I love the sourness of blackberries. As a child I used to pick baskets full to be made into pies by my aunt. As a grown up in Guelph (that’s in Canada) there was a huge blackberry tree next door and I would pick baskets full and make pies.
Six of the 11 people who’ve been diagnosed have been hospitalized, according to the Food and Drug Administration, which is investigating the outbreak with the Centers for Disease Control and Prevention.
A Nov. 20 notice from the FDA said hepatitis A illnesses in Indiana, Nebraska and Wisconsin are potentially linked to fresh conventionally-grown blackberries. Patients told FDA investigators they bought and consumed the berries from Fresh Thyme Farmers Markets in those three states.
The blackberries came from a distribution center that served 11 states, and the FDA is working with “federal and state partners to obtain additional information during the traceback investigation,” according to the notice.
Fresh Thyme released a statement that there is no indication the berries were contaminated by in-store handling and only conventional blackberries sold from Sept. 9-30 are involved.
Don and Ben start the episode talking about kimchi fermentation and all the cabbage that needed to be washed and salted. The conversation went towards collaborations with fun people that might seem a bit unnatural to outsiders. The guys talk about a few outbreaks including two pathogenic E. coli ones linked to Romaine lettuce and Hep A in blackberries. They then do some listener feedback on foreign objects, bad cleaning and sanitizing machines and chitterlings. Also, bacteria is everywhere.
Food safety recalls are always either too early or too late. If you’re right, it’s always too late. If you’re wrong, it’s always too early.
– Dr. Paul Mead
Salted clams from China and Korea appear to be the common factor in a spate of hepatitis A cases in various countries.
According to the Korea Biomedical Review, the Korea Centers for Disease Control and Prevention (KCDC) said that it has confirmed that contaminated fermented shellfish was the main culprit behind the hepatitis A outbreak this summer.
The KCDC came to the conclusions after conducting an in-depth epidemiological investigation.
The agency randomly sampled 270 of the 2,178 hepatitis A patients, diagnosed between July 28 and August 24, and surveyed whether they consumed fermented shellfish this summer. It found that 42 percent of the patients had eaten fermented shellfish during the incubation period.
KCDC also found that 80.7 percent of the 26 patients diagnosed with hepatitis A in August also ate fermented shellfish, while discovering Hepatitis A virus genes in 11 batches out of the 18 batches collected after the outbreak.
Notably, five of these genes found in the research showed close relations with the virus detected in hepatitis A patients.
As of now, the disease control agency has confirmed 10 products that have tested positive to the hepatitis A virus. Nine of them were imported from China, and one was made in Korea.
“Out of the total 10 products, weighing 37,094kg, 31,764kg has already been sold to the markets, while the remaining 5,330 kg were recovered and disposed of,” the agency said.
Yesterday, the Australian NSW Food Authority advised that Byul Mi Kim Chi is conducting a recall of Salted clams, due to a possible microbial (Hepatitis A virus) contamination. Further, Koryo Food Co. is conducting a recall of Pickled clams, due to a possible microbial (Hepatitis A virus) contamination.
NSW Food Authority CEO, Lisa Szabo said testing was underway on a number of products but full results may take a number of weeks.
“Although a contamination has not yet been confirmed, we have advised the companies of a potential link to 8 cases of hepatitis A in NSW, and they have both undertaken a recall of the product,” Dr Szabo said.
The U.S. Centers for Disease Control reports that waterborne hepatitis A outbreaks have been reported to CDC. Person-to-person transmission of hepatitis A has increased in recent years.
Reported drinking water–associated hepatitis A outbreaks have declined since introduction of universal childhood vaccination recommendations and public drinking water regulations. However, unvaccinated persons who use water from untreated private wells remain at risk.
Public health officials should raise awareness of risks associated with untreated ground water among users of private wells and of options for private well testing and treatment. Water testing and treatment are important considerations to protect persons who use these unregulated systems from HAV infection.
Hepatitis A virus (HAV) is an RNA virus primarily transmitted via the fecal-oral route and, in rare cases, causes liver failure and death in infected persons. Although drinking water–associated hepatitis A outbreaks in the United States are rarely reported (1), HAV was the most commonly reported etiology for outbreaks associated with untreated ground water during 1971–2008 (2), and HAV can remain infectious in water for months (3). This report analyzes drinking water–associated hepatitis A outbreaks reported to the Waterborne Disease and Outbreak Surveillance System (WBDOSS) during 1971–2017. During that period, 32 outbreaks resulting in 857 cases were reported, all before 2010. Untreated ground water was associated with 23 (72%) outbreaks, resulting in 585 (68.3%) reported cases. Reported outbreaks significantly decreased after introduction of Advisory Committee on Immunization Practices (ACIP) hepatitis A vaccination recommendations* and U.S. Environmental Protection Agency’s (USEPA) public ground water system regulations.† Individual water systems, which are not required to meet national drinking water standards,§ were the only contaminated drinking water systems to cause the last four reported hepatitis A outbreaks during 1995–2009. No waterborne outbreaks were reported during 2009–2017. Water testing and treatment are important considerations to protect persons who use these unregulated systems from HAV infection.
U.S. states and territories have voluntarily reported waterborne disease outbreaks to WBDOSS since 1971.¶ Waterborne hepatitis A outbreaks (1971–2017) reported as of March 13, 2018, were reviewed. An outbreak of hepatitis A was defined as two or more cases of HAV infection epidemiologically linked by time and location of water exposure. To compare occurrence with other waterborne exposure pathways, outbreaks reviewed included those caused by drinking, recreational, environmental (i.e., nondrinking, nonrecreational water), or undetermined water exposures.** As described previously (1), data reviewed included location; date of first illness; estimated number of primary cases, hospitalizations, and deaths; water system type according to USEPA Safe Drinking Water Act definitions (i.e., community, noncommunity, and individual); setting of exposure; drinking water sources (i.e., ground water, surface water, and unknown); and water system characteristics.†† Community and noncommunity water systems are public water systems that have 15 or more service connections or serve an average of 25 or more residents for ≥60 days per year.§§ A community water system serves year-round residents of a community, subdivision, or mobile home park. A noncommunity water system serves an institution, industry, camp, park, hotel, or business. Individual water systems are small systems (e.g., private wells and springs) not owned or operated by a water utility that have fewer than 15 connections or serve fewer than 25 persons. The number of outbreaks before and after public health interventions were compared; chi-squared tests were used to identify significant (p-value<0.05) differences. Data were analyzed using SAS software (version 9.4; SAS Institute) and visualized in ArcGIS (version 10.6.1; Environmental Systems Research Institute).
Thirty-two drinking water–associated hepatitis A outbreaks were reported to CDC during 1971–2017; the last one occurred in 2009 (Table). These drinking water–associated outbreaks accounted for 857 cases (range = 2–50), with no reported deaths. Data on number of deaths were unavailable for three outbreaks. Data on hospitalizations were unavailable for all outbreaks. Outbreaks occurred in 18 states, all in the lower continental United States (Figure 1). One environmental outbreak (1975) and one recreational water outbreak (1989) were reported during this period, but were excluded from this analysis.
The most commonly reported water system type associated with an outbreak was individual, accounting for 13 of 32 (41%) outbreaks and 257 of 857 (30.0%) cases, followed by community (10 [31%] outbreaks; 241 [28.1%] cases) and noncommunity (9 [28%] outbreaks; 359 [41.9%] cases). All individual water systems with outbreaks were supplied by private wells or springs. The majority of all drinking water outbreaks and cases were associated with systems supplied by ground water (30 [94%] outbreaks; 804 [93.8%] cases) and with an absence of water treatment (23 [72%] outbreaks; 585 [68.3%] cases).
The incidence of reported drinking water–associated hepatitis A outbreaks significantly decreased after introduction of the 1989 USEPA Total Coliform and Surface Water Treatment Rules (77% decline from 1971–1989 [24 outbreaks] to 1990–2017 [eight]; p = 0.003), the 1996 ACIP hepatitis A vaccination recommendations (87% decline from 1971–1996  to 1997–2017 [three]; p<0.001), and the 2006 Ground Water Rule and expanded ACIP vaccine recommendations (78% decline from 1971–2006  to 2007–2017 [two]; p = 0.038) (Figure 2). From 1995 through 2009, all four hepatitis A drinking water–associated outbreaks, resulting in 35 cases, were attributed to individual water systems using untreated ground water sources. No water-associated hepatitis A outbreaks have been reported since July 2009.
Reported drinking water–associated hepatitis A outbreaks have declined since reporting began in 1971, and none have been reported since 2009, mirroring the overall decline in U.S. cases (4,5). Vaccination for hepatitis A, combined with USEPA regulations that require testing and, where necessary, corrective actions or treatment for drinking water supplies, likely played a role in reducing reported hepatitis A drinking water–associated outbreaks.
Vaccination efforts have led to significant changes in hepatitis A epidemiology (4,6,7). HAV infection rates in the United States have decreased since the introduction of hepatitis A vaccine in 1995 (4,5). Vaccine recommendations were originally targeted to children in communities with high rates of hepatitis A infections west of the Mississippi and other groups at risk (e.g., international travelers, men who have sex with men, illicit drug users, persons with clotting factor disorders, and persons with occupational risk). By 2006, routine hepatitis A vaccination was recommended for all children aged ≥l year regardless of geographic area of residence (5). Although vaccination was never recommended for users of individual ground water systems, this group likely benefited from the recommendations targeting children and other groups at risk. Incidence of HAV infection is now lowest among persons aged 0–19 years (4). However, the proportion of HAV-associated hospitalizations steadily increased during 1999–2011, likely because of more severe disease in older adults, with persons aged ≥80 years experiencing the highest rates of infection (6). The number of hepatitis A cases in the United States reported to CDC increased by 294% during 2016–2018, compared with the period 2013–2015 (8), primarily because of community-wide outbreaks in persons reporting homelessness or drug use (7). ACIP recommends vaccination to persons who use drugs and recently expanded recommendations to persons experiencing homelessness.¶¶
Reported drinking water–associated hepatitis A outbreaks were most commonly linked to individual water systems that used wells with untreated ground water. Recreational and environmental outbreaks were only reported twice, suggesting that drinking water is a more common waterborne exposure pathway for hepatitis A. Nearly 43 million U.S. residents, or 13% of the population, are served by individual water systems, primarily from ground water sources (https://pubs.er.usgs.gov/publication/cir1441external icon). Untreated ground water sources were associated with 30% of all drinking water–associated outbreaks reported to CDC during 1971–2008 (1). The USEPA Total Coliform and Surface Water Treatment Rules of 1989 and Ground Water Rule of 2006 provide enhanced safety measures for public water systems using ground water sources and might have contributed to the absence of reported hepatitis A outbreaks linked to community water sources since 1990. However, federal regulations do not apply to individual water systems, which often have inadequate or no water treatment (9). Private wells or springs were the only contaminated drinking water systems to cause the last four reported hepatitis A outbreaks during 1995–2009. CDC recommends that owners of private wells test their water annually for indicators of fecal contamination (https://www.cdc.gov/healthywater/drinking/private/wells/testing.html). Factors contributing to fecal contamination of ground water include nearby septic systems or sewage, weather patterns (e.g., heavy rainfall), improper well construction and maintenance, surface water seepage, and hydrogeologic formations (e.g., karst limestone) that allow for rapid pathogen transport (2,9).
The findings in this report are subject to at least three limitations. First, waterborne hepatitis A outbreak reporting is through a passive, voluntary surveillance system; health departments have varying capacity to detect, investigate, and report outbreaks, which might result in incomplete data on outbreak occurrence and characteristics within and across jurisdictions. Thus, outbreak surveillance data might underestimate the actual number of drinking water–associated hepatitis A outbreaks and might underreport information regarding health outcomes such as cases of illness. Second, attributing the source of an outbreak to individual water systems can be particularly difficult because hepatitis A can also be spread through person-to-person transmission within a household. Finally, outbreak data before 2009 did not include case-specific information; thus, demographic factors, including age, could not be assessed.
Drinking water–associated hepatitis A outbreaks have declined and essentially stopped, likely in large part because of the introduction of an efficacious vaccine as part of the routine childhood immunization program and microbial drinking water regulations for public water systems. The degree to which these interventions have contributed to the decline in outbreaks is uncertain. However, waterborne outbreak surveillance data is not yet finalized for 2018, and the recent increase in person-to-person transmission of hepatitis A (7,8) has the potential to cause a resurgence in waterborne outbreaks through increased fecal HAV contamination of private ground water supplies. Outbreak data suggest that individual water systems, primarily those systems drawing untreated ground water from wells, pose the highest risk for causing drinking water–associated hepatitis A outbreaks. These systems are not regulated by USEPA; CDC recommends that owners evaluate their well water quality at least yearly. If indicators of fecal contamination are detected, remediation and treatment of private well water is recommended. Guidance on private well testing and treatment solutions for microbial contamination is provided by USEPA (https://www.epa.gov/privatewells/protect-your-homes-waterexternal icon) and CDC (https://www.cdc.gov/healthywater/drinking/private/wells/index.html). Although the current nationwide outbreak of hepatitis A is not water-associated, considering ground water as a possible transmission route is warranted during community-wide outbreaks of hepatitis A. Ground water can be contaminated with HAV during community transmission of hepatitis A, increasing the risk for persons using untreated water. Public health education about the risks associated with drinking untreated ground water from individual systems, as well as relevant safety measures (i.e., water testing, water treatment, and vaccination), is needed to prevent future drinking water–associated hepatitis A outbreaks.
US: Impact of public health interventions on drinking water-associated outbreaks of hepatitis A-United States, 1971-2017
Driving down I-75 from Detroit to Englewood, Florida (starting point was Brantford, Ontario, that’s in Canada) for a couple of weeks became a summer-time routine because gramps was only there in his mobile home in the winter months, and I guess it prepped me for summers in Kansas and Brisbane.
But we never stopped at a Cracker Barrel which littered the Interstate.
Despite its down-home appearance, the food was shit and over-priced.
According to Fox 55the clock is ticking for customers to get vaccinated after a Saginaw County restaurant worker tests positive for Hepatitis A.
The person last worked at the Bridgeport Township Cracker Barrel on Sunday, Aug. 25.
But the Saginaw County Health Department (SCHD) is urging anyone who ate there between Sunday, Aug. 25 and Wednesday, Aug. 28 to get vaccinated right away.
“With an exposure you have up to two weeks to get vaccinated,” explained Health Officer Christina Harrington with the SCHD. “It’s going to prevent you from getting the disease.”
And yes, I own this album (above, left, listen for the reference to I-75 in the version below) and Chapman hates it.
Tommy Tobin of Forbes reports Franklin County, Missouri, joins a handful of jurisdictions across the country with mandatory Hepatitis A vaccine programs aimed at preventing further cases. This development is part of a larger trend aimed at expanding vaccinations for Hepatitis A and addressing future outbreaks of the disease.
The CDC is investigating outbreaks of Hepatitis A across 29 states. According to the CDC, 233 individuals have died from Hepatitis A between 2016 and 2019 out of over 24,000 reported cases. Several states, including Kentucky, Florida, Ohio, and West Virginia, have seen thousands of cases.
In an effort to curb the increase in reported cases of Hepatitis A, many local jurisdictions are considering mandatory Hepatitis A vaccines for food service workers. For example, Missouri has reported 387 cases of Hepatitis A in the past two years. Over 50 of these cases are from Franklin County, which has a population of about 100,000 residents. Franklin County officials have imposed mandatory vaccinations for individuals who handle food. Food establishments, including restaurants, have 90 days to ensure their employees are vaccinated. Nearby St. Louis County, Missouri enacted a mandatory vaccine requirement nearly 20 years ago. Similar ordinances requiring vaccines for food service workers were enacted in Kentucky’s Ashland and Boyd Counties last year.
With the numerous cases across the country of Hepatitis A, the National Restaurant Association recently issued guidance to its member restaurants in an effort to reduce future cases. In this guidance, the Association recommended that restaurant managers and operators encourage employees to get vaccinated, educate restaurant staff about the virus, and monitor for any signs of the disease. (Note: The National Restaurant Association did not respond to requests for comment on this story). Separately, a CDC advisory panel recently recommended expanding the use of the Hepatitis A vaccine to all youth aged 2 to 18.
The apparent international rise in foodborne virus outbreaks attributed to fresh produce and the increasing importance of fresh produce in the Australian diet has led to the requirement to gather information to inform the development of risk management strategies.
A prevalence survey for norovirus (NoV) and hepatitis A virus (HAV) in fresh Australian produce (leafy greens, strawberries and blueberries) at retail was undertaken during 2013–2014 and data used to develop a risk profile. The prevalence of HAV in berries and leafy greens was estimated to be <2%, with no virus detected in produce during the yearlong survey. The prevalence of NoV in fresh strawberries and blueberries was also estimated to be <2% with no virus detected in berries, whilst for leafy greens the NoV prevalence was 2.2%.
Prevalence of a bacterial hygiene indicator, Escherichia coli, was also investigated and found to range from <1% in berries to 10.7% in leafy greens. None of the NoV positive leafy green samples tested positive for E. coli, indicating it is a poor indicator for viral risk.
The risk was evaluated using standard codex procedures and the Risk Ranger tool. Taking all data into account, including the hazard dose and severity, probability of exposure, probability of infective dose and available epidemiological data, the risk of HAV and NoV foodborne illness associated with fresh Australian berries (strawberries and blueberries) sold as packaged product was deemed to be low. The risk of foodborne illness from HAV associated with leafy greens was also deemed to be low, but higher than that for fresh berries, due mainly to the potential for recontamination post-processing if sold loose. The risk of foodborne illness from NoV associated with leafy greens was deemed to be low/moderate. Despite the prevalence of NoV in leafy greens being low and the inability to discriminate between infective and non-infective virus using PCR based methodologies, the fact that NoV was detected resulted in a higher risk associated with this pathogen-product pairing; compounded by the higher prevalence of NoV within the community compared to HAV, and the potential for leafy greens to become contaminated following processing if sold loose.
Estimating risk associated with human norovirus and hepatitis A virus in fresh Australian leafy greens and berries at retail 26 August 2019
The hepatitis A vaccine is the best way to prevent HAV infection.
The following groups are at highest risk for acquiring HAV infection or developing serious complications from HAV infection in these outbreaks and should be offered the hepatitis A vaccine in order to prevent or control an outbreak:
People who use drugs (injection or non-injection)
People experiencing unstable housing or homelessness
Men who have sex with men (MSM)
People who are currently or were recently incarcerated
People with chronic liver disease, including cirrhosis, hepatitis B, or hepatitis C
One dose of single-antigen hepatitis A vaccine has been shown to control outbreaks of hepatitis A and provides up to 95% seroprotection in healthy individuals for up to 11 years.1,2
Pre-vaccination serologic testing is not required to administer hepatitis A vaccine. Vaccinations should not be postponed if vaccination history cannot be obtained or records are unavailable.
“Outbreak-associated” status is currently determined at the state level in accordance with each state’s respective outbreak case definition.
Outbreak-related hepatitis A deaths are defined at the state level in accordance with each state’s respective hepatitis A-related death definition. Some states are reviewing death certificates on a regular basis to actively find hepatitis A-related deaths, while other states are utilizing passive surveillance.
Outbreak start date is defined at the state level and may represent the earliest onset date of an outbreak case (AR, AZ, UT), the left censor date for which cases are considered part of the outbreak based on the state outbreak case definition (AL, CA, CO, FL, GA, ID, IL, IN, KY, LA, MA, MI, MO, NC, NH, OH, SC, TN, VA), or when a state declared a hepatitis A outbreak (NM, WV).
In response to all hepatitis outbreaks, CDC provides ongoing epidemiology and laboratory support as well as support on vaccine supply and vaccine policy development. When requested, CDC sends “disease detectives” to affected areas to evaluate and assist in an outbreak response. CDC alerts other public health jurisdictions of any increases in disease. All jurisdictions are encouraged to be watchful for increases in hepatitis A cases. CDC also works with state and local health officials to ensure hepatitis A vaccine is targeted to the correct at-risk populations and that supply is adequate.
Postexposure prophylaxis (PEP) is recommended for unvaccinated people who have been exposed to hepatitis A virus (HAV) in the last 2 weeks; those with evidence of previous vaccination do not require PEP.
NOTE: CDC recommends that all children be vaccinated against hepatitis A at age 1 year. Parents or caregivers who are unsure if a child has been vaccinated should consult the child’s health-care provider to confirm vaccination status.
HAV Specimen Requests
State health departments wanting to submit specimens must contact CDC at firstname.lastname@example.org for approval before shipping specimens to CDC. Only specimens that that have tested positive for anti-hepatitis A IgM and meet any of the following criteria will be considered.
Specimen from a case patient in a county that has not yet reported a hepatitis A case in an at-risk population;
Specimen from a case patient who doesn’t report any known risk factors or contact with at-risk populations (e.g., household or sexual contact, volunteering at a homeless shelter);
Specimen from a case patient suspected to be associated with foodborne transmission;
Archived/stored specimen from a patient who has died, and whose classification as an outbreak-related death requires nucleic acid testing beyond anti-HAV IgM-positivity; or
Other patient specimens not meeting the above criteria that require nucleic acid testing or molecular characterization (to be discussed on a case-by-case basis).
CDC is developing educational materials to support the outbreak at the state and local levels. Most materials include an area where local information can be inserted. Your organization’s contact information can be typed into the blue colored rectangle. To upload your logo, click on the white space below the blue colored rectangle. In the pop-up box, select browse and upload a PDF version of your logo.
One page visual fact sheets encouraging vaccination for:
Printing Instructions: These cards should be printed double-sided on 4.25” x 5.5” perforated postcard templates that print four double-sided cards per page. The print settings must be set to “Actual size” or “Custom Scale 100%” to ensure accurate alignment of the two sides of the cards.
Pocket Card Printing Instructions: These cards should be printed double-sided on business card templates that print six double-sided cards per page. The print settings must be set to “Actual size” or “Custom Scale 100%” to ensure accurate alignment of the two sides of the cards.
The U.S. Centers for Disease Control reports that Hepatitis A is a vaccine-preventable viral infection of the liver that is primarily transmitted through consumption of microscopic amounts of feces.
During 2016–2018, reports of hepatitis A infections in the United States increased by 294% compared with 2013–2015, related to outbreaks associated with contaminated food items, among men who have sex with men, and primarily, among persons who report drug use or homelessness.
What are the implications for public health practice?
Increasing vaccination among groups at risk for hepatitis A infection might halt ongoing outbreaks and prevent future outbreaks.
Hepatitis A virus (HAV) is primarily transmitted fecal-orally after close contact with an infected person (1); it is the most common cause of viral hepatitis worldwide, typically causing acute and self-limited symptoms, although rarely liver failure and death can occur (1). Rates of hepatitis A had declined by approximately 95% during 1996–2011; however, during 2016–2018, CDC received approximately 15,000 reports of HAV infections from U.S. states and territories, indicating a recent increase in transmission (2,3). Since 2017, the vast majority of these reports were related to multiple outbreaks of infections among persons reporting drug use or homelessness (4). In addition, increases of HAV infections have also occurred among men who have sex with men (MSM) and, to a much lesser degree, in association with consumption of imported HAV-contaminated food (5,6). Overall, reports of hepatitis A cases increased 294% during 2016–2018 compared with 2013–2015. During 2016–2018, CDC tested 4,282 specimens, of which 3,877 (91%) had detectable HAV RNA; 565 (15%), 3,255 (84%), and 57 (<1%) of these specimens were genotype IA, IB, or IIIA, respectively. Adherence to the Advisory Committee on Immunization Practices (ACIP) recommendations to vaccinate populations at risk can help control the current increases and prevent future outbreaks of hepatitis A in the United States (7).
Hepatitis A infections among persons who meet the Council of State and Territorial Epidemiologists (CSTE) hepatitis A case definition (https://wwwn.cdc.gov/nndss/conditions/hepatitis-a-acute/) are notified to CDC through the National Notifiable Diseases Surveillance System (NNDSS). Cases reported to CDC through NNDSS during 2013–2018 were used to calculate percent change (2013–2015 versus 2016–2018) by state and mapped using RStudio software (version 1.2.1335; RStudio, Inc.). Serum specimens from CSTE confirmed cases submitted to the CDC laboratory were tested for HAV RNA by polymerase chain reaction, and isolated virus was amplified to characterize a 315–base-pair fragment of the VP1/P2B region, which defines the genotype of the virus.
Overall, reports of hepatitis A cases increased 294% during 2016–2018 compared with 2013–2015 (Figure). Eighteen states had lower case counts during 2016–2018 compared with 2013–2015. Nine states and Washington, DC had an increase of approximately 500%. During 2013–2018, 4,508 HAV anti-immunoglobulin M–positive specimens underwent additional testing at CDC. During 2013–2015, 226 specimens underwent additional testing, of which 197 (87%) had detectable HAV RNA; of the RNA-positive specimens, 76 (39%), 121 (61%), and 0 (0%) tested positive for a genotype IA, IB, or IIIA viral strain, respectively. In comparison, 4,282 specimens were tested by CDC during 2016–2018, of which 3,877 (91%) had detectable HAV RNA; 565 (15%), 3,255 (84%), and 57 (<1%) of these specimens were genotype IA, IB, or IIIA, respectively.
The number of hepatitis A infections reported to CDC increased during 2016–2018, along with the number of specimens from infected persons submitted to CDC for additional testing. In the past, outbreaks of hepatitis A virus infections occurred every 10–15 years and were associated with asymptomatic children (8). With the widespread adoption of universal childhood vaccination recommendations (https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5507a1.htm), asymptomatic children are no longer the main drivers of hepatitis A outbreaks (3,9). Although the overall incidence rate of HAV infections has decreased within all age groups, a large population of susceptible, unvaccinated adults who were not infected by being exposed to the virus during childhood remain vulnerable to infection by contaminated foods (typically imported from countries with endemic HAV transmission) and recently, on a much larger scale, through behaviors that increase risk for infection in certain vulnerable populations, such as drug use (3).
Increasingly, molecular epidemiology is employed by public health laboratories to better characterize hepatitis A transmission patterns. When combined with reliable epidemiologic data, these laboratory data can be used to identify transmission networks and confirm the source of exposure during common-source outbreaks, facilitating prompt and effective public health response. Historically, genotype IA has been the most common genotype circulating in North and South America. During 2013–2018, HAV genotype IB predominated in the United States. Increasing numbers of genotype IIIA were seen, a genotype that is considered rare in the United States.
Decreasing new infections from hepatitis A virus can be achieved and sustained by maintaining a high level of population immunity through vaccination. There is no universal vaccination recommendation for adults in the United States; however, ACIP does recommend vaccination for adults who plan travel to HAV-endemic countries, MSM, persons who use drugs, persons with chronic liver disease, and recently, persons experiencing homelessness (7). Continued efforts to increase hepatitis A vaccination coverage among the ACIP-recommended risk groups is vital to halting the current hepatitis A outbreaks and reducing overall hepatitis A incidence in the United States.
Members of the Division of Viral Hepatitis Laboratory, Division of Viral Hepatitis HAV Incident Management Team, Food and Drug Administration CORE Signals Teams; state and local health departments; medical and mental health partners; corrections partners; syringe service providers.