Study of diagnosis and spatial epidemiology on paragonimiasis in Lao PDR.

尽管缺乏老挝自1973年以来的肺吸虫病资料，5个省的8个区；通过我们的研究，澄清了阿都坡、占巴塞、沙万那杰、万象和琅南塔存在和/或可能的疾病风险。在老挝首都万象以北80公里处的Hinheup地区，对2种河蟹（7种Potamon lipkei和5种Chulathelphusa brandti）进行了特别调查，共采集到约700个囊蚴。虽然数量较少，但在尘螨种群中发现了印度支那地区已知的人类吸虫病病原种异吸并吸虫和韦斯特马尼疟原虫。在主要种群中，利用从实验犬感染中获得的成虫，鉴定并澄清了2种未报道的harinastai和bankokensis并殖吸虫。在各种实验动物中，大鼠实验感染3个月后，哈氏单胞虫成虫无法存活，这是首次证实。此外，在实验感染中，成虫的回收率（80%）证实了狗是银行假单胞虫的适宜宿主。采用已建立的PCR技术。为鉴定Hinheup人吸虫病的实际致病种，采集了6份居民唾液中的寄生虫卵，并建立了PCR技术；利用引物对4种寄生虫的种特异区（ITS2）进行分析。所有样本均检出异吸弓形虫，因此强烈建议该地区存在人类吸虫病的病原寄生虫。

In spite of lack of information on paragonimiasis in Laos since 1973, eight districts in 5 provinces; Attopeu, Champasak, Savannakhet, Vientiane, and Luangnamtha, which exist and/or possible risk of the disease were clarified through our research. Around 700 metacercariae were collected from 2 species of the river crabs (7 Potamon lipkei and 5 Chulathelphusa brandti) obtained in Hinheup district which was especially investigated as a dense infested area in Vientiane province, where is 80 km north from Vientiane Capital in Lao PDR. Though the numbers were smaller, Paragonimus heterotremus, a known causative species of human parogonimiasis in Indochina region, and P. westermani were identified at the metacercariae population. On the major population, 2 unreported Paragonimus species of harinastai and bankokensis were identified and clarified using adult worms obtained from experimental infections of dogs in the laboratory. Among various experimental animals, adult worms of P. harinastai never survive after 3 month of the experimental infections in rats, which was demonstrated for the first time. Furthermore, dog is a suitable host for P. bankokensis was confirmed by recovery (80%) of the adult worms at the experimental infections. And the established PCR technology was used. To identify the actual causative species of human paragonimiasis in Hinheup, 6 samples of the parasite eggs from the sputa of dwellers were collected, and the established PCR technique; using primers of species specific region (ITS2) of the 4 parasites, was performed. All these samples resulted in P. heterotremus, thus the causative parasite of human paragonimiasis was strongly suggested as this species in the region.