山东地区秋冬型恙虫病传播媒介的调查研究

目的：探讨山东地区恙虫病传播媒介。方法：1995年5月～2002年4月在山东恙虫病疫区捕鼠。观察鼠体外恙螨季节消长，分离恙虫病东方体(Ot)。结果：室内外共捕捉到的527只活鼠(黑线姬鼠335只，大仓鼠119只，黑线仓鼠6只，小麝鼩2只，褐家鼠63只，小家鼠2只)，从活鼠体外共检获15467只恙螨，其中太平洋无前恙螨最多5720只，其它螨数量依次为小盾纤恙螨4175只，临淮岗纤恙螨3090只，须纤恙螨1687只，泰山纤恙螨466只，脆弱无前恙螨329只。恙螨季节变化：小盾纤恙螨主要出现在9～12月，高峰在11月，是秋季鼠体外绝对优势种；须纤恙螨出现在10～翌年4月，高峰在12月，为冬季优势螨种，临淮岗纤恙螨5月出现，11月消失，高峰在8月，为夏季优势种；泰山纤恙螨主要出现在6～10月，数量较少，且起伏较大；太平洋无前恙螨、脆弱无前恙螨全部采自仓鼠，主要出现在4～12月，高峰期在7月。Ot分离：小盾纤恙螨共接种11批，分离到5株Ot；须纤恙螨、临淮岗纤恙螨和太平洋无前恙螨分别接种4批，分离到4株、2株和2株Ot。小盾纤恙螨是恙虫病发病季节疫区鼠体外优势螨种，季节消长与当地人群恙虫病季节分布基本一致；能自然感染、叮刺传播和经卵传递恙虫病东方体；被恙螨叮刺或悬液接种的小白鼠血清中能检测到特异性抗体，以上结果证明小盾纤恙螨为当地秋冬型恙虫病的传播媒介。血清学分型：除从临淮纤恙螨分离到的1株为Karp型外，其余分离株均为Gilliam型。从不同材料中分离到的Ot毒力相差不大，均属弱毒株，分离株与标准株间有交叉免疫保护能力。现场和实验室杀螨实验表明，小盾纤恙螨对敌敌畏和以二氯苯醚菊酯为主的杀虫剂均很敏感，且防治效果至少可维持1个月以上。结论：小盾纤恙螨为当地秋冬型恙虫病的主要传播媒介，同时其它螨种也有充当恙虫媒介的可能。

Investigation on the vectors of scrub typhus in the foci of Shandong province

Objective:In order to investigate the vectore of scrub typhus in Shandong province.Methods:Rodents were captured from May 1995 to April 2002,Observation of fluctuation of chigger mites and isolation of Orientia tsutsugamushi(Ot) therefrom were carried out.Results:A total of 15467 chigger mites,consisting of 6 species from two genera,were collected from 527 rodents(including 335 Apodemus(A.) agrarius,119 Cricetulus(C.) triton,6 C.barabensis,63 Rattus(R.) norvegicus,2 Crocidura(C.) suaveolens,2 Mus(M.) musculus) captured in Fei county,Jinan,Junan and zouping.Walchia(W.) pacifica was the most predominant in number,followed by leptotrombidium(L.) scutellare,L.linhuaikongense,L.palpale,L.taishanium,and W.fragilis.L.scutellare was present from September to December(the epidemic season of scrub typhus in Shandong) with a remarkable peak in November,whereas L.palpale occurred from October to April(the second year) with peak in December.L.linhuaikongense was found from May to November,with peak in August.W.pacifica appeared from April to December with peak in July.Ot was isolated from L.scutellare,L.palpale,L.linhuaikongense and W.pacifica.The main serotypes of Ot isolated from the chigger mites were of the Gilliam type,but Karp type also existed in L.linhuaikongense.Conclusion:L.scutellare is the most important vector whice caused the endemic of this disease in Shangdong province,and L.palpale,L.linhuaikongense and W.pacifica may serve as the vectors in this and L.palpale,L.linhuaikongense and W.pacifica may serve as the vestors in this area.