title: Impact of seasonal variation on Leishmania donovani infection in hamsters.
abstract: The impact of seasonal variation on the course of L. donovani infection in hamsters was investigated. Though the animals were maintained in controlled climatic conditions (25 degrees C +/- 2), parasites exhibited seasonal rhythm. During summer (April-July) when the atmospheric temperature ranged from 20.5 degrees C to 41.8 degrees C, the parasite load from an inoculum of 1 x 10(7) amastigotes/animal was found to be less than 1 to 9 per 100 cell nuclei (based on spleen biopsy) on day 25-35 post infection. An escalation in count was observed from August onwards, which reached the peak (approximately 30/100 cell nuclei) in February-March (temp. range 11.3 degrees C to 31.4 degrees C). The multiplication rate monitored 15 days after the initial assessment also showed a similar pattern. The secondary organs examined showed no parasites. The study revealed that despite the non-involvement of the vector in experimental infection in hamster, the parasites retained its periodic character as in man, corresponding to cyclicity of vector.
authors.affiliation: Division of Parasitology, Central Drug Research Institute, Lucknow.
authors.forename: R
authors.initials: R
authors.lastname: Pal
authors.lastname: Anuradha
authors.forename: P Y
authors.initials: PY
authors.lastname: Guru
authors.forename: J C
authors.initials: JC
authors.lastname: Katiyar
mesh_terms: D000818:Animals; D006224:Cricetinae; D007893:Leishmania donovani / Q000254:growth & development*; D007898:Leishmaniasis, Visceral / Q000469:parasitology*; D008297:Male; D008647:Mesocricetus; D011446:Prospective Studies; D012621:Seasons; D013696:Temperature