Characteristics of Imported Malaria and Species of Plasmodium Involved in Shandong Province, China (2012-2014).

Malaria remains a serious public health problem in Shandong Province, China; therefore, it is important to explore the characteristics of the current malaria prevalence situation in the province. In this study, data of malaria cases reported in Shandong during 2012-2014 were analyzed, and Plasmodium species were confirmed by smear microscopy and nested-PCR. A total of 374 malaria cases were reported, 80.8% of which were reported from 6 prefectures. Of all cases, P. falciparum was dominant (81.3%), followed by P. vivax (11.8%); P. ovale and P. malariae together accounted for 6.4% of cases. Notably, for the first time since 2012, no indigenous case had been reported in Shandong Province, a situation that continued through 2014. Total 95.2% of cases were imported from Africa. The ratio of male/female was 92.5:1, and 96.8% of cases occurred in people 20-54 years of age. Farmers or laborers represented 77.5% of cases. No significant trends of monthly pattern were found in the reported cases. All patients were in good condition after treatment, except for 3 who died. These results indicate that imported malaria has increased significantly since 2012 in Shandong Province, especially for P. falciparum, and there is an emergence of species diversity.

[Genetic Variation of Oncomelania hupensis in Weishan Lake of Shandong Province Using Microsatellite DNA Markers].

Objective: To identify the genetic variation of Oncomelania hupensis between Weishan Lake population and Yangtze River population. Methods: O. hupensis snails were collected from Jiangdu District of Yangzhou City, Yizheng City, Danyang City, and Liuhe District of Nanjing City in Jiangsu Province, as well as Weishan Lake of Jining City in Shandong Province. Four polymorphic microsatellite DNA loci（A18, C22, T4-33 and T6-17） were amplified by using microsatellite PCR to analyze the number of alleles （Na）, the expected heterozygosity （He）, the observed heterozygosity （Ho） and the average number of pairwise differences between populations. Analyses of molecular variance (AMOVA) and cluster analysis were performed to find the genetic variation between O. hupensis snail populations. Unweighted pair group method with arithmetic mean （UPGMA） and neighbour joining (NJ) method were used to construct the phylogenetic tree to describe genetic variation and clustering among populations. Mantel test was carried out to detect the correlation between the genetic distance and geographical distance. Results: A total of 103 snails were collected. The snail populations of Jiangdu, Yizheng, Danyang, Liuhe, and Weishan Lake had Na of 7.50, 12.50, 10.00, 11.50; Ho of 0.16, 0.27, 0.17, 0.30, 0.22; and He of 0.81, 0.91, 0.84, 0.90, 0.92, respectively. The Weishan Lake population showed relatively higher levels of the three indicators, indicating a higher genetic diversity, but with no significant difference with the other four populations. The average number of pairwise differences was lowest between the Weishan Lake and Jiangdu populations（0.79）, and it was higher between Danyang population and the others（0.87-0.97）. AMOVA result showed the inter-individual genetic variation accounted for 92.50% of the total variations. NJ and UPGMA analysis showed Jiangdu and Weishan Lake populations gathered together in one branch, Yizheng and Liuhe populations formed another relatively independent branch, and then was Danyang population. Genetic distance and geographical distance showed no correlation by Mantel test. Conclusion: There is a high genetic diversity of O. hupensis in Weishan Lake and Yangtze River populations, and no significant genetic divergence between Weishan Lake snail population and its original Yangtze River population.

[Application of Nested PCR in the Diagnosis of Imported Plasmodium Ovale Infection].

OBJECTIVE: To identity Plasmodium ovale infection by 18S rRNA gene nested PCR. METHODS: Whole blood and filter paper blood samples of malaria patients in Shandong Province were collected during 2012-2013. The parasites were observed under a microscope with Giemsa staining. The genome DNA of blood samples were extracted as PCR templates. Genus- and species-specific primers were designed according to the Plasmodium 18S rRNA gene sequences. Plasmodium ovale-positive specimens were identified by nested PCR as well as verified by sequencing. RESULTS: There were 7 imported cases of P. ovale infection in the province during 2012-2013. Nested PCR results showed that the P. ovale specific band (800 bp) was amplified in all the 7 specimens. Blast results indicated that the PCR products were consistent with the Plasmodium ovale reference sequence in GenBank. CONCLUSION: Seven imported cases of ovale malaria in Shandong Province in 2012-2013 are confirmed by nested PCR.

[Epidemiological analysis of malaria prevalence in Shandong Province in 2014].

OBJECTIVE: To understand the malaria epidemic situation and characteristics in Shandong Province in 2014, so as to provide evidences for taking targeted strategies and measures for malaria elimination. METHODS: The data of malaria epidemic and malaria cases of Shandong Province in 2014 were collected from Information Management System for Infectious Diseases Report and Information Management System for Parasitic Diseases Control and Prevention. The epidemiological characteristics of malaria situation and the diagnosis and treatment of malaria cases were analyzed by Microsoft Excel 2007. RESULTS: A total of 150 malaria cases were reported in Shandong Province in 2014, which increased by 14.50% compared with that in 2013 (131 cases). All the cases were imported from other countries except one imported from Yunnan Province in China, and most of the imported cases were from Africa (142 cases, 95.30%). All the cases were confirmed in Shandong Provincial Reference Laboratory and there were 121 cases (80.67%) infected with Plasmodium falciparum, 16 cases (10.67%) infected with P. vivax, 9 cases (6.00%) infected with P. ovale and 4 cases (2.67%) infected with P. malariae. The cases were mainly distributed in Tai'an (40 cases, 26.67%), Yantai (17 cases, 11.33%), Weihai (13 cases, 8.67%), Jining (11 cases, 7.33%) and Heze (11 cases, 7.33%) cities. CONCLUSIONS: There have been no local malaria cases reported in Shandong Province in the continuous 3 years. However, the reported number of imported malaria cases shows an increasing trend in the province in recent years, and the species of infected Plasmodium are diverse. Imported malaria from other countries is the key of malaria control in Shandong Province at present.

[Survey of infection situation of intestinal parasites of rural residents in plain area of Shandong Province].

OBJECTIVE: To understand the current situation of infections of intestinal parasites of rural residents in four cities namely Dongying, Weifang, Jining and Heze of Shandong Province. METHODS: Twenty-four villages were randomly selected as study areas. The Kato-Katz technique was applied to test the stool samples of adult residents and the cellophane tape anus method was applied to test the infection of Enterobius vermicularis of children aged 12 years or below. Fifty families were randomly selected from each village and surveyed with questionnaires for the general situation of the family, and the knowledge of prevention and control of parasites, and healthy behaviors of the family members. RESULTS: Totally 8,227 adult residents and 1,313 children were investigated and the total infection rate of intestinal parasites was 0.55% (45 cases). The infection rates of Ascaris lumbricoides, hookworm, Trichuris trichura, E. vermicularis and Clonorchis sinensis were 0.15% (12 cases), 0.06% (5 cases), 0.09% (7 cases), 1.37% (18 cases) and 0.04% (3 cases), respectively. Totally 3,767 residents were surveyed with questionnaires, and the awareness rate of the knowledge of prevention and control of parasites was 28.72% (1,082 cases), the formation rates of washing hands before meal, washing hands after toilet, washing fruit and vegetables before eating, and never drinking unboiled water were 60.66% (2,285 cases), 50.17% (1,890 cases), 48.71% (1,835 cases), and 87.07% (3,280 cases), respectively. CONCLUSION: In the plain area of Shandong Province, the infection rates of A. lumbricoides, hookworm, T. trichura and C. sinensis are low but the infection rate of E. vermicularis of children is relatively high; the awareness rates of the knowledge of parasites as well as the formation rates of healthy behaviors are low. Therefore, the health education and promotion should be strengthened.

[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.

[Analysis of malaria situation and discussion of control strategy in Shandong Province, 2013].

OBJECTIVE: To understand the malaria situation of Shandong Province in 2013, so as to provide the evidence for formulating targeted prevention and control strategy and measures. METHODS: The data of malaria cases of Shandong Province in 2013 were collected from the Information Management System for Infectious Diseases Report and Information Management System for Parasitic Diseases Control and Prevention. The data of epidemiological characteristics of malaria situation and the diagnosis and treatment of malaria cases were analyzed by Microsoft Excel 2007. RESULTS: There were 131 malaria cases reported in 2013, all of them were imported cases, and 127 cases (96.95%) were imported from African countries. A total of 116 cases (88.55% ) were falciparum malaria cases. Totally 97.71% of the cases were male and the average age of malaria cases was 39 years. A total of 61.83% of the cases were peasants and 65.65% of the cases only received junior high school education. The distribution of malaria cases was concentrated in Tai'an City (32 cases), Yantai City (19 cases) and Weihai City (17 cases),totally acounting for 53.13%. There was no significant seasonal variation in the reporting time of the cases. The median time from on- set to seeing doctor was four days and the median time from seeing doctor to being diagnosed was one day. Totally 35.88% of the cases were misdiagnosed when the first visit to a doctor. All of the cases were laboratory confirmed and 100% of them received the standard treatment after diagnosis. CONCLUSIONS: All of the malaria cases were imported cases in Shandong Province in 2013. To control the imported malaria in Shandong Province, it is necessary to further strengthen the multi-sectoral cooperation, health education, malaria screening and professional training.

[Large trophozoites in blood smear of falciparum malaria: one case report].

This paper reports one case of atypical falciparum malaria imported from Africa, whose blood smear contains many large trophozoites, with punctiform or massive brown pigment granules, the body shape of the plasmodium is similar to that of Plasmodium vivax and Plasmodium ovale. After the gene detection by PCR, the case was diagnosed as falciparum malaria. As large trophozoites were rarely seen in the peripheral blood of non-severe falciparum malaria cases, much attention should be paid to the identification of Plasmodium falciparum and other plasmodia in microscopic examinations.

[Survey of infections of intestinal parasites and related factors in north-west Shandong Province].

OBJECTIVE: To understand the infection status of intestinal parasites and related knowledge and behavior factors of the residents in north-west Shandong Province, so as to provide the evidence for taking targeted preventive measures. METHODS: Eighteen villages were randomly selected as survey spots by the stratified multi-stage sample method. The Kato-Katz technique was used to detect intestinal parasite eggs among the residents and the cellophane tape anus test was used to detect Enterobius vermicularis eggs among 3-12 years old children. Questionnaires were applied to investigate related knowledge and behavior factors about the intestinal parasite infections in the residents. RESULTS: Totally 6 366 residents were detected for intestinal parasites and the infection rate was 0.28% (18 cases). Totally 895 children were detected for E. vermicularis and the infection rate was 5.70% (51 cases). Totally 2 915 residents were investigated by questionnaires and the awareness rate of knowledge about preventing parasitic diseases was 26.72%. The formation rates of washing hands before meal and after WC, washing fruit and vegetable before eating, never drinking unboiled water were 55.42%, 42.87%, 43.54% and 83.04% respectively. The awareness rate of knowledge about preventing parasitic diseases of 3-12 years old children was 12.24%; and the formation rates of washing hands before meal and after WC were 47.04% and 30.44% respectively. CONCLUSIONS: The total infection rate of intestinal parasites is low but the E. vermicularis infection rate is high among children in north-west Shandong Province. The awareness rate of knowledge about preventing parasitic diseases and the formation rates of healthy behaviors are all low. Therefore, the targeted health education should be taken to increase the awareness rate and guide the residents to develop their healthy behaviors.

[Investigation on awareness status of malaria control knowledge of primary and secondary school students in Shandong Province].

OBJECTIVE: To understand the awareness status of malaria control knowledge of primary and secondary school students in malaria endemic areas of Shandong Province, so as to provide the baseline information for formulating the malaria control strategy. METHODS: A cross-sectional survey was conducted in 5 Type II malaria-endemic counties in Shandong Province. A structured questionnaire survey was administrated to students in primary and secondary schools. RESULTS: A total of 1 884 students were completed with the questionnaires and all were effective. The total awareness rate of malaria control knowledge was 65.9%, and 54.7% of the students knew the transmission route of malaria and only 31.5% of the students were aware of the preventive methods of malaria. There were significant differences of the awareness scores of malaria control knowledge among different malaria endemic areas but there were no significant differences between the awareness rates of male and female students and between two different education levels. CONCLUSIONS: The awareness of malaria control knowledge of primary and secondary school students in Shandong Province is poor; therefore, the health education of malaria control knowledge for primary and secondary school students should be strengthened.

[Survey of intestinal parasitic infections and related knowledge and behavior of residents in Jiaodong area of Shandong Province].

OBJECTIVE: To understand the status of intestinal parasitic infections and the related knowledge and behavior in residents of Jiaodong area of Shandong Province, so as to provide the evidence for making an appropriate preventive and control strategy. METHODS: A total of 18 villages from 6 counties in Jiaodong area were selected as investigation sites according to the stratified sampling method. The feces samples of the permanent residents aged above 3 years were collected and examined by Kato-Katz technique to find the intestinal parasite eggs, and the children under 12 years old were examined by the method of cellophane anal swab to detect the Enterobius vennrmicularis eggs. In addition, 50 households in each survey sites were randomly selected to investigate the basic family situation and the condition of awareness on prevention knowledge and formation of correct behavior of residents by using a structured questionnaire. RESULTS: Totally 6 163 residents involved in the feces examinations, and the total infection rate of intestinal parasites was 6.91%. The infection rates of Trichuris trichiura, Ascaris lumbricoides and hookworm were 6.56%, 0.62% and 0.21%, respectively. The infection rate of E. vermicularis in children under 12 years old was 0.51%. The eggs of Clonorchis sinensis and Taenia solium were not found in this survey. The awareness rate of knowledge about preventing parasitic diseases was 49.54%. The formation rates of washing hands before eating, washing hands after using the toilet, never eating raw fruit and vegetable without washing clean, never working in the field with bare feet, and never drinking unboiled water were 97.78%, 91.95%, 88.81%, 92.42% and 86.48% respectively. CONCLUSIONS: The infection rate of intestinal parasites is low in Jiaodong area, but there is a significant difference among different counties. The awareness rate of knowledge about preventing parasitic diseases is low, but the formation rate of healthy behavior is high. In the future, the health education and the strategy of taking medicine among the key population should be enhanced, and the project of reconstructing safe water supply and lavatory should be advanced.

[Analysis of results of technique competition for diagnosis of parasitic diseases in Shandong Province].

OBJECTIVE: To understand the capacity of Plasmodium detection and helminth detection and the mastery degree of basic knowledge of parasitic diseases. METHODS: Three professionals from each city were selected as contestants. The content of the competition contained three parts. The first part included making blood slides and Giemsa staining of Plasmodium, and identification of species and number with microscopy, the second part included making stool slides with Kato-Katz technique and identification of common helminth eggs with microscopy, and the third part was basic knowledge of parasitic diseases. RESULTS: Totally 51 contestants took part in the competition. The average score of the test of making blood slides was 14.8 +/- 3.3, and the passing rate was 82.4%. The average score of the identification of species and number of Plasmodium with microscopy was 19.2 +/- 9.3, and the passing rate was 29.4%. The average score of the test of making stool slides was 9.3 +/- 0.7, and the passing rate was 100%. The average score of the identification of common helminth eggs with microscopy was 28.0 +/- 2.6, and the passing rate was 100%. The average score of basic knowledge of parasitic diseases was 76.3 +/- 11.9, and the passing rate was 88.2%. The average score of the test of making blood slides in the female was higher than that in the male (15.7vs.13.5, P < 0.05), and the average score of the test of making blood slides in the intermediate title contestants was higher than that in the junior title contestants (16.1 vs.14.1, P < 0.05). The average score of the basic knowledge of parasitic diseases in the contestants from cities was higher than that in the contestants from towns (83.2 vs. 72.6, P < 0.05), and the average score of basic knowledge of parasitic diseases in the contestants from high economic level cities was higher than that in the contestants from low economic level cities (82.4 vs. 71.5, P < 0.01). CONCLUSIONS: For professionals in Shandong Province, the capacity of helminth detection was strong and the basic knowledge of parasitic diseases was mastered well, while the capacity of Plasmodium detection was weak.

[Epidemiological analysis of malaria prevalence in Shandong Province in 2012].

OBJECTIVE: To understand the characteristics of malaria prevalence and epidemic in Shandong Province in 2012 so as to provide the evidence for improving the work of the elimination of malaria. METHODS: The epidemiological data of malaria cases collected from the Disease Surveillance Information Reporting System of Chinese Center for Disease Control and Prevention were analyzed with the descriptive epidemiological method for epidemiological characteristics of malaria. RESULTS: A total of 93 malaria cases were reported in Shandong Province in 2012 with the incidence of 0.097 per 100 thousand, with a reduction of 19.83% as compared to 2011. There were 93 imported cases which decreased by 4.12% compared with 97 cases in 2011 and it was the first year that there was no local infection. Jining, Qingdao and Weihai cities reported more cases, with 62.37% (58/93) of the total number of the whole province. Totally 93.55% of malaria cases were imported from Africa, most from Equatorial Guinea, Nigeria and Angola. There were 3 cases of imported ovale malaria firstly reported. CONCLUSIONS: There were no local malaria cases reported in Shandong Province in 2012, but the imported malaria prevention and control was still not optimistic. In order to achieve the goal of malaria elimination in Shandong Province, it needs to continue to strengthen epidemic management, professional training and work supervision, strengthen management, advocacy and detection on the floating population, and explore multisectoral coordination mechanisms.

[Analysis of malaria endemic situation in Shanxian County from 2002 to 2011].

OBJECTIVE: To analyze the endemic situation of malaria in Shanxian County, Shandong Province, China in the last 10 years, so as to understand the epidemiological characteristics of the disease and provide the evidence for the establishment of control strategy to eliminate malaria. METHODS: The data related to the endemic situation of malaria in Shanxian County from 2002 to 2011 were collected and analyzed. RESULTS: From 2002 to 2011, 125 cases of malaria were reported, and the annual incidences were in the range of 0.18/100,000-2.00/100,000. Totally 60.80% of the cases focused on 3 townships, namely Fugang, Huanggang and Caozhuang. All the 125 cases were new vivax malaria cases, among them, 121 were locally infected, and the other 4 were imported. The epidemic season was from June to October, and the peak time was from July to September. There were more male cases than female cases. The ages of the cases were from 1 to 83 years old, and the incidence in those aged from 46-60 years old was higher. CONCLUSIONS: The malaria incidence in Shanxian County is on the rise, and the 3 townships in the south are the key areas for control. The control measures including the surveillance of floating population and mosquitoes, and malaria control health education should be strengthened.

[Effects of integrated malaria control measures in Shandong Province, 2010].

A total of 117 malaria patients were reported in Shandong Province, 2010 and the annual incidence was 0.13 per hundred thousand. Totally 23 cases of malaria were reported in Shanxian County, which was the most; and 6 patients who came back from Africa were reported in Daiyue County, which was the second. A total of 296 230 fever patients were examined with blood tests, and the positive rate was 0.03%. Totally 101 diapause patients were administered with medicine, and the administered rate was 95.28% and the regular administered rate was 100%. For the present patients, the regular administered rate was 100%. There were 73 malaria epidemic foci and they were all treated, and the area of residual spraying was 51.98 hm2. The malaria epidemic was steady declined in Shandong Province. Although the prevention and control work achieved desired results, the monitor for mobile population and mosquitoes still should be strengthened to prevent the malaria epidemic increasing or outbreak.