An echovirus 30 outbreak with a high meningitis attack rate among children and household members at four day-care centers

Echovirus 30 (E 30) outbreaks in defined cohorts have rarely been reported. In June 1996, an outbreak of E 30 occurred in four day-care centers (DCCs) in neighboring villages in Germany. A retrospective cohort study of DCC children, employees and household members was done to determine the extent of the outbreak and risk factors for illness. Forty-two percent (39/92) of DCC children, 13% (30/228) of their household members, 5% (1/19) of employees and 2% (1/49) of household members of employees were ill. Onsets occurred over 31 days. Thirteen percent (12/92) of DCC children had meningitis. In only one of 16 households with multiple family members ill, illness in a family member preceeded that of the DCC child. Household members of ill DCC children were 15 times more likely to report illness than those of non-ill DCC children. We conclude that this outbreak was associated with a very high incidence of meningitis, the outbreak began in the DCCs and then spread to household members, and that household members of ill children compared to those of non-ill children were much more likely to report illness.     

Protecting contacts of hepatitis A: what's the difference between vaccine and human normal immunoglobulin?

The efficacy of vaccine when time since exposure is prolonged (more than 1 week from onset of illness in the index case) is unknown, but is likely to be significantly lower than human normal immunoglobulin (HNIG). We estimated the number of additional secondary cases that may occur through giving vaccine instead of HNIG to contacts of cases of hepatitis A who are identified more than 1 week after onset in the index case. This was calculated for different levels of vaccine efficacy, assuming HNIG efficacy to be 80-90%. The number of households that need to be treated to prevent one secondary case was calculated using estimates of secondary attack ratios (AR). If more than 1 week has elapsed from onset of illness in the index case, for an average household size of 2.3 people, a vaccine efficacy of 50% and an AR of 10-25%, 8-26 households would need to be treated with vaccine before one additional secondary case would be observed. As UK public health professionals manage around one hepatitis A case per month, it would take from 8 months to over 2 years for them to observe one additional case amongst contacts using vaccine rather than HNIG. It is unlikely that an average practitioner would notice if vaccine were 30% less effective than HNIG. Public health practice and advice to patients and contacts should be based on evidence as well as experience.     

Telephone survey assessment of household patterns of influenza vaccination, Twin Cities seven county metro area, 2008-2009

Major national surveys do not collect the influenza vaccination status of all household members, thus limiting current understanding of household influenza vaccination patterns. In an early 2009 telephone survey of 800 households in the metropolitan Minneapolis-St Paul area, household respondents reported the age, gender, and 2008-2009 seasonal influenza vaccination status of all household members. After poststratification to adjust for nonresponse, the full household influenza vaccination rate for multiperson households is 35.2%, partial household influenza vaccination rate is 39.9% and the rate of complete household nonvaccination is 24.9%. Full household influenza vaccination is more common in households with an elderly resident, intermediate in households with a child under 5 years of age, and less common in the remaining households. No household members are vaccinated in approximately 10% of multiperson households with either an elderly adult or young child; the corresponding rate in other households is 32.8%. An estimated 51.4% of households with children over 1 year of age have all children vaccinated against influenza; 43.5% of households with children had no children vaccinated against influenza. Households with younger children are more likely to have all children vaccinated and less likely to have no children vaccinated. We believe this is the first study to describe the prevalence of household influenza vaccination patterns. Continued efforts to monitor and increase household vaccination may be a valuable strategy to protect individuals and communities from influenza.     

Risk factors for secondary transmission in households after a common-source outbreak of Norwalk gastroenteritis

In November 1984, a foodborne outbreak of Norwalk gastroenteritis occurred in a K-12 public school in northern Vermont. The outbreak offered an opportunity to systematically study in detail secondary transmission rates in households. Eating salad at Tuesday's school-sponsored Thanksgiving Banquet was associated with illness among students and staff members (p less than 0.025). Seven of 11 serum pairs from ill persons showed a fourfold or greater rise in antibody titer to Norwalk virus compared with one of nine controls (p = 0.028). The study of secondary household transmission revealed that households with persons with primary illness were 5.5 times more likely to experience secondary illness than households with well school children or adults. As the number of individuals with primary illness in the household increased, the secondary illness rates increased. Pre-school children were twice as likely as adults to develop secondary illness.     

Experience of hepatitis A vaccination during an outbreak in a nursery school of Tuscany,Italy.

An outbreak of hepatitis A started in late October 1996 in a nursery school in Tuscany, Italy. A programme of hepatitis A vaccination without the use of immunoglobulin started at the beginning of December 1996 and included 33 children, 21 household contacts and 6 adults working in the school. Overall, 11 cases occurred in children attending the school (attack rate 27%) and 10 among their household contacts (attack rate 9 %). The latter also included parents, and, in two cases, grandmothers. The data indicate that susceptibility to HAV has increased over recent decades in central Italy. Past and recent experience shows that the usual duration of hepatitis A epidemics in the absence of immune prophylaxis is longer than that described here. The use of hepatitis A vaccine probably contributed to the early extinction of the outbreak, because no further cases were notified in the area after 7 February 1997.     

Mumps Postexposure Prophylaxis with a Third Dose of Measles-Mumps-Rubella Vaccine,Orange County,New York,USA

Although the measles-mumps-rubella (MMR) vaccine is not recommended for mumps postexposure prophylaxis (PEP), data on its effectiveness are limited. During the 2009–2010 mumps outbreak in the northeastern United States, we assessed effectiveness of PEP with a third dose of MMR vaccine among contacts in Orthodox Jewish households who were given a third dose within 5 days of mumps onset in the household’s index patient. We compared mumps attack rates between persons who received a third MMR dose during the first incubation period after onset in the index patient and 2-dose vaccinated persons who had not. Twenty-eight (11.7%) of 239 eligible household members received a third MMR dose as PEP. Mumps attack rates were 0% among third-dose recipients versus 5.2% among 2-dose recipients without PEP (p = 0.57). Although a third MMR dose administered as PEP did not have a significant effect, it may offer some benefits in specific outbreak contexts.     

Long-term protective effect of post-exposure Havrix TM administration during viral hepatitis Type A outbreaks

Administration of human normal immunoglobulin (HNIG) post-exposure has been routinely used in Slovakia for outbreak control of hepatitis A, but requires deep intramuscular injection, provides only short-lived protection and is a human blood product. The protective effect of post-exposure administration of an inactivated hepatitis A vaccine was evaluated during 10 outbreaks in Slovakia. Direct contacts of confirmed hepatitis A cases received either: a single dose of hepatitis A vaccine (n = 2171) or immunoglobulin (HNIG, n = 3837). In the HNIG group the number of hepatitis A confirmed cases dropped within the first 7 weeks, however the decrease was not as rapid or as marked as that observed in the vaccinated group where the number of hepatitis A cases dropped within the first 4 weeks after vaccination. Among contacts, 67 cases of hepatitis A were detected during the maximum incubation period of 45 days: 16 cases (0.7%) in the vaccine group and 51 cases (1.3%) in the HNIG group (p  <  0.05). After two and three years respectively, 50 and 39 volunteers who had previously received one dose of hepatitis A vaccine received a booster dose and anti-HAV antibodies were measured. Differences in anti-HAV antibody GMCs before and after the booster were statistically significant. The longer time interval (3 years instead of 2) between primary vaccination and booster administration did not seem to impact the magnitude of the booster response. The results of this study show that active post-exposure immunisation with only one dose of inactivated vaccine confers high and long-term protection and effectively controls viral hepatitis A outbreaks.     

COVID-19 vaccine confidence and reasons for vaccination among health care workers and household members

BackgroundThe majority of healthcare workers (HCW) in the US report being fully vaccinated against COVID-19, yet little is known about vaccine decision-making for their household members, including children.MethodsCross-sectional survey July–August 2021 of HCW and their household members in Minnesota.Results94 % of eligible participants were vaccinated with the most common reasons being wanting to protect oneself, family and loved ones. Safety concerns were the most commonly reported reasons for not being vaccinated; a significantly higher proportion of unvaccinated compared to vaccinated HCW (58 % vs 12 %, p = 0.0035) and household adults (25 % vs 5 %, p = 0.03) reported prior SARS-CoV-2 infection. Nearly half of unvaccinated adults and two-thirds of unvaccinated children would be vaccinated if a vaccine mandate were in place.ConclusionsDespite high COVID-19 vaccine acceptance among HCWs, more research is required to identify and address the needs and concerns of healthcare workers who decline COVID-19 vaccination despite availability.     

Control of a measles outbreak in an elementary school. Baltimore County,Md. 1975.

Between April 18 and May 20, 1975, 16 cases of measles occurred in pupils in an elementary school in Baltimore County, Md., and 1 case occurred in a sibling at a junior high school. Measles was serologically confirmed in 16 of these pupils. Attack rates were determined by grade and by vaccine status. The measles attack rate was 2.1 percent for the 377 children who had been given measles vaccine at 1 year of age or later. The rates were 27.8 percent (13 times higher) for those vaccinated at less than 10 months of age and 20.0 percent (10 times higher) for those with no definite history of vaccine. The higher attack rates for children who were vaccinated only before 10 months of age supports the 1972 recommendation of the Public Health Service Advisory Committee on Immunization Practices that children vaccinated before this age need to be revaccinated with live measles virus vaccine to assure full protection. The finding that 2 of 10 children with a history of measles became ill during the outbreak suggests that such histories are not a totally reliable indicator of immunity. Containment of the outbreak was attributed to the high level of immunity in the community and prompt initiation of control measures.     

Vaccination policy against hepatitis A in Italy

In Italy, improved sanitation and living conditions have led to a decline in the rate of hepatitis A infection among children generating an increasing proportion of adults susceptible to this virus. Shellfish consumption is a major source of infection while person to person transmission is important in the spread of infection and in the maintenance of outbreaks. Thus prevention of secondary HAV infection is a crucial point. A randomised controlled trial of hepatitis A vaccine in household contacts of people with sporadic HAV infection in Italy has shown a protective efficacy of 82% (CI 20-96%). The two secondary infections in the vaccine group were symptomless, suggesting that the disease expression may be weaker in vaccinated subjects.     

Mumps vaccine effectiveness and risk factors for disease in households during an outbreak in New York City

Background and objectives

Mumps outbreaks have been reported among vaccinated populations, and declining mumps vaccine effectiveness (VE) has been suggested as one possible cause. During a large mumps outbreak in New York City, we assessed: (1) VE of measles-mumps-rubella vaccine (MMR) against mumps and (2) risk factors for acquiring mumps in households.

Methods

Cases of mumps were investigated using standard methods. Additional information on disease and vaccination status of household contacts was collected. Case households completed follow-up phone interviews 78–198 days after initial investigation to ascertain additional cases. Mumps cases meeting the study case definition were included in the analysis. Risk factors for mumps were assessed, and VE was calculated using secondary household attack rates.

Results

Three hundred and eleven households with 2176 residents were included in the analysis. The median age of residents was 13 years (range <1–85), and 462 (21.2%) residents met the study mumps case definition. Among 7–17 year olds, 89.7% received one or more doses of MMR vaccine, with 76.7% receiving two doses. Young adults aged 10–14 years (OR = 2.4, CI = 1.3–4.7) and 15–19 years (OR = 2.5, CI = 1.3–5.0) were at highest risk of mumps. The overall 2-dose VE for secondary contacts aged five and older was 86.3% (CI 63.3–94.9).

Conclusions

The two-dose effectiveness of MMR vaccine against mumps was 86.3%, consistent with other published mumps VE estimates. Many factors likely contributed to this outbreak. Suboptimal MMR coverage in the affected population combined with VE may not have conferred adequate immunity to prevent transmission and may have contributed to this outbreak. Achieving high MMR coverage remains the best available strategy for prevention of mumps outbreaks.     

An outbreak of chickenpox at a child care centre in Western Australia. Costs to the community and implications for vaccination policy

OBJECTIVE: Between May and June 2002 an outbreak of chickenpox (CP) occurred at a child care centre in Perth, Western Australia. An epidemiological study was undertaken in order to determine the characteristics of the outbreak, assess vaccine effectiveness, and to define the direct and indirect costs associated with CP infections in young children. METHODS: A cohort study of the outbreak utilising attendance records and a telephone survey of parents was conducted. RESULTS: Of the 211 children attending the child care centre at the time of the outbreak, 44 contracted CP (attack rate 25.7%). In addition, two staff members, five secondary household contacts (secondary attack rate 38.5%) and four secondary non-household associated contacts were infected. There were no severe complications or any hospitalisations recorded in infected persons. Two cases had been vaccinated previously. Vaccine effectiveness for CP of any severity was 78.0% (95% CI 15.4-94.3%) while vaccine effectiveness against severe CP was 100%. Direct costs during this outbreak were estimated to be $54 per case and the total costs, including cost of parental time off work or study, were estimated to be $525.73 per case. CONCLUSIONS AND IMPLICATIONS: Although morbidity associated with CP in young children is not great, infection in childhood is almost universal. This study found that the average costs associated with each CP case were considerable. Since varicella vaccine affords good protection against CP, the recent inclusion of this vaccine in the Australian childhood vaccination schedule should save the community a considerable amount in direct and indirect costs if high coverage rates can be achieved.     

Social inequalities in COVID-19 vaccine acceptance and uptake for children and adolescents in Montreal,Canada

BackgroundThe success of current and prospective COVID-19 vaccine campaigns for children and adolescents will in part depend on the willingness of parents to accept vaccination. This study examined social determinants of parental COVID-19 vaccine acceptance and uptake for children and adolescents.MethodsWe used cross-sectional data from an ongoing COVID-19 cohort study in Montreal, Canada and included all parents of 2 to 18-year-olds who completed an online questionnaire between May 18 and June 26, 2021 (n = 809). We calculated child age-adjusted prevalence estimates of vaccine acceptance by parental education, race/ethnicity, birthplace, household income, and neighbourhood, and used multinomial logistic regression to estimate adjusted prevalence differences (aPD) and ratios (aPR). Social determinants of vaccine uptake were examined for the vaccine-eligible sample of 12 to 18 year-olds (n = 306).ResultsIntention to vaccinate children against COVID-19 was high, with only 12.4% of parents unlikely to have their child vaccinated. Parents with younger children were less likely to accept vaccination, as were those from lower-income households, racialized groups, and those born outside Canada. Children from households with annual incomes <$100,000 had 18.4 percent lower prevalence of being vaccinated/very likely vaccinated compared to household incomes ≥$150,000 (95% CI: 10.1 to 26.7). Racialized parents reported greater unwillingness to vaccinate vs. White parents (aPD = 10.3; 95% CI: 1.5, 19.1). Vaccine-eligible adolescents from the most deprived neighbourhood were half as likely to be vaccinated compared to those from the least deprived neighbourhood (aPR = 0.48; 95% CI: 0.18 to 0.77).Interpretation.This study identified marked social inequalities in COVID-19 vaccine acceptance and uptake for children and adolescents. Efforts are needed to reach disadvantaged and marginalized populations with tailored strategies that promote informed decision making and facilitate access to vaccination.     

Association between household food insecurity and nutritional outcomes among children in Northeastern of Peninsular Malaysia

BACKGROUND/OBJECTIVES

The purpose of the study was to investigate the relationship between household food insecurity and nutritional status of children in low-income households. A cross sectional study involved a survey of households (n = 223) receiving the financial assistance.

SUBJECTS/METHODS

Eligible mothers that fulfilled the inclusion criteria such as non-pregnant, non-lactating mothers, aged 18 to 55 years with their youngest children aged 2 to 12 years, were purposively selected. The Radimer/Cornell hunger and food-insecurity instrument was administered and children''s height and weight were measured.

RESULTS

About 16.1% of the households were food secure, while 83.9% experienced some kind of food insecurity. Out of food insecure category, 29.6% households were food insecure, 19.3% women were individual food insecure and 35.0% fell into the child hunger category. Education of the mother (P = 0.047), household size (P = 0.024), number of children (P = 0.024), number of children going to school (P = 0.048), total monthly income (P < 0.001), income per capital (P < 0.001), number of household members contributing to the income (P = 0.018) and food expenditure (P = 0.006) were significant risk factors for household food insecurity. The prevalence of underweight, stunting and wasting in children were 61.0%, 61.4% and 30.6% respectively. Based on multinomial logistic regression, children in food-insecure households were 2.15 times more likely to be underweight and three times to be stunted than children in the food-secure households.

CONCLUSIONS

The findings suggest that household food insecurity is associated with the nutritional status of the children in the rural area of Northeastern Peninsular Malaysia.     

An outbreak of influenza A in a nursing home.

An outbreak of influenza A occurred in an elderly population in a Maryland nursing home between December 8, 1980 and January 13, 1981 and involved 76 of the 170 residents. Throat swabs from two of 10 acutely ill residents yielded influenza A virus similar to the A/Taiwan/1/79 strain. Fourfold or greater increases in the titer of complement-fixing (CF) or hemagglutination-inhibiting (HI) antibodies were detected in paired sera from four of five ill residents and from none of four well residents. One hundred (62.9 per cent) of 159 residents with known vaccination histories had been vaccinated with trivalent influenza virus vaccine in October and November 1980. Crude illness attack rates and mortality rates were similar in vaccinees and nonvaccinees. Various risk factors and hypotheses were examined in an attempt to explain the apparent lack of vaccine efficacy.     

Reemergence of Human Monkeypox and Declining Population Immunity in the Context of Urbanization,Nigeria, 2017–2020

A monkeypox outbreak in Nigeria during 2017–2020 provides an illustrative case study for emerging zoonoses. We built a statistical model to simulate declining immunity from monkeypox at 2 levels: At the individual level, we used a constant rate of decline in immunity of 1.29% per year as smallpox vaccination rates fell. At the population level, the cohort of vaccinated residents decreased over time because of deaths and births. By 2016, only 10.1% of the total population in Nigeria was vaccinated against smallpox; the serologic immunity level was 25.7% among vaccinated persons and 2.6% in the overall population. The substantial resurgence of monkeypox in Nigeria in 2017 appears to have been driven by a combination of population growth, accumulation of unvaccinated cohorts, and decline in smallpox vaccine immunity. The expanding unvaccinated population means that entire households, not just children, are now more susceptible to monkeypox, increasing risk of human-to-human transmission.     

某幼儿园水痘暴发事件调查和疫苗保护效果研究

目的调查水痘暴发事件，了解水痘疫苗保护效果，为制定科学防控策略和措施提供依据。 方法搜索2018年9月1日至2019年1月23日，该幼儿园儿童和教职员工中出现典型的水痘样皮疹(丘疹或疱疹或结痂)者。采集8例患者的咽拭子标本开展病原学检测；利用"问卷星"和"江苏省预防接种综合服务管理信息系统"平台，收集6个班级的所有儿童的水痘疫苗接种等信息，调查疫苗的保护效果。 结果共搜索到水痘患者106例，儿童罹患率为14.5%(104/717)，教职工罹患率为2.8%(2/72)；首例患者为小6班儿童，2018年9月6日发病，疫情持续4个月，流行曲线显示为增殖模式，患者可分为8代。暴发波及8个班级，班级罹患率17.5%～58.5%；接种水痘疫苗者中的水痘罹患率为12.9%(8/62)，未接种水痘疫苗者中水痘罹患率为54.4%(81/149)，水痘疫苗保护率为76%(95%CI＝54%～88%)；37.5%(3/8)患者咽拭子标本水痘-带状疱疹病毒核酸阳性。 结论在低免疫水平人群中暴发水痘的防控难度大，水痘疫苗保护效果较好，建议进一步加强水痘疫苗接种宣传，将儿童水痘疫苗接种纳入扩大免疫规划。     

An outbreak of measles in a rural Queensland town in 1997; an opportunity to assess vaccine effectiveness.

This report describes a measles outbreak in a rural town in south-east Queensland and presents the results of a vaccine effectiveness (VE) study performed during this outbreak. It is important to assess the effectiveness of a vaccine in an outbreak to determine if the outbreak is due to failure of the vaccine or failure to vaccinate. There were 44 cases of measles amongst local residents, which represents a notification rate of 396.7 per 100,000 population. Case investigations identified a group of people who had been exposed to measles at a seminar. The attack rate for the seminar cohort was 18% (11/61). This presented an opportunity to conduct a VE study using data about children aged less than 16 years who attended the seminar. In this cohort of 23 attendees, all 7 children who had not received any measles vaccinations became cases whilst the 6 who were fully vaccinated for their age according to NHMRC guidelines were protected from measles illness. Although there were insufficient fully vaccinated cohort members to reliably estimate VE for this group, the vaccine was 84.6% (95% CI: 15.0-99.7%) effective for those who had received at least one validated dose of vaccine. Despite the sample size limitations, the results support the view that failure to vaccinate rather than vaccine failure contributed to the high infection rate in the seminar cohort.     

Influenza vaccination—acceptance in an industrial population

Smith, J. W. G., Pollard, R., Fletcher, W. B., Barker, R., and Lewis, J. R. (1974).British Journal of Industrial Medicine,31, 292-297. Influenza vaccination—acceptance in an industrial population. Influenza vaccination was offered in a pharmaceutical factory of approximately 6 000 employees in December 1971 and again in December 1972. The rate of acceptance of vaccination was 42% in 1971 but fell to only 27% in 1972, and was highest among middle-aged married women and lowest among young men. Only 57% of employees who were vaccinated in 1971 and were still employed in 1972 accepted vaccination on the second occasion. Re-vaccination was commoner in staff (64%) than in works employees (52%) in all age and sex categories, and was commoner in older than in younger employees. Only 6% of employees who did not accept vaccination in 1971 accepted the vaccine in 1972. Among new employees who were not in the factory in December 1971 the acceptance rate was 21% in 1972.

Between January 1971 and 1972 vaccinated employees left the factory less commonly (15%) than those who had not accepted vaccination (22%). Loss of working time in April to September 1972, i.e., when it is unlikely that influenza would have influenced the returns, was 21% higher among non-vaccinated employees than in vaccinated employees, the difference being due to certified illness of more than three days' duration.

The benefit to be derived from offering influenza vaccination to a factory or office population will depend, among other factors, on the proportion of employees who accept the offer and on the characteristics of this volunteers group. The low take-up rate (27%) observed in the second year suggests that annual influenza vaccination is unlikely at the present time to have a marked effect on absence during outbreak periods. In comparison with the non-volunteers in the present study, the volunteers included a higher proportion of married women, older persons, and staff employees and were less inclined to leave employment, and lost less working time from certificated sickness absence. The value of offering vaccine may therefore be greatest in an established office employing a high proportion of older women. The differences between the volunteers and non-volunteers, particularly the better sickness absence record of the former, indicates that the effect of influenza vaccination cannot reliably be assessed only from a comparison of absence returns between vaccinated and unvaccinated employees.