Elimination of Lymphatic Filariasis in Shandong Province, China, 1957-2015.

China used to be one of the most heavily endemic countries for lymphatic filariasis (LF) in the world. Bancroftian filariasis, which is caused by the filarioid nematode Wuchereria bancrofti, is the only filariasis in Shandong Province. A total of 864 endemic counties (cities) in 16 provinces/autonomous regions/municipalities with a total population of 330 million people were at risk of infection. Shandong Province was a highly LF-endemic area in the 1950s, the epidemiological investigation of LF conducted in 1957 indicated that the disease was endemic in 74 counties and the highest microfilaria rate was up to 26%. There were ∼5 million people in the province infected with LF; among which almost 2.5 million people had lymphedema, elephantiasis, or hydrocele. Through vigorous prevention and scientific research, Shandong Province was the first to propose to treat LF with fortified diethylcarbamazine salt, more than 25 million people in the province had taken the salt, and more than 3 million people took intermittent medication. After more than 50 years of unremitting efforts, Shandong Province basically eliminated LF in 1983 and became the first province in China that successfully eradicated LF in 2004, which has played an important role in accelerating the elimination of filariasis in the country in 2007 and has made tremendous contributions to social and economic development of China. Since 1980, Shandong Province has carried out extensive international cooperation as the WHO Collaborating Center for Lymphatic Filariasis. This article is intended to share the experience in eliminating LF to other parts of the world and improve public health capacity in regions such as Africa and Oceania where the disease is still endemic for interest.

Review of the control of clonorchiasis in Shandong Province, China from 1962 to 2015.

OBJECTIVES: The aim of this study was to investigate the epidemic scope, epidemic pattern and degree of damage of clonorchiasis as well as to summarize the diagnosis and control effect of clonorchiasis in Shandong Province, China. METHODS: A retrospective study was conducted to summarize the research on the dynamic epidemiology and the prevention and treatment measures of clonorchiasis in Shandong Province, China from 1962 to 2015. RESULTS: After unremitting efforts and three nationwide surveys on the distribution and infection of human parasites, the infection rate of clonorchiasis decreased from 1.51% (1,500, 000) in the1960s to 0.16% in 1991, 0.04% in 2000 and 0.007% in 2015, respectively. The infection rate for villages with perennial water accumulation and rainy season water accumulation was higher than that of villages with rainy season water accumulation and non-water accumulation. The egg flotation in 70% potassium iodide solution method was applied to accurately test the specific proportion of C. sinensis eggs, which was 1.42. Using the modified Kato thick smear method, the detection rate of eggs was over 98%; hexachloroparaxylene yielded satisfactory therapeutic effects with slight adverse reactions, it is effective in the treatment of clonorchiasis. CONCLUSIONS: After 50 years of active prevention and treatment, the disease has been successfully controlled in Shandong Province and had been used for reference in other endemic areas of clonorchiasis in China.

[Study on shell shape changes of filial generation Oncomelania hupensis snails in Weishan Lake region, Shandong Province].

OBJECTIVE: To explore the shape change characteristics of Oncomelania hupensis snail shell after the snails being passively migrated into Shandong intake area of the South-to-North Water Diversion Project. METHODS: The snails raised on the Dushan island in Weishan Lake region were captured, and 115 the first filial generation snails and 107 the second filial generation ones were selected. The length and width of shells and apertures, and the labial ridge thickness of those snails were measured, the longitudinal rib number of snail spiral was counted, and 107 parental snails were chosen as controls. RESULTS: The labial ridge thickness of the filial generation snail was significantly reduced with the increase of algebras, and the labial ridge thickness among the 3 generations had a significant difference (P < 0.01). Both the length of snail shell and the width of snail apertures were decreased, while the width of snail shell, the length of snail apertures, the multiplication product of snail aperture's length and width and the longitudinal rib number of snail spiral were all increased. CONCLUSION: The body size of Oncomelania snails in Weishan Lake region becomes smaller, and their shells become thinner, which indicates that the environment of the lake region is not suitable for snail breeding, and the snails have natural decay tendency with the extension of time.

[Control strategy and practice of soil-transmitted parasitic diseases in Shandong Province].

OBJECTIVE: To explore the sustainable development control strategies on soil-transmitted parasitic diseases appropriate to current epidemic characteristics so as to effectively reduce the epidemic level and harm to people in Shandong Province. METHODS: This project was led by the Shandong Medical Department, governed and instructed by the Shandong Institute of Parasitic Diseases, concretely implemented by the centers for disease control and prevention in counties or cities. All the work was carried out according to the Control Programming of National Key Parasitic Diseases, and with the combination of routine and key control strategies according to the actual situation. RESULTS: The average infection rate of soil-transmitted parasitic diseases in Shandong Province was 18.26% in 2003. During the 2007 to 2009 period, 3,115,194 people from 74 counties in 9 cities received anthelmintic medicine. The numbers receiving health education were 39 866 923 in county, 34,730,663 in city, 3,2000 in province, respectively. The coverage rate of non-hazardous sanitary latrines was 58.05%. In 2009, 6,581 people were surveyed from 7 counties or cities and the infection rate of soil-transmitted parasitic diseases was 7.61%. During three years, 30 provincial training classes were held and 2,130 people attended, 52 municipal classes were held and 3110 people attended, and 403 county classes were held and 12,789 people attended. In the whole province, the infection rate of soil-transmitted parasitic diseases reduced to 7.10% in 2009, with the reduction rate of 61.12%, reaching the national objective. CONCLUSIONS: The comprehensive control model for soil-transmitted parasitic diseases is very successful in Shandong Province.

[Epidemiological study on taeniasis and cysticercosis in Shandong Province].

OBJECTIVE: To investigate current epidemiological status of Taenia solium infection and cysticercosis in Shandong Province. METHODS: By house to house interview in the field, fecal examination and serological tests, the prevalence data of taeniasis and cysticercosis in human and pig population, and epidemiological factors in relation to the diseases were carried out. RESULTS: The prevalence of Taenia infection and cysticercosis in human population were 0.048% and 0.057% respectively. The sero-positive rate of the specific IgG4 of anti-Cysticercus was 1.91%. The prevalence differed among occupations and from region to region, but there was no significant difference between men and women, city and suburb. Unhealthy eating and unhygienic habits commonly practised among residents, 92.3% of the families have "latrines connected to pigsties". The surrounding sanitation and the disposal of fecal material were poor. The detection rate of porcine cysticercosis was 0.06%, and the positive rate of anti-Cysticercus antibody in pigs was 1.99%. CONCLUSION: The prevalence of taeniasis and cysticercosis is decreasing. However, the endemic area is expanding and the epidemiological factors are still existing. Continued effort is therefore needed for sustain the control programme.