May is Hepatitis Awareness Month
He
patitis is inflammation of the liver which can result from infectious and noninfectious causes. Infections due to hepatitis A, B, and C are all reportable in California.
- Hepatitis A virus (HAV) is typically spread person-to-person through the fecal-oral route, such as by ingesting contaminated food or water or through sexual contact. HAV can cause acute hepatitis but does not lead to chronic disease.
- Hepatitis B virus (HBV) is spread primarily through percutaneous or permucosal exposure to infectious body fluids, including via injection drug use, sexual contact, and perinatal exposure to an infected mother.
- Hepatitis C virus (HCV) is primarily transmitted through percutaneous exposure to infected blood, most commonly injection drug use. Other methods of HCV transmission include mother-to-infant and via contaminated personal devices such as razors or toothbrushes. Sexual transmission of HCV also occurs but generally seems inefficient except among HIV-infected men who have unprotected sex with men.
Both HBV and HCV can cause chronic liver infection which can lead to cirrhosis and increase the risk of hepatocellular carcinoma
.
Hepatitis A Clusters in Homeless Populations Continue to be Reported Nationally
There were 15-26 cases reported annually in Orange County from 2012-2017. The primary risk factor for HAV infection in Orange County is international travel to a HAV-endemic area.
San Diego’s 2017 Hepatitis A Outbreak
San Diego has experienced a hepatitis A outbreak since early 2017 with 588 cases reported as of April 26 of this year. Peak case rates were seen in September of last year, and the outbreak has waned following a significant public health response. Disease centered on that community’s homeless and illicit drug using populations and was one of the largest local outbreaks seen in this country since routine pediatric vaccination was introduced over a decade ago. Twenty deaths occurred in relation to this outbreak. Severe disease and death was weighted toward those already chronically infected with hepatitis B or hepatitis C.
Orange County identified two cases of HAV associated with the outbreak in San Diego. Only one had a history of homelessness with apparent exposure in San Diego, and there have been no subsequent infections/transmissions tied to either case. However, nine additional HAV cases with no history of travel were identified in Orange County in 2017. Because of the long incubation period, assessing potential exposures for hepatitis A cases can be complex, and some or all of these cases may have been related to the San Diego outbreak. A sustained outbreak did not occur in Orange County, but the Orange County Health Care Agency was active in vaccinating high risk populations here.
Outbreaks of HAV in homeless and/or illicit drug-using populations, each involving hundreds of cases, are ongoing in Michigan, Utah, and Kentucky.
Recommendations for Providers
- Consider HAV infection in persons with signs and/or symptoms of hepatitis, including jaundice, dark urine, fever, malaise, anorexia, nausea, diarrhea, and abdominal discomfort, and increased transaminases (AST/ALT). The incubation period for HAV infection ranges from 15–50 days.
- Send serum for HAV IgM testing in all suspect hepatitis A patients.
- All patients with compatible symptoms who are hepatitis A IgM positive and have no history of international travel should have serum forwarded to OCHCA laboratory to arrange for genotypic testing. Genotyping testing enhances public health surveillance and allows identification of cases that are related to the statewide outbreak.
- Contact OCHCA to arrange rapid identification of close contacts and administration of post-exposure prophylaxis (PEP) to susceptible (non-immune) close personal contacts, including household and sexual contacts, of persons with hepatitis A.
HAV Vaccination Recommendations
HAV vaccination is safe and highly effective. Multiple studies have shown that over 99% of persons who have received the recommended two doses develop long-term protection.
- All children are recommended by the Centers for Disease Control and Prevention (CDC) to receive two doses of hepatitis A vaccination, separated by six months, beginning at one year of age.
- Given the recent outbreak in San Diego and ongoing outbreaks in homeless populations around the country, OCHCA continues to recommend hepatitis A vaccination for homeless persons over one year of age.
HAV vaccination is also recommended by the CDC for the following groups:
- Persons with chronic liver disease, including those with hepatitis B or C virus (HBV or HCV) infection
- Users of injection and non-injection illicit drugs
- Men who have sex with men (MSM)
- Persons traveling to or working in countries that have intermediate or high levels of hepatitis A virus transmission
- Any person wishing to obtain immunity to hepatitis A virus
- Persons who have been exposed to HAV in the prior two weeks and are not known to be immune (immune globulin is an alternative to vaccine or given in addition to vaccine in some instances).
Hepatitis C Infection Rates are Increasing in Young Adults in Orange County
Reports of HCV infection in Orange County residents 20-29 years of age
have increased 10-fold over the last five years, and increases in reports in this age group have been seen throughout California and the country. Measuring community HCV epidemiology accurately is challenging. Because an estimated 50-75% of persons with HCV are undiagnosed and because it is a chronic infection, increased reports of diagnosed cases may reflect increased testing by providers rather than changes in disease prevalence. Nevertheless, Hepatitis C infection rates in young adults appear to be increasing in the County and throughout the state. This increase in case rates coincides with a nationwide opioid epidemic; in Orange County, rates of opioid overdose admissions to local emergency departments doubled from 2005 to 2015. Increases in illicit injection drug use likely accounts for a significant proportion of HCV rate increases.
While young adults compose an increasing proportion of newly reported chronic hepatitis C cases in recent years, persons born during 1945-1965 ("baby boomers") still make up 75% of all persons living with HCV infection. Persons in this age group have an estimated 3% prevalence of HCV antibodies, which is six times higher than the prevalence seen in adults born in other years.
