MMWR

Morbidity and Mortality Weekly Report

Multistate Outbreak of Norovirus Gastroenteritis Among Attendees at a Family Reunion — Grant County, West Virginia, October 2006

PRESS CONTACT: West Virginia Department of Health and Human Resources
Office of Communications and Legislative Affairs
(304) 558-7899

During times of peak norovirus activity, multiple sources of infection and viral strains may converge in a single outbreak, emphasizing the importance of appropriate handwashing practices and the exclusion of ill persons from social gatherings as disease-prevention strategies. In October of 2006, an outbreak of acute gastroenteritis caused by norovirus was reported among attendees at a family reunion in West Virginia. In response, the West Virginia Department of Health & Human Resources led a collaborative, multijurisdictional epidemiologic investigation including a cohort study and laboratory analyses to determine the source of infection and appropriate control measures. The results of this investigation suggest that illness was independently introduced into the reunion by potential two persons from West Virginia and one family of four from New York. Food items likely were contaminated by these ill persons when they attended the reunion and infection was then propagated through a combination of person-to person contact and foodborne transmission. Laboratory evidence confirmed that at least two different norovirus strains were circulating among attendees. This outbreak highlights challenges of investigating and controlling norovirus outbreaks, particularly during periods of peak norovirus activity, including the variable modes of infection transmission and the convergence of multiple sources of infection and viral strains in a single outbreak. As this outbreak demonstrates, prompt public health investigations of norovirus outbreaks often require effective collaboration among multiple state and local health departments. To prevent outbreaks of this highly transmissible infection, public health officials should emphasize the importance of appropriate handwashing practices and the exclusion of ill persons from social gatherings.

Hepatitis A Vaccination Coverage Among Children Aged 24–35 Months — United States, 2004–2005

PRESS CONTACT: CDC Division of Media Relations
(404) 639-3286

The highest hepatitis A vaccination coverage levels among children aged 24-35 months and the greatest decline in acute hepatitis A infections occurred in states, counties and communities where hepatitis A vaccination has been routinely recommended since 1999. Hepatitis A vaccine was licensed for use in children =24 months of age in 1995. Since 1999, the vaccine has been routinely recommended for children living in states, counties and communities where the rate of hepatitis A virus (HAV) infections was twice the 1987-1997 national average. In 2005, 57 percent of children aged 24-35 months living in these areas received one dose of hepatitis A vaccine compared with 3 percent of children aged 24-35 months living in areas where no specific vaccination recommendation existed. The national incidence of hepatitis A infections has substantially declined from 12 per 100,000 in 1995 to 1.5 per 100,000 in 2005. The decline in HAV infections has been greatest in areas where childhood vaccination has been routinely recommended and rates in these areas now approach those seen in areas where there has been no specific recommendation for childhood vaccination. The 2005 licensure of the hepatitis A vaccine for use in children aged =12 months and the 2006 recommendation for routine hepatitis A vaccination of all children should result in improved coverage and further reductions in disease incidence.

Progress Toward Interruption of Wild Poliovirus Transmission — Worldwide, January 2006–May 2007

PRESS CONTACT: CDC Division of Media Relations
(404) 639-3286

The most common type of poliovirus – wild poliovirus type 1 – has been substantially curtailed worldwide; the world has the opportunity to reach the goal of global polio eradication, as long as there is collective global will and sustained political commitment from the highest levels. The transmission of wild poliovirus type 1 – the most common type of poliovirus – has been substantially curtailed in the remaining endemic countries of Afghanistan, India, Nigeria, and Pakistan. Challenges to achieving polio eradication continue in these countries, including low coverage during supplementary immunization activities and routine services in Nigeria, intense virus circulation in some districts in northern India, and accessing children in insecure areas of Afghanistan-Pakistan border areas. Strategies are being implemented to address each of these challenges. With collective global will and sustained political commitment from the highest levels, the world has the opportunity to reach the goal of global polio eradication.

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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES