (p = 0.0026).

Conclusion

Antibody levels to EBA175 were significantly higher in children co-infected with malaria and E. histolytica compared to children infected with malaria alone. It is important to further investigate why and how the presence of these protozoans might modulate the immune response to malaria antigens.

Quantitative versus qualitative risk assessment of meat and its products: what is feasible for Sub-Saharan African countries?

Prevalent risks in meat value-chains of sub-Saharan African (SSA) countries are increasingly attributed to microbial rather than chemical hazards. Resource constraints and lack of capacity has limited the utilization of risk assessment tools in the instituting of food controls to mitigate the risks. The review sought to bring to light the focus of risk assessment studies in SSA while generating evidence of feasible options to further the contribution of this component in risk mitigation. The informal street vending sector emerges as a priority in the meat value chain with a vendor population that are unwilling to abandon it. Campylobacter and Staphylococcus aureus are prevalent risks that have bedeviled this sector. However, limited risk assessment studies with capacity to inform proper food controls for the sector have been done. Evidence in place indicate that the incorporation of qualitative aspects in quantitative approaches serve as less-costly and effective ways of generating risk estimates. Limitations of capacity and gaps in epidemiological data are also circumvented. Considering that the street-vending sector is robust and its dynamics of operation are not fully in the picture of policy actors; incorporation of a participatory approach that combines qualitative and quantitative aspects of risk assessment is highly recommended.

Does suboptimal household flooring increase the risk of diarrhoea and intestinal parasite infection in low and middle income endemic settings? A systematic review and meta-analysis protocol

BACKGROUND

Water, sanitation, and hygiene interventions often fail to show long-term impact on diarrhoeal and/or intestinal parasite risk in many low- and middle-income countries. Less attention has been paid to wider contextual factors that may contribute to high levels of contamination in the domestic environment such as household flooring. The purpose of this study will be to assess the association between diarrhoeal and/or intestinal parasite infection status and unimproved/unfinished flooring in low- and middle-income countries.

METHODS

We will conduct a comprehensive search of published studies (randomized controlled trials, non-randomized controlled trials, and observational studies) that examined the association between unimproved/unfinished household flooring and diarrhoeal and/or intestinal parasite infection status from January 1, 1980, onwards with no language restriction. The primary outcome will include diarrhoeal and/or intestinal parasite infection status. Databases to be searched include EMBASE, MEDLINE, Web of Science, and Google Scholar. The secondary outcome will be the association between specific pathogens (laboratory confirmed) and unimproved/unfinished household flooring. Independent screening for eligible studies using defined criteria and data extraction will be completed in duplicate and independently. Any discrepancies between the two reviewers will be resolved by consensus and/or arbitration by a third researcher. If data permits, random effects models will be used where appropriate. Subgroup and additional analyses will be conducted to explore the potential sources of heterogeneity (e.g. age group, geographical region) and potential risk of bias of included studies.

DISCUSSION

This review will provide a comprehensive examination of a possible association between suboptimal household flooring and increased risk of enteric pathogen infection, highlight gaps for future research in high risk areas, and inform intervention design for future planned studies in Kenya and/or elsewhere in the region.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42019156437.

Dysbiosis Signatures of Fecal Microbiota in South African Infants with Respiratory, Gastrointestinal, and Other Diseases

OBJECTIVE

To determine the association between the fecal microbiota diversity of the infants with different disease conditions, and vitamin A supplementation, antibiotic, and deworming therapies.

STUDY DESIGN

In this case-control study, the bacterial community variations and the potential pathogens were identified through 16S ribosomal RNA gene-based amplicon sequencing and quantitative insights into microbial ecology pipeline in fecal samples. The participants were South African infants (mean age, 16 ± 8 months; 17 male and 17 female) hospitalized and diagnosed with gastrointestinal, respiratory, and other diseases.

RESULTS

The top phyla of the infants with respiratory disease were Proteobacteria, followed by Firmicutes, which were equally abundant in gastrointestinal disease. A significant difference in Shannon (alpha) diversity index (95% CI, 2.6-4.4; P = .008), among the microbiota of the fecal samples categorized by disease conditions, was observed. In beta diversity analysis of fecal microbiota, remarkable variations were found within the groups of deworming therapy (95% CI, 0.40-0.90; P = .033), disease conditions (95% CI, 0.44-0.86; P < .012) through unweighted and antibiotic therapy (95% CI, 0.20-0.75; P = .007), vitamin A intake (95% CI, 0.10-0.80; P < .033) and disease conditions (95% CI, 0.10-0.79; P = .006) through weighted UniFrac distances. The candidate pathogen associated with the disease groups were identified through analysis of the composition of microbiomes analysis.

CONCLUSIONS

This study provides preliminary evidence for the fecal microbiome-derived dysbiosis signature and pathobiome concept that may be observed in young children during illness.

Cyclospora cayetanensis and Cyclosporiasis: An Update

Cyclospora cayetanensis is a coccidian parasite of humans, with a direct fecal-oral transmission cycle. It is globally distributed and an important cause of foodborne outbreaks of enteric disease in many developed countries, mostly associated with the consumption of contaminated fresh produce. Because oocysts are excreted unsporulated and need to sporulate in the environment, direct person-to-person transmission is unlikely. Infection by C. cayetanensis is remarkably seasonal worldwide, although it varies by geographical regions. Most susceptible populations are children, foreigners, and immunocompromised patients in endemic countries, while in industrialized countries, C. cayetanensis affects people of any age. The risk of infection in developed countries is associated with travel to endemic areas and the domestic consumption of contaminated food, mainly fresh produce imported from endemic regions. Water and soil contaminated with fecal matter may act as a vehicle of transmission for C. cayetanensis infection. The disease is self-limiting in most immunocompetent patients, but it may present as a severe, protracted or chronic diarrhea in some cases, and may colonize extra-intestinal organs in immunocompromised patients. Trimetoprim-sulfamethoxazole is the antibiotic of choice for the treatment of cyclosporiasis, but relapses may occur. Further research is needed to understand many unknown epidemiological aspects of this parasitic disease. Here, we summarize the biology, epidemiology, outbreaks, clinical symptoms, diagnosis, treatment, control and prevention of C. cayetanensis; additionally, we outline future research needs for this parasite.

Monocyte activation, HIV, and cognitive performance in East Africa

Chronic inflammation associated with monocyte activation has been linked to HIV-related cognitive outcomes in resource-rich settings. Few studies have investigated this relationship in the African context where endemic non-HIV infections may modulate effects. We characterized immune activation biomarkers in Kenyan and Ugandan participants in relation to neuropsychological testing performance (NTP) from the African Cohort Study (AFRICOS). We focused on activation markers associated with monocytes (sCD14, sCD163, neopterin), T cells (HLA-DR⁺CD38⁺ on CD4⁺ and CD8⁺ T lymphocytes), and microbial translocation (intestinal fatty acid-binding protein, I-FABP). The HIV-infected (n = 290) vs. HIV-uninfected (n = 104) groups were similar in age with mean (SD) of 41 (9.5) vs. 39 (9.9) years, respectively (p = 0.072). Among HIV-infected participants, the mean (SD) current CD4⁺ count was 402 (232); 217 (75%) were on combination antiretroviral therapy (cART) and 199 (69%) had suppressed plasma HIV RNA. sCD14 was inversely correlated to NTP (r = - 0.14, p = 0.037) in models that included both HIV-infected and uninfected individuals, adjusted for HIV status and research site, whereas sCD163 was not (r = 0.041, p = 0.938). Neither of the T cell activation markers correlated with NTP. In the HIV-infected group, I-FABP was inversely associated with NTP (r = - 0.147, p = 0.049), even among those with suppressed plasma virus (r = - 0.0004, p = 0.025). Among the full group, HIV status did not appear to modulate the effects observed. In this cohort from East Africa, sCD14, but not sCD163, is associated with cognitive performance regardless of HIV status. Findings among both HIV-infected and HIV-uninfected groups is supportive that HIV and non-HIV-related inflammatory sources contribute to cognitive performance in this setting.

Prevalence of enteric non-typhoidal Salmonella in humans in the Middle East and North Africa: A systematic review and meta-analysis

To enhance efforts related to controlling foodborne pathogens in the Middle East and North Africa (MENA), information on epidemiology of non-typhoidal Salmonella enterica (hereafter termed "Salmonella") is limited. We quantified the overall regional and country-specific Salmonella prevalence in different human populations and identified the most common serotypes. Published literature of Salmonella prevalence was systematically reviewed and reported following the Preferred Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Pooled Salmonella prevalence measures were estimated using a random-effects model. We identified 46 research reports that reported 84 Salmonella prevalence measures in 15 out of 24 countries in MENA. There were 252,831 tested humans with 6,356 Salmonella-positive cases. The pooled Salmonella prevalence in MENA was estimated at 6.6% (95% confidence interval (CI): 5.4%-7.9%). The highest pooled Salmonella prevalence measures were in Morocco (17.9%, 95% CI: 5.7%-34.8%, 1997-2012), Tunisia (10.2%, 95% CI: 4.3%-18.0%, 1988-2009) and Sudan (9.2%, 95% CI: 6.5%-12.2%, 2006-2008), while the lowest were in Jordan (1.1%, 95% CI: 0.1%-3.0%, 1993-2010), Oman (1.2%, 95% CI: 1.2%-1.3%, 1998-2002) and Palestine (1.2%, 95% CI: 0.4%-2.1%, 1999-2011). In MENA, Salmonella pooled prevalence in gastrointestinal symptomatic, gastrointestinal asymptomatic and food handlers population groups was 13.0% (95% CI: 7.6%-19.6%), 11.4% (95% CI: 2.2%-25.7%) and 3.8% (95% CI: 1.0%-8.0%), respectively. Salmonella prevalence was 14.5% (95% CI: 8.7%-26.1%) in studies tested <100 subjects, whereas 4.6% (95% CI: 3.6%-5.8%) in studies tested ≥100 subjects. Salmonella Enteritidis (29.8%) and Typhimurium (23.6%) were the most common serotypes. Salmonella was a common foodborne pathogen in MENA countries, particularly in North African countries. Findings inform the scientific community, the public and the decision-makers with Salmonella prevalence and gaps in evidence in MENA to support control and prevention strategies and could leverage more research studies.

Prevalence of feco-oral transmitted protozoan infections and associated factors among university students in Ethiopia: a cross-sectional study

Background

An estimated 60% of the world’s population is infected with one form of intestinal parasites. Amoebiasis and giardiasis are among the leading intestinal protozoan infections that affected mankind. However, literature that shows the magnitude of the problem among university students in Ethiopia is at scarce. Therefore, this study was aimed at assessing the prevalence of feco-oral transmitted protozoan infections and associated factors among sport festival participant universities in Ethiopia.

Methods

A cross-sectional study design was conducted among 483 randomly selected university sport festival participant students. A self-administered questionnaire was used to collect the data. Stool specimens were examined using direct wet mount and formol-ether concentration techniques. The data were entered into Epi Info version 6.04 and were analyzed using SPSS version 20.0 statistical software. Multivariable logistic regression analysis was done to control the possible confounders and an odds ratio with a 95% confidence interval at p < 0.05 was used to identify an association between variables.

Result

The overall prevalence of intestinal protozoan infections was 140(28.9%) with the predominantly higher prevalence of E. histolytica/E. dispar 95(19.7%). The female respondents were at lower risk of infections compared to their male counterparts (AOR = 0.48, 95% CI: 0.22, 0.97]. Participants with educated father (AOR = 0.62, 95% CI: 0.12, 0.86) and those who received pocket money of > 347 Ethiopian Birr (~ 14 USD) per month (AOR = 0.20, 95% CI: 0.12, 0.74) were at lower risk of infections. However, being married (AOR = 1.42, 95% CI: 1.10, 2.23), rural resident (AOR = 1.82, 95% CI: 1.21, 3.32) and university stay for two or more years (AOR = 2.21, 95%CI: 1.48, 3.87) were more likely to be infected with protozoan infections.

Conclusion

The prevalence of intestinal protozoan infection among students who attend higher educational institutions was very high. Infection prevention strategies should be undertaken at respective universities with special focus to senior students and students from the rural area.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4095-z) contains supplementary material, which is available to authorized users.

Weather and gastrointestinal disease in Spain: A retrospective time series regression study

BACKGROUND

A few studies in high-income countries have investigated the relationship between ambient temperature and/or precipitation and the occurrence of gastroenteritis. In most of the cases, hot temperatures and heavy precipitation events have been related to increases in infections. This is of concern as climate change predictions indicate an increase of those extreme events. Our aim was to evaluate the association between meteorological variables and daily gastroenteritis hospitalizations in Spain for the period 1997-2013.

METHODS

We obtained data on all hospitalizations which occurred in Spain for the study period from administrative databases and selected those with gastroenteritis as the main diagnosis. Meteorological data was obtained from the European Climate Assessment & Dataset. Daily counts of hospitalizations were linked to meteorological variables in a retrospective ecological time series study using quasi-Poisson regression models with overdispersion and applying the Distributed Lag Non-linear Model (DLNM) framework.

RESULTS

Both high and cold temperatures increased the risk of gastroenteritis hospitalizations (relative risk (RR) = 1.21, 95% confidence interval (CI): 1.09, 1.34; and RR = 1.07, 95% CI: 1.00, 1.15, respectively), whereas heavy precipitation was found protective for those hospitalizations (RR = 0.74, 95% CI: 0.63, 0.86). Hot temperatures increased hospitalizations for gastroenteritis classified as foodborne or idiopathic but not those in the group of Others, which were composed mainly of infections by rotavirus and were associated with cold temperatures.

CONCLUSIONS

Our findings suggest an important role of ambient temperatures, especially hot temperatures, in increasing gastroenteritis hospitalizations, while the exposure to heavy precipitation events pose opposite and unexpected effects on these infections.

Caregivers' knowledge and attitudes about childhood diarrhea among refugee and host communities in Gambella Region, Ethiopia

BACKGROUND

Maternal knowledge, attitudes, and practices related to hygiene, breastfeeding, sanitary food preparation, and appropriate weaning practices are potentially important determinants in the occurrence of diarrhea in children. However, few studies have been carried out about the knowledge and attitudes about childhood diarrhea among parents in refugee camps and host communities.

OBJECTIVE

This study aims at assessing the caregivers' knowledge and attitudes regarding acute diarrhea in under-five children among refugee and host communities in Gambella Region, Ethiopia.

METHODOLOGY

This cross-sectional study, employing multistage sampling, was carried out from September to December 2016. Data was collected by a questionnaire-based interview, and 1667 caregivers were included in this study. A composite knowledge score was calculated, and a five-point Likert type of attitude scale was developed to assess the attitudes of the caregivers towards childhood diarrhea. Appropriate descriptive statistics and logistic regression models were used. Odds ratios (ORs) are presented with their 95% confidence intervals (CIs), and all analyses were performed at the 5% significance level (p < 0.05).

RESULT

The study indicates that 633 (28.0%) of the caregivers had poor knowledge, while 393 (23.6%) of them had unfavorable attitudes towards childhood diarrhea. Knowledge of the caregivers was significantly associated with formal education (AOR, 1.3; 95% CI, 1.03-1.5) and health information obtained from a health care institution (AOR, 1.8; 95% CI, 1.28-2.3). Caregivers' knowledge is a single predictor of their attitude (p < 0.001), and Pearson's correlation coefficient revealed that there was a significant positive correlation (r = 0.2, p < 0.001) between knowledge and attitude scores.

CONCLUSION

The study indicates that significant numbers of caregivers had inadequate knowledge and unfavorable attitudes about diarrhea in under-five children. Designing and implementing an inclusive health education intervention focusing on uneducated child caregivers may be beneficial for improving knowledge and attitudes towards reducing the incidence of acute childhood diarrhea in the region.

Diagnosis and Treatment of Human Salmonellosis in Addis Ababa City, Ethiopia

BACKGROUND

Diagnosis using reliable tools and treatment following in vitro antimicrobial susceptibility tests are critical to proper addressing of antibiotic-resistant Salmonella infection.

METHODOLOGY

A cross-sectional study was conducted to assess the practice of diagnosis and treatment of salmonellosis in Addis Ababa. Tube Widal test (for blood samples only), culture, biochemical and carbohydrate fermentation, serotyping, and antimicrobial susceptibility tests were employed for both blood and stool samples.

RESULTS

Of all the diseases listed in the diagnosis, nontyphoidal (n = 72, 13.71%) and typhoidal (n = 47, 8.95%) salmonellosis were the second and third common diseases. Among the 288 blood samples, almost half were positive for O, H, or both antigens. However, only 1 (0.68%) of the positive blood samples yielded Salmonella isolate during culture. The study demonstrated low specificity (0.68%) and positive predictive value (48.78%) of Widal test. Conversely, the test showed 100% sensitivity and negative predictive values. Salmonella isolates were identified from 7 (7.07%) of 99 stool samples. Two-thirds of salmonellosis suspected patients received antibiotic treatment. However, only half of the confirmed salmonellosis patients were treated with appropriate antibiotics. All of the isolates were susceptible to ciprofloxacin and ceftriaxone but resistant to ampicillin.

CONCLUSIONS

Majority of the patients who participated in this study were wrongly diagnosed using symptoms, clinical signs, and tube Widal test. Consequently, most of the patients received inappropriate treatment.

Brief Report: Differential Associations of Interleukin 6 and Intestinal Fatty Acid-Binding Protein With Progressive Untreated HIV-1 Infection in Rakai, Uganda

The significance of HIV-associated immune activation and microbial translocation in Sub-Saharan African population remains poorly defined. We assessed biomarkers of inflammation, microbial translocation, and cellular activation and found most factors elevated in Ugandan HIV-1 seroconverters compared with community-matched controls. In contrast to previous findings in Western cohorts, C-reactive protein, neopterin, and intestinal fatty acid binding protein were not elevated. Higher T-cell activation and IL-6 were associated with faster disease progression. Surprisingly, intestinal fatty acid binding protein, indicative of enterocyte turnover, was higher in slow than in fast progressors. These data suggest differential relationships among biomarkers of intestinal barrier integrity and innate immune activation between developed countries and Sub-Saharan Africa.

Descriptive epidemiology of infectious gastrointestinal illnesses in Sydney, Australia, 2007-2010

OBJECTIVE

There is a lack of information about the prevalence of gastrointestinal illnesses in Australia. Current disease surveillance systems capture only a few pathogens. The aim of this study is to describe the epidemiology of infectious gastrointestinal illnesses in Sydney, Australia.

METHODS

A retrospective cross-sectional study of patients with gastrointestinal symptoms who visited tertiary public hospitals in Sydney was conducted between 2007 and 2010. Patients with diarrhoea or loose stools with an enteric pathogen detected were identified. Demographic, clinical and potential risk factor data were collected from their medical records. Measures of association, descriptive and inferential statistics were analysed.

RESULTS

In total, 1722 patients were included in this study. Campylobacter (22.0%) and Clostridium difficile (19.2%) were the most frequently detected pathogens. Stratified analysis showed that rotavirus (22.4%), norovirus (20.7%) and adenovirus (18.1%) mainly affected children under 5 years; older children (5-12 years) were frequently infected with Campylobacter spp. (29.8%) and non-typhoid Salmonella spp. (24.4%); infections with C. difficile increased with age.Campylobacter and non-typhoid Salmonella spp. showed increased incidence in summer months (December to February), while rotavirus infections peaked in the cooler months (June to November).

DISCUSSION

This study revealed that gastrointestinal illness remains a major public health issue in Sydney. Improvement of current disease surveillance and prevention and control measures are required. This study emphasizes the importance of laboratory diagnosis of enteric infections and the need for better clinical data collection to improve management of disease risk factors in the community.

Prevalence of human Salmonellosis in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Human Salmonellosis is one of the major diseases in Ethiopia and several factors including under and mal-nutrition and HIV-AIDS may substantially contribute to its occurrence. Despite its importance, surveillance and monitoring systems are not in place and a comprehensive picture of its epidemiology is not available. The objectives of this study were to systematically review and estimate the prevalence of the disease and identify the dominant serogroups and serotypes in Ethiopia.

METHODS

Published studies on Salmonellosis in Ethiopia were electronically and manually searched. Eligible studies were selected by using inclusion and exclusion criteria. Generic, methodological and statistical information were extracted from the eligible studies. The extracted data included sample sizes, the numbers of Salmonella positive samples, serogroups and serotypes. The variations in prevalence estimates attributable to heterogeneities were assessed and pooled prevalence was estimated by the random effects model.

RESULTS

Twenty studies carried out between 1974 and 2012 were eligible. The pooled prevalence estimates of Salmonella in stool samples of diarrheic children, diarrheic adults and carriers were 8.72%, 5.68%, and 1.08% respectively. Invasive infections in children (5.71%) and adults (0.76%) were significantly different (p < 0.001). Non-typhi isolates accounted for 57.9% of the isolates from patients. Serogroup D occurred more frequently than serogroups C and B. S. Concord, S. Typhi, S. Typhimurium and S. Paratyphi were dominant and accounted for 82.1% of the serotypes isolated from patients.

CONCLUSION

The prevalence of Salmonellosis is considerable and most infections are due to four serotypes. The results imply the need for a policy to promote public hygiene and regularly screen individuals in contact with food items for public consumption.

Prevalence of gastrointestinal pathogens in developed and developing countries: systematic review and meta-analysis

ABSTRACT

Diarrhoeal illness is a leading cause of child mortality and morbidity worldwide. There are no precise or current estimates of the types and prevalence of pathogens associated with diarrheal illnesses in developed and developing settings. This systematic review assessed data from 60 studies published in the English language from five developing regions and developed countries worldwide to provide regional estimates of enteric pathogens affecting children. The random-effect method was used to establish the weighted average prevalence of pathogens in adults and children for each region. Significantly more pathogens were reported by studies from developing regions compared with Organisation for Economic Co-operation and Development countries (P<0.016). The identification rates of pathogens from community based and hospital based studies were similar (58.5% and 58.1% respectively, P<0.619). The overall detection of enteric pathogens in developing countries was higher in adults (74.8%; 95% CI 63.1-83.8%) compared with children (56.7%; 95% CI 53.0-60.4%) (P<0.001). Rotavirus was the most frequently detected pathogen in all regions with the highest rate, 24.8% (95% CI 18.0-33.1%), detected in the developed countries. This systematic review is the first to provide an estimate of the prevalence of enteric pathogens associated with diarrhoeal illnesses in adults and children in developed and developing settings. While pathogen detection rate is greater in developing regions the consistently high prevalence of rotavirus in both developed and developing settings underscores the urgent need for access to rotavirus vaccines. Increased travel between developing and developed countries increases disease risk, and hence developed countries have a vested interest in supporting vaccine accessibility in developing settings.

Enteric protozoa in the developed world: a public health perspective

Several enteric protozoa cause severe morbidity and mortality in both humans and animals worldwide. In developed settings, enteric protozoa are often ignored as a cause of diarrheal illness due to better hygiene conditions, and as such, very little effort is used toward laboratory diagnosis. Although these protozoa contribute to the high burden of infectious diseases, estimates of their true prevalence are sometimes affected by the lack of sensitive diagnostic techniques to detect them in clinical and environmental specimens. Despite recent advances in the epidemiology, molecular biology, and treatment of protozoan illnesses, gaps in knowledge still exist, requiring further research. There is evidence that climate-related changes will contribute to their burden due to displacement of ecosystems and human and animal populations, increases in atmospheric temperature, flooding and other environmental conditions suitable for transmission, and the need for the reuse of alternative water sources to meet growing population needs. This review discusses the common enteric protozoa from a public health perspective, highlighting their epidemiology, modes of transmission, prevention, and control. It also discusses the potential impact of climate changes on their epidemiology and the issues surrounding waterborne transmission and suggests a multidisciplinary approach to their prevention and control.