Community-wide Outbreak Of Hepatitis Research Articles

Investigating a community wide outbreak of hepatitis A in Kerala, India.

Background:There was an outbreak of acute hepatitis in Nellikuzhy panchayat of Kothamangalam taluk, Ernakulam district, Kerala, during November and early December 2016. Objective of this study is to describe the epidemiological features of the outbreak and to identify the probable source.Materials and Methods:The outbreak was defined in terms of time, place, and person. A hypothesis was generated and tested using a case–control study. Cases were selected by simple random sampling from the line list and controls were age-matched neighborhood individuals without any history of jaundice. Chi-square test, univariate analysis, and multi-variate logistic regression analyses were done to identify the probable risk factors.Results:Around 223 hepatitis A cases were identified. Attack rate was found to be highest among the age group of 16-30 years at 1.44% and was eight times higher among males. Epidemic curve suggested a point source outbreak possibly from exposure to food or water from a newly opened hotel in the area. The case–control study confirmed the hypothesis with a statistically significant association between cases and history of exposure to food from the hotel [OR 120; 95% CI 14.6–996.2; P value < 0.001].Conclusion:Observations and results of the case–control study revealed that the probable source of the Hepatitis A outbreak at Nellikuzhy panchayat was a hotel. The study findings also add evidences to the changing epidemiological pattern of hepatitis A in Kerala, and warrant the necessity to enforce food safety rules in the State.

Comments on investigating a community wide outbreak of hepatitis a in India.

Comments on investigating a community wide outbreak of hepatitis a in India.

The important role of early diagnosis and preventive management during a large-scale outbreak of hepatitis A in Thailand

Introduction: Acute hepatitis A is a worldwide public health problem especially in developing countries. Recently, a large, community-wide outbreak of hepatitis A occurred in the northeast part of Thailand.Methods: Demographic and clinical data as well as blood samples were collected and analyzed from patients with acute hepatitis who attended the Buengkan Provincial Hospital from June to September 2012. About 1619 patients with clinical symptoms of hepatitis A visited the hospital during the outbreak which manifested in three waves. Blood samples were collected from 205 patients.Results: One hundred and seventy eight patients had hepatitis A confirmed by the presence of anti-hepatitis A virus (HAV) IgM and/or HAV-RNA. The sensitivities for anti-HAV IgM and HAV-RNA were 95·5% (170/178) and 61·8% (110/178), respectively. When HAV-RNA was combined with anti-HAV IgM test, this increased the diagnostic yield by 7·2% (8/111) in the early phase of the acute infection (less than 5 days). Investigation of the molecular structure of the detected viruses indicated that all of the infections were caused by HAV genotype IA. There were no fatalities from this outbreak. Rapid detection, health education, sanitation campaigns, and vaccination offered on a voluntary basis have steadily reduced the number of infected patients and stopped the outbreak.Conclusion: Occasionally a large-scale outbreak of HAV genotype IA can occur. A combination of HAV-RNA and anti-HAV IgM tests can increase the diagnostic yield during the early phase of the acute infection. Early diagnosis and preventive management campaigns can slow down and stop the outbreak.

Community-wide outbreak of hepatitis A in Latvia in 2008 – an update

An outbreak of hepatitis A has been ongoing in Latvia with 2,817 confirmed cases reported between 20 November 2007 and 31 December 2008. Initially the spread of infection was due to transmission among drug users and other high-risk groups, as well as several outbreaks in Riga (affecting a school and a restaurant), but in the second half of the year led to a community-wide increase in the number of cases. Molecular analysis of 100 strains showed that 95 belonged to genotype IA, of which 89 were identical and six were single nucleotide variants of the same sequence.

Community-wide outbreak of hepatitis A in Latvia, in 2008

Since November 2007, an increase in the number of reported hepatitis A cases has been observed in Latvia. The aim of this report is to provide an update on the descriptive epidemiology of hepatitis A in Latvia and suggest some possible explanations of the recent increase in incidence.

The role of child care in a community-wide outbreak of hepatitis A.

To evaluate the role of child care centers in a community-wide hepatitis A epidemic. We analyzed surveillance data during an epidemic in Maricopa County, Arizona, from January to October 1997 and conducted a case-control study using a sample of cases reported from June to November. Cases were physician-diagnosed and laboratory confirmed; control subjects were frequency matched by age and neighborhood. Information regarding hepatitis A risk factors, including child care-related exposures, was collected. Characteristics of all licensed child care centers in the county were obtained through review of computerized lists from the Arizona Office of Child Day Care Licensing. Surveillance data were linked to the child care list to determine which centers had reported hepatitis A cases. We conducted univariate and multivariate conditional logistic analyses and calculated population attributable risks (PAR). In total, 1242 cases (50/100 000 population) were reported. The highest rates occurred among people aged 0 to 4 (76/100 000), 5 to 14 (95/100 000), and 15 to 29 (79/100 000) years. The most frequently reported risk factor was contact with a hepatitis A patient (45%). However, nearly 80% of these contacts were with individuals who attended or worked in a child care center. Overall, child care center-related contact could have been the source of infection for 34% of case-patients. In the case-control study, case-patients (n = 116) and control subjects (n = 116) did not differ with respect to demographic characteristics. A total of 51% of case-patients compared with 18% of control subjects reported attending or working in a child care setting (direct contact; adjusted odds ratio [OR]: 6.0; 95% confidence interval [CI]: 2.1-23.0) or being a household contact of such a person (indirect contact; OR: 3.0; 95% CI: 1.3-8.0). In age-stratified analyses, the association between hepatitis A and direct or indirect contact with child care settings was strongest for children <6 years old and adults aged 18 to 34 years. Household contact with a person with hepatitis A also was associated with hepatitis A (OR: 9.2; 95% CI: 2.6-58.2). The presence of a child <5 years old in the household was not associated with hepatitis A. The estimated PAR for direct child care contact was 23% (95% CI: 16-34), for indirect child care contact was 21% (95% CI: 13-35), and for any child care contact was 40% (95% CI: 30-53). Information on 1243 licensed child care centers was obtained, with capacity ranging from 5 to 479 slots (mean: 87). Thirty-four (2.7%) centers reported hepatitis A cases. Centers that had a mean capacity of >50 children were more than twice as likely to have had a reported case of hepatitis A (OR: 2.6; 95% CI: 1.1-6.7). Among the 747 centers that accepted >50 children, having infant (OR: 3.7; 95% CI: 1.6-8.3), toddler (OR: 6.3; 95% CI: 2.2-20.0), or full-day service (OR; undefined; 95% CI: 1.7- ~) was associated with having a reported case of hepatitis A. In Maricopa County, people associated with child care settings are at increased risk of hepatitis A, and child care attendees may be an appropriate target group for hepatitis A vaccination. Considering the estimated proportion of children who attended child care and were old enough to receive hepatitis A vaccine (>/=2 years of age) and the calculated PAR, approximately 40% of cases might have been prevented if child care center attendees and staff had been vaccinated. However, epidemiologic studies indicate that the proportion of cases that are attributable to child care center exposure varies considerably among counties, suggesting that this exposure may be associated with an increased risk of hepatitis A in some communities but not in others. To prevent and control hepatitis A epidemics in communities, the Advisory Committee on Immunization Practices and the American Academy of Pediatrics have adopted a long-term strategy of routine vaccination of children who live in areas with consistently elevated hepatitis A rates. After demonstrating cost-effectiveness, a rule was implemented in January 1999 to require hepatitis A vaccination of all children who are aged 2 to 5 years and enrolled in a licensed child care facility in Maricopa County. Other communities with similar epidemiologic features might consider routine vaccination of child care center attendees as a long-term hepatitis A prevention strategy. Consistent with current recommendations, in communities with persistently elevated hepatitis A rates where child care center attendance does not play an important role in hepatitis A virus transmission in the community, child care centers may nonetheless provide a convenient access point for delivering hepatitis A as well as other routine childhood vaccinations.

Genetic relatedness of hepatitis A virus isolates during a community‐wide outbreak

In 1993–94, a community-wide outbreak of hepatitis A occurred in Stanislaus County, California. Stool specimens collected from a sample of 33 case patients were used to evaluate the duration of hepatitis A virus (HAV) excretion and the genetic relatedness of HAV isolates. Twenty-four percent of the patients had a stool sample positive for HAV antigen by enzyme immunoassay, whereas 91% had at least one stool positive for HAV RNA by RT-PCR amplification. Children were found to excrete low levels of HAV RNA for up to 10 weeks after the onset of symptoms. Analysis of the HAV VP1 amino terminus and VP1/P2A regions showed that a limited number of HAV isolates circulated during the epidemic and the majority of the cases were infected with the same strain. J. Med. Virol. 62:144–150, 2000. © 2000 Wiley-Liss, Inc.

Genetic relatedness of hepatitis A virus isolates during a community-wide outbreak

In 1993-94, a community-wide outbreak of hepatitis A occurred in Stanislaus County, California. Stool specimens collected from a sample of 33 case patients were used to evaluate the duration of hepatitis A virus (HAV) excretion and the genetic relatedness of HAV isolates. Twenty-four percent of the patients had a stool sample positive for HAV antigen by enzyme immunoassay, whereas 91% had at least one stool positive for HAV RNA by RT-PCR amplification. Children were found to excrete low levels of HAV RNA for up to 10 weeks after the onset of symptoms. Analysis of the HAV VP1 amino terminus and VP1/P2A regions showed that a limited number of HAV isolates circulated during the epidemic and the majority of the cases were infected with the same strain.

Use of hepatitis A vaccine in a community-wide outbreak of hepatitis A.

Hepatitis A outbreaks in communities are often difficult to control. From July 1994 through June 1995, 676 cases of hepatitis A were reported in Shelby County, Tennessee. With the licensure of a hepatitis A vaccine in February 1995, a new tool for outbreak control became available. During August-October 1995, a mass vaccination campaign was conducted. A total of 34,054 children received the first dose of hepatitis A vaccine. From December 1995 through December 1996, the number of hepatitis A cases reported inside the intervention area declined by 64%; outside the intervention area, the number of cases declined by 40%. The precise contribution of the vaccine campaign to the decline in the number of outbreak cases is difficult to quantify because community outbreaks often wane over time. The vaccine campaign may have hastened the decline of the number of outbreak cases. Future interventions should consider an earlier campaign with greater vaccine coverage.

A community-wide outbreak of hepatitis a: Risk factors for infection among homosexual and bisexual men

To assess risk factors for hepatitis A infection among homosexual and bisexual men during a community-wide outbreak of hepatitis A in New York City. Twenty-five homosexual and bisexual men, 20 to 49 years of age with hepatitis A identified from health department surveillance data (cases) were compared with 42 homosexual and bisexual men of similar age distribution who were seronegative for hepatitis A virus and identified from private physician offices (controls). Odds ratio (OR) were determined for acute hepatitis A infection according to demographics, numbers of sexual partners, frequency of specific sexual behaviors, and self-reported human immunodeficiency virus status. Cases had more anonymous sex partners (0 to 1 partner versus > 1 partner) than controls during the 6 weeks before illness onset (OR = 4.4, 95% confidence interval [CI] 1.4 to 14.4). Cases were more likely than controls to have engaged in group sex (OR = 3.8, 95% CI 1.1 to 12.6). Among specific sexual behaviors examined, oral-anal intercourse (oral role) and digital-rectal intercourse (digital role) with anonymous sex partners were more commonly reported by cases than controls (OR = 9.7, 95% CI 1.2 to 78.7 and OR = 2.6, 95% CI 1.0 to 7.4, respectively). Multivariate analysis showed that > 1 anonymous sex partner, group sex, oral-anal intercourse, and digital-rectal intercourse were associated with illness in models controlling for duration of sexual activity. Because these variables were highly correlated, independent risk could not be evaluated in a single model. Hepatitis A infection among homosexual and bisexual men is associated with oral-anal and digital-rectal intercourse, as well as with increasing numbers of anonymous sex partners and group sex. These findings reinforce the importance of developing educational activities for homosexual and bisexual men that focus on risk reduction for hepatitis A as well as other sexually transmitted disease spread via the fecal-oral route.

Community wide outbreak of hepatitis A linked to children in day care centres and with increased transmission in young adult men in Florida 1988-9.

To investigate a community wide outbreak of hepatitis A (HA). Description of the outbreak, with a case-control study to assess transmission. A Florida county, USA, 1988-9. A total of 311 cases of HA. A 13 month outbreak of HA is described. Most of the 311 cases (95%) were residents of a large metropolitan area (attack rate per 10,000 population (AR) = 3.7) and two smaller cities (AR = 61.5 and AR = 6.4). The ARs were greater for males than females and for residents aged 25-34 years (9.7) and < 5 years (8.3). Altogether 37% of cases were linked to day care centres, independent of the city of residence. A household case-control study showed an increased risk of HA in households in which a child attended a day care centre (p = 0.02), and centres that could take more than 50 children had an increased risk of HA introduction than smaller ones (p = 0.05). Day care centres were an important source of HA in the community, and the need for timely surveillance and immunoglobin prophylaxis is emphasised. Homosexual transmission may have played an important role in this outbreak.

Community-wide Outbreak of Hepatitis A Among an Indian Population in Oklahoma

Between September 1983 and September 1984, 118 cases of hepatitis A were reported from Caddo County, Oklahoma. No common source was identified, and the epidemic curve suggested person-to-person transmission. In July 1984, enhanced control measures were implemented; these consisted of improvements in surveillance, standardization of case investigation, an expanded, although targeted, use of immune globulin, and a public awareness campaign. Control measures resulted in a decrease in the delay between onset of symptoms and case report (from 12 days to 4 days), an increase in the percentage of patients with confirmed cases interviewed (from 77% to 100%), an increase in the percentage of patients reporting contact with a previous case (from 39% to 72%), and an increase in the average number of household-like contacts per case (from seven to 27). Within two incubation periods of the implementation of enhanced controls, the outbreak ended. These data indicate that community-wide outbreaks of hepatitis A can be stopped with an intensive epidemiologic approach, coupled with the expanded and targeted use of immune globulin.