Hepatitis A in a Food Service Worker: Alert for New Hampshire Clinicians

|August 08, 2013

The New Hampshire Division of Public Health Services (NH DPHS) Bureau of Infectious Disease Control has received a report of a confirmed case of hepatitis A virus (HAV) infection in a New Hampshire food service worker. A public health assessment of the employee's illness and food and beverage preparation practices in the establishments has determined that restaurant patrons may be at risk for HAV infection. NH DPHS is therefore recommending administration of postexposure prophylaxis to certain patrons according to the guidelines below.

The NH DPHS recommends:

  1. Awareness that a New Hampshire food service worker has been confirmed to have HAV infection and that unvaccinated, exposed restaurant patrons are advised to receive either hepatitis A vaccine or immune globulin according to the enclosed guidelines.

  2. Awareness that the Department of Health and Human Services (DHHS) will conduct public clinics to administer the vaccine or immune globulin to exposed patrons. Clinics will be held on Friday, August 9, 2013, from noon to 8:00 p.m. and Saturday, August 10, 2013, from 9 a.m. to 2 p.m., both at Hopkinton High School located at 297 Park Avenue in Contoocook, NH.

  3. That any person who consumed foods or beverages from July 20, 2013, through August 3, 2013, at the American Legion in Contoocook, NH, or the Covered Bridge Restaurant in Contoocook, NH, receive a single dose of single-antigen vaccine or IG (0.02 mL/kg) as soon as possible.

  4. That exposed patrons who develop symptoms consistent with hepatitis A virus infection be evaluated by their primary care physician.

  5. Reporting suspected and confirmed cases of hepatitis A virus infection to the Bureau of Infectious Disease Control at 1-603-271-4496 (after hours, 1-800-852-3345, ext. 5300) .


Worldwide, HAV is commonly transmitted through person-to-person contact via the fecal–oral route (ie, ingestion of something that has been contaminated with the feces of an infected person). In the United States, however, most HAV infections result from close personal contact with an infected household member or sex partner. Transmission of HAV is less commonly associated with exposure to fecally contaminated food or water.

In New Hampshire, HAV cases have declined over the last 10 years, possibly from routine administration of hepatitis A vaccine to children. In the late 1990s and early 2000s, approximately 20 cases of HAV infection were reported each year. In 2005, 82 cases were reported due to an outbreak among illicit drug users. Since 2009, fewer than 10 cases have been reported each year. HAV infection in food service workers is rare in New Hampshire, with the last case requiring public notification and mass prophylaxis occurring in 2004.

Diagnosis and Laboratory Testing

The clinical case definition for acute viral hepatitis is (1) discrete onset of symptoms and (2) jaundice or elevated serum aminotransferase levels. Because the clinical characteristics are the same for all types of acute viral hepatitis, hepatitis A diagnosis must be confirmed by a positive serologic test for immunoglobulin M (IgM) antibody to the hepatitis A virus.

Some infected persons, particularly young children, may be asymptomatic. In children younger than 6 years, 70% of infections are asymptomatic. When symptoms are present, they usually occur abruptly and can include fever, fatigue, nausea, vomiting, joint pain, and jaundice (yellowing of the eyes and skin), dark urine, and clay-colored bowel movements. When illness occurs in children younger than 6 years, it is typically not accompanied by jaundice. Among older children and adults, infection is typically symptomatic, with jaundice occurring in more than 70% of patients.

The average incubation period (time from exposure to onset of illness) for HAV is 28 days (range: 15-50 days). A person with HAV is generally infectious for up to 2 weeks prior to symptom onset and for 1 week afterward.

Testing for HAV antibody response is available at most commercial laboratories. Serologic testing for IgM antibody to HAV (IgM anti-HAV) is required to confirm a diagnosis of acute HAV infection. In the majority of persons, serum IgM anti-HAV becomes detectable 5-10 days before onset of symptoms. IgG anti-HAV, which appears early in the course of infection, remains detectable for the person's lifetime and provides lifelong protection against the disease. In the majority of patients, IgM anti-HAV declines to undetectable levels 6 months after infection.

The NH Public Health Laboratories (PHL) offers HAV total antibody (Anti-HAV) and IgM testing. For testing at the NH PHL, required specimens are 3-4 mL of serum or plasma (ideally, 2 serum-separating tubes). Specimens may be refrigerated at 2°-8°C for up to 5 days prior to transport on ice. For longer storage, serum or plasma (separated from whole blood by centrifugation at 2000 rpm for 10 minutes) may be frozen at −20°C or below prior to transport on ice. All specimens require a completed PHL requisition form available at: http://www.dhhs.nh.gov/dphs/lab/documents/labrequisition.pdf.

Preexposure Vaccination

Vaccination with the full, 2-dose series of hepatitis A vaccine before exposure to disease is the best way to prevent HAV infection. Hepatitis A vaccine has been licensed in the United States for use in persons 12 months of age and older. The vaccine is recommended for persons who are more likely to get HAV infection or are more likely to get seriously ill if they get hepatitis A, and for any person wishing to obtain immunity. A list of persons specifically recommended for vaccine is available at: http://www.cdc.gov/hepatitis/HAV/HAVfaq.htm.

Postexposure Prophylaxis

Persons who have been exposed to HAV and who previously have not received hepatitis A vaccine should be administered a single dose of single-antigen vaccine or immune globulin (IG) (0.02 mL/kg) as soon as possible, within 2 weeks after exposure. The efficacy of IG or vaccine when administered more than 2 weeks after exposure has not been established. For healthy persons aged 12 months to 40 years, single antigen hepatitis A vaccine at the age-appropriate dose is preferred to IG because of vaccine advantages that include long-term protection and ease of administration. For persons older than 40 years, IG is preferred because of the absence of information regarding vaccine performance and the more severe manifestations of hepatitis A in this age group; vaccine can be used if IG cannot be obtained. IG should be used for children younger than 12 months, immunocompromised persons, persons who have had chronic liver disease diagnosed, and persons for whom vaccine is contraindicated. For persons who receive vaccine, the second dose should be administered according to the licensed schedule to complete the series.

For Healthcare Providers Evaluating Exposed Persons

NH DPHS is currently recommending that any person who consumed foods or beverages from July 20, 2013, through August 3, 2013, at the American Legion in Contoocook, NH, or the Covered Bridge Restaurant in Contoocook, NH, receive a single dose of single-antigen vaccine or IG (0.02 mL/kg) as soon as possible. See the prophylaxis guidelines on the NH DPHS website.

NH DPHS, in conjunction with the Capital Area Public Health Network, will be offering hepatitis A vaccine and IG at public clinics on the following dates and locations:

  • Friday, August 9, 2013, from 12 noon to 8:00 p.m. at Hopkinton High School located at 297 Park Avenue in Contoocook, NH

  • Saturday, August 10, 2013, from 9 a.m. to 2 p.m. at Hopkinton High School located at 297 Park Avenue in Contoocook, NH

Exposed persons may choose to receive prophylaxis at their primary care provider or at one of the public clinics.

In addition, exposed persons should be aware of the symptoms of HAV infection, monitor for symptoms for up to 50 days following his or her exposure, and seek medical evaluation if symptoms develop (see Diagnosis and Laboratory Testing above).

NH DPHS has established a public information line for exposed persons to call for additional information. This number is 1-800-562-8236.

For additional information on Hepatitis A Virus please refer to:

  1. NH DHHS website

  2. The Centers for Disease Control and Prevention Hepatitis A FAQs for Health Professionals

If you or other healthcare providers have questions, please call the Bureau of Infectious Disease Control at 1-603-271-4496 or 1-800-852-3345, ext. 4496, during business hours (8:00 AM-4:30 AM). Nights or weekends call the New Hampshire Hospital switchboard at 1-800-852-3345, ext. 5300, and request the Public Health Professional on call.

To obtain a copy of NH-HAN #20130807, dated August 7, 2013, please visit the NH DHHS website.

Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:


All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.