Age specific aetiological agents of diarrhoea in hospitalized children aged less than five years in Dar es Salaam, Tanzania

\ud This study aimed to determine the age-specific aetiologic agents of diarrhoea in children aged less than five years. The study also assessed the efficacy of the empiric treatment of childhood diarrhoea using Integrated Management of Childhood Illness (IMCI) guidelines. This study included 280 children aged less than 5 years, admitted with diarrhoea to any of the four major hospitals in Dar es Salaam. Bacterial pathogens were identified using conventional methods. Enzyme Linked Immunosorbent Assay (ELISA) and agglutination assay were used to detect viruses and intestinal protozoa, respectively. Antimicrobial susceptibility was determined using Kirby-Bauer disk diffusion method. At least one of the searched pathogens was detected in 67.1% of the cases, and mixed infections were detected in 20.7% of cases. Overall, bacteria and viruses contributed equally accounting for 33.2% and 32.2% of all the cases, respectively, while parasites were detected in 19.2% patients. Diarrhoeagenic Escherichia coli (DEC) was the most common enteric pathogen, isolated in 22.9% of patients, followed by Cryptosporidium parvum (18.9%), rotavirus (18.1%) and norovirus (13.7%). The main cause of diarrhoea in children aged 0 to 6 months were bacteria, predominantly DEC, while viruses predominated in the 7-12 months age group. Vibrio cholerae was isolated mostly in children above two years. Shigella spp, V. cholerae and DEC showed moderate to high rates of resistance to erythromycin, ampicillin, chloramphenicol and tetracycline (56.2-100%). V. cholerae showed full susceptibility to co-trimoxazole (100%), while DEC and Shigella showed high rate of resistance to co-trimoxazole; 90.6% and 93.3% respectively. None of the bacterial pathogens isolated showed resistance to ciprofloxacin which is not recommended for use in children. Cefotaxime resistance was found only in 4.7% of the DEC. During the dry season, acute watery diarrhoea is the most common type of diarrhoea in children under five years in Dar es Salaam and is predominantly due to DEC, C. parvum, rotaviruses and noroviruses. Constant antibiotic surveillance is warranted as bacteria were highly resistant to various antimicrobial agents including co-trimoxazole and erythromycin which are currently recommended for empiric treatment of diarrhoea.\u

Prevalence of enteropathogenic viruses and molecular characterization of group A rotavirus among children with diarrhea in Dar es Salaam Tanzania

Different groups of viruses have been shown to be responsible for acute diarrhea among children during their first few years of life. Epidemiological knowledge of viral agents is critical for the development of effective preventive measures, including vaccines. In this study we determined the prevalence of the four major enteropathogenic viruses - rotavirus, norovirus, adenovirus and astrovirus - was determined in 270 stool samples collected from children aged 0 - 60 months who were admitted with diarrhea in four hospitals in Dar es Salaam, Tanzania, using commercially available ELISA kits. In addition, the molecular epidemiology of group A rotavirus was investigated using reverse transcriptase multiplex polymerase chain reaction (RT-PCR). At least one viral agent was detected in 87/270 (32.2%) of the children. The prevalence of rotavirus, norovirus, adenovirus and astrovirus was 18.1%, 13.7%, 2.6% and 0.4%, respectively. In most cases (62.1%) of viruses were detected in children aged 7-12 months. The G and P types (VP7 and VP4 genotypes respectively) were further investigated in 49 rotavirus ELISA positive samples. G9 was the predominant G type (81.6%), followed by G1 (10.2%) and G3 (0.2%). P[8] was the predominant P type (83.7%), followed by P[6] (0.4%) and P[4] (0.2%). The following G and P types were not detected in this study population; G2, G4, G8 G10, P[9], P[10] and P[11]. The dominating G/P combination was G9P[8], accounting for 39 (90.7%) of the 43 fully characterized strains. Three (6.1%) of the 49 rotavirus strains could not be typed. Nearly one third of children with diarrhea admitted to hospitals in Dar es Salaam had one of the four viral agents. The predominance of rotavirus serotype G9 may have implication for rotavirus vaccination in Tanzania