Current status of Japanese encephalitis in Japan

Japanese encephalitis (JE) cases confirmed by serological and/or virological tests, and clinically typical fatal JE cases have been collected using individual report cards in Japan since 1965. A total of 324 confirmed cases (male: 167, female: 157) reported between 1982 and 1996 were analyzed. Annual incidence of JE cases was less than one hundred cases from 1982 to 1991, and less than 10 cases after 1992. Age distribution of the patients was: 0-9 years old, 43 cases (13%); 10-39 years old, 30 cases (9%); 40-69 years old, 161 cases (50%); over 70 years old, 90 cases (29%). The highest incidence in male cases was observed in the age group of 50-59 years, and that in female was in 60-69 years. Most of the patients (95%) were living in the western parts of Japan. No patient was reported from Okinawa, southern-most prefecture of Japan, and from Tohoku-Hokkaido area, northern parts of Japan. The date of onset were distributed from the end of July to the end of October, and the highest incidence was observed in the end of August. Prognosis of the patients were: complete recovery, 99 cases (31%); sequelae, 156 cases (48%); total, 56 cases (17%); unknown, 13 cases (4%). Vaccination histories of patients were reported as vaccinee, 4 cases (1%); incomplete vaccinee, 14 cases (4%); non-vaccinee, 181 cases (56%); unknown, 125 cases (39%). Spread of JE virus in Japan has not been diminished as shown by the data of antibody acquisition of young swine in every summer in Japan. Based on these observations we conclude that JE vaccination has contributed to maintaining the low JE incidence among children in Japan.     

Surveillance for Japanese encephalitis in Vietnam, 1998-2007

Japanese encephalitis (JE) is recognized as an important public health problem in Vietnam. A JE immunization program was introduced in 1997 in high-risk districts and expanded to additional districts over subsequent years. We reviewed national acute encephalitis syndrome (AES) surveillance data for 1998-2007 and analyzed more detailed data regarding JE from five northern provinces in 2004 and 2005. The annual reported incidence of AES in Vietnam ranged from 3.0 to 1.4 cases per 100,000 population with a decreasing trend over the 10-year period. The mean annual incidence of AES was highest in the northern region of the country. Of 421 AES cases from five northern provinces with laboratory results reported, 217 (52%) had laboratory evidence of recent JEV infection. As Vietnam moves closer to control of JE through immunization, accurate JE surveillance data will be important to evaluate and guide the program.     

云南省大理州1992～2001年流行性乙型脑炎流行现状分析(摘要)

目的本文对云南省大理州12个县(市)1992～2001年流行性乙型脑炎(简称乙脑)的流行现状进行了分析.方法乙脑病例和疫苗接种率资料从大理州疾病预防控制中心收集,气象和稻田种植面积资料分别从大理州气象局和大理州土地局获得.统计学分析用STADA 6.0 软件进行.结果在这10年间,大理州共报道839例乙脑病例,其中死亡101例,发病率为0.91/10万～ 6.45/10万,死亡率为0.09/10万～ 0.52/10万, 病死率为7.92% ～16.47%.每年乙脑病例从4月出现,12月止,主要流行季节8至10月(占病例数的90.46%),9月为流行高峰 (占病例数的41.72%).大理州12县(市)都有乙脑病例分布,各县市发病率由高到低分别为宾川(7.3/10万)、祥云 (5.2/10万) 、漾濞 (5.2/10万) 、剑川(4.4/10万) 、巍山 (4.2/10万) 、洱源 (2.8/10万) 、大理市 (2.7/10万) 、弥渡(2.7/10万) 、南涧(2.7/10万) 、鹤庆 (1.8/10万) 、永平 (1.6/10万)和云龙(0.7/10万).从1997～2001年所报道的297例乙脑病例分析,1997年5～9岁为发病率最高年龄组,但是,随后几年,这种流行模式发生了变化,发病率的最高年龄组从5～9岁组逐渐迁移到大于15岁组.对于成人,发病率最高的人群为农民.乙脑病例中,男∶女比率为1.4∶ 1;死亡病例中,男∶女比率为4∶ 1.统计学分析发现各县市乙脑年发病率与年平均温度,年平均降雨量和水稻面积无明显相关,而乙脑疫苗接种是一种有效的预防控制方法.结论鉴于流行模式的改变,为防止乙脑的流行, 不仅要重视1～14岁年龄组乙脑疫苗的接种,而且要加强对15岁年龄组疫苗的预防接种.     

2005~2013 年成都市流行性乙型脑炎流行病学分析

目的 分析2005~2013 年成都市乙脑报告发病情况,探讨乙脑防治措施。方法 采用Excel软件对2005~2013 年成都市乙脑病例资料进行分析。结果 2005~2013 年成都市共报告乙脑病例124 例,死亡3 例,病例主要分布在金堂、金牛、郫县和双流。男女比例为1.70∶1,年龄最小6 个月,最大61 岁,以3~5 岁为主,占41.94%。无免疫史或免疫史不详占69.44%。蚊密度监测三带喙库蚊占4.27%。结论 成都市近年乙脑呈低水平散发态势,应做好乙脑疫苗查验补种,尤其要加强农村、偏远地区和流动人口密集地区的免疫接种,提高乙脑疫苗覆盖率,减少免疫空白,同时做好宣传教育、防蚊灭蚊等防控措施,减少乙脑发病。     

Measles epidemiology and elimination strategies in Turkey

In Turkey, 15,000-30,000 measles cases have been reported annually since the 1990s. Epidemics occur every 3-4 years, and >/=90% of cases are <15 years old. The high incidence is due to inadequate vaccination coverage (nationally 84% in 2001) and immunity provided by the first dose of vaccine administered at age 9 months. The second dose, which has been recommended for first grade students since 1998, has been insufficient to provide the herd immunity necessary to control measles. The Ministry of Health launched a comprehensive program for 2002-2010 targeting measles elimination. This plan calls for a national vaccination campaign among all children aged 9 months to 14 years and routine two-dose vaccination coverage will be increased to >/=95% or follow-up campaigns will be conducted in areas not achieving high coverage levels. Also, all military recruits in 2002-2009 will be vaccinated and case-based, laboratory supported surveillance will be initiated.     

Epidemiological profile of Japanese encephalitis in Gorakhpur district, Uttar Pradesh, 1982-1988.

An in-depth study of Japanese Encephalitis (JE) situation in Gorakhpur district of Uttar Pradesh from 1982-1988 showed increasing trend in the incidence of JE. Total number of annual cases and case fatality rate (CFR) rose from 118 and 23.7 per cent in 1982 to 772 and 32.2 per cent in 1988 respectively. A definite increase was noticed in the number of cases per block following lull years in 1984 and 1987. Among the total affected 1201 villages, 1083 were affected only once. All age groups were affected and the disease showed marked seasonality during August to November. JE, which came in epidemic form in earlier years has established in the area in endemic form.     

Laboratory-based Japanese encephalitis surveillance in Nepal and the implications for a national immunization strategy

We report on two years of Japanese encephalitis (JE) surveillance in Nepal and the implications for a national immunization strategy. From May 2004 to April 2006, 4,652 patients with encephalitis were evaluated. A serum or cerebrospinal fluid specimen was collected from 3198 (69%) patients of which 1,035 (32%) were positive by Japanese encephalitis IgM ELISA. Most cases (N = 951, 92%) were from the 24 Terai districts (i.e., southern plains, 12.3 million persons) with the majority (N = 616, 65%) from four western Terai districts (population = 1.8 million). The case fatality ratio was 14.7% and 6.3% and the proportion of cases under 15 years old was 52% and 62% in the four western and 20 non-western Terai districts, respectively. Japanese encephalitis immunization targeting residents one year of age and older in the western districts and one through 14 years old in the non-western Terai districts may have reduced Japanese encephalitis cases by 84% and deaths by 92%, nationally.     

1949-2018年石家庄市流行性乙型脑炎发病趋势分析

目的 分析流行性乙型脑炎(简称乙脑)流行特征的长期趋势。方法 对石家庄市疫情资料汇编((1949-2018年)、国家传染病报告信息管理系统(2004-2018年)与急性脑炎脑膜炎监测合作项目(2007-2018年)中的乙脑资料,采用年度变化百分比(annual percent change,APC)和圆形分布定量评估乙脑疫情变化特征。结果 1949-2018年,石家庄市累计报告乙脑病例5 884例,病死率为19.02%。职业中,农民占51.16%。2001-2018年,流动人口病例占40.85%。年发病率范围为0.03/10万~72.43/10万,年均发病率1.72/10万,APC为-2.57(t=6.38,P<0.001)。1949-1993年的1~14岁病例占62.59%,而2016-2018年的50岁及以上病例占76.56%。每20年左右出现一次明显的流行高峰。病例主要集中在7-9月份。1949-1999年的发病高峰为8月24日(8月1日-9月17日)(z=4712.17,P<0.001),2000-2018年的发病高峰为8月6日(7月18日~10月25日)(z=146.10,P<0.001),两阶段的发病高峰期差异具有统计学意义(t=2.03,P<0.05)。结论 石家庄市乙脑疫情明显下降,高发人群年龄呈上升趋势,流动人口成为新的易感人群,严格的季节性发病高峰特征有所减弱,高峰日提前,高峰期间增宽。     

2003～2012年广西钦州市流行性乙型脑炎疫情分析

目的了解钦州市流行性乙型脑炎（简称乙脑）的流行情况,为有效预防控制乙脑提供科学依据。方法对钦州市2003-01~2012-12的乙脑疫情资料用描述流行病学方法进行整理分析。结果 2003~2012年该市共报告乙脑病例91例,年均发病率为0.29/10万;散居儿童发病69例,占75.82%;男性、女性分别占69.23%、30.77%;2~10岁儿童发病77例,占发病总数为84.62%;5~7月份发病90例,占病例总数的98.90%,呈明显的夏秋季发病高峰;病例主要集中在农村边远地区,共65例,占病例总数的71.43%。结论预防控制乙脑要重点抓好农村边远地区2~10岁散居儿童的乙脑疫苗常规接种和查漏补种工作,在乙脑高发的夏秋季节加强监测力度和宣传教育力度,落实防蚊措施,减少乙脑发病。     

Endemic Japanese encephalitis in the Kathmandu valley, Nepal

Japanese encephalitis (JE) is endemic in the Terai region of Nepal. There is little information on the occurrence of JE outside the Terai and particularly in the densely populated Kathmandu valley. Acute encephalitis syndrome (AES) cases were detected using a sentinel surveillance system that has been functioning since 2004. JE was confirmed using anti-JE IgM ELISA. All laboratory-confirmed JE cases that occurred in the Kathmandu valley during 2006 were followed up for verification of residence and travel history. JE was confirmed in 40 residents of the Kathmandu valley, including 30 cases that had no history of travel outside the valley during the incubation period. Incidence was 2.1/100,000 and the case fatality was 20% (8/40). Currently, JE prevention is focused on the Terai region in Nepal; given the evidence, this should be reviewed for the possible inclusion of the Kathmandu valley in the national JE prevention and control program.     

1996～2004年新疆巴州地区性传播疾病疫情分析

目的了解和掌握新疆巴音郭楞蒙古自治州地区1996~2004年性传感染(STI)流行动态及特征。方法对巴州地区1996~2004年STI疫情年报资料进行统计分析。结果巴州地区在1996~2004年期间,共报告STI3796例,STI年平均报告发病率为61.61/10万,年平均增长速度为30.30%;在2000年发病率达最高峰,为130.27/10万;从流行趋势来看,发病呈逐年上升的趋势;淋病居报告发病首位,但有下降趋势,而非淋菌性尿道(宫颈)炎(NGU)、梅毒有上升趋势;男性发病率高于女性,20~40岁年龄段为高发人群。结论巴州地区STI流行仍未得到根本控制,STI的预防和控制工作仍需加大力度。     

Evaluation of the potency and safety of inactivated Japanese encephalitis vaccine in US inhabitants

In 1981 and 1982, two US citizens died from Japanese encephalitis (JE) acquired in China. In 1983, the Centers for Disease Control initiated an evaluation of a purified, inactivated, mouse-brain-derived JE vaccine produced and used in Japan since 1966. Two doses of this vaccine given 1-2 weeks apart evoked neutralizing antibody titers greater than or equal to 8 in only 77% of recipients. After three JE vaccine doses administered 1-2 weeks apart, 99% developed titers greater than or equal to 8. When a third dose was given to 29 participants 6-12 months after the primary series, all developed titers greater than or equal to 16. Reported adverse reactions included injection site tenderness (18%), erythema (6%), or swelling (3%); headache (9%); and dizziness, fatigue, sleepiness, nausea, chills, fever, or lower back pain (less than or equal to 5%). On the basis of this study, three doses of BIKEN JE vaccine are recommended for US citizens who may be at risk of exposure to JE virus.     

福建省三明市1989～1999年梅毒流行病学分析

目的了解和掌握三明市梅毒流行动态,为有关部门防治性病提供决策依据.方法对1989～1999年全市梅毒疫情资料进行整理分析.结果1989～1999年全市登记性病20236例,其中梅毒2322例,占同期性病数的11.47%.1989年首先报告3例,占性病总数的0.37%,1999年报告433例,占17.64%,呈逐年上升趋势.1992年以前每年报告在20例以下,1993年后呈跳跃式上升,1995年起每年报告在300例以上,并出现胎传梅毒、小儿梅毒和晚期隐性梅毒.男女性别比为1.301,年龄4天～67岁,职业以工人、个体及无业人员居多,占62.19%,已婚占77.09%,非婚性接触传染占70.20%.结论 11年来三明市梅毒流行呈逐年上升趋势,早期梅毒占多数,传染性强,如不采取有效措施,今后几年梅毒仍有可能在较高水平流行.     

Estimation of the Impact of a Japanese Encephalitis Immunization Program with Live,Attenuated SA 14-14-2 Vaccine in Nepal

Wider availability of the live, attenuated SA 14-14-2 Japanese encephalitis (JE) vaccine has facilitated introduction or expansion of immunization programs in many countries. However, information on their impact is limited. In 2006, Nepal launched a JE immunization program, and by 2009, mass campaigns had been implemented in 23 districts. To describe the impact, we analyzed surveillance data from 2004 to 2009 on laboratory-confirmed JE and clinical acute encephalitis syndrome (AES) cases. The post-campaign JE incidence rate of 1.3 per 100,000 population was 72% lower than expected if no campaigns had occurred, and an estimated 891 JE cases were prevented. In addition, AES incidence was 58% lower, with an estimated 2,787 AES cases prevented, suggesting that three times as many disease cases may have been prevented than indicated by the laboratory-confirmed JE cases alone. These results provide useful information on preventable JE disease burden and the potential value of JE immunization programs.     

Use of IgM-capture ELISA for confirmation of Japanese encephalitis infections in the Philippines

In 2001, the Research and Biotechnology Division (RBD) of St Luke's Medical Center, in collaboration with the Institute of Tropical Medicine of Nagasaki University in Japan, initiated a long-term study of Japanese encephalitis in the Philippines. Laboratory confirmation of acute cases of Japanese. encephalitis was done by IgM-capture ELISA, which detects anti-JEV immunoglobulin M in cerebrospinal fluid (CSF) samples. In the period 2002-2004, a total of 614 CSF samples were submitted to RBD, and of these, 11.7% were positive for anti-JEV IgM: 17 in 2002, 18 in 2003, 32 in 2004, and 5 in 2005. Positive cases came from patients aged 2-77 years. In the 72 positive cases where gender was identified, 44 were male and 28 female. Possible co-infections with dengue virus were also detected by separate testing for anti-dengue IgM by ELISA in 17 CSF samples positive for JE.     

Tuberculosis in Japan at present and in near future

The high incidence of tuberculosis in the elderly people and no decrease in the incidence rate of the young people are two main features of current tuberculosis problem in Japan. To examine the near future prediction of the incidence rate and the rate of clinical breakdown by age group, the incidence rates of the newly registered tuberculosis cases of the cohorts born before 1918, in 1919-28, 1929-38, 1939-48, 1949-58 and 1959-68 were studied every ten years. The curves of incidence rate in each cohort were extrapolated to the future to obtain the incidence rates in 2008 and 2018. The numbers of predicted new cases in 2008 and 2018 were estimated to be some 31,000 and 23,000, respectively. The percentage of the cases above 60 y.o. was estimated to be 59%, 59% respectively. As the number of new cases in 1998 was 41,000, 55% of which was above 60 y.o., it will steadily decrease from now on, but the elderly people more than 60 y.o. will continue to occupy high percentage of the new cases. The incidence rate of the new cases will also decrease from 32.4 (per 100,000 populations) in 1998 to 24.5 in 2008 and 19.4 in 2018, and Japan in 2018 will still be a middle prevalence country in the world as now. The rate of clinical breakdown is obtained from dividing the incidence rate by the prevalence of tuberculosis infection. The latter is theoretically calculated from the annual risk of tuberculosis infection assuming that it doesn't depend on age. In Japan the annual risk of infection was supposed to be constant and about 4% till 1947. Since then it declined by some 10% annually till around 1977. Thereafter the annual speed of its decline was estimated to have slowed down. But we cannot know the true annual risk of tuberculosis infection, as BCG vaccination hinders the interpretation of the result of tuberculin skin testing in Japan. We postulated it declined 5% annually (Model A) or it was constant to be 0.17% since 1977 (Model B). Using these models of annual risk of tuberculosis infection, the prevalence of tuberculosis infection by age group was calculated in every calendar year. The incidence rate of each age group was assumed to be equal to that of median age in each age group. For example, the incidence rate of the cohort born in 1919-28 was assumed to be equal to that of the cohort born in 1923. In this way, the annual rates of clinical breakdown of the cohorts born in 1923, 1933, 1943, 1953, 1963 and 1973 were calculated. The rates of clinical breakdown for the cohorts born in 1923, 1933 and 1943 were similar with each other and were approximately 100 per 100,000 in both models. The rate of clinical breakdown at 25 years old for the cohort born in 1953 was 0.64 times smaller than that for the cohort born in 1943. It might due to the improvement of nutritional state and the effectiveness for adult tuberculosis of compulsory BCG vaccination which has been done after World War II in Japan. But for the cohort born after World War II, the later the cohort was born, the larger its rate of clinical breakdown was in both models. And, for example, the rate of clinical breakdown at age 25 years old for the cohort born in 1973 was 2.4 times (in Model A) or 1.7 times (in Model B) larger than that for the cohorts born in 1953. This may imply that there has been some factor(s) which facilitates tuberculous disease after tuberculous infection in young people in modern Japan. One explanation for this is the possibility that immune ability to tuberculosis might be weakened in young generations by some factor(s) such as environmental pollution.     

现代结核病控制模式的实施效果分析

目的　探索和建立一种适合湖南省乃至全国国情的现代结核病控制模式,实现结核病的高发现率和高治愈率。方法 结合实际,根据结核病控制的组织机构、筹资机制、病人发现、治疗管理、药品供应、健康促进、业务培训、激励政策、督导管理、科学研究、国际合作和监控评价等工作,制定出相应的实施方法和管理办法与措施。结果 (1)实现了肺结核病人的高发现率。新涂阳病人登记率从1992年的1.71/10万逐年上升到2005年的47.97/10万;病人发现率从1992年的2.9%逐年上升到2005年的81.4%。(2)获得了结核病人的高治疗率。1992—2005年,全省涂阳病人治愈率为90.5%;治疗成功率为93.8%。(3)取得了显著的社会效益。1992—2005年,全省已治愈涂阳肺结核病人273104例,减少了136550人因结核病死亡,使5462000～8193000健康人免遭结核病的感染。全省总投入直接成本为1.64亿元;产生的直接效益为1.91亿元。家庭的成本直接5.22亿元,产生的家庭直接效益为12.30亿元。(4)结核病疫情获得了有效的控制:①肺结核病涂阳患病率由1990年的179/10万下降至2000年的107/10万,下降了40.4%。②复治涂阳病人比例逐年降低,从1992年的64.9%降到2005年的8.2%。③患病年龄向老年推移。2005年0～14岁组人群的患病人数的构成比与1993年相比下降了80.0%;平均患病年龄由1993年的41.9岁,推移至2005年的44.3岁。结论 湖南省逐步建立和完善了政府承诺、机构建设、病人发现、治疗管理、药品供应、健康促进、业务培训、激励政策、督导管理、科学研究、国际合作和监控评价共12个要素组成的现代结核病控制模式,是实现结核病人高发现率与高治愈率,有效控制结核病流行的有效方法与措施。     

Trends in malaria cases in Japan

Just after World War II, more than 10,000 malaria cases per year were reported in Japan, including indigenous, imported and induced malaria. Malaria has been successfully eradicated since 1961 in Japan and now only imported malaria cases are encountered. However, as the number of Japanese people who are going abroad and also the number of foreigners who are visiting Japan increases (about 16 and 5 millions, respectively, in 2001), so does the chance for Japanese doctors to see imported malaria or transfusion-transmitted malaria cases. In fact, the total number of the patients with acute malaria in Japan has been around 100-150 annually for the last 10 years. Of those, about 75% are Japanese and 25% are foreigners, and about 75% are male and 25% are female. The peak age is in the 20s. Recently, about 45% of patients are Plasmodium falciparum and another 45% Plasmodium vivax infections. The former species is likely to be seen in travelers coming back from African countries and the latter is mainly from Asian countries. The important issue is that patients in Japan have not been diagnosed promptly nor treated properly because doctors in Japan are no longer familiar with tropical medicine. Therefore, some patients are dying from severe malaria as a consequence. As it is, most of the effective medicines for drug-resistant malaria or severe malaria have not been registered in Japan. There is now a need for medical practitioners to focus on travel medicine in Japan.     

Reports of clinical hepatitis A from Public Health and hospital microbiology laboratories to the PHLS Communicable Disease Surveillance Centre during the period 1980-1988

Clinical hepatitis, diagnosed as being caused by virus type A by tests for specific immunoglobulin M, has been reported from laboratories in England, Wales and Ireland since 1980. There were 25541 reports in the following 9 years, a yearly average of 2838. A 7-year cycle is suggested by peaks in the numbers of reports of 4502 in 1982 and 4167 in 1988 with a continuing rise in 1989. Contact with other cases of acute hepatitis was recorded for 3899 patients (15%) of which 2497 (64%) were in families, 258 (7%) were in schools, 94 (2%) were in institutions/hospitals, 197 (5%) were in the neighbourhood, while 140 (4%) were contacts at work or socially. A possible food source was recorded for 122 (3%) with shellfish being specified in 56 cases. Recent travel abroad was reported for 3692 patients (15%) of whom 3027 (82%) had visited areas of high prevalence for hepatitis A. About half of them had been to the Indian sub-continent, in strong contrast to visits abroad by the general population each year of which only 7% of the 22 million visits are to areas of high prevalence for hepatitis A. Association with the Indian sub-continent was particularly high for children.     

Implementation of a mass measles campaign in central Afghanistan,December 2001 to May 2002

In Afghanistan health services have been disrupted by 23 years of conflict and 1 of 4 children die before age 5 years. Measles accounts for an estimated 35,000 deaths annually. Surveillance data show a high proportion of measles cases (38%) among those >/=5 years old. In areas with complex emergencies, measles vaccination is recommended for those aged 6 months to 12-15 years. From December 2001 to May 2002, Afghan authorities and national and international organizations targeted 1,748,829 children aged 6 months to 12 years in five provinces in central Afghanistan for measles vaccinations. Two provinces reported coverage of >90% and two >80%. Coverage in Kabul city was 62%. A subsequent cluster survey in the city found 91% coverage (95% confidence interval [CI], 0.85-0.91) among children 6-59 months and 88% (95% CI, 0.87-0.95) among those 5-12 years old. Thus, this campaign achieved acceptable coverage despite considerable obstacles.