Category Archives: Hepatitis A

Germany – Resurgence of an international hepatitis A outbreak linked to imported frozen strawberries, Germany, 2018 to 2020


Hepatitis A virus (HAV) causes acute inflammatory hepatic infections in humans. Transmission occurs primarily via the faecal-oral route through contaminated food or water or person-to-person spread [1]. While the disease is often asymptomatic or mild in younger children, it can cause debilitating symptoms and fulminant hepatitis in adults. After an abrupt onset with fever, malaise and abdominal discomfort, jaundice is the predominant symptom. The average incubation period is 28 to 30 days (range: 15–50) with maximum infectivity during the latter half of the incubation period, i.e. while being asymptomatic [1]. HAV retains infectivity after freezing and can persist in the environment, being able to withstand food-production processes routinely used to inactivate bacterial pathogens [2].

Direct or indirect detection of HAV infection in humans is notifiable in Germany to local public health authorities (LPHA), which transmit case reports electronically via the state level to the national public health institute (Robert Koch Institute, RKI). The case definition of hepatitis A in place for surveillance purposes in Germany is: a symptomatic disease (defined as one or more of the following: fever, abdominal discomfort, increase of serum transaminases, jaundice), plus laboratory confirmation (i.e. detection of HAV nucleic acid or HAV-specific IgM or a distinct increase of HAV-IgG concentrations). Symptomatic cases with an epidemiological link to a laboratory-confirmed hepatitis A case also fulfil the case definition. Forwarding of HAV-reactive serum or stool samples from diagnosing laboratories to the National Consultant Laboratory for HAV for sequencing is voluntary, and is intensified during outbreaks.

In 2016, the European Union/European Economic Area (EU/EEA) incidence of hepatitis A was 2.4 cases per 100,000 population; the highest incidences were in eastern EU countries, while HAV infections in other EU/EAA regions were mostly associated with infections acquired abroad [3]. Like most high-income countries, Germany is a low-incidence country with a median hepatitis A incidence of 1.02 per 100,000 inhabitants between 2010 and 2018. The median hepatitis A incidence in Berlin, Germany is slightly higher (1.79/100,000 in 2010–2018). European outbreaks of hepatitis A among men who have sex with men caused higher case numbers in Berlin and the EU/EEA in 2017 [4,5]. Recently, several hepatitis A outbreaks associated with frozen berries have been described in Europe [6,7].

This HAV subgenotype IB strain has previously caused outbreaks in Sweden (June–July 2018) and Austria (July–September 2018) [8], comprising a total of 34 reported cases. Combined epidemiological and microbiological outbreak investigations identified imported frozen strawberries produced in Poland as the vehicle. In Sweden, the HAV outbreak strain was detected in frozen strawberries and the contaminated batch was withdrawn from the Swedish market. Trace-back investigations from both Sweden and Austria identified Polish producer Y as the source for the implicated frozen strawberries.

Shortly after outbreak control in both countries, cases with the identical virus sequence started to appear in Germany in October 2018. The Federal Office of Consumer Protection and Food Safety (BVL) and all federal public health authorities were informed about this by the RKI and sequencing of samples of autochthonous hepatitis A cases was intensified.

Here we describe the results of the epidemiological investigation of an outbreak of hepatitis A in Germany presenting in two waves, one in 2018 and another in 2019.

Research – Hepatitis A outbreak with the concurrence of Salmonella Typhi and Salmonella Poona infection in children of urban Vellore, south India – 2019

IJID Online

Background: Outbreaks of Hepatitis A virus (HAV) infection continue to be reported from India, that have transitioned from hyper-to-intermediate endemicity. Hepatitis A and Salmonella sp. share similar routes of transmission and may co-infect individuals at risk. We report here an outbreak of hepatitis A with concomitant Salmonellosis from an urban settlement of Vellore in south India between July and August 2019.

Our findings highlight that Hepatitis A infection can present as sporadic outbreaks in communities with sub-standard water and sewage systems, along with the co-infection of other enteric infections such as invasive Salmonellosis. Thus, population-based surveillance for Hepatitis A is required in India, to identify populations and geographical regions at risk, and thereby potentially plan implementation strategies for Hepatitis A vaccination.

USA – NY Dunkin Donuts Hepatitis A Employee Worked While Infectious

Food Poisoning Bulletin

Close up 3d render of an influenza-like virus isolated on white

In Schuyler County, New York, a Dunkin Donuts hepatitis A employee worked while infectious, according to a press release by the Chemung County Health Department. An investigation has been launched because that person worked at two area Dunkin Donuts locations.

Research – Evaluation of a test method to detect hepatitis A virus in salted shellfish

Wiley Online

Contaminated salted shellfish were a suspected cause of the 2019 hepatitis A outbreak in Korea; however, no virus was detected in the shellfish by the virus detection tests used. In this study, we investigated the shortcomings of these detection tests for identifying hepatitis A virus in salted shellfish to serve as a guide for improvement of these tests. Salted shellfish were washed and desalted before collecting the mid‐guts for testing. For verification of the method, the mid‐guts were first inoculated with norovirus and then RT‐qPCR was performed to determine the presence of norovirus genes. The norovirus gene was amplified normally along with an internal positive control; however, when the nucleic acid was extracted to be concentrated, gene amplification was inhibited. Since NaCl was the suspected contaminant, RT‐qPCR was then performed on samples that had been desalinated for 2 days, and hepatitis A virus genes were successfully detected. Gene amplification enabled analyzing the relationship between patients in the outbreak and the distributed salted shellfish. To detect viral contamination in salted and fermented specimens such as salted shellfish, it is imperative to extract the mid‐gut intestinal tract and remove any PCR inhibitors (e.g., excess salt). In this study, desalting salted shellfish using sterile distilled water before harvesting the mid‐gut was effective in facilitating hepatitis A detection. Development of future test methods requires accurately determining the effect of PCR inhibitors through the incorporation of an IPC in genetic detection tests.

Research – Inactivation of Foodborne Viruses by High-Pressure Processing (HPP)



High-pressure processing (HPP) is an innovative non-thermal food preservation method. HPP can inactivate microorganisms, including viruses, with minimal influence on the physicochemical and sensory properties of foods. The most significant foodborne viruses are human norovirus (HuNoV), hepatitis A virus (HAV), human rotavirus (HRV), hepatitis E virus (HEV), human astrovirus (HAstV), human adenovirus (HuAdV), Aichi virus (AiV), sapovirus (SaV), and enterovirus (EV), which have also been implicated in foodborne outbreaks in various countries. The HPP inactivation of foodborne viruses in foods depends on high-pressure processing parameters (pressure, temperature, and duration time) or non-processing parameters such as virus type, food matrix, water activity (aw), and the pH of foods. HPP was found to be effective for the inactivation of foodborne viruses such as HuNoV, HAV, HAstV, and HuAdV in foods. HPP treatments have been found to be effective at eliminating foodborne viruses in high-risk foods such as shellfish and vegetables. The present work reviews the published data on the effect of HPP processing on foodborne viruses in laboratory media and foods. View Full-Text

RASFF Alert – Hepatitis A – Dried Tomato’s

European Food Alerts


hepatitis A virus (presence /25g) in dried tomatoes from Turkey in Greece

Norway – Infectious substances in lettuce and herbs 2017-2019


Lettuce and herbs on the Norwegian market mainly have good hygienic quality, the Norwegian Food Safety Authority’s monitoring program shows. However, the samples analysed make up a small proportion of the total amount of lettuce and herbs sold.

What did we investigate? Imported and Norwegian-produced salad and fresh imported herbs

A total of 580 samples – 426 of lettuce and 154 of herbs

Period: 2017 -2019
What were we looking for? E. coli, Salmonella, Cryptosporidium , hepatitis A virus and norovirus.

Not all analyses were performed on all samples.

What did we find? In the 575 samples analysed for E. coli , was detected E. coli in low numbers (<100 cfu / g) in 57 samples and E. coli ≥100 cfu / g in 36 samples. 13 samples contained such high values ​​of E. coli that the products were withdrawn from the market. 10 of these were imported herbs from Southeast Asia.

Salmonella, Cryptosporidium , hepatitis A virus or norovirus were not detected in any of the samples analysed for these infectious agents.

Findings of high values ​​of E. coli in lettuce and herbs indicate a fresh faecal contamination, which may indicate that the product may also be contaminated with pathogenic bacteria, viruses and parasites. Herbs from Southeast Asia are a known risk product for Salmonella . The Norwegian Food Safety Authority recommends that such herbs be heat-treated before they are eaten.

Who performed the assignment? The bacterial analyses were performed at the Veterinary Institute and the parasite and virus analyses at NMBU Veterinary College.

Germany – Bakery link investigated in hepatitis A outbreak in Germany

Food Safety News

More than 20 people have been infected with hepatitis A in an outbreak in a German municipality.

There have been 23 infections in the community of Dummerstorf in the Rostock district of Mecklenburg-Vorpommern. Three more test results are pending. Officials believe the virus has been spread through food.

Of those affected, 21 live in and around the municipality and two in neighboring districts. Four people have needed hospital treatment. More than 100 potential contacts have been identified and contacted by the health department.

Bakery staff link
Investigations by the health department and food control authorities are concentrated on the employees of a bakery branch in the region that officials did not name but have temporarily closed.

Samples of drinking water have been taken and ruled out as a pathway of infection. Vaccinations are being offered.

USA – Potential Hepatitis A Exposure at Trading Post in Yates County, NY

Food Poisoning Bulletin

A potential Hepatitis A exposure at the Trading Post Restaurant in Yates County, New York may have exposed patrons to the virus, according to the Yates County Health Department. The notice did not definitively state what the risk was, although it’s usually an employee who worked while infectious.

USA – Bangor Texas Roadhouse linked to Hepatitis A scare

Food Poison Journal

The Maine Center for Disease Control and Prevention (Maine CDC) has identified a case of acute hepatitis A virus infection in a Bangor, Maine, food service worker. The case handled food while infectious on October 16-18, 20, 22-25, 27 and 29.

Epidemiological assessment of the employee’s illness determined that restaurant patrons may be at risk for hepatitis A infection. Maine CDC is recommending that anyone who may have eaten food prepared at or who worked at the Texas Roadhouse in Bangor on the dates listed above between October 20th through October 29th receive hepatitis A vaccine within 14 days of their last exposure as there is a 14-day window during which prophylaxis is effective.

This recommendation includes anyone who may have had dine-in, take-out, delivery, or curbside pickup of food from the restaurant. Anyone who visited the restaurant from October 16th through October 19th, 2020, is outside the window for which prophylaxis is recommended, but is advised to watch for symptoms and seek medical attention should they develop symptoms.