Hepatitis A Is Much More Common in US than Thought

HEPATITIS A - USA: UPDATE ************************* A ProMED-mail post <http://www.promedmail.org> ProMED-mail, a program of the International Society for Infectious Diseases <http://www.isid.org> [1] Date: Wed 8 May 2002 From: ProMED-mail <promed@promedmail,org> Source: Reuters Health, Mon 6 May 2002 [edited] <http://www.nlm.nih.gov/medlineplus/news/fullstory_7460.html> Hepatitis A Is Much More Common in US than Thought -------------------------------------------------- NEW YORK: Every year, a quarter of a million people in the US may become infected with hepatitis A, nearly 10 times the number of cases that are reported to the federal government. What's more, the majority of these cases may occur in children under the age of 10, a finding which may have implications for future immunization practices, according to researchers from the US Centers for Disease Control and Prevention. Hepatitis A virus is a liver-infecting virus spread through contaminated food and water. It is rarely fatal and most often causes jaundice, a yellowing of the skin due to reduced liver function, and flu-like symptoms that can persist for weeks. Unlike other forms of hepatitis, it does not cause a chronic, lingering infection. National surveys have suggested that 47 million Americans have antibodies in their body that recognize hepatitis A virus, meaning that these individuals were exposed to the virus at some point in their life. Yet, the number of reported disease cases has been much lower; only 26 000 a year between 1980 and 1999. Doctors may not report cases to the federal government, and symptoms in children are often nonexistent or unrecognizable. For example, symptoms such as fever and diarrhea are typical of many types of illnesses, and may not even warrant a doctor's visit. In a paper published in the May 2002 issue of the journal Pediatrics (2002;109:839-845), Armstrong and Bell use a mathematical model to estimate actual cases of hepatitis A virus infection by taking into account under-reporting by doctors and patients. Based on the model, Armstrong and Bell estimate that an average of 271 000 hepatitis A virus infections occurred every year between 1980 and 1999, 10.4 times the actual number reported. Nearly 60 percent of these cases occurred in children aged 9 years and under, and only about 40 percent were accompanied with recognizable jaundice symptoms. The high number of cases in children suggests that: "Vaccinating children should have a strong herd immunity effect, such that by vaccinating one child you prevent him or her from becoming infected and from transmitting an infection to other children and adults," Armstrong said. Armstrong noted that: "Although it is too early to make policy changes based on these findings, the data gives further support to the notion that immunizing children will have a big impact on reducing hepatitis A rates overall." [Byline: Charnicia E. Huggins] ****** [2] Date: Mon 6 May 2002 From: ProMED-mail <promed@promedmail.org> Source: Associated Press report, Sun 5 May 2002 [edited] Polk County Florida: Hepatitis A Outbreak ----------------------------------------- Following the death of a 29-year-old woman in Bartow, Florida, from hepatitis A in February 2002, investigators linked her death with a cook at John's Restaurant who had also been diagnosed with the disease. A total of 5 other people who became infected with the virus also ate at the restaurant. Polk County has recorded 138 cases of hepatitis A already this year, compared to 153 for all of 2000. Based on data from the Centers for Disease Control and Prevention, Polk County is reporting cases of hepatitis A at 6 times the national average. Health officials in the county assert that the outbreak of hepatitis A is due to methamphetamine users who transmit the virus through sex and needle sharing, and they are working to research each patient with hepatitis A in order to determine where it started and provide vaccinations to prevent further spread of the virus. ****** [3] Date: 9 May 2002 From: ProMED-mail <promed@promedmail.org> Source: 51st Annual Epidemic Intelligence Service (EIS) Conference 22 Apr 2002 [edited] Abstract: Evaluating the Impact of Hepatitis A Vaccination -- United States, 1990-2001; Taraz Samandari (Presenter), Wasley A, Bell B. Background: Hepatitis A is one of the most frequently reported vaccine-preventable diseases in the United States. In 1999, the Advisory Committee on Immunization Practices recommended routine hepatitis A vaccination for children living in 11 high-incidence states (HIS) (average rate greater than or equal to 20 per 100 000 population during the period 1987-1997), and suggested it for children in 6 intermediate incidence states (IIS) (average rate 10-19 per 100 000 population). We examined incidence trends to assess the impact of this policy. Methods: Hepatitis A rates were determined using data from the National Notifiable Diseases Surveillance System and population estimates from the U.S. Census Bureau. Data from 2001 are provisional. Results: During 1990-2001, overall hepatitis A rates declined 70 percent from 12.5 per 100 000 to a historic low of 3.8 per 100 000. Rates declined most dramatically among children 2-18 years (82 vs 61 percent among persons greater than 18 years old). Despite declines among all racial/ethnic groups, the decline among Hispanic children (78 percent) lagged behind non-Hispanic children (92 percent). Compared to average 1987-1997 rates, by 2001, the rate in HIS declined by 83 percent to 4.5 per 100 000, in IIS by 77 percent to 3.8 per 100 000 but by only 39 percent to 3.4 per 100 000 elsewhere. HIS cases accounted for 48 percent of the national total during 1987-97, but for only 26 percent of 2001 cases. During 1998-2000, public sector pediatric vaccine doses purchased by the 17 states increased from 532 885 to 2 723 685, and in 2000, accounted for 95 percent of all such hepatitis A vaccine purchased. Conclusions: The precipitous decrease in hepatitis A rates in states where routine vaccination is recommended and where vaccine purchase was greatest, suggests that this strategy is reducing disease rates. Continued monitoring is needed to verify that low rates are sustained and attributable to vaccination. Reasons for the differential decline in rates between Hispanic and non-Hispanic children should be identified. -- ProMED-mail <promed@promedmail.org> ..............ll/cp/mpp/pg/jw *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at <http://www.promedmail.org>. Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). 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