1986—1990年我国丝虫病防治研究进展

根据丝虫病流行区各省、自治区、直辖市的统计资料,1986—1990年全国共血检普查22 350 772人次,查出微丝蚴阳性者268 034人,海群生治疗78 550 945人次。5年内又有162个县、市达到基本消灭丝虫病的指标,使累计达到基本消灭丝虫病指标的县、市增至823个,占全国(除台湾省外)864个流行县、市的95.3％。已达基本消灭丝虫病指标的地区,正将丝虫病防治工作转入监测管理阶段。据各地开展定点纵向监测的初步结果,显示在不追加防治措施的情况下,人群微丝蚴率几乎均持续降低,IFAT阳性率和抗体滴度亦呈下降趋势,仅个别班氏丝虫病流行区的纵向监测点,由于尚存在较高密度的残存微丝蚴血症者,仍可发现阳性蚊媒。5年中,有关丝虫病防治后期流行规律、血清学监测方法及丝虫病症状体征治疗方法等项研究亦取得了新的进展。     

Mass treatment of filariasis using DEC-medicated salt.

Diethylcarbamazine (DEC)-medicated salt was used to control bancroftian filariasis in 20 endemic counties and cities of Fujian Province in China. The population was 5,189,126 and the microfilaria (mf) rates were between 1.56 and 11.81%. The total dose of DEC was 6-10.5 g per person over a period of 2-4 months. Six to 9 months after treatment the mf rate was reduced to 0-0.57% with a mean of 0.07% (621/823,796). In 184 villages sampled one year post treatment the mf rate was 0.22% (371/171,067) and in 29 villages 2-4 years after treatment the mf rate was 0.05% (31/56,459). In a region of endemic Malayan filariasis, with a population of 67,778 and mf rate of 3.82-4.36%, treatment with DEC-medicated salt to a dosage of 3.2 g DEC per person was administered for 2 months. Six months after treatment the mean mf rate was reduced from 4.08 to 0.26% (10/3841). Filariasis in all the villages controlled with DEC-medicated salt reached the basic criteria of elimination (mf rate below 1%).     

贵州省消除丝虫病后的监测

目的　巩固贵州省消除丝虫病后的防治成果 ,防止丝虫病的再度流行。　方法　对边远、贫困和防治监测中存在薄弱环节的地区及原流行区外来人口进行蚊媒、病原学、血清学监测 ;对慢性丝虫病病人进行相关治疗和照料。　结果蚊媒监测中华按蚊 75 41只 ,嗜人按蚊 2 5 3只均为阴性 ;病原学检测 7180人 ,未发现微丝蚴血症者 ;血清学检测 937人 ,阳性率 0 .5 34 % (5 /937) ;对象皮腿患者治疗的有效率为 5 2 .6 3% (10 /19) ,中链油和海群生治疗乳糜尿的近期有效率分别为 93.3% (2 8/30 )和 90 .0 % (18/2 0 ) ,1年后有效率分别为 88% (2 2 /2 5 )、75 % (6 /8)。　结论　贵州省消除丝虫病的成果是巩固的。鉴于全国尚未消除丝虫病 ,仍需加强监测 ,同时还应加强对慢性丝虫病病人的照料。     

Filariasis surveillance at the post-control stage in China.

From 1956, when filariasis control was first listed in our national program, up to 1991, a cumulative total of 677,931,521 person-time blood examinations and 217,472,045 person-time diethylcarbamazine treatments were made in the whole country, and 835 (96.6%) out of the 864 endemic counties achieved the criterion for control of filariasis. Surveillance data collected in various provinces, autonomous regions and municipalities starting from the second year after they reached the criterion for control of filariasis demonstrated that in 1991 the microfilarial rate in human populations and natural infection of filarial larvae in mosquito vector populations in previous endemic areas had already declined to a very low level, even zero, without resurgence in quite a number of villages. In some places where filariasis was brought under control relatively early, the anti-filarial antibody positive rate of the human population has fallen to a level the same as or similar to that in nonendemic areas. Therefore, the data suggest that in most places where filariasis has been controlled, the transmission of bancroftian filariasis and periodic malayan filariasis has been interrupted. However, filariasis is still endemic in 29 counties in China at present, the danger of introduction of sources of infection by the floating population hasn't been extinguished yet, and there are still a few areas with weak links in filariasis control. Therefore, control work still needs to be strengthened and systematic surveillance must be pursued until the elimination of filariasis in the whole country.     

湖南省丝虫病流行特点及防治效果

湖南省丝虫病分布于55个县、市。据1958年22个县、市调查,平均微丝蚴率为5.6％(180 046/3 194 102),晚期丝虫病患病率为3.3％。致倦库蚊和中华按蚊分别为我省班氏和马来丝虫病的主要媒介,自然感染率分别为3.0～9.O％和18.1～48.0％。1970年以后,全省开展了大规模的防治,以消灭传染源为主。在马来丝虫病和低度班氏丝虫病流行的18个县市进行反复查治,微丝蚴血症者给予海群生系统治疗;在中、高度班氏丝虫病和边远山区班氏丝虫病流行区的37个县、市,采取全民服用海群生药盐的措施。至1985年,以村为单位的微丝蚴率降至1％以下。1986年卫生部确认湖南省已达到基本消灭丝虫病标准。     

安徽省丝虫病流行及防治

安徽原是全国丝虫病流行严重省份之一。据５０年代末期调查全省平均微丝蚴率为１２．０％，估计全省约有微丝蚴血症者３６０余万人，全省８２个县、市均有不同程度的丝虫病流行，其中单纯马来丝虫１８个县、市，单纯班氏丝虫３１个县、市，混合流行区３３个县、市。班氏丝虫病主要传播媒介为淡色库蚊、致倦库蚊和嗜人按蚊，马来丝虫病主要传播媒介为中华按蚊和嗜人按蚊。经４０年的积极防治，尤其是１９８７年以来，在单纯抽查的基础上，根据不同的流行程度采用不同剂量疗程的海群生药盐的防治措施，加快了基本消灭丝虫病的进程，于１９９４年卫生部组织考核组抽查复核黄山市黄山区和濉溪县，微丝蚴率分别为０和０．４５％，达到了基本消灭丝虫病的标准。     

The Global Programme to Eliminate Lymphatic Filariasis: History and achievements with special reference to annual single-dose treatment with diethylcarbamazine in Samoa and Fiji

Diethylcarbamazine (DEC), first introduced in 1947, was shown to have strong efficacy and safety for treatment of human lymphatic filariasis, which is caused mostly by a species Wuchereria bancrofti. Many studies to optimize the dosage and treatment schedule of DEC followed, and, based on the results, control programs with various regimens were implemented in different endemic areas/countries. By the mid 1970s, with endorsement by the WHO Expert Committee on Filariasis (3rd report, 1974), the standard DEC regimen for W. bancrofti infection in mass treatment had been established in principle: a total dose of 72 mg/kg of body weight given in 12 divided doses, once weekly or monthly, at 6 mg/kg each. Not long after the committee report, the efficacy of annual single-dose treatment at 6 mg/kg, which is only one twelfth of the WHO-recommended dose in a year, was reported effective in French Polynesia (study period: 1973-78), and later in Samoa (study period: 1979-81). These results were published between 1978 and 1985 in the Bulletin of WHO but received little attention. In the mid 1980s, the efficacy of ivermectin, the first-choice drug for onchocerciasis, against lymphatic filariae came to light. Since the effect at a single dose was remarkable, and often better than DEC, it was predicted that the newly introduced drug would replace DEC. Treatment experiments with ivermectin increased quickly in number. Meanwhile, annual single-dose mass drug administration (MDA) with DEC at 6 mg/kg was under scrutiny in Samoa and Fiji. In the early 1990s, the Samoan study, which covered the entire population of 160,000 with 3 annual MDAs, reported a significant reduction in microfilaria (mf) prevalence and mean mf density, while in Fiji, the efficacy of 5 rounds of annual MDA (total dose, 30 mg/kg) was shown to be as effective as 28 multi-dose MDA spread over 2 years (6 weekly plus 22 monthly treatments at 5 mg/kg; total dose, 140 mg/kg). Several additional studies carried out in Samoa in relation to the annual single-dose MDAs revealed that low density mf carriers, who have a very low mf count of 1-20/ml of venous blood, could not play a significant role in filariasis transmission.From around 1990, studies on spaced low-dose DEC treatments and various types of combination chemotherapy with DEC and ivermectin increased. Albendazole, a well-known anti-intestinal helminths agent, was later added to the combination. The main findings of these studies with W. bancrofti are: (i) a single dose of DEC at 6 mg/kg reduced mean mf density by ca. 90% 1 year after treatment; (ii) the same dose could damage/kill adult worms; (iii) a single dose of ivermectin at ca. 400 μg/kg was more effective than DEC in reducing mf density during the first year and was similarly or less effective in the second year; (iv) ivermectin probably could not kill adult worms; (v) a single combined dose of albendazole (400 mg) and DEC (6 mg/kg) was effective to reduce mf density by 85 to nearly 100% 12-24 months after treatment; and (vi) ivermectin or albendazole included in the combination chemotherapy produced "beyond-filariasis" benefits: clearance/reduction of intestinal helminths, and, additionally, in the case of ivermectin, skin-dwelling ectoparasites.The Global Programme to Eliminate Lymphatic Filariasis (GPELF) started its worldwide activities in 2000, with the target of elimination by 2020. The basic strategy is to conduct annual single-dose MDAs for 4-6 years. In 2000-2007, a minimum of 570 million individuals were treated in 48 of 83 endemic countries. The drugs used are DEC 6 mg/kg plus albendazole 400 mg in most countries, or ivermectin 200-400 μg/kg plus albendazole 400 mg particularly in onchocerciasis endemic countries in Africa. (MDAs with DEC alone had been used in India.)The GPELF achieved impressive results in terms of parasitological cure/improvement, clinical benefits, social and economic impacts, etc. However, the most impressive result of all was the programme's success in mobilizing hundreds of millions of local people, who not only took drugs but many of them actively supported MDAs as drug distributors and volunteers. Beyond filariasis, the role people can play in supplementing rural health services is now a topic of discussion and a source of hope for a new sustainable system.     

Two-year follow-up of the microfilaraemia of asymptomatic brugian filariasis, after treatment with two, annual, single doses of ivermectin, diethylcarbamazine and albendazole, in various combinations

Repeated, single, oral doses of combinations of ivermectin, diethylcarbamazine (DEC) or albendazole are recognized as important tools for parasite control in lymphatic filariasis. In order to assess the effects of re-treatment using these combinations in Brugia malayi infections, 40 asymptomatic microfilaraemics were re-treated at the end of the first year, with an additional, single, dose of the combination they had previously received. They were then followed-up for another year. The subjects, of both sexes and aged 14-70 years, each received a two-drug combination: ivermectin (200 micrograms/kg) with DEC (6 mg/kg); ivermectin (200 micrograms/kg) with albendazole (400 mg); or DEC (6 mg/kg) with albendazole (400 mg). The kinetics of microfilarial clearance were similar to that seen during the first treatment, the members of the two groups given DEC having less intense microfilaraemias, 1 year after the re-treatment, than those given ivermectin with albendazole (P < 0.001 for each comparison). At this time, the two DEC groups also had a higher proportion of amicrofilaraemic individuals (22 of 26) than the ivermectin + albendazole group (three of nine). There were fewer adverse reactions in all the groups after re-treatment than seen after the first treatment. In countries such as India, where there is no co-endemicity of onchocerciasis or loiasis, the options for control programmes in areas where brugian filariasis is endemic are DEC alone or DEC in combination with ivermectin or albendazole. Where there is no access to ivermectin, transmission control must be based on DEC alone or in combination with albendazole.     

四川省基本消灭丝虫病后的巩固和监测措施(1982～1996年)

四川省于1979～1983年在秀山县试点取得一个县净化丝虫病的成功经验，并于1982年开始逐步在全省丝虫病流行区推广。30个流行县（市、区）在基本消灭丝虫病后三年内实施巩固措施，经过11—14年病原学、媒介和血清学监测已连续8～14年来检出微丝蚴血症者，9～14年未发现感染人体幼丝虫的蚊媒，纵向监测点人群抗体阳性率接近非流行区人群抗体水平，达到卫生部颁布的消灭丝虫病标准，证实基本消灭丝虫病后的巩固和监测措施适合四川省实际情况。分析认为基本消灭丝虫病后实施巩固措施和进行足够范围的人群横向监测和重点人群监测可较迅速彻底地检出和消除残存传染源，尽快达到消灭丝虫病的标准。     

Efficacy of diethylcarbamazine medicated salt in interrupting Brugia malayi transmission in hill tribe settlements in Kerala State.

A filariasis survey carried out about eight years after achieving zero microfilaria (mf) rates following administration of diethylcarbamazine (DEC) medicated salt in the Kani hill tribe settlements in Quilon and Thiruvananthapuram districts of Kerala State revealed that there was no reappearance of Brugia malayi infection in the experimental areas. Mf rates were maintained at zero level in the experimental villages, while in the control villages, 2.9 per cent mf positives were observed. Mansonia (Mansonioides) uniformis dissected did not reveal filarial infection. It is concluded that DEC medicated salt regime in the experimental areas of Kani hill tribe settlements has been successful in effectively interrupting B. malayi transmission. Pilot studies in other B. malayi endemic areas of India using DEC medicated salt regime with the objective of eliminating B. malayi transmission are advocated, since the parasite has a restricted distribution in India and is already showing a declining trend.     

湖南省基本消灭丝虫病后慢性丝虫病的抽样调查

目的：了解基本消灭丝虫病后慢性丝虫病的患病情况。方法：在原班氏丝虫病流行区、马来丝虫病流行区和两种丝虫病混合流行区的５５个县、市，分层随机抽样调查１２个县（市）１０８个村，对１０岁以上居民进行询问病史和体检。结果：在调查的１１１１２７人中共查见慢性丝虫病患者４７０例，患病率为０．４％，其中象皮肿者１５７例（０．１％）、鞘膜积液者２０８例（０．２％）、乳糜尿者１０５例（０．１％）。基本消灭丝虫病前、后慢性丝虫病患病例数分别为３８６例（０．４％）和８４例（０．０７％）。新患病例原班氏丝虫病流行区７３例（０．１％）；两种丝虫病混合流行区１１例（０．０４％）。结论：湖南省基本消灭丝虫病后马来丝虫病流行区未发现象皮肿新患病例；班氏丝虫病流行区和两种丝虫病混合流行区仍继续出现少数鞘膜积液和乳糜尿新患病例。     

徐闻县消除丝虫病的研究

目的 总结和分析徐闻县消除丝虫病的经验、措施和效果。方法 采用回顾性调查方法,对徐闻县丝虫病的流行分布情况、丝虫病防治试点研究和控制丝虫病的策略和措施及其效果进行总结和分析。结果 1970年徐闻县有94.44％(17/18)的乡镇流行班氏丝虫病,人群微丝蚴率为4.06％(878/216440),传播媒介为致倦库蚊。在流行病学调查的基础上,开展了海群生不同治疗方案治疗丝虫病的疗效,人群微丝蚴率与蚊媒自然感染率的关系及反复查治防治丝虫病的效果等丝虫病防治试点研究,确立了以消灭传染源为主导的策略,采取了反复查治结合重点人群服药的措施。至1986年省级基本消除丝虫病达标考核,人群平均微丝蚴率下降为0.24％。随后采取分层整群监测方法进行监测,1988～1992年病原学监测10个乡镇44个村,微丝蚴率为0.019％;1994年后,病原和蚊媒监测均未发现人体丝虫感染。2000年8月经省审评组审评,达到卫生部消灭丝虫病标准。结论 在流行病学调查和防治试点研究的基础上,采取以消灭传染源为主导的策略和基本消除丝虫病后分层整群的监测方法对消除丝虫病都是切实可行、卓有成效的。     

Comparison of effects of mass annual and biannual single dose therapy with diethylcarbamazine for the control of Malayan filariasis

Annual and biannual mass single dose diethylcarbamazine citrate (DEC) at 6 mg/kg body weight was administered to people in a Brugia malayi endemic area in Shertallai part of Kerala, India, in 1987 and 1988. The coverage of population ranged between 41.33% and 66.01% in different rounds. The highest percentage of treated population developing side reactions was 8.4%. Both annual and biannual regimens were effective in reducing the microfilaria prevalence significantly from 4.90% to 1.23% and from 6.27% to 0.62% respectively and the incidence of infection was minimal in the adult population and zero among children. There was significant reduction in mean microfilaria count in both annual (81.08%) and biannual (98.00%) areas. Marked reduction in the proportion of high density carriers and infectivity index of the population after DEC therapy was also observed. Beneficial effect of mass single dose DEC on clinical cases of filariasis was evident from the reduction in the prevalence of acute manifestations, recent edema cases and the proportion of chronic cases with acute episodes. Results obtained from mass treatment areas were compared with those of the control area.     

湖北省丝虫病监测

湖北省基本消灭丝虫病后１９８９～１９９４年横向监测６９个县（市）的１０９６个村，血检１１１５３０２人，查出微丝蚴血症者１４３人，平均微丝蚴率为０．０１３％，各年微丝蚴率依次为０．０２８％、０．０２５％、０．００８％、０．００６％、０．００４％、０．００２％。解剖致倦库蚊２６７２５只，未发现幼丝虫，解剖中华按蚊３２９６０只，仅１９８９年发现阳性蚊２只，１９９２年发现阳性蚊１只。血清学监测流行区人群平均抗体阳性率为２．０８％～２．７０％，与非流行区抗体水平相近，表明湖北省已有效地阻止了丝虫病的传播。     

湖北省丝虫病纵向监测结果

Aim To find out epidemiological characters of filariasis in original endemic after filariasis basically controlled.In order to provide clear evidence what it is helpful to evaluate works of filariasis control programme,a Longitudinal Surveillance of Filariasis in Hubei Province was conducted form 1989 to 1996.Methods Pathogenesis,vector and serology for filariasis surveillance at 10 trail villages.Results Total of 19 microfilarimiae was found,microfilarial rate were 0.0712% in 1989 and 0.0666% in 1990 and positive rate of mosquite were 0.0455% in1989.0.0199% in 1990 and 0.0211% in 1991 respectively.Antibody rate for filariasis reduce down from 28.57%(1991) to 7.86% (1994).Conclusion Since filariasis has been basically controlled through control programme,microfilarial rate was reducing yearly and microfilarial density was follow down.Residual microfilarimiae of positive has turned to negative during 5 years.It concluded that our control strategies for filariasis measure was efficacious with technology,and achievements gain was successful in Hubei province.lymphatic filariasis could be eradicted in one certain county or city,even in one province via surveillance.     

以嗜人按蚊为主要媒介的马来丝虫病流行区防治后期的流行动态观察

1982年以来,对以嗜人按蚊为主要媒介的马来丝虫病流行区防治后期的流行动态进行了观察。纵向观察8个村,其中3个村于1985、1987、1988年进行普查,微丝蚴率由1.0％下降至0.14％,嗜人按蚊幼丝虫阳性率由0.74％(1984年)降至0.09％(1990年);另5个村于1987、1988年分别普查6148和5496人,1990年复查原微丝蚴血症者368人,未发现微丝蚴阳性,1982—1991年解剖嗜人按蚊17693只和中华接蚊7914只,亦未发现幼丝虫感染蚊。横向监测17个县855个村,9年间(1982—1991)共血检213934人,检出微丝蚴血症56例,其中53例为1986年以前检出,1987、1988年分别检出1例和2例,1989—1991年未再检出微丝蚴血症者。认为通过较大区域的防治使微丝蚴率降至1％以下后,以嗜人按蚊为主的病区,微丝蚴率未见回升,马来丝虫病传播流行呈下降态势。     

湖北省丝虫病纵向监测结果

目的进一步摸清基本消灭丝虫病后原流行区丝虫病流行病学特征,藉以为消灭丝虫病提供科学依据,评价丝虫病防治工作成效。方法在湖北省选择有代表性的丝虫病纵向监测点１０个进行病原学、蚊媒和血清学纵向监测。结果仅于１９８９～１９９０年发现１９例微丝蚴血症者,微丝蚴率分别０．０７１２％和０．０６６６％。蚊媒阳性率为０．０４５５％（１９８９）、０．０１９９％（１９９０）和０．０２１１％（１９９１）。血清学监测抗体阳性率由１９９０年的２８．５７％降至１９９４年的７．８６％。结论原丝虫病流行区经过防治达到基本消灭丝虫病标准后,通过监测人群微丝蚴率逐年下降,微丝蚴密度亦相应降低,残存微丝蚴血症者于基本消灭丝虫病５年内陆续转阴,证明我省基本消灭丝虫病的成果是巩固的,所采取的防治措施是行之有效的。消灭丝虫病于一个县市、一个地区,乃至全省及全国范围内是有望在短期内实现的。     

Mathematical modelling and the control of lymphatic filariasis

The current global initiative to eliminate lymphatic filariasis represents one of the largest mass drug administration programmes ever conceived for the control of a parasitic disease. Yet, it is still not known whether the WHO-recommended primary strategy of applying annual single-dose mass chemotherapy with a combination of two drugs for 4-6 years will effectively break parasite transmission from all endemic communities. Here we review recent work on the development and application of a deterministic mathematical model of filariasis transmission, to show how models of parasite transmission will help resolve the key currently debated questions regarding the ultimate effectiveness of the global strategy to control filariasis. These critical questions include the required duration of mass treatment in different endemic areas, the optimal drug coverage required to meet control targets within prescribed timeframes, the impact and importance of adding vector control to mass chemotherapy regimens, and the likelihood of the development of drug resistance by treated worm populations. The results demonstrate the vital role that integrating these models into control programming can have in providing effective decision-support frameworks for undertaking the optimal design and monitoring of regional and global filariasis-control programmes. Operationally, the models show that the effectiveness of the strategy to achieve filariasis control will be determined by successfully addressing two key factors: the need to maintain high community treatment coverages, and the need to include vector control measures especially in areas of high endemicity.     

广东省阳山县丝虫病防治与监测

目的了解广东省阳山县丝虫病流行情况,总结消除丝虫病的策略及经验,巩固丝虫病的防治成果。方法采取以消灭传染源为主导,反复查治,重点人群服药治疗,全民普服海群生药盐的综合性防治措施控制丝虫病的流行。基本消除丝虫病后继续开展流行病学监测,清除残存传染源,阻断其传播。结果经过反复查治,阳山县微丝蚴率从防治前的4.35%降至0.12%,1980年达到基本消除丝虫病标准,1996年经广东省卫生厅组织评审,确认全县范围已阻断丝虫病传播,达到了消除丝虫病标准。基本消除和消除丝虫病后进行的病原及蚊媒监测,均未发现新的微丝蚴血症者及蚊媒幼丝虫感染。结论阳山县防治丝虫病各项技术措施可行,防治效果和消除丝虫病的远期效果巩固。     

Frequency,severity, and costs of adverse reactions following mass treatment for lymphatic filariasis using diethylcarbamazine and albendazole in Leogane,Haiti, 2000

In October 2000, 71,187 persons were treated for lymphatic filariasis using albendazole and diethylcarbamazine (DEC) or DEC alone in Leogane, Haiti. We documented the frequency of adverse reactions, severity and cost of treatment. Adverse reactions were classified as minor, moderate, or severe. Overall, 24% (17,421) of the treated persons reported one or more adverse reactions. There were 15,916 (91%) minor and 1502 (9%) moderate adverse reaction reports. Men outnumbered women 2:1 in reporting moderate problems. Three patients, representing roughly one in 25,000 persons treated, were hospitalized with severe adverse reactions judged to be treatment-associated by physician review. The cost per person treated for adverse reactions was more than twice the cost per person treated for lymphatic filariasis (dollar 1.60 versus dollar 0.71). Severe adverse reactions to lymphatic filariasis treatment using DEC with or without albendazole are uncommon. Minor and moderate reactions are more commonly reported and their management represents a challenge to lymphatic filariasis elimination programs.