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Background: Cryptosporidium is a major pathogen associated with diarrheal disease in young children. We studied Cryptosporidium diarrhea in children enrolled in the Global Enteric Multicenter Study (GEMS) in rural Gambia. Methods: We recruited children <5 years of age with moderate-to-severe diarrhea (MSD) for 3 years (2008–2010), and children with either MSD or less severe diarrhea (LSD) for one year (November 2011-November 2012) at sentinel health centers. One or more randomly selected controls were matched to each case. Stool samples were tested to identify Cryptosporidium by immunoassay. A subset of randomly selected case-controls pairs were tested for Cryptosporidium species. We investigated the epidemiology of, and evaluated possible risk factors for, Cryptosporidium-positive diarrhea. Results: We enrolled 1938 cases (1381 MSD, 557 LSD) and 2969 matched controls; 231/1929 (12.0%) of diarrhea cases and 141/2962 (4.8%) of controls were positive for Cryptosporidium. Most Cryptosporidium diarrhea cases (85.7%, 198/231) were aged 6–23 months, and most (81.4%, 188/231) occurred during the rainy season. Cryptosporidium hominis (C. hominis) was the predominant (82.6%) species. We found associations between increased risk of Cryptosporidium-positive MSD or LSD, or both, with consumption of stored drinking water and certain animals living in the compound—cow, cat (MSD only) and rodents (LSD only). Larger households, fowl living in the compound, and the presence of Giardia infection were associated with decreased risk of Cryptosporidium MSD and LSD. Conclusion: Cryptosporidium-positive diarrhea is prevalent in this setting, especially at 6–23 months of age. The preponderance of Cryptosporidium infection in the rainy season and increased risk of Cryptosporidium-positive diarrhea with consumption of stored drinking water suggest water-borne transmission. Further investigation is needed to clarify the role of animals and contamination of stored drinking water in Cryptosporidium transmission. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus bacteremia is a substantial cause of childhood disease and death, but few studies have described its epidemiology in developing countries. Using a population-based surveillance system for pneumonia, sepsis, and meningitis, we estimated S. aureus bacteremia incidence and the case-fatality ratio in children <5 years of age in 2 regions in the eastern part of The Gambia during 2008-2015. Among 33,060 children with suspected pneumonia, sepsis, or meningitis, we performed blood culture for 27,851; of 1,130 patients with bacteremia, 198 (17.5%) were positive for S. aureus. S. aureus bacteremia incidence was 78 (95% CI 67-91) cases/100,000 person-years in children <5 years of age and 2,080 (95% CI 1,621-2,627) cases/100,000 person-years in neonates. Incidence did not change after introduction of the pneumococcal conjugate vaccine. The case-fatality ratio was 14.1% (95% CI 9.6%-19.8%). Interventions are needed to reduce the S. aureus bacteremia burden in The Gambia, particularly among neonates. [ABSTRACT FROM AUTHOR]

Background: Malaria is a risk factor for invasive non-typhoidal Salmonella (NTS) infection in children. In the last 10 years, indices of malaria infection in The Gambia have fallen substantially. Methods: We compared temporal trends of childhood malaria and NTS infection in two Gambian locations. In Fajara, on the coast, the incidence of NTS infection at three time points between 1979 and 2005 was compared to the percentage of malaria positive outpatient thick blood films and the percentage of admissions associated with malaria over time. In Basse, in the eastern part of the country, the incidence of NTS infection at three time points between 1989 and 2008 was compared to the prevalence of malaria parasitaemia at four time points between 1992 and 2008. Results: The estimated incidence of NTS infection in Fajara fell from 60 (1979-1984) to 10 (2003-05) cases per 100,000 person years. The proportion of outpatients in Fajara with suspected malaria who were parasitaemic fell from 33% (1999) to 6% (2007) while the proportion of admissions associated with malaria fell from 14.5% (1999) to 5% (2007). In Basse, the estimated incidence of NTS infection fell from 105 (1989-1991) to 29 (2008) cases per 100,000 person years while the prevalence of malaria parasitaemia fell from 45% (1992) to 10% (2008). The incidence of pneumococcal bacteraemia in Fajara and Basse did not fall over the study period. Conclusions: These data support an association between malaria and NTS infection. Reductions in malaria infection may be associated with reduced rates of invasive childhood NTS infection. [ABSTRACT FROM AUTHOR]

The introduction of molecular diagnostic methods is crucial for improved understanding of the aetiology and epidemiology of bacterial infections in communities in resource poor settings. A blood sample from a 7 month old patient diagnosed with malaria in 2001 in a Gambian outpatient clinic was reported as culture negative after it was subjected to traditional bacterial culture protocols. We re-addressed the analysis of the blood sample from this case more recently (after 6.5 years in archival storage) in pilot work establishing 16S rRNA PCR in our molecular laboratory. Initial 16S rRNA PCR results confirmed the presence of bacterial DNA in the sample. 16S rRNA sequence analysis identified the organism as Campylobacter spp. In light of the molecular evidence we successfully grew the organism using appropriate culture conditions and subsequently biochemically confirmed that the isolate was Campylobacter jejuni. PCR and DNA sequencing of a set of seven C. jejuni housekeeping genes and in silico Multilocus Sequence Typing (MLST) analysis revealed that the isolate exhibits a novel sequence type (ST) of C. jejuni (ST 2928) and belongs to ST-443 clonal complex. This study demonstrates the potential for molecular tools to enhance the diagnosis of bacterial infections, which remain a major killer globally, not least in children in the developing world. Improvements in diagnostics are needed, and will be important not only for sick individuals but also for populations, where better measures of disease burden will contribute significantly to the improvement of public health policy. [ABSTRACT FROM AUTHOR]