Abstract:

Objective To ascertain the causes of the outbreak via investigation and management of a clustered outbreak of visceral leishmaniasis in Akto County, Xinjiang Uygur Autonomous Region, for scientific basis in formulating more effective prevention and control measures for similar infections. Methods B-mode ultrasound and rK39 immunochromatographic test strips were used to screen key populations from May 28^th to June 10^th, 2022, and field study was conducted to investigate the potential transmission vectors in the affected area. Descriptive epidemiology was used to analyze the results investigate. Results The index case was a 1-year-and-4-month-old girl living at home in Village D, Township X, Akto County. She had no history of travel before infection. She first developed a fever on February 10, 2022, and was diagnosed with visceral leishmaniasis on May 8^th. She was cured and discharged from the hospital on June 3^rd. A total of 375 individuals were screened, and 1 clinically diagnosed case and 6 asymptomatic infections were identified, all of whom were local residents in Village D, Township X, Akto County. The first clinically diagnosed case developed symptoms in early September 2021 and reported no travel history within the year prior to onset, but had a history of mosquito bites. There were 4 males and 3 females, with ages ranging from 9 to 55 years old, including 3 individuals aged 10 or younger and 4 older than 10. By occupational distribution, three were students and four farmers. All cases or asymptomatic infections had a history of sandfly bites. A vector survey was conducted on June 1-2, 2022, during which three Phlebotomus longiductus Parrots were captured. Conclusion This endemic is a local clustered outbreak of visceral leishmaniasis, with the possible transmission vector being Phlebotomus longiductus Parrot. During the investigation and response period, spraying was carried out to eliminate sandflies in all residential houses, animal pens, and courtyards in the areas where confirmed and clinically diagnosed cases were located. The transmission was eventually and effectively controlled.

Key words: Visceral leishmaniasis, Kala-azar, Aggregation epidemic, Investigation and management, Xinjiang Uygur Autonomous Region