World Hepatitis Day, observed on July 28th, raises awareness of viral hepatitis, an inflammation of the liver that causes severe liver disease and cancer 1. Hepatitis A (HAV) is a highly contagious virus that can cause severe health problems, from flu-like symptoms to liver failure. In this comprehensive blog post, we will explore the science behind HAV contamination in food and water and highlight the importance of robust testing solutions such as those offered by Invitek Diagnostics.
A serious threat to human health
Food safety is of paramount importance to safeguard public health. HAV poses a significant threat to human health, as it is easily transmitted through contaminated food and water sources or through direct contact with an infectious person. Infected individuals can shed the virus in their stool, leading to the contamination of fruits, vegetables, and shellfish, which after consumption can result in outbreaks and widespread illness. In 2022 alone, the European Union reported 4,548 cases of HAV which represents a notification rate of one case per 100,000 population 2. The countries with the highest notification rates were Hungary (5.5), Croatia (5.3), Romania (4.8), and Bulgaria (4.4) 2. In the United States, 49% of all HAV cases reported in 2022 occurred in people 30–49 years old 3. Even though between 2021-2022, there was nearly a 60% decrease in the number of newly reported HAV cases, this number remained almost 2 times as high as in 2015. Therefore, it is crucial to prevent the spread of HAV to protect public health, and that starts with effective testing measures.
Recent outbreaks due to food and water contamination
HAV is a small, non-enveloped RNA virus known for its environmental stability. It can survive in a wide range of temperatures and pH levels, enabling it to persist in food and water sources. Fresh produce, such as lettuce and berries, can become contaminated during cultivation, harvesting, or packaging. Shellfish, particularly bivalves like oysters, can also shelter HAV. Additionally, poor sanitation practices during food processing or the use of contaminated water sources for irrigation can contribute to HAV contamination. Understanding the routes of contamination is vital for developing robust testing strategies.
Recent outbreaks of HAV contamination have highlighted the urgent need for effective testing methods. In Kerakala, India, a waterborne HAV outbreak occurred due to global warming, which caused higher water temperatures, providing favorable conditions for viral survival and transmission. This outbreak serves as a sheer reminder that climate change can deeply impact food and water safety. In 2024, both the United States and European countries reported important strawberry HAV outbreaks that have raised concerns in the Food and Drug Administration (FDA) and the European Centre for Disease Prevention and Control (ECDC), who launched investigations to identify the sources of contamination and prevent further spread. Both outbreaks ended up being connected with fruits imported from countries with less strict standards and regulations regarding food testing and facilities.
HAV standard testing workflow
ISO/TS 15216-2:20194 is a technical specification developed by the International Organization for Standardization (ISO). It outlines a method for the detection of HAV)and Norovirus genogroup I (GI) and II (GII) RNA from test samples of from test samples of foodstuffs or surfaces using real-time PCR. The method outlined in ISO 15216 can be divided into three major parts:
- Recovery and Concentration:
To effectively test for HAV contamination in food, it is essential to recover and concentrate the virus from the sample. This is typically done using a process called elution, where the virus is detached from the food particles. The eluted sample is then concentrated, often through processes like ultracentrifugation or ultrafiltration, to increase the likelihood of detecting the virus if it is present.
- Viral RNA Extraction:
Once the virus has been concentrated, the viral RNA is extracted. This is usually done using a lysis buffer, which breaks open the virus and releases the RNA. The RNA is then purified and concentrated for further analysis. Invitek Diagnostics offers a range of RNA isolation kits that effectively extract viral RNA from various food matrices. Both the RTP® Pathogen Kit and the Universal kits (InviSorb® and Invimag®) have been successfully used to efficiently extract high-quality RNA from food samples.
- Detection of Virus: Real-Time PCR Assays:
The final step is the detection of the viral RNA using real-time PCR. This technique amplifies specific regions of the viral RNA, making it possible to detect even small amounts of the virus. Invitek Diagnostics offers real-time PCR assays, such as the highly sensitive InviScreen® Hepatitis A Virus Detection Kit, which accurately detects HAV in food samples. This kit allows for rapid results in compliance with ISO 15216, enabling timely actions to prevent the consumption of contaminated food.
It's time for action!
Hepatitis A contamination in food poses a significant risk to public health. Understanding the science behind HAV contamination, implementing robust testing workflows, and utilizing advanced testing products are key to preventing outbreaks and protecting consumers. Invitek Diagnostics offers comprehensive solutions for detecting HAV in food, including RNA extraction kits and real-time PCR assays. By prioritizing food safety testing and incorporating advanced technologies, we can ensure the availability of safe and healthy food for everyone. Let us work together to prevent HAV contamination and promote a healthier future.
REFERENCES
- World Hepatitis Day. Published July 28, 2024. https://www.who.int/campaigns/world-hepatitis-day
- European Centre for Disease Prevention and Control. Hepatitis A. In: ECDC. Annual Epidemiological Report for 2022. Stockholm: ECDC; 2024.
- Hepatitis A basics. Hepatitis A. Published January 25, 2024. https://www.cdc.gov/hepatitis-a/about/index.html#:~:text=49%25%20of%20all%20hepatitis%20A,as%20high%20as%20in%202015.
- ISO 15216-2:2019, Microbiology of the food chain — Horizontal method for determination of hepatitis A virus and norovirus using real-time RT-PCR
