[Investigation on transmitting vectors of visceral leishmaniasis in Jiashi County, Xinjiang].

OBJECTIVE: To investigate sandfly vectors transmitting visceral leishmaniasis, including species and seasonal distribution in Jiashi county of Xinjiang Uygur Autonomous Region. METHODS: Sandflies were collected in the field, counted and identified. The specimens were dissected to analyze the gonotrophic cycle and to find infection of promastigotes. The resting places were observed by using oil-paper and sandfly-capturing trap. RESULTS: 4540 sandflies were collected with 99.9% of Phlebotomus wui and only 0.1% Sergentomyia minutus sinkiangensis. On the seasonal distribution, the first peak appeared by the end of May and the first ten-day of June, and the second peak was in the middle of August. Observation showed that the activity of sandflies occurred mainly from 22:00 to 4:00, reaching to the maximum in the midnight. Analysis on the gonotrophic cycle revealed that Ph. wui was an exophilic species and appeared nocturnally for feeding with preference to human blood. Natural infection with promastigotes was found in 4 sandflies, more in the field than the residential area. Resting places included the aperture on the wall of livestock sheds and in the caves. CONCLUSION: Ph. wui is the predominant species in Jiashi, with higher infection rate of natural promastigotes in the field and with two life generations annually.

[An epidemiological survey of visceral leishmaniasis in Hamangou coal mine area of Korla City, Xinjiang].

OBJECTIVE: To investigate the epidemiological status of visceral leishmaniasis in Hamangou coal mine area of Korla City of Xinjiang Uygur Autonomous Region. METHODS: Based on a hint of possible existence of patients, a retrospective survey was carried out house by house to find cases with suspected signs/symptoms of the disease. Meanwhile, a survey on current status was conducted, including physical examination (liver and spleen palpation) to those less than 15 years-old, leishmanin skin test and rk39 immunochromatographic strip test for part of the residents. Bone marrow smears were examined for the cases with clinical signs/symptoms and positive rk39 strip test. Sandflies were collected using routine methods in and around the area, identified, and dissected to find infection of promastigotes. RESULTS: Leishmanin skin test was performed in 185 people with a positive rate of 21.1% (39/185), 39 out of 140 local residents who have lived there for more than 6 years showed positive (27.9%), while all residents who have lived less than 6 years and children under 5 years old were negative. Of the 81 children under 15 years old with a negative skin test, one showed positive for rk39 strip test, and leishmania body was found in the bone marrow smear of this case, so confirmed as visceral leishmaniasis. 12 sandflies were identified as Phlebotomus alexandri, and natural infection with promastigotes was found in one sandly. CONCLUSION: The investigation confirms that visceral leishmaniasis is endemic in the Hamangou coal mine area.

[Field test of sandfly-catching by light traps and attractants].

Three kinds of light traps, attractants and their combination were used to collect sandflies in Andier township, Minfeng County of Xinjiang. The combined use of carbon dioxide and tungsten lamp showed better attraction effect to sandflies, also an easier way for the separation of insects collected.

[A newly identified endemic area of visceral leishmaniasis in Minfeng county of South Xinjiang I. epidemiological survey].

OBJECTIVE: To investigate the epidemiological status of visceral leishmaniasis in Minfeng county, a newly identified endemic area in south Xinjiang, China. METHODS: Based on a hint of possible existence of patients, a retrospective survey was carried out house by house in Andier Township of the county to find cases with suspected signs/symptoms of the disease in the past 20 years including those died. Meanwhile, a survey on current status was conducted, including physical examination(liver and spleen palpation) to those under 15 years-old, leishmanin skin test and rk39 immunochromatographic strip test for part of the residents. RESULTS: The investigation covered 313 local residents and revealed no case with present illness but 60 cases with a history of suspected signs/symptoms including 13 deaths, traced back as visceral leishmaniasis. Leishmanin skin test was performed in 171 people with a positive rate of 99.4% and 28 out of 29 suspected cases showed positive (96.6%). rk39 immunochromatographic strip test was conducted in 197 people with a positive rate of 10.2% (20/197) and 19.4% (6/31) in those with a history of suspected signs/symptoms. CONCLUSION: The epidemiological investigation indicates that the Andier Township of Minfeng County is an endemic area of visceral leishmaniasis.

[A newly identified endemic area of visceral leishmaniasis in Minfeng county of south Xinjiang II. Investigation on phlebotomine vectors].

OBJECTIVE: To investigate the transmitting phlebotomine sandfly in Minfeng County, a newly-identified endemic area of visceral leishmaniasis in the south of Talim Pendi of Xinjiang. METHODS: Sandflies were collected using routine methods in and around the Yatonggusi village of Andier Township. The sandflies were identified to get their composition. Sandfly density was calculated following an observation at a given spot and time-period, and their appearance was recorded at night-time and day-time. Sandflies were dissected to analyze the gonotrophic cycle and to find infection of promastigotes. RESULTS: Phlebotomus wui was identified as the transmitting vector of visceral leishmaniasis in Andier Township, which occupied 99.2% of the sandflies collected. The first and second ten-day period of June was the first peak of its seasonal distribution. Analysis of the gonotrophic cycle revealed that Ph. wui was an exophilic species and appeared nocturnally for feeding with preference to human blood. Natural infection with promastigotes was found in 2 sandflies. CONCLUSION: Phlebotomus wui is the transmitting vector for visceral leishmaniasis in the newly found endemic area of south Xinjiang.