Risk assessment of flavivirus transmission in Namibia
| Autor: | Larai Aku-Akai, Milka Musuuo, Robert J. Wilkinson, Bruce H. Noden, Israel Chipare, Berta E. van der Colf |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Adult
Male Veterinary medicine Adolescent Culex viruses Veterinary (miscellaneous) Enzyme-Linked Immunosorbent Assay Aedes aegypti Dengue virus medicine.disease_cause Antibodies Viral Arbovirus Risk Assessment Dengue fever Young Adult Aedes Seroepidemiologic Studies Surveys and Questionnaires medicine Disease Transmission Infectious Animals Humans Prospective Studies biology Age Factors virus diseases Outbreak Dengue Virus Flaviviridae Infections Middle Aged biology.organism_classification medicine.disease Virology Namibia Flavivirus Infectious Diseases Cross-Sectional Studies Insect Science Immunoglobulin G Parasitology Female Entomology |
| Zdroj: | Acta tropica. 137 |
| ISSN: | 1873-6254 |
| Popis: | The role of arboviruses causing acute febrile illness in sub-Saharan Africa is receiving more attention. Reports of dengue in tourists were published nearly 10 years ago in Namibia, but the current epidemiology of arboviruses is unknown and surveys of mosquito vectors have not been carried out since the 1950s. To begin addressing this knowledge gap, a prospective cross-sectional study was conducted using samples from volunteer blood donors linked to questionnaire. Serum samples were tested using a Dengue IgG Indirect ELISA which measured exposure to dengue virus/flaviviruses. Entomological samples were collected from tires during the rainy season (February-March 2012) in six locations across Namibia's capital city, Windhoek. Among 312 blood donors tested, 25 (8.0%) were positive for dengue virus/flavivirus exposure. The only significant risk factor was age group with high exposure rates among those older than 50 (29%) compared with those below 40 years old (between 2.9% and 8.3%) (P0.002). Larvae and pupae of Aedes aegypti and Culex pipiens complex accounted for 100% of the 2751 samples collected, of which only 12.2% (n=336) were Ae. aegypti. Each site demonstrated high variability of species composition between sampling times. While the significant dengue virus/flavivirus exposure rate among those above 50 years old is likely indicative of the West Nile epidemic in the 70s and 80s, the low exposure among those under 50 suggests that flaviviruses are still circulating in Namibia. While Ae. aegypti and C. pipiens sp. may play a role in future epidemics, the significance of presence may be reduced due to short rain periods, dry, arid, cold winters and policies and social understandings that limit non-structured storage and use of tires in low income areas. Future studies should further characterize the circulating arboviruses and investigate mosquito ecology nationally to map areas at higher risk for future arbovirus outbreaks. |
| Databáze: | OpenAIRE |
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