Arizona's Roadmap to Containing a Hepatitis A Outbreak

Arizona is facing an unusual spike in cases of hepatitis A virus (HAV) that are challenging public health and health care efforts. Although HAV is a vaccine-preventable disease and there has been a decrease in cases over the last decade, several outbreaks since 2015 have increased case counts. Unfortunately, Arizona is facing an outbreak among 2 very vulnerable patient populations: displaced individuals and people who inject drugs.

HAV is often transmitted via the fecal-oral route or through consumption of contaminated food or water. Symptoms often resolve in less than 2 months and those infected tend to experience symptoms such as fatigue, loss of appetite, stomach pain, jaundice, and nausea. The good news is that once resolved an infected person has protective antibodies that offer life-long protection against the viral infection. Ultimately though, the best way to avoid HAV is through vaccination.

Despite making great strides in reducing the burden of HAV, Arizona is experiencing a growing outbreak that began in late 2018. Currently, there have been 424 cases and 3 deaths documented since November 2018, with a 79% hospitalization rate. The outbreak has spread to 7 counties within Arizona, including the largest—Maricopa.

A total of 48% of Arizona’s HAV cases have occurred in those individuals who are homeless and report drug use, 25% of cases have been in those reporting using drugs (ie, no reported homelessness), and 22% of cases are in individuals with no identified risk factors. Public health investigators found that 28% of the cases have been in patients who are currently or were recently incarcerated. Five percent of the HAV cases in this ongoing Arizona outbreak have been reported in patients who report homelessness, but no drug use.

More recently, an employee at a restaurant in Maricopa County tested positive for HAV and may have exposed people visiting the restaurant over a 9-day period from late May to June. Public health officials are encouraging those patrons to get vaccinated against HAV to reduce the risk of transmission.

In response to these cases and the growing outbreak, Maricopa County Department of Public Health has been working with local hospitals and health care systems to establish a more proactive approach to vaccination. Through the coordinated effort, hospitals provide HAV vaccination to any patient who reports homelessness and/or drug use, whether they are admitted to the facility or seen in an emergency department. The hope is that by casting a wide net for surveillance and proactive vaccination, they will prevent potential cases in high-risk populations.

Although the inactivated vaccine does provide immunity after 1 administration, long-lasting protection only comes from 2 doses, given at least 6 months apart. This requires coordination between public health through health care facilities as well as the internal collaboration between infection prevention, frontline physicians and nurses, and usually IT to ensure providers are given alerts within the electronic medical record systems to trigger vaccination efforts.

This outbreak, like most vaccine-preventable diseases, has posed unique challenges that require effective and functional efforts between public health departments and health care systems, which is no easy task. By integrating frontline health care facilities though, public health has a chance to get ahead of an outbreak that has spread in vulnerable populations where it is often challenging to implement control measures.

For the most recent case counts in the hepatitis A outbreak in Arizona, and the ongoing hepatitis A outbreaks across the United States, check out the Contagion® Outbreak Monitor.