[Geography and host distribution of Crimean-Congo hemorrhagic fever in the Tarim Basin].

OBJECTIVE

To determine the infective status and natural distribution of Xinjiang hemorrhagic fever (XHF; Crimean-Congo hemorrhagic fever, CCHF) in ticks, rodents and livestock in the Tarim Basin.

METHODS

The pathogenic materials of ticks or rodents' viscera and blood samples of sheep were inoculated into sucking mouse of 24 to 48-hour old. Materials with typical clinic symptoms were identified with RPHA and IFA. RT-PCR was taken to detect special S gene segment of Crimean-Congo hemorrhagic fever virus (CCHFV) in the objective material.

RESULTS

All the samples of ticks, rodents' viscera and blood samples of sheep from 21 counties (cities) in the Tarim Basin were divided into 422 groups and inoculated into sucking mouse at laboratory. 49 materials with typical clinic symptoms were obtained. The morbidity rate with typical clinic XHF was high in Bachu, Yuli, Yutian and Ruoqiang. There were 43 samples identified with RPHA with 6 positive samples and positive rate of 1.4%. The materials with positive RPHA were found in Yuli, Luntai and Yutian. 42 samples were identified with IFA and 13 positive samples with the positive rate of 3.1%. The positive materials of IFA were found in Bachu, Yuli, Minfeng, Luntai and Yutian. 32 samples were detected with RT-PCR and there were 31 samples with special S gene segment of CCHFV (329- 548 nt). The positive materials was widely distributed in Aksu, Awat, Bachu, Luopu, Yuli, Minfeng, Qiemo, Ruoqiang, Luntai and Yutian. The highest infective rate was in Hyalomma asiaticum kozlovi, and followed by sheep. S gene segment was detected in viscera of M. meridianus.

CONCLUSIONS

XHF relied on the river in the southern part of Xinjiang and distributed in the areas with Populus euphratica shrub in desert and oasis in the Tarim Basin. The main vector and host were Hyalomma asiaticum kozlovi. Livestock such as sheep, camel, L. yarkandensis, M. meridianus and Euchoreutes naso could serve as the deposited host of XHF.