Identifying target groups for a potential vaccination program during a hepatitis A communitywide outbreak

Infectious Diseases: The Role of the Healthcare Professional

For the healthcare professional dealing with infections presents two main problems. First, managing detainees or police personnel who have contracted a disease and may be infectious or unwell, and second, handling complainants of assault, including police officers, who have potentially been exposed to an infectious disease. This chapter addresses some general principles of infection control and safety in the working environment and then goes on to discuss some infections that may be encountered in police custody and how they can best be managed.

The impact of epidemics of vaccine-preventable disease on vaccine uptake: lessons from the 2011-2012 US pertussis epidemic

Conventional wisdom suggests that if there is a vaccine that is effective in preventing a disease, vaccine uptake will increase when the disease risk is high. Recent evidence, however, suggests that this may not always be the case. In a study we conducted in Washington State, we found no population-level increase in pertussis vaccination of infants during a pertussis epidemic. In this paper, we aim to review what is known about the history of vaccine uptake during epidemics of vaccine-preventable disease, the challenges facing public health campaigns responding to these epidemics, and how the effect of a vaccine-preventable disease epidemic on vaccine uptake can be studied.

The changing epidemiology of hepatitis A in Arizona following intensive immunization programs (1988-2007)

INTRODUCTION

Arizona had the highest hepatitis A incidence of any U.S. state during 1987-1997. In 1995, the first hepatitis A vaccines became available in the U.S. A series of hepatitis A vaccination policies and recommendations were implemented in 1996-2006. Our objective was to examine the shifting epidemiologic patterns in hepatitis A in Arizona from 1988 to 2007.

METHODS

Passive surveillance reports to the Arizona Department of Health Services were used to compare hepatitis A rates by age, race/ethnicity and geographic area, before and after widespread vaccination. Reported risk factors and possible sources of infection were compared for two time periods. Age-adjusted incidence during three periods was mapped.

RESULTS

Overall hepatitis A incidence in Arizona fell from 58 cases per 100,000 in 1988 to 2 per 100,000 in 2007. The proportion of reported cases among children dropped from 62% in 1994-1995 to 32% in 2006-2007. Racial/ethnic disparities between American Indians and non-Hispanic White populations have been eliminated. The geographic distribution of cases within the state has shifted. Earlier cases were likely to report contact with another hepatitis A case or childcare facilities, while later cases indicated recent international travel.

CONCLUSION

A major shift in the overall burden of hepatitis A and hepatitis A transmission has occurred in Arizona since the widespread implementation of immunization policies and the concomitant rise in vaccination rates in the state. Current transmission has shifted to older age groups and disparities by race/ethnicity are now highest in Hispanic populations. Future strategies to further reduce hepatitis A transmission may require broadening recommendations to include general adult populations without previous vaccination history.

Infectious Diseases: The Role of the Forensic Physician

Infections have plagued doctors for centuries, both in the diagnosis of the specific diseases, and the identification and subsequent management of the causative agents. There is a constant need for information as new organisms emerge, existing ones develop resistance to current drugs or vaccines and there are changes in epidemiology and prevalence. In the twenty-first century, obtaining this information has never been more important. Population migration, and the relatively low cost of flying, means that unfamiliar infectious diseases may be brought into industrialised countries. An example of this was an outbreak of severe acute respiratory syndrome (SARS), which was first recognised in 2003. Despite modern technology and a huge input of money, it took months for the agent to be identified, a diagnostic test to be produced, and a strategy for disease reporting and isolation to be established.

Response to hepatitis A epidemic: emergency department collaboration with public health commission

In 2004, a hepatitis A outbreak occurred in Boston, Massachusetts with an incident rate of 14.8 per 100,000, compared to 4.2 in 2003. The majority of cases had risk factors of homelessness, injection drug use, or incarceration. In September 2004, the Boston Public Health Commission began an immunization campaign partnering with health centers, detoxification centers, homeless shelters, and our Emergency Department (ED) to increase the number of hepatitis A vaccinations and stem the epidemic. The ED rapidly developed (within days) a vaccination protocol. Hepatitis A vaccinations were offered to patients over age 21 years who were homeless, substance users, or incarcerated. From October 2004 through January 2005, the ED vaccinated 122 patients notable for 64% male, 61% homeless, 28% substance users, and 11% incarcerated. No reported vaccination reactions occurred. There was a 51% decrease in the number of cases of Hepatitis A in Boston in the first 4 months of 2005. As a partner, the ED helped stem the epidemic by rapidly providing vaccinations to those most vulnerable. This project provides a model for future collaborations between EDs and local, state, and federal organizations to address epidemics.

Convenience is the key to hepatitis A and B vaccination uptake among young adult injection drug users

BACKGROUND

Despite CDC recommendations to vaccinate injection drug users (IDUs) against hepatitis A virus (HAV) and hepatitis B virus (HBV) infections, coverage remains low. Vaccination programs convenient to IDUs have not been widely implemented or evaluated. We assessed whether convenience and monetary incentives influenced uptake of free vaccine by 18-30-year-old IDUs in five U.S. cities.

METHODS

IDUs recruited from community settings completed risk behavior self-interviews and testing for antibodies to HAV (anti-HAV) and hepatitis B core antigen (anti-HBc). Vaccine was offered presumptively at pre-test (except in Chicago); on-site availability and incentives for vaccination differed by site, creating a quasi-experimental design.

RESULTS

Of 3181 participants, anti-HAV and anti-HBc seroprevalence was 19% and 23%, respectively. Although 83% of participants were willing to be vaccinated, only 36% received > or =1 dose, which varied by site: Baltimore (83%), Seattle (33%), Los Angeles (18%), New York (17%), and Chicago (2%). Participation was highest when vaccine was available immediately on-site and lowest when offered only after receiving results. Monetary incentives may have increased participation when on-site vaccination was not available.

CONCLUSION

IDUs were willing to be vaccinated but immediate, on-site availability was critical for uptake. Convenience should be a key consideration in designing strategies to increase vaccine coverage among IDUs.

Exposure to school children as a risk factor in a community outbreak of hepatitis A in young adults: a case control study

To investigate risk factors during a community outbreak of hepatitis A we carried out a case- control study of 35 cases and 49 matched controls using an interviewer-administered questionnaire on clinical history, travel, household details including domestic toilet facilities, infectious contacts, and food history. Of 99 cases notified in the city during the outbreak year, 50 (51%) were young adults age 15-34 years. Hepatitis A infection was independently associated with household contact with a case (P=0.0005), and sharing a household with children in primary school (OR 3.4, 95% CI 1.2-9.5, P=0.008) with risk increasing with number of primary-school pupils in the household (chi(2) for linear trend 6.47, P=0.01). We concluded that in a population with a low prevalence of hepatitis A, adults who live in the same household as primary-school-age children are at increased risk of acquiring the infection during community outbreaks.

Parental knowledge, attitudes, and practices associated with not receiving hepatitis A vaccine in a demonstration project in Butte County, California

OBJECTIVE

To determine hepatitis A vaccination coverage and factors associated with not receiving hepatitis A vaccine among children.

METHODS

A random cluster sample survey was conducted of parents of children who attended kindergarten in Butte County, California, in 2000. Because of a history of recurrent epidemics, an aggressive hepatitis A vaccination program was ongoing during the time this study was conducted. Receipt of 1 or 2 doses of hepatitis A vaccine was studied.

RESULTS

Of 896 surveys sent, 648 (72%) were completed. The vaccination coverage for at least 1 dose of hepatitis A vaccine was 398 (62%) and for 2 doses was 272 (42%). Factors associated with not receiving the vaccine included lack of provider recommendation (vs having recommendation; odds ratio [OR]: 7.8; 95% confidence interval [CI]: 4.9-12.2), not having heard of the vaccine (OR: 2.4; 95% CI: 1.2-4.9), and parent's not perceiving child is likely to get hepatitis A (vs perceiving child might get disease; OR: 2.1; CI: 1.6-2.9).

CONCLUSIONS

Vaccination coverage among kindergartners did not reach high levels (ie, >90%), despite aggressive vaccination efforts in this community. Lack of provider recommendation and lack of parental awareness of hepatitis A vaccine were the 2 most significant factors associated with failure to receive vaccine. These findings will facilitate the development of vaccination strategies for communities in which hepatitis A vaccination is recommended.

Risk groups for hepatitis A virus infection

We report the conduct and results of a systematic search for evidence of risk of infection with hepatitis A virus (HAV) among blood transfusion recipients, travellers, the military, healthcare workers, sewage workers, foodhandlers, day care assistants, institutionalised subjects, blood transfusion recipients, drug addicts, homosexuals, prisoners and other risk groups such a liver transplantees. We report our recommendations for the use of the HAV vaccine in these groups.

Prevalence of hepatitis A virus infection among sewage workers in Georgia

BACKGROUND

Wastewater (WW) workers could have opportunity for direct contact with raw sewage, which might contain hepatitis A virus (HAV).

METHODS

A serologic survey of WW workers and a comparison population of roads and drainage workers (RD). Factors potentially associated with anti-HAV positivity were evaluated in univariate and multivariate analyses.

RESULTS

Among the 365 WW workers, overall anti-HAV prevalence was 38%, similar to that (35%) of the 166 RD workers (P = 0.5). Prevalence varied by wastewater job type from 45% among the 164 field crew workers to 32% among the 201 treatment plant workers. In multivariate modeling, factors associated with anti-HAV positivity included age > or = 40 years (odds ratio [OR] = 2.4; 95% CI = 1.6-3.7), black compared to other races (OR = 2.4; 95% CI = 1.5-3.8), birth outside the United States (OR = 7.5; 95% CI = 3.0-18.6), a high school education or less (OR 2.1; 95% CI = 1.4-3.2) and work on the field crew compared to RD work (OR 1.6; 95% CI = 1.1-2.4).

CONCLUSIONS

These results are consistent with no or a small increased risk of hepatitis A among WW workers, and do not provide a clear mandate for hepatitis A vaccination of these workers. Am. J. Ind. Med. 43: 172-178, 2003.

Foodborne viruses

Foodborne and waterborne viral infections are increasingly recognized as causes of illness in humans. This increase is partly explained by changes in food processing and consumption patterns that lead to the worldwide availability of high-risk food. As a result, vast outbreaks may occur due to contamination of food by a single foodhandler or at a single source. Although there are numerous fecal-orally transmitted viruses, most reports of foodborne transmission describe infections with Norwalk-like caliciviruses (NLV) and hepatitis A virus (HAV), suggesting that these viruses are associated with the greatest risk of foodborne transmission. NLV and HAV can be transmitted from person to person, or indirectly via food, water, or fomites contaminated with virus-containing feces or vomit. People can be infected without showing symptoms. The high frequency of secondary cases of NLV illness and - to a lesser extent - of hepatitis A following a foodborne outbreak results in amplification of the problem. The burden of illness is highest in the elderly, and therefore is likely to increase due to the aging population. For HAV, the burden of illness may increase following hygienic control measures, due to a decreasing population of naturally immune individuals and a concurrent increase in the population at risk. Recent advances in the research of NLV and HAV have led to the development of molecular methods which can be used for molecular tracing of virus strains. These methods can be and have been used for the detection of common source outbreaks. While traditionally certain foods have been implicated in virus outbreaks, it is clear that almost any food item can be involved, provided it has been handled by an infected person. There are no established methods for detection of viruses in foods other than shellfish. Little information is available on disinfection and preventive measures specifically for these viruses. Studies addressing this issue are hampered by the lack of culture systems. As currently available routine monitoring systems exclusively focus on bacterial pathogens, efforts should be made to combine epidemiological and virological information for a combined laboratory-based rapid detection system for foodborne viruses. With better surveillance, including typing information, outbreaks of foodborne infections could be reported faster to prevent further spread.

Multiple modes of hepatitis A virus transmission among methamphetamine users

Methamphetamine users are at increased risk of hepatitis A, but modes of transmission are unclear. The authors conducted a case-control study among methamphetamine users during an outbreak in Iowa in 1997. Twenty-eight reported, laboratory-confirmed, hepatitis A cases did not differ from 18 susceptible controls with respect to age, sex, or number of doses used. When compared with controls in multivariate analysis, case-patients were more likely to have injected methamphetamine (odds ratio (OR) = 5.5, 95% confidence interval (CI): 1.1, 27), to have used methamphetamine with another case-patient (OR = 6.2, 95% CI: 0.95, 41), and to have used brown methamphetamine (OR = 5.5, 95% CI: 0.51, 59). Receptive needle sharing was reported by 10 of the 20 case-patients who injected. Methamphetamine use with another case-patient was also associated with hepatitis A in an analysis restricted to noninjectors (OR = 17, 95% CI: 1.0, 630). During this outbreak, hepatitis A may have been transmitted from person to person among methamphetamine users through the fecal-oral and the percutaneous routes. Methamphetamine users should be vaccinated against hepatitis A and should be given immune globulin if they used methamphetamine with a case-patient in the last 2 weeks. Persons who intend to continue using methamphetamine should be advised about safer practices.