Widespread co-endemicity of human cystic and alveolar echinococcosis on the eastern Tibetan Plateau, northwest Sichuan/southeast Qinghai, China.
Cystic echinococcosis (CE) or hydatid disease is known to be cosmopolitan in its global distribution, while alveolar echinococcosis (AE) is a much rarer though more pathogenic hepatic parasitic disease restricted to the northern hemisphere. Both forms of human echinococcosis are known to occur on the Tibetan Plateau, but the epidemiological characteristics remain poorly understood. In our current study, abdominal ultrasound screening programs for echinococcosis were conducted in 31 Tibetan townships in Ganze and Aba Tibetan Autonomous Prefectures of northwest Sichuan Province during 2001-2008. Hospital records (1992-2006) in a major regional treatment centre for echinococcosis in Sichuan Province were also reviewed. Of 10,186 local residents examined by portable ultrasound scan, 645 (6.3%) were diagnosed with echinococcosis: a prevalence of 3.2% for CE, 3.1% for AE and 0.04% for dual infection (both CE and AE). Human cystic and alveolar echinococcosis in pastoral areas was highly co-endemic, in comparison to much lower prevalences in semi-pastoral or farming regions. The high ultrasound prevalence in these co-endemic areas in northwest Sichuan Province was also reflected in the hospital study, and hospital records furthermore indicated another possible highly co-endemic focus in Guoluo Prefecture of Qinghai Province, located at the border of northwest Sichuan. These chronic cestode zoonoses constitute an unparalleled major public health problem for pastoral Tibetan communities, and pose great difficulties for adequate treatment access and effective transmission control in such remote regions.
Li
Tiaoying
T
Institute of Parasitic Diseases, Sichuan Centers for Disease Control and Prevention, Sichuan Province, People's Republic of China. litiaoying@sina.com
Chen
Xingwang
X
Zhen
Ren
R
Qiu
Jiamin
J
Qiu
Dongchuan
D
Xiao
Ning
N
Ito
Akira
A
Wang
Hu
H
Giraudoux
Patrick
P
Sako
Yasuhito
Y
Nakao
Minoru
M
Craig
Philip S
PS
D000005:Abdomen / Q000000981:diagnostic imaging; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D004444:Echinococcosis, Hepatic / Q000453:epidemiology*; D004445:Echinococcosis, Pulmonary / Q000453:epidemiology*; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015995:Prevalence; D018609:Tibet / Q000453:epidemiology; D014463:Ultrasonography; D055815:Young Adult