Understanding the ecological drivers of avian influenza virus infection in wildfowl: a continental-scale study across Africa.

Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), empirical investigations of ecological drivers of AIV prevalence in wild birds are still scarce. Here we used a continental-scale dataset, collected in tropical wetlands of 15 African countries, to test the relative roles of a range of ecological factors on patterns of AIV prevalence in wildfowl. Seasonal and geographical variations in prevalence were positively related to the local density of the wildfowl community and to the wintering period of Eurasian migratory birds in Africa. The predominant influence of wildfowl density with no influence of climatic conditions suggests, in contrast to temperate regions, a predominant role for inter-individual transmission rather than transmission via long-lived virus persisting in the environment. Higher prevalences were found in Anas species than in non-Anas species even when we account for differences in their foraging behaviour (primarily dabbling or not) or their geographical origin (Eurasian or Afro-tropical), suggesting the existence of intrinsic differences between wildfowl taxonomic groups in receptivity to infection. Birds were found infected as often in oropharyngeal as in cloacal samples, but rarely for both types of sample concurrently, indicating that both respiratory and digestive tracts may be important for AIV replication.

Kingella kingae infections in children.

OBJECTIVE: To increase awareness of Kingella kingae infections in children by presenting four cases seen at the Gold Coast Hospital, Southport, Queensland, and reviewing the literature. METHODOLOGY: Records of the four cases were reviewed and relevant information described. A MEDLINE search of the English literature from 1983 to 1998 was conducted. RESULTS: Osteoarticular infections are the commonest type of invasive paediatric infection but bacteraemia and endocarditis also occur. Isolation of the organism is difficult but inoculation of the specimen into enriched blood culture systems improves the recovery rate. The majority of isolates are sensitive to beta-lactam antibiotics but resistance has been described. CONCLUSIONS: Kingella kingae infections in children are more common than previously recognized. The organism should be actively sought in any child with suspected osteoarticular infections. Recommended empiric therapy is a third generation cephalosporin until susceptibility to penicillin is confirmed.