Cooperative studies of seroepidemiology and pathogenesis of Viral and parasitie diseases in Okinawa and Thailand

合作研究包括三个领域：1.黄病毒感染，特别是乙脑和登革出血热。2单纯疱疹病毒2型(HSV-2)感染。1.用中和(N)试验检测乙脑和DHF的交叉免疫反应。当已有乙脑或登革热病毒N抗体的个体依次感染登革热或乙脑病毒时，不仅对引起病毒的N滴度有显著的增加，而且对先前感染的病毒的N滴度也以35%-40%的频率显著增加。因此，即使是N试验也不能总是识别黄病毒再感染的致病病毒。对重组杆状病毒产生的登革4E蛋白进行了截短检测，以探讨诊断抗原鉴别登革热和乙脑感染的可能性。结果表明，表达的蛋白可用于…登革热的鉴别诊断。乙脑感染较多，特异性略低于N试验。RT-PCR方法用于DHF的早期诊断。结论：1.通过选择合适的RT-PCR引物，建立了4种登革热病毒血清型的鉴定方法，并与病毒分离株进行了比较。对冲绳和清迈的HSV-2分离株进行了限制性内切酶酶切图谱分析和对小鼠的毒力测定。观察到了每个区域分离株特有的一些裂解模式。冲绳分离株表现出较高、中等和较低的毒力，而Chii和Mai分离株仅通过外周注射对小鼠表现出中等毒力。清迈地区现场调查发现，成年村民阳性率为46.3%，学龄儿童阳性率为6.9%。新研制的酶联免疫吸附试验检测结果与冲绳样本的粪便培养检测结果一致，但对清迈样本的检测结果不一致，可能是由于与其他肠道寄生虫的交叉反应所致，这些寄生虫在清迈地区高度流行。较少

The cooperative study consists of three fields : 1. Flavivirus infections, specifically Japanese encephalitis(JE) and dengue hemorrhagic fever(DHF). 2. Herpes simplex virus type 2(HSV 2) infection. 3. Strongyloidiasis.Results obtained are described briefly as follows :1. Cross immune response between JE and DHF was examined by neutralization(N) tests. When individuals with pre-existing N antibody to JE or dengue virus were infected sequentially with dengue or JE virus, significant increases of N titer were observed not only to the causative virus but also to the previously infected virus at the frequency of 35%-40%. Thus, even the N test could not always identify the causative virus in re-infection of flaviviruses.The truncated dengue-4 E protein produced by a recombinant baculovirus was wxamined for the possibility of diagnostic antigen to differentiate dengue and JE infection. Results indicated that the expressed protein was a useful diagnostic antigen in differentiation of dengue in … More fection from JE with slightly lower specificity than N test.RT-PCR method was examined for the early diagnosis of DHF. Appropriate selections of primers for RT-PCR resulted in a useful identification method of 4 serotypes of dengue virus in comparison with virus isolation.2. HSV 2 isolates in Okinawa and Chiang Mai were analyzed by the restriction endonuclease cleavage patterns and virulence to mice. Some cleavage patterns characteristic to each regional isolate were observed. The Okinawan isolates showed higher, intermediate and lower virulence while the Chiand Mai isolates showed only intermediate virulence to mice by peripheral injection3. Field study on strongyloidiasis in Chiang Mai gave positive rates of 46.3% in adult villagers and 6.9% in school children.The newly developed ELISA for strongyloidiasis gave well-corresponding results with those of the stool culture examination for the Okinawan samples but did not for the Chiang Mai samples, possibly due to cross reactions caused by co-infections with other intestinal parasites such as Opisthorchis viverrini and hookworm, which were found to be highly prevalent in the Chiang Mai area. Less