Epidemic situation of imported malaria in Beijing City, 2017 / 中国血吸虫病防治杂志

Objective To explore the epidemic situation and epidemiological characteristics of imported malaria in Beijing City in 2017, so as to provide the evidence for developing malaria control interventions. Methods The data of registered malaria cases were collected and analyzed by using descriptive epidemiological methods. Results A total of 90 malaria cases were reported in Beijing in 2017, and all the cases were imported. The 90 cases included 74 cases of falciparum malaria (82.22%), 10 cases of vivax malaria (11.11%), 4 cases of ovale malaria (4.45%) and 2 cases of malariae malaria (2.22%), and 97.78% of the malaria patients were at ages of 19 to 61 years. Eighty-one cases (90.00%) came back from Africa and 44 cases (48.89%) suffered two or more courses of malaria. Among the 66 patients with disease onset after returning from abroad, 53 cases (80.30%) of falciparum malaria had an onset within two weeks. The patients went to the malaria-endemic areas were mainly because of working (46.34%) or business (41.46%). Eighty-nine cases used mosquito nets while living in malaria-endemic areas and 59 cases used mosquito repellents in addition. Conclusions The prevention and control for imported malaria is still the major target for the surveillance in Beijing City. The highly efficient surveillance system for malaria should be sustained, and the awareness of the disease among migrant workers should be enhanced.

Epidemic situation of imported malaria in Beijing City, 2017 / 中国血吸虫病防治杂志

Objective To explore the epidemic situation and epidemiological characteristics of imported malaria in Beijing City in 2017, so as to provide the evidence for developing malaria control interventions. Methods The data of registered malaria cases were collected and analyzed by using descriptive epidemiological methods. Results A total of 90 malaria cases were reported in Beijing in 2017, and all the cases were imported. The 90 cases included 74 cases of falciparum malaria (82.22%), 10 cases of vivax malaria (11.11%), 4 cases of ovale malaria (4.45%) and 2 cases of malariae malaria (2.22%), and 97.78% of the malaria patients were at ages of 19 to 61 years. Eighty-one cases (90.00%) came back from Africa and 44 cases (48.89%) suffered two or more courses of malaria. Among the 66 patients with disease onset after returning from abroad, 53 cases (80.30%) of falciparum malaria had an onset within two weeks. The patients went to the malaria-endemic areas were mainly because of working (46.34%) or business (41.46%). Eighty-nine cases used mosquito nets while living in malaria-endemic areas and 59 cases used mosquito repellents in addition. Conclusions The prevention and control for imported malaria is still the major target for the surveillance in Beijing City. The highly efficient surveillance system for malaria should be sustained, and the awareness of the disease among migrant workers should be enhanced.

The impact of water level changes on the Oncomelania snail habitats in Poyang Lake regions before and after the impoundment of Three Gorges reservoir / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the impact of the impoundment of Three Gorges reservoir on Oncomelania snail habitats of Poyang Lake.</p><p><b>METHODS</b>Four counties with schistosomiasis endemic around the Poyang Lake, naming as Xingzi, Duchang, Jinxian and Xinjian, were selected as study areas. The average daily water level of four major hydrological stations near the above 4 counties from 1997 to 2008 were collected, as well as the elevation of 215 marshlands with snails in those 4 counties, the data of schistosomiasis endemic situation and snail survey of 4 counties in the year before the impoundment of Three Gorges reservoir (2002) and the 6th year after the impoundment of Three Gorges reservoir (2008). The fluctuations of water levels of Poyang Lake, flooding day of marshland with snails as well as the changes of the indicators in snail survey and prevention and control measures before and after the impoundment of Three Gorges reservoir were compared.</p><p><b>RESULTS</b>Before the impoundment of Three Gorges reservoir, the fluctuations of average water level of the four hydrological stations around Poyang Lake was 6.91-12.93 m; which reduced to 5.72 - 10.75 m after the impoundment. The D-value of the fluctuations of average water level was (1.06 ± 0.47) m. The date of the annual maximum water level delayed by an average of 12 d; while the date of annual minimum water level arrived an average of 12 d earlier than the impoundment of Three Gorges reservoir. The average flooding days of marshland with snails were separately (100.04 ± 42.06) d before the impoundment and (64.13 ± 22.30) d after the impoundment. The difference was statistically significant (t = 3.70, P < 0.05). The density of snails in the 4 counties around Poyang Lake was 0.8437/0.1 m(2) after the impoundment; declining by 31.04% from the snail density (1.2234/0.1 m(2)) before the impoundment. The density of infectious snails was 0.0014/0.1 m(2) after the impoundment; dropping by 67.34% from it (0.0042/0.1 m(2)) before the impoundment; the infection rate of snails was separately 0.34% after the impoundment and 0.16% before the impoundment. The difference was statistically significant (χ(2) = 53.25, P < 0.05). The coverage rate of chemotherapy increased from 4.45% (35 558/798 200) in 2002 to 9.80% (79 457/810 400) in 2008; the difference was statistically significant (χ(2) = 17 336.63, P < 0.05). The coverage rate of snail killing increased from 1.35% (389.04/28 824.66) in 2002 to 7.49% (2260.90/30 166.22) in 2008; the difference was also statistically significant (χ(2) = 28 824.66, P < 0.05).</p><p><b>CONCLUSION</b>The impact of the impoundment of Three Gorges reservoir shortened the flooding days of marshland with snails and helped the prevention and control of schistosomiasis in Poyang Lake regions as the environment went against the breeding of the snails.</p>

Epidemiological characteristics and molecular typing of Salmonella in Beijing from 2008 to 2009 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the epidemiological characteristics and molecular phenotypes of Salmonella by pulsed-field gel electrophoresis (PFGE) in Beijing from 2008 to 2009.</p><p><b>METHODS</b>A total of one hundred thirty-seven isolates recovered from the WHO Global Salmonella Surveillance system and entero clinic surveillance system were identified by biochemical tests and serotyping. The related epidemiological informations were also analyzed. The isolates were further typed by PFGE.</p><p><b>RESULTS</b>The prevalence of Salmonella from 2008 to 2009 showed obvious seasonal character. High incidence occurred from June to September, and 64.1% (84/131) isolates were recovered in this period. Patients of 18 - 40 year-old were 46.1% (58/128) and 80 patients were male and 40 patients were female with the ratio of 1.57:1. These 137 Salmonella isolates belonged to 20 serotypes, including Enteritidis (46.7%, 64/137) and Typhimurium (17.5%, 24/137) as the dominant serotype. In total, 71 PFGE profiles were identified. Four PFGE patterns of S. Enteritidis isolates (JEGX01.CN0001, JEGX01.CN0003, JEGX01.CN0002, JEGX01.CN0019) and S. Typhimurium pattern of JPXX01.CN0001 were dominant patterns.</p><p><b>CONCLUSION</b>The prevalence of Salmonella from 2008 to 2009 showed distribution characteristics of sex, age and seasons. The numerous PFGE patterns of Salmonella showed diversity of these isolates and different clones existed in Beijing.</p>

Effects of land surface temperature on supervising the existing area of snails / 中华预防医学杂志

<p><b>OBJECTIVE</b>To discuss the land surface temperature's effect on supervising the areas with snails, comparing the land surface temperature (LST) of the areas with snails with the LST of those without snails.</p><p><b>METHODS</b>Choosing the lake areas of farmland in Jiangxi Province and the beach in the bank of Ganjiang, dividing into four areas according to snails. Picking up the normalized difference vegetation index (NDVI) and LST from the remote sensing data to find the difference between the areas with snails and the areas without snails, so as to illuminate the effects of the LST on distinguishing the areas with snails.</p><p><b>RESULTS</b>The NDVI of Dongfeng Wei (an area from farmland to lake) was 0 - 0.20, the NDVI of the areas with snails was 0.20 - 0.40. The NDVI of four areas is different (chi(2) = 104.69, P < 0.01). The LST of Dongfeng wei was 24 - 30 degrees C, Wuzhoutou without snails is 23 - 28 degrees C, Wuzhoutou with snails is 22 - 26 degrees C, Changjiangzhou was 20 - 24 degrees C. The LST of four areas is different (chi(2) = 115.23, P < 0.01). The analysis farther indicates the NDVI of areas without snails was lower than that of areas with snails, but the LST was higher.</p><p><b>CONCLUSION</b>The NDVI and (or) the LST should be significantly different between the areas with snails and the areas without, it might be concluded that the LST should be a indication to some extent on judging whether some areas may be fit for snails.</p>