Long-term trends in hepatitis A incidence following the inclusion of Hepatitis A vaccine in the routine nationwide immunization program

Summary.  For many years hepatitis A was one of the most common vaccine preventable diseases in Israel. In 1999, Israel became the first country to introduce an inactivated hepatitis A vaccine into its national childhood vaccination program. The objectives of the present study were to study trends in disease incidence after the implementation of the new vaccination policy and to assess vaccination coverage among children and adults in Israel. We used the databases of the second largest HMO in Israel (1.7 million members) to identify patients who had evidence of hepatitis A in 1998 and 2007 and to collect information on all subjects who received at least one dose of hepatitis A vaccine during the study period. Hepatitis A vaccination coverage in children <5 years and 5–14 years of age increased from 9% and 15% in 1998 to 89% and 68% in 2007, respectively. During this period the annual incidence of hepatitis A dropped from 142.4 per to 7.6 per 100 000. The most prominent reduction in the age-specific annual incidence rates was calculated in children <5 years from 239.4 per 100 000 in 1998 to 2.2 per 100 000 in 2007 and from 310.3 per 100 000 to 3.0 per 100 000 in children aged 5–14 years. In endemic areas, vaccination of infants and children against hepatitis A can greatly reduce the total burden of the disease.     

Patterns of susceptibility in an outbreak of Bordetella pertussis: Evidence from a community-based study.

OBJECTIVE: To describe an outbreak of Bordetella pertussis and to assess which factors were associated with the development of clinical pertussis in children and adults during the outbreak. DESIGN: A case series was described to define the epidemiology of the pertussis outbreak. A school-based survey of children was used to measure the incidence of clinical pertussis over the previous six months. Vaccination records from the local public health facility were used to look at the relationship between age and vaccination parameters, and susceptibility to clinically diagnosed pertussis. A cross-sectional survey of teachers, parents and some hospital workers was used to assess these associations in adults. SETTING: An outbreak of pertussis in an isolated northern community in British Columbia. POPULATION STUDIED: All children in the community who attend daycare, kindergarten or school, and their parents were surveyed. In addition, some health care workers and mothers of preschool children were surveyed. MAIN RESULTS: A total of 31 suspected cases of pertussis were identified over a three-month period. Ninety per cent of the affected children who had available vaccination records had received four or five doses of pertussis vaccine. Sixty per cent of the town's 209 children returned completed surveys. Of these, 69% had available vaccination records. Thirty-six children (28%) reported symptoms that fit the case definition for pertussis over the previous three months. Attack rates were highest for the group of children aged 10 to 14 years. In a multivariate logistic regression analysis, receiving prophylactic medication and an increased number of years from the last vaccine dose were found to be significant predictors for developing pertussis. Thirty-four per cent of the estimated 291 adults in the community returned completed surveys. The attack rate of pertussis in the adults was only 9%. Being a member of the school staff and/or having a household contact with pertussis were significant predictors of developing pertussis. CONCLUSIONS: Immunity to pertussis appears to wane during childhood. Peak susceptibility appears to be during early adolescence. Adults do not seem to be at greater risk than adolescents for developing the disease, but it seems unlikely that this is due to better immunity. Rather, it is probably related to a lower risk of exposure to pertussis and a lower rate of progression to symptomatic disease when adults are infected.     

Economics of an adolescent meningococcal conjugate vaccination catch-up campaign in the United States.

BACKGROUND: In June 2005, the Advisory Committee on Immunization Practices recommended the newly licensed quadrivalent meningococcal conjugate vaccine for routine use among all US children aged 11 years. A 1-time catch-up vaccination campaign for children and adolescents aged 11-17 years, followed by routine annual immunization of each child aged 11 years, could generate immediate herd immunity benefits. The objective of our study was to analyze the cost-effectiveness of a catch-up vaccination campaign with quadrivalent meningococcal conjugate vaccine for children and adolescents aged 11-17 years. METHODS: We built a probabilistic model of disease burden and economic impacts for a 10-year period with and without a program of adolescent catch-up meningococcal vaccination, followed by 9 years of routine immunization of children aged 11 years. We used US age- and serogroup-specific surveillance data on incidence and mortality. Assumptions related to the impact of herd immunity were drawn from experience with routine meningococcal vaccination in the United Kingdom. We estimated costs per case, deaths prevented, life-years saved, and quality-adjusted life-years saved. RESULTS: With herd immunity, the catch-up and routine vaccination program for adolescents would prevent 8251 cases of meningococcal disease in a 10-year period (a 48% decrease). Excluding program costs, this catch-up and routine vaccination program would save US$551 million in direct costs and $920 million in indirect costs, including costs associated with permanent disability and premature death. At $83 per vaccinee, the catch-up vaccination would cost society approximately $223,000 per case averted, approximately $2.6 million per death prevented, approximately $127,000 per life-year saved, and approximately $88,000 per quality-adjusted life-year saved. Targeting counties with a high incidence of disease decreased the cost per life-year saved by two-thirds. CONCLUSIONS: Although costly, catch-up and routine vaccination of adolescents can have a substantial impact on meningococcal disease burden. Because of herd immunity, catch-up and routine vaccination cost per life-year saved could be up to one-third less than that previously assessed for routine vaccination of children aged 11 years.     

La coqueluche en pratique en 2006

Universal vaccination of infants against pertussis has transformed the epidemiology of the disease. Pertussis has however become frequent, although not often diagnosed, in adolescents and adults and thus contributes to permanent transmission of Bordetella pertussis in France and contamination of young infants at risk of severe disease. Control of transmission of pertussis in France necessitates reinforcement of vaccination with late boosters in adolescents and adults and, in addition, education of physicians to recognize and treat early cases of pertussis, especially in adolescents and adults with a persistant or chronic cough, and to take appropriate prophylactic measures (antibiotics and recall vaccination) of those in contact with confirmed cases. Effective treatment does little to reduce symptoms but it does reduce transmission. Macrolides are the recommended treatment for pertussis.     

A multi-season national estimate of adult influenza vaccination by U.S. office-based pediatricians, 2006-2011

Please cite this paper as: Toback and Ambrose (2012) A multi‐season national estimate of adult influenza vaccination by US office‐based pediatricians, 2006–2011. Influenza and Other Respiratory Viruses 6(4), 231–234. There is no national estimate of adult influenza vaccination by US office‐based pediatricians. De‐identified patient‐level data from an electronic healthcare claims database submitted to private and public insurers were analyzed for pediatric offices from the 2006–2007 through 2010–2011 seasons. An average of 321 000 (range: 225 000–434 000) influenza vaccinations per year were estimated to be administered to adults; 52%, 22%, and 26% were given to adults 19–49, 50–64, and ≥65 years of age, respectively. Consistent with the 2010 changes to national guidelines, recommending influenza vaccination of all individuals 6 months of age and older, pediatricians appear to be providing an increasing proportion of adult vaccinations against influenza to adults 19–49 years of age (probably parents of their pediatric patients).     

Field epidemiology investigation on measles outbreak started from a junior high school at Kita Ibaraki City

We studied measles outbreak in Ibaraki Prefecture in spring 2002 as members of Field Epidemiology Training Program Japan (FETPJ). Of 84 cases diagnosed by not laboratory test but clinically, 67 (79.8%) were junior high school students, 9 (10.7%) were other students, and 8 (9.5%) were ordinary adult and infant citizens. Of the 84, 46 (54.8%) had been vaccinated. Most did not show typical Koplik spots. The city in which the school was located promoted vaccinations for infants and children aged 7.5 years old to grade 1 in High school. Questionnaire given to junior high students were detected 86 cases, of whom 57 (66.3%) were male. Overall, 4 peaks of clusters were observed in an epidemic curve, among which graduates' farewell parties and graduation ceremonies were the most common opportunities for measles virus exposure. The overall vaccination rate at school was 82.2%, vaccine efficacy extremely low at 72.5%, and vaccine failure high at 15.2%. Symptoms among those vaccinated were significantly milder than those not vaccinated. Immunity of those vaccinated as infants may have been decreased due to scarcity of measles cases in the last 10 years. In such situations--much less in typical measles among susceptible non affected and non vaccinated subjects--atypical or mild measles may be difficult to diagnose. These findings may keep clarify the need to introduce two-dose measles immunization in Japan.     

Rationale for pertussis booster vaccination throughout life in Europe

Although the introduction of universal pertussis immunisation in infants has greatly reduced the number of reported cases in infants and young children, disease incidence has been increasing in adolescents and adults in recent years. This changing epidemiological pattern is probably largely attributable to waning immunity after natural infection or vaccination. Furthermore, improved diagnostic testing, active surveillance, changes in disease susceptibility, vaccine characteristics, and increased awareness of the disease might also be contributing factors. Susceptibility to pertussis in adolescents and adults results not only in direct morbidity in these age groups, but also poses a transmission risk to susceptible non-immune infants who are often too young to be vaccinated. Because vaccination schedules vary across Europe, we review the pertussis situation in this region and propose considerations for use of pertussis booster vaccinations at different ages to reduce individual morbidity and transmission from present rates and increase herd protection.     

杨浦区水痘疫情特征分析及病例疫苗接种史调查

目的 掌握杨浦区水痘疫情特征,用发病资料评价疫苗流行病学免疫效果.方法 对2003-2005年发病资料进行描述分析,同时对所有病例进行疫苗接种史回顾性调查.结果 3年平均年发病率21.13/10万,暴发疫情中小学生占96.91%;发病时间和地区分布有集中趋势,年龄分布5～14岁组,占66.33%,94.75%病例无疫苗接种史.结论 水痘疫情呈上升趋势,0～4岁幼年组和年龄较大的在校学生均是水痘易感人群,疫情常在中小学校和幼托机构集体性单位频繁发生;病例疫苗接种率低.提高接种率是控制水痘发病的有效手段,当前应扩大疫苗接种年龄范围.     

Mortality associated with HIV infection in rural Rakai District, Uganda

OBJECTIVE: To assess mortality impact of HIV in rural Uganda. METHODS: An open cohort of 19983 adults aged 15-59 years, in Rakai district was followed at 10 month intervals for four surveys. Sociodemographic characteristics and symptomatology/disease conditions were assessed by interview. Deaths among residents and out-migrants were identified household census. Mortality rates were computed per 1000 person years (py) and the rate ratio (RR) of death in HIV-positive/HIV-negative subjects, and the population attributable fraction (PAF) of death were estimated according to sociodemographic characteristics. Mortality associated with potential AIDS defining symptoms and signs was assessed. RESULTS: HIV prevalence was 16.1%. Mortality was 132.6 per 1000 py in HIV-infected versus 6.7 per 1000 py in uninfected subjects, and 73.5% of adult deaths were attributable to HIV infection. Mortality increased with age, but the highest attributable risk of HIV associated deaths were observed in persons aged 20-39 years (PAF > 80%) and in women. HIV associated mortality was highest in the better educated (PAF > or = 75%) and among government employees (PAF > or = 82%). Of the HIV-positive subjects 40.5% reported no illness < 10 months preceding death, symptoms were poor predictors of death (sensitivity 1.6-38.8%), and only 9.1% met the World Health Organization clinical definition of AIDS. Infant mortality rates in babies of HIV-infected and uninfected mothers were 209.4 and 97.7 per 1000, respectively. CONCLUSION: HIV is taking substantial toll in this population, particularly among the younger better educated adults, and infants. Symptomatology or the World Health Organization definition of AIDS are poor predictors of death.     

Epidemiologic relation between HIV and invasive pneumococcal disease in San Francisco County, California

BACKGROUND: Patients with AIDS have a high incidence of invasive pneumococcal disease, but no population-based data are available on secular trends or rates of this disease in specific demographic groups. OBJECTIVE: To compare clinical characteristics, rates, and trends of pneumococcal disease in HIV-infected and non-HIV-infected persons. DESIGN: Population-based laboratory surveillance and chart review. SETTING: All of the 13 microbiology laboratories in San Francisco County, California. PATIENTS: Persons who had a sterile site culture that was positive for Streptococcus pneumoniae between October 1994 and June 1997. MEASUREMENTS: Stratified incidence rates and adjusted rate ratios, serotyping of isolates, and comparison of secular trends and rates according to census tract by Poisson regression. RESULTS: Persons infected with HIV accounted for 54.2% of 399 patients 18 to 64 years of age who had pneumococcal disease. The incidence of pneumococcal disease per 100 000 person-years was 35.0 cases overall and 802.9 cases in patients with AIDS. Compared with persons who were not known to be HIV-infected, the rate ratio for patients with AIDS was 46:0 (95% CI, 36.0 to 58.9); 55.2% of cases were attributable to HIV. In HIV-infected patients, 82.5% of isolates were serotypes that are included in the pneumococcal polysaccharide vaccine. The incidence of pneumococcal disease in black patients with AIDS (2384.6 cases per 100 000 person-years) was 5.4 times that in nonblack patients with AIDS. Rates by census tract were inversely associated with income (P < 0.001), During the study period, the incidence of pneumococcal disease decreased from 10.6 cases per 1000 person-years to 4.2 cases per 1000 person-years in patients with AIDS (P = 0.004, Poisson regression). CONCLUSIONS: In a community with a high prevalence of HIV infection, much of the burden of pneumococcal disease was attributable to AIDS. High incidence rates were seen in young adults and especially in black persons. Efforts to increase pneumococcal vaccination rates should target HIV-infected adults, particularly those living in poor urban areas.     

An outbreak of rubella among hospital personnel and measures taken against hospital infection--cost-benefits of the measure

There is no nationwide outbreak of rubella after 1992 in Japan, but a local outbreak remains. Recently, some cases of congenital rubella syndrome (CRS) were reported after a local outbreak. An outbreak of rubella among hospital personnel occurred in our hospital located on Tanegashima Island on March and April 2003 after a visit of one rubella patient. Fifteen employees, including 7 clerks, 6 nurses, one doctor, and one radiologist, experienced rubella. A total of 259 employees in our hospital employees were examined for anti rubella hemagglutination inhibition (HI) tests with informed consent and recommended to take rubella vaccines. Sixty-seven employees (26%) among 257 examined for tests were found susceptible to rubella, and 53 employees were vaccinated. After vaccination, the outbreak was stamped out immediately. There was no rubella patient infected from employee. Nine among the 15 infected employees had declared to have a history of rubella or rubella vaccines before onsets, suggesting interviews are not reliable. There were many susceptible persons and rubella patients among elderly women and male personnel; therefore, measures are needed for elderly personnel as well as younger employees. In addition, adequate measures should be taken to prevent CRS, because many female personnel capable of pregnancy work in hospitals. The cost of the rubella HI tests and vaccination was approximately yen 200,000 (about dollar 1,600). The absence due to illness per one person was 6 days, and the wage per one day was about yen 12,000 (about dollar 100) on the average. The overall cost required in the outbreak was estimated to be approximate yen 1,400,000 (about dollar 12,000). Considering that an outbreak of rubella causes not only a large amount of expenditure but also loss of hospital income, the investment to prevent a rubella outbreak is quite valuable in the management of a hospital.     

Effect of age on outcome of secondary dengue 2 infections.

OBJECTIVE: Dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) is a growing global health problem. It is not known how age affects the outcome of secondary dengue infections. In an island setting, a large DHF/DSS outbreak in Cuba occurred in 1981. Involved were individuals, 3-40 year old, whose only lifetime dengue exposure was to DEN-1 in 1977 and DEN-2 in 1981. In this report we calculate age-specific DHF/DSS hospitalization and death rates based on secondary DEN 2 infections. METHODS: Published and unpublished hospital and seroepidemiologic data from the 1981 DHF/DSS outbreak were used for the analysis. RESULTS: Children, aged 3 and 4 years, with secondary DEN-2 infections were found to have a high death rate (25.4/10 000 secondary DEN-2 infections). The death rate fell with increasing age, being 15.9-fold lower in the 10-14-year age group. The death rate for children aged 3-14 years was 14.5-fold higher than in young adults aged 15-39 years. The death rate rose somewhat in adults aged 50 years and older. DHF/DSS hospitalization rates showed the same trend as death rates. CONCLUSIONS: Age is an important variable in the outcome of secondary DEN-2 infections. DHF/DSS case fatality and hospitalization rates are highest in young infants and the elderly. The risk that a child will die during a secondary DEN-2 infection is nearly 15-fold higher than the risk in adults.     

Invasive Haemophilus influenzae disease in children less than 5 years of age in Manhiça, a rural area of southern Mozambique

Objective To measure the disease burden and epidemiological characteristics of invasive Haemophilus influenzae in rural Mozambican children. Methods As part of the clinical management of children admitted to Manhiça District Hospital, blood and cerebrospinal fluid samples were collected between May 2001 and April 2005 for children aged <5 years. The level of antibiotic resistance of the isolates was analysed. Results During the surveillance period, there were 106 episodes of invasive H. influenzae disease. The estimated minimum incidence rate of invasive disease among children <5 years of age was 125/100 000 per child‐year‐at‐risk. Fifty‐six (59/106) per cent of cases were infants aged 3 to <12 months. Confirmed meningitis explained 16% of the episodes (n = 17) but was probably underestimated, as meningitis surveillance was not well implemented in the setting during the study. The case‐fatality‐rate was 21%, being highest among children with meningitis (odds ratio = 4.38, P = 0.011). Resistance to the antibiotics most commonly used in Mozambique was high – chloramphenicol 39%, ampicillin 35% and cotrimoxazol 74%– and had increased over the years (P < 0.001 for chloramphenicol). Conclusion Invasive H. influenzae disease is of considerable public health importance in Mozambique; implementing H. influenzae type b vaccination in sub‐Saharan Africa has the potential to increase child survival.     

Recent developments in pertussis

Pertussis causes nearly 300,000 deaths in children every year. Most deaths take place in developing countries, but the infection remains a priority everywhere. Pertussis vaccination protects infants and children against death and admission to hospital, but breakthrough disease in vaccinated people can happen. In high-mortality countries, the challenge is to improve timeliness and coverage of childhood vaccination and surveillance. In regions with low mortality and highest coverage, pertussis is frequently the least well-controlled disease in childhood vaccination programmes. Some countries have reported a rise in pertussis in adolescents, adults, and pre-vaccination infants, but how much these changes are real or a result of improved recognition and surveillance remains uncertain. In response, several countries have introduced adolescent and adult acellular pertussis vaccine boosters. The effect so far is unknown; assessment is impeded by poor data. Uncertainties still persist about key variables needed to model and design vaccination programmes, such as risk of transmission from adults and adolescents to infants. New vaccination strategies under investigation include vaccination of neonates, family members, and pregnant women.     

The largest outbreak of measles in the United States during 1999: imported measles and pockets of susceptibility

The largest measles outbreak in the United States during 1999 was traced to a 34-year-old minister with an undocumented history of vaccination, infected while traveling outside the United States. Local health departments in the Central Virginia Health District performed an epidemiological and laboratory investigation that identified 14 additional confirmed cases of measles, including 2 in health care providers and 5 in congregation members. Eight cases (53%) occurred among adults aged 30-35 years and 7 (47%) among children aged 13 months to 8 years. Although no religious exemptions were cited, only 2 case patients had documented proof of vaccination. This outbreak demonstrates the potential for limited indigenous spread of measles that occurs when imported cases expose susceptible groups. Almost half of the imported measles cases in the United States occur in US residents returning from foreign travel. Vaccination is highly recommended for all overseas travelers who are without documented proof of adequate immunization or measles immunity.     

Patterns of susceptibility in an outbreak of Bordetella pertussis: Evidence from a community-based study

OBJECTIVE:

To describe an outbreak of Bordetella pertussis and to assess which factors were associated with the development of clinical pertussis in children and adults during the outbreak.

DESIGN:

A case series was described to define the epidemiology of the pertussis outbreak. A school-based survey of children was used to measure the incidence of clinical pertussis over the previous six months. Vaccination records from the local public health facility were used to look at the relationship between age and vaccination parameters, and susceptibility to clinically diagnosed pertussis. A cross-sectional survey of teachers, parents and some hospital workers was used to assess these associations in adults.

SETTING:

An outbreak of pertussis in an isolated northern community in British Columbia.

POPULATION STUDIED:

All children in the community who attend daycare, kindergarten or school, and their parents were surveyed. In addition, some health care workers and mothers of preschool children were surveyed.

MAIN RESULTS:

A total of 31 suspected cases of pertussis were identified over a three-month period. Ninety per cent of the affected children who had available vaccination records had received four or five doses of pertussis vaccine. Sixty per cent of the town''s 209 children returned completed surveys. Of these, 69% had available vaccination records. Thirty-six children (28%) reported symptoms that fit the case definition for pertussis over the previous three months. Attack rates were highest for the group of children aged 10 to 14 years. In a multivariate logistic regression analysis, receiving prophylactic medication and an increased number of years from the last vaccine dose were found to be significant predictors for developing pertussis. Thirty-four per cent of the estimated 291 adults in the community returned completed surveys. The attack rate of pertussis in the adults was only 9%. Being a member of the school staff and/or having a household contact with pertussis were significant predictors of developing pertussis.

CONCLUSIONS:

Immunity to pertussis appears to wane during childhood. Peak susceptibility appears to be during early adolescence. Adults do not seem to be at greater risk than adolescents for developing the disease, but it seems unlikely that this is due to better immunity. Rather, it is probably related to a lower risk of exposure to pertussis and a lower rate of progression to symptomatic disease when adults are infected.Key Words: Immunity, Pertussis, VaccinationVaccination against Bordetella pertussis has resulted in a dramatic reduction in the incidence of this disease in Canada. Outbreaks of pertussis, however, still occur. While many outbreaks reported elsewhere occur in populations where vaccination rates have declined, many others occur in populations with high vaccination coverage (1,2). This has not changed with the introduction of the acellular pertussis vaccine. The reasons for this are not clear, but waning immunity and the transmission of disease from adolescents and adults to younger children have been proposed as possible mechanisms (3,4). An additional constraint in studying this problem is that there is no known level of antibody that can be shown to be protective against developing pertussis (5).The idea of waning immunity has been challenged recently. De Serres and colleagues (6) found that the attack rates were the same in adolescent (12%) and adult (11%) household contacts of pertussis index cases. The authors (6) felt that this similar attack rate was more consistent with a decreasing proportion of susceptible subjects with age and with longlasting immunity. They did not suggest that this immunity comes solely from vaccination, but more likely from subclinical boosting from endemic disease. Clearly, this has implications as to the utility of introducing an adolescent booster dose to reduce further the incidence of disease in the population.In May 2000, an outbreak of pertussis was reported in an isolated northern community in British Columbia. Pertussis outbreaks have been known to occur in three- to five-year cycles in British Columbia. The last such outbreak occurred in 1996 and 1997, and resulted in more than 1100 reported cases. Increased rates of pertussis transmission had already been reported throughout the province since January 2000 (British Columbia Centre for Disease Control, internal report). By mid-May 2000, nearly 400 cases had been reported to the British Columbia Centre for Disease Control. Rates of infection were highest among young adolescents (aged 10 to 14 years), followed by older children (aged seven to nine years). The Northwest Coastal Health Services Society (the region that includes the town of Stewart) was not among those health regions that had previously reported increased numbers of cases.The town of Stewart, which has a population of approximately 500 people, has one health centre for both curative and preventive care, and is more than 150 km from the nearest settlement (excluding the hamlet of Hyder, Alaska, which is only 1.6 km away). There are three schools - a public primary school, a public secondary school and a small, private Christian school. The local health region and the Department of Health Care and Epidemiology at the University of British Columbia initiated an investigation of the pertussis outbreak in Stewart. It was thought that the relative isolation of the community and its small size would allow investigators to see whether immunization status, age and the length of time from the last vaccine dose would significantly affect disease attack rates. It was hoped that vaccination records for most of the town''s children could be verified and then compared with the results of a school-based survey for pertussis-like symptoms. As well, a survey of adults was undertaken to determine whether symptoms also occurred in this susceptible group, and whether this was related to recalled vaccination history. Disease control measures (7), including erythromycin prophylaxis of close contacts of index cases and enhanced surveillance among symptomatic individuals, had already been implemented before the present study was undertaken and were not interrupted during the course of the study.     

Seroepidemiology of hepatitis B virus infection and impact of vaccination

AIM: To investigate hepatitis B virus (HBV) prevalence in the general population in China.METHODS: A total of 148931 individuals were investigated by multistage random sampling in Eastern China. Data were collected on demographics and hepatitis B vaccination history, and serum was tested for hepatitis B surface antigen (HBsAg) by ELISA.RESULTS: A total of 11469 participants (7.70%, 95%CI: 7.57%-7.84%) were positive for HBsAg. HBsAg prevalence was 0.77% among children < 5 years old but increased progressively from adolescents (1.40%-2.55%) to adults (5.69%-11.22%). A decrease in HBsAg prevalence was strongly associated with vaccination and familial history of HBV among both children and adult groups. Meanwhile, HBsAg risk in adults was associated with invasive testing and sharing needles. The HBV immunization rate among participants aged < 20 years was 93.30% (95%CI: 93.01%-93.58%). Significant difference in HBsAg prevalence appeared between vaccinated and unvaccinated participants (3.59% vs 10.22%).CONCLUSION: Although the national goal of HBsAg prevalence < 1% among children < 5 years old has been reached, immunization programs should be maintained to prevent resurgence.     

2005~2014年安徽石台县肺结核病流行特征及时空聚集分析

【摘要】 目的  描述石台县肺结核病流行状况,探讨肺结核病的时空分布特征。 方法  肺结核病数据资料均来源于结核病管理信息系统,采用SPSS 20、SaTScan 9.3和ArcGIS 10.2软件进行数据分析。 结果  石台县2005~2014年报告肺结核病病例1297例,年平均患病率为127.82/10万,男性患病率高于女性,肺结核患病率随年龄增加呈上升趋势,75岁以上组患病率最高为339.37/10万。农民占总病例数的84.30%,患病无明显的季节变化,各乡镇的年平均患病率存在统计学差异,年平均患病率最高的乡镇为大演乡（167.56/10万）。时空聚集分析共检测到2个时空聚集区,其中一类聚集区为丁香镇、小河镇、仙寓镇、矶滩乡和大演乡。 结论  石台县肺结核病流行水平仍较高,时空上存在聚集,应该继续加强重点人群和重点地区防控工作。     

Measles outbreak after a post-honeymoon period in Mongolia, 2001

In spite of the routine 2-dose vaccination and three recent supplemental immunizations, Mongolia experienced a measles outbreak in 2001, the largest epidemic in the country since 1984. The majority of cases were reported in the capital city, and the disease incidence was higher in infants and adolescents than in other age groups. Young adults who received the immunization only once may have low immunity, and may be exposed to the virus most frequently. Immunization strategies such as the age range that is targeted for vaccination and the interval between supplemental immunizations should be based on reasonable epidemiological observations.