Epidemic characteristics and viral antibody level among healthy people of Japanese B encephalitis in Henan province in 2010 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To understand the epidemic characteristics and viral antibody level among healthy people of Japanese B encephalitis (JE) in Henan province in 2010.</p><p><b>METHODS</b>A total of 433 selected JE cases in Henan province in 2010 were analyzed by descriptive epidemiological method. Xinyang and Luoyang were selected as survey sites in 2010.12 administrative villages were randomly selected from both cities. As the investigation objects, 519 healthy people from the two cities were randomly selected by eight age groups:less than one year old, 1 - 2 years old, 3 - 4 years old, 5 - 6 years old, 7 - 14 years old, 15 - 19 years old, 20 - 59 years old, and above 60 years old. A total of 1008 samples of blood specimens were collected both in May and November, and JE viral antibody was detected by micro-cytopathic effect neutralization test.</p><p><b>RESULTS</b>The incidence rate of JE was 0.46/100 000 (433/94 130 434) in Henan province in 2010.97.69% (423/433) of the patients were found between July and September, and 81.06% (351/433) were distributed in Nanyang, Xinyang, Luoyang, Zhumadian and Zhoukou city. Children aged 0 to 14 years were the primarily affected group (82.22%, 356/433), the people above 15 years old accounted for 17.78% (77/433) of whole cases in Henan province, but the same group accounted for 65.79% (50/76) of whole cases in Luoyang city, which obviously higher than the percentage in Henan province (χ(2) = 79.57, P < 0.05). Most patients were scattered children in Henan province, accounting for 58.89% (255/433). In Luoyang city, most patients were peasants, accounting for 44.74% (34/76). The antibody positive rate of JE among health people above 15 years old in Luoyang city was 48.94% (46/94), which was lower than it in Xinyang city at 97.78% (88/90). The difference showed statistical significance (χ(2) = 55.42, P < 0.05). The antibody positive rate among healthy people under vaccination was 50.41% (61/121), which was obviously higher than that among people without vaccination, at 16.67% (6/36) in Luoyang city. The difference showed statistical significance (χ(2) = 12.92, P < 0.05). The antibody positive rate among healthy people under vaccination was 67.11% (51/76) in Xinyang city, which was obviously higher than that among people without vaccination, at 46.39% (45/97). The difference showed statistical significance (χ(2) = 7.40, P < 0.05).</p><p><b>CONCLUSION</b>The incidence of JE showed seasonal and regional characteristics, there were differences among ages and occupations. The difference was consistent with the difference in viral antibody level among health people in Henan province and Luoyang city.</p>

Surveillance of healthy people's Japanese encephalitis neutralizing antibody in some areas of Henan Province / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To analyze the prevalence characteristics and influence factors of Japanese encephalitis (JE) neutralizing antibody in healthy people.</p><p><b>METHODS</b>Xinyang and Luoyang is the two cities in Henan Province. In 2010, healthy people of these two cities were selected by random sampling method to eight age groups: less than one year old, 1 -2 years old, 3 -4, 5 -6, 7 -14, 15 -19, 20 -59,and above 60 years old, their blood specimens were collected in May before JE infection and in November after JE infection, then followed with epidemiological investigation for JE neutralizing antibody by MCPENT.</p><p><b>RESULTS</b>519 healthy people were surveyed, 1008 effective blood specimens were collected and tested. The JE neutralizing antibody positive rate was 59.52% in men, and 67.39% in male, these two rates had no statistical significance (chi2 = 3.41, P > 0.05). The JE neutralizing antibody was 58.66% in May, and 61.20% in November, these two rates had no statistical significance (chi2 = 0.68, P > 0.05). The JE neutralizing antibody positive rate of 0 - 14 years old age group was 55.19% in Xinyang, and 45.03% in Luoyang,these two rates had no statistical significance (chi2 = 3.53, P > 0. 05). The JE neutralizing antibody positive rate of above 15 years old age group is 97.78% in Xinyang,and 48.94% in Luoyang, these two rates had statistical significance (chi2 = 55.42, P < 0.05). The JE neutralizing antibody positive rate of JE vaccination was 56.85%, and 38.35% in no JE vaccination, these two rates had statistical significance (chi2 = 10.88, P < 0.05).</p><p><b>CONCLUSION</b>The JE neutralizing antibody positive rate was showing significant differences in people above 15 years old between Xinyang and Luoyang. The JE neutralizing antibody positive rate was showing significant differences between JE vaccination and no vaccination. Xinyang and Luoyang City, recommended strengthening the 0 - 14 year-olds immunized, and at the same time, exploring and paying attention to JE immunization strategy of people above 15 years old in Luoyang.</p>