for Prevention

Clinical Recognition and Management of Hepatitis A:
Preventing Outbreaks in Los Angeles County

CME available

November 2024

This article was adapted from a prior Rx for Prevention article.

Prabhu Gounder, MD, MPH, FACP

Sharon Balter, MD

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Since April 2024, the Los Angeles County Department of Public Health (LAC DPH) has been responding to an outbreak of hepatitis A among people experiencing homelessness (PEH) and people who use illicit drugs (PWUD). This outbreak has now surpassed the size of the local outbreak among PEH and PWUD that occurred in 2017-2018.

This article summarizes the current outbreak and reviews actions clinicians can take to improve the recognition, reporting, management, and prevention of hepatitis A.

 

Background

Hepatitis A virus (HAV) is an RNA picornavirus and humans are its only known reservoir.1 The virus infects the liver and is then secreted into feces where it is present from 2 weeks before until about a week after symptom onset.2 It is primarily transmitted through the fecal-oral route via ingestion of contaminated food or water, contact with contaminated surfaces or objects, or close physical contact (such as oral-anal sex) with an infected person.3 HAV is very contagious. It can persist on environmental surfaces and is resistant to the processes usually used to eliminate bacterial pathogens from food.4

When healthy people are infected with HAV, the illness is usually mild and self-limited. However, people who are older or immunocompromised, have chronic liver disease, or have other underlying health conditions are at higher risk for serious disease.5

Vaccination is the best way to prevent hepatitis A and is recommended for children (ages 1-18), adults at higher risk of infection, and adults more likely to develop severe disease from the virus.5 (See Hepatitis A Vaccination Recommendations.)

 

Outbreaks Among Persons Experiencing Homelessness or Who Use Drugs

People experiencing homelessness or using illicit drugs in settings with inadequate environmental sanitation are at high risk of hepatitis A infection and are more likely to develop severe disease. Outbreaks are not uncommon. During the last large outbreak in LA County, between May 2017 and January 2018, a total of 18 outbreak-associated cases were reported, with 12 hospitalizations and no deaths. Sporadic cases and small outbreaks of hepatitis A have continued to occur in LA County among PEH/PWUD until this most recent outbreak.

The current outbreak of hepatitis A among PEH/PWUD in LA County was identified in April 2024 (see LAHAN). Through October 2024, a total of 41 outbreak-associated cases have been identified. Among these cases, 24 were known to be PEH including 14 who also reported illicit drug use; 14 cases had no risk factors but were linked to the outbreak by genomic sequencing which identified infection with the same strain. To date, 17 cases have been hospitalized, and 1 death.

 

Clinical Presentation

The time between hepatitis A infection and onset of symptoms is about 4 weeks but can range from 15–50 days.6 Approximately 70% of adults with acute hepatitis A infection experience symptomatic illness.7

Typical presentation includes the abrupt onset of fever, malaise, nausea, vomiting, and abdominal pain.7,8 These are followed in several days by signs of hepatic dysfunction, including jaundice, which develops in approximately 70% of symptomatic persons, scleral icterus, dark urine, and clay-colored stools. Symptoms generally last for several weeks. Unlike hepatitis B and C, hepatitis A does not cause chronic liver disease, but some people with HAV infection may have prolonged illness lasting up to six months or a relapsing course.9,10 Those with prolonged and relapsing disease will shed the virus and be infectious for longer periods. See the Centers for Disease Control and Prevention (CDC) figure below for typical course of HAV infection.

 

CDC chart with typical course of hepatitis A infection and recovery

Typical course of HAV infection and recovery, CDC.

 

 

Diagnosis

Clinicians should suspect hepatitis A in patients who have risk factors for infection and who have abrupt onset of prodromal symptoms (nausea, anorexia, fever, malaise, or abdominal pain) and jaundice or elevated serum aminotransferase levels.7 In the context of the current outbreak, consider hepatitis A in patients who present with non-specific gastrointestinal symptoms who have unstable housing (see box).

Diagnosis of hepatitis A is supported by demonstration of an antibody response to infection. Anti-HAV IgM becomes detectable several days before the onset of symptoms and typically remains positive for 3–6 months after infection.11 Rarely, detectable anti-HAV IgM has been reported to persist for up to 5 years.12 Generally, the presence of anti-HAV IgG and the absence of IgM indicates immunity to hepatitis A through vaccination or previous infection.11 See Table 1 for interpretations of HAV serologies. Because HAV IgM has a high false-positive rate, testing of asymptomatic individuals is not recommended.12

A hepatitis serology panel should be obtained to identify additional causes of viral hepatitis. The groups at risk in the current LA County outbreak are also at increased risk for hepatitis B and hepatitis C. HIV testing is also recommended for those whose HIV-status is undocumented.

 

In the context of the current hepatitis A outbreak, clinicians should take a broader view of homelessness when assessing risk. Risk extends beyond people living on the streets or in shelters to include those living in single-room occupancy units without a private bathroom, those in supportive housing designed for people with a history of homelessness, and those “couch surfing” (staying with a series of friends or extended family members due to unstable housing).

 

Consider hepatitis A early in differential diagnosis and order liver function tests in PEH/PWUD with non-specific gastrointestinal symptoms. The prodromal symptoms of hepatitis--nausea, vomiting, abdominal pain, diarrhea--may be easily misdiagnosed as gastroenteritis or other viral syndromes. If the ALT or total bilirubin is elevated, follow-up anti-HAV IgM tests.

 

PEH with suspected hepatitis A should not be discharged to a street, shelter, or shared living situation until the anti-HAV IgM result excludes infection.

 

See Key Steps for Recognizing and Reporting Hepatitis A in PEH.

 

 

Table 1. Interpretation of Hepatitis A Virus (HAV) Serologies
Serologic Result Possible Interpretations*
Anti-HAV IgM positive
  • Acute hepatitis A infection
  • False positive
  • Prolonged (>6 months) persistence after acute infection (rare)
Anti-HAV IgG positive
  • Previous immunization with hepatitis A vaccine
  • Previous hepatitis A infection
Anti-HAV IgM and IgG positive
  • Late symptomatic infection
  • Chronic relapsing hepatitis A infection
Anti-HAV IgG negative
  • No immunity to hepatitis
  • Loss of detectable antibodies years after vaccination (does not necessarily indicate loss of immunity to hepatitis A)

* Not intended to be exhaustive; other interpretations are possible.

 

Management

No specific treatment exists for acute hepatitis A illness. Supportive therapy is recommended. Hospitalization may be needed for patients who are dehydrated or have fulminant liver disease.

For persons experiencing homeless or who use illicit drugs, hospitalization can improve nutrition, reduce transmission risk, and provide linkages to services such as housing support. During the hepatitis A outbreak in San Diego during 2016–2018, PEH had 4-times higher odds of death compared with the general population.13

PEH with suspected or confirmed hepatitis A should not be discharged to the street, shelters, or any settings where they may transmit the infection to others. Under California Senate Bill 1152, hospitals are required to have written policies and procedures to ensure that patients experiencing homelessness have post-discharge plan that addresses their medical needs (see AFL 19-01). Discharge planning should identify a location with a private room and bathroom where the patient can isolate for the duration of their infectious period (i.e., 14 days after symptom onset) and arrange for transportation to that location.

Infected individuals should be instructed to wash their hands after using the bathroom and before handling food, especially during the first 2 weeks after symptom onset. Infected food handlers should be advised not to return to work until at least 2 weeks after symptom onset or 7 days after the onset of jaundice.

 

Reporting and Infection Control

Healthcare providers must report all patients with acute hepatitis A infection (defined as compatible symptoms or signs and positive anti-HAV IgM) to Public Health (Title 17, CCR, Section 2500). See box below for more detailed reporting information. In brief:

  • Hepatitis A infection in patients experiencing homelessness should be reported to LAC DPH immediately upon receipt of a positive anti-HAV IgM result. Immediate reporting of PEH with acute hepatitis A is critical to control this outbreak. LAC DPH will attempt to interview the patient before they leave the facility to identify contacts who could benefit from post exposure prophylaxis (PEP).
  • Patients with hepatitis A and stable housing must be reported within 1 working day of receiving the positive anti-HAV IgM result.

LAC DPH investigates all acute hepatitis A case reports to confirm infection, identify and control the source of infection, and protect those who already have been exposed. LAC DPH will attempt to identify and provide PEP to people who had close personal contact with the case such as household members or intimate contacts. For a case experiencing homelessness, this would include all residents and staff of a congregate setting such as a homeless shelter or all people living in the same encampment.

Hepatitis A illness occurring in a food handler is investigated urgently to assess the likelihood of transmission to facility patrons during the infectious period. A public notification might be considered if potentially exposed patrons can be identified and offered PEP within 2 weeks of exposure.

 

Reporting Hepatitis A in Los Angeles County

Immediate Reporting

Persons experiencing homelessness with symptoms or signs consistent with hepatitis A infection should be tested for hepatitis A; if the anti-HAV IgM result is positive, the patient should be immediately reported by phone. Report PEH while they are still at the facility.

 

Food handlers with confirmed hepatitis A infection should be immediately reported by phone.

  • Weekdays 8:30 am–5:00 pm: call 213-240-7941.
  • After-hours: call 213-974-1234 and ask for the physician on call.

 

Routine reporting

Report confirmed hepatitis A infection within 1 working day from identification (Title 17, CCR, Section 2500)

Note: Report hepatitis A cases that are residents of Long Beach, Pasadena, or another county to the appropriate local health department. See Local Health District Reporting List.

 

Visit LAC DPH Health Professional Mandatory Reporting to learn more: publichealth.lacounty.gov/clinicians/report.

 

 

 

Post-Exposure Prophylaxis (PEP) Recommendations

People with a known exposure to HAV who have not been previously vaccinated should receive hepatitis A PEP as soon as possible and within 2 weeks of the last exposure.14 HAV PEP is given as single-antigen hepatitis A vaccine, immune globulin (IG), or both.

Recommendations for PEP vary with patient age and risk factors for severe infection. Single antigen hepatitis A vaccine generally is recommended as part of the PEP regime to provide more long-lasting protection; exceptions include infants and those with severe allergic reaction (e.g., anaphylaxis) to a previous dose or to a vaccine component. See table below for a summary of PEP recommendations.

LAC DPH will assist in the management of contacts.

 

Table 2. Post Exposure Prophylaxis Recommendations (adapted from ACIP and CDPH)
Age group Risk category and health status Hepatitis A vaccine
1 dose^
Immune Globulin*
0.1ml/kg
<12 months Healthy No Yes
12 months - 40 years Healthy Yes

No

> 40 years Healthy Yes May be given based on provider’s risk assessment
> 12 months Immunocompromised or chronic liver disease Yes Yes
> 12 months Vaccine contraindicated No Yes

^ A second dose of single antigen hepatitis A vaccine is not required for PEP; however, for long-term immunity, the vaccination series should be completed with a second dose at least 6 months after the first dose.

* Measles, mumps, and rubella vaccine should not be administered for at least 2 weeks before and 6 months after administration of IG.

¶ Persons receiving both vaccine and IG for post-exposure prophylaxis may receive them simultaneously, or they may receive whichever product is available first and the second product when it is available, providing it is administered within the 14-day PEP window. Vaccine and IG should be administered at anatomically distant sites (such as different limbs).

 

Vaccination Recommendations

Vaccination is the best way to prevent hepatitis A. More than 95% of adults will develop protective antibodies within 4 weeks of single dose of vaccine, and nearly 100% will seroconvert after receiving 2 doses. Serologic testing for HAV immunity is not recommended prior to vaccination. Attaining 80% immunity to hepatitis A in a population can stop outbreaks.15 The CDC’s Advisory Committee on Immunization Practices (ACIP) recommendations5 for hepatitis A vaccine are summarized in the box below.

Visit the LAC DPH Hepatitis A Vaccine Information website for local patient and provider resources.

 

Recommendations for Hepatitis A Vaccination, ACIP 2020

Children

  • All children at age 12 - 23 months
  • Unvaccinated children and adolescents aged 2 - 18 years

Persons at increased risk for HAV infection

  • International travelers
  • Men who have sex with men
  • Persons experiencing homelessness
  • Persons who use injection and non-injection drugs (i.e., all those who use illegal drugs)
  • Those with occupational risk for exposure
  • Those who anticipate close personal contact with an international adoptee

Persons at increased risk for severe disease from HAV infection

  • Persons with chronic liver disease
  • Persons with HIV infection

Other persons recommended for vaccination

  • Pregnant women at risk for HAV infection or severe outcome from HAV infection
  • Any person who requests vaccination

Vaccination during outbreaks

  • Unvaccinated persons in outbreak settings who are at risk for HAV infection or at risk for severe disease from HAV

Implementation strategies for settings providing services to adults*

  • Persons in settings that provide services to adults in which a high proportion of those persons have risk factors for hepatitis A infection.

* In LA county, this includes people who work in settings providing direct services to persons experiencing homelessness or who use drugs, such as shelters and needle exchange programs . This group includes food handlers, personal care service providers, janitors, and sanitation workers.

Note: Hepatitis A vaccination is no longer recommended for persons who receive blood products for clotting disorders (e.g., hemophilia)

 

 

Hygiene and Sanitation

Good handwashing is important to prevent the spread of hepatitis A infection. Soap and water are preferred over hand sanitizer. If using the latter, alcohol concentrations of 70% or higher are most effective. Some cities in LA County have installed handwashing stations and restroom facilities accessible to people experiencing homelessness, but hygiene and sanitation remain significant challenges for this population.

HAV is resistant to many commonly used commercial disinfectants. A 10% bleach (>5,000 ppm) solution is effective if it is left on the surface to be cleaned for 1 minute before rinsing with water. Two percent glutaraldehyde and a quaternary ammonium formulation containing 23% hydrochloric acid (e.g., toilet bowl cleaner) also have been shown to be effective.16 In several studies, phenolics; iodine-based products; alcohols; and solutions of acetic, peracetic, citric, and phosphoric acids were ineffective. To assess other products, review the product label or product specification sheet for effectiveness against hepatitis A. Patient education materials on hygiene and sanitation are available on the LAC DPH Hepatitis A Education and Outreach webpage.

 

Conclusions

The successful control of hepatitis A in LA County requires continued collaboration between clinicians and DPH to ensure that vulnerable populations are vaccinated and that patients with hepatitis A infection are promptly diagnosed, reported, and investigated. Providers are encouraged to visit the LAC DPH Hepatitis A Vaccine webpage for resources for patients and providers. LAC DPH offers clinical consultations on weekdays 8:30am-5pm at 213-240-7941.

 


Key Steps for Recognizing and Reporting Hepatitis A in PEH

  • Order liver function tests in patients with unstable housing who present with non-specific symptoms potentially compatible with early hepatitis A infection (e.g., nausea, vomiting, abdominal pain, diarrhea).
  • Patients with evidence of clinical hepatitis should be tested for anti-HAV IgM. This includes jaundice, elevated ALT, or total bilirubin.
  • Do not discharge the patient until the anti-HAV IgM result returns negative. If the IgM test is a send out lab and the patient is otherwise stable for discharge, work with case management to find placement in a venue with a private room and bathroom until hepatitis A is excluded.
  • If the anti-HAV IgM test is positive, immediately report the case to LAC DPH by calling 213-240-7941. After hours call 213-974-1234.
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References

  1. Feinstone SM, Kapikian AZ, Purceli RH. Hepatitis A: detection by immune electron microscopy of a viruslike antigen associated with acute illness. Science. 1973;182(4116):1026-1028.
  2. Lima LR, De Almeida AJ, Tourinho Rdos S, Hasselmann B, Ximenez LL, De Paula VS. Evidence of hepatitis A virus person-to-person transmission in household outbreaks. PLoS One. 2014;9(7):e102925.
  3. Klevens RM, Miller JT, Iqbal K, et al. The evolving epidemiology of hepatitis a in the United States: incidence and molecular epidemiology from population-based surveillance, 2005-2007. Arch Intern Med. 2010;170(20):1811-1818.
  4. World Health Organization. Hepatitis A. Fact sheet http://www.who.int/mediacentre/factsheets/fs328/en/. Updated July 2017. Accessed November 1, 2017.
  5. Nelson NP, Weng MK, Hofmeister MG, et al. Prevention of Hepatitis A Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020. MMWR Recomm Rep 2020;69(No. RR-5):1–38. DOI: http://dx.doi.org/10.15585/mmwr.rr6905a1
  6. Lemon SM. Type A viral hepatitis. New developments in an old disease. N Engl J Med. 1985;313(17):1059-1067.
  7. Lednar WM, Lemon SM, Kirkpatrick JW, Redfield RR, Fields ML, Kelley PW. Frequency of illness associated with epidemic hepatitis A virus infections in adults. Am J Epidemiol. 1985;122(2):226-233.
  8. Tong MJ, el-Farra NS, Grew MI. Clinical manifestations of hepatitis A: recent experience in a community teaching hospital. J Infect Dis. Mar 1995;171 Suppl 1:S15-18.
  9. Glikson M, Galun E, Oren R, Tur-Kaspa R, Shouval D. Relapsing hepatitis A. Review of 14 cases and literature survey. Medicine. 1992;71(1):14-23
  10. Sjogren MH, Tanno H, Fay O, et al. Hepatitis A virus in stool during clinical relapse. Ann Intern Med. 987;106(2):221-226.
  11. US Centers for Disease Control and Prevention. Clinical Screening and Diagnosis for Hepatitis A. Updated January 11, 2024. Accessed October 29, 2024 
  12. Positive test results for acute hepatitis A virus infection among persons with no recent history of acute hepatitis--United States, 2002-2004. MMWR Morb Mortal Wkly Rep. 2005;54(18):453-456.
  13. Peak CM, Stous SS, Healy JM, Hofmeister MG, Lin Y, Ramachandran S, Foster MA, Kao A, McDonald EC. Homelessness and Hepatitis A-San Diego County, 2016-2018. Clin Infect Dis. 2020 Jun 24;71(1):14-21. doi: https://academic.oup.com/cid/article/71/1/14/5550168.
  14. Nelson NP, Link-Gelles R, Hofmeister MG, et al. Update: Recommendations of the Advisory Committee on Immunization Practices for Use of Hepatitis A Vaccine for Postexposure Prophylaxis and for Preexposure Prophylaxis for International Travel. MMWR Morb Mortal Wkly Rep 2018;67:1216–1220. DOI: http://dx.doi.org/10.15585/mmwr.mm6743a5
  15. McMahon BJ, Beller M, Williams J, Schloss M, Tanttila H, Bulkow L. A program to control an outbreak of hepatitis A in Alaska by using an inactivated hepatitis A vaccine. Arch Pediatr Adolesc Med. 1996;150(7):733-739.
  16. Mbithi JN, Springthorpe VS, Sattar SA. Chemical disinfection of hepatitis A virus on environmental surfaces. Appl Environ Microbiol. 1990;56(11):3601-3604.
 

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Author Information:

Prabhu Gounder, MD, MPH, FACP
Medical Epidemiologist

Sharon Balter, MD
Director

Acute Communicable Disease Control Program

County of Los Angeles
Department of Public Health

acdc2@ph.lacounty.gov

www.publichealth.lacounty.gov/acd


Rx for Prevention, 2024
November.


Published: November 20, 2024