Studies on the transmission of Kyasanur Forest disease virus by Haemaphysalis spinigera newman
| Autor: | M.G.R Varma, Pavri Km, H.E Webb |
|---|---|
| Rok vydání: | 1960 |
| Předmět: |
Larva
animal structures Haemaphysalis spinigera biology Public Health Environmental and Occupational Health General Medicine Forests Tick medicine.disease biology.organism_classification Virology Virus Encephalitis Viruses Tick-Borne Serology Ticks Infectious Diseases Virus Diseases medicine Animals Parasitology Nymph Kyasanur forest disease Encephalitis |
| Zdroj: | Transactions of the Royal Society of Tropical Medicine and Hygiene. 54:509-516 |
| ISSN: | 0035-9203 |
| Popis: | 1. 1) Four batches of larvae of the tick Haemaphysalis spinigera were infected with Kyasanur Forest disease virus by feeding on four young White Leghorn chicks circulating the virus. Larvae from all batches ingested the virus. Nymphs emerging from the larvae and adults emerging from the fed nymphs were shown to be infected. 2. 2) The titre of the suspensions of unfed nymphs after storage at −50°C. varied from 5.0 to 6.8. Titre of the virus in adult tick suspensions after storage at −50°C. varied from to 6.0. Infection rates in adults from the four batches varied from 25 per cent. to 70 per cent., the average being 52 per cent. Forty-two per cent. of the males and 61 per cent. of the females were found to be infected. Virus was recovered from adults up to at least 176 days after the infecting feed as larvae. 3. 3) Virus isolated from the nymphs as well as the adults was shown to be identical with KFD virus. 4. 4) Nymphs from all four batches transmitted the infection to young White Leghorn chicks by bite. Of 33 chicks tested, definite evidence of transmission was obtained in 25 (76 per cent.). Partially fed nymphs were shown to be capable of transmitting the infection to clean chicks whilst feeding to repletion. Single nymphs transmitted the infection. 5. 5) A young buffalo calf, on which infected adults fed, circulated virus and developed neutralizing and low III antibodies, but not CF antibodies, to KFD virus. 6. 6) In a second chick-tick-chick cycle, clean H. spinigera larvae fed on a chick that had acquired the infection following the bite of an infected nymph. Nymphs emerging from the larvae transmitted the infection to clean chicks. The virus isolated from nymphs and adults of this batch was identified as KFD virus. |
| Databáze: | OpenAIRE |
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