Characterization of influenza A viruses isolated from wild waterfowl in Zambia.

Although the quest to clarify the role of wild birds in the spread of the highly pathogenic H5N1 avian influenza virus (AIV) has yielded considerable data on AIVs in wild birds worldwide, information regarding the ecology and epidemiology of AIVs in African wild birds is still very limited. During AIV surveillance in Zambia (2008-2009), 12 viruses of distinct subtypes (H3N8, H4N6, H6N2, H9N1 and H11N9) were isolated from wild waterfowl. Phylogenetic analyses demonstrated that all the isolates were of the Eurasian lineage. Whilst some genes were closely related to those of AIVs isolated from wild and domestic birds in South Africa, intimating possible AIV exchange between wild birds and poultry in southern Africa, some gene segments were closely related to those of AIVs isolated in Europe and Asia, thus confirming the inter-regional AIV gene flow among these continents. Analysis of the deduced amino acid sequences of internal proteins revealed that several isolates harboured particular residues predominantly observed in human influenza viruses. Interestingly, the isolates with human-associated residues exhibited higher levels of virus replication in the lungs of infected mice and caused more morbidity as measured by weight loss than an isolate lacking such residues. This study stresses the need for continued monitoring of AIVs in wild and domestic birds in southern Africa to gain a better understanding of the emergence of strains with the potential to infect mammals.

Molecular identification of Schistosoma mattheei from feces of Kinda (Papio cynocephalus kindae) and grayfoot baboons (Papio ursinus griseipes) in Zambia.

Terminal-spined Schistosoma sp. eggs were detected in several groups of baboons living in Kafue National Park in central Zambia. A total of 166 fecal samples was screened; egg prevalence overall ranged between 7% and 10%, while infection intensities were low. Formalin-fixed eggs had an average length of 144.5 microm and a breadth of 48.3 microm, but the schistosome species could not be unambiguously identified by size or morphology. We used molecular methods to definitively identify the parasite species. Parasite DNA was amplified from stools by polymerase chain reaction (PCR). Sequence analysis of fragments of the first internal transcribed spacer (ITS-1), mitochondrial 12S rDNA, NADH dehydrogenase subunit 6 (nad6), and cytochrome C oxidase subunit 1 (cox1) from 3 egg-positive samples revealed the presence of S. mattheei in these samples. This is the first molecular identification of S. mattheei from free-ranging baboons. Schistosoma mattheei is typically a parasite of bovids, but it can also infect humans. Schistosoma mattheei in baboons in Zambia may affect other wildlife species and humans that live in close proximity to baboons.