First discovery of new plague natural foci in Alataw Mountain, Xinjiang. Otkrytie novogo prirodnogo otchaga tchoumy v gorakh Alataou, Sin’tszyan. [Première d&ecute;couverte d’un nouveau site naturel de peste dans le mont Alataou, Xinjiang].

Résumé

Objective of our investigation was to confirm whether the Alataw mountain is plague natural foci or not, and the relate fauna of the animals and insects. The investigation of Epidemiology, Medical zoology and entomology, serology and bacteriology,ect. were carried out. A investigation of plague natural foci was carried out, situated 79?53'-81?20'E and 44?55'-45?10'N, on one side mountain of China-Alataw mountain which associated with a research team by Xinjiang disease prevention control center and sanitary and anti-epidemic station of Wenquan County in June to August 2003. The investigation is main according to Alataw mountain District, which discovers big area of died Marmota baibacina since 1999, and one positive serum of plague F1 antibody was discovered in dog by sanitary and anti-epidemic station of Wenquan Countyat Kundelun ranch in 2002. The animals of Ten species were captured in the investigated area, including Lepus capensis, Marmota baibacina, Citellus undulates, Citellus erythrogenys, Sicista tianschanica, Apodemus sylvaticus, Cricetulus migratorius, Microtus arvalis, Alticola argentatus and Allactaga sibirica. The Predommated rodents is Marmota baibacina having at an altitude of 2000- 3000 meters in the area, the second is Citellus undulates which is same habitat with Marmota baibacina, there are Citellus erythrogenys at some area of situated 1600-1900 meters. The population density of the marmot was 2.5-5.5/hm2 by fixed observation. The best density was 2.36/hm2 and the lowest was 0.01/hm2 by a route method. The infecting flea of the marmot is 3.6% in the neck of hole and is 6.2% on the body of the marmot. The 18 species of the fleas, 2 of the ticks and 1 of the louse were collected on the body of the rodents. Oropsylla silantiewi and Frontopsylla elatoides were the main carriers on marmot. 180 serum specimens from various rodents and 114 from dogs were examined by hemagglutination test for antibody to Y. pestis, the antibody to F 1 antigen was detected in the sera of two marmots and one dog. Four strains of Y. pestis were isolated from 25 animals of the naturaliy dead; four strains were all from marmot. The investigation supplied the evidence for the first time that natural plague foci existed in the surveyed areas.