Introduction

Brief overview of hepatitis E virus (HEV)^1,2

Hepatitis E is an inflammation in the liver that is caused by the hepatitis E virus. The virus has 4 genotypes; genotypes 1,2,3 and 4. Genotypes 1 and 2 are found in humans, whereas genotypes 3 and 4 can be found in animals, such as pigs, deer, and wild boars. 

Transmission routes 

This infection is found worldwide but is more common in low to middle-income countries and regions with limited access to water, hygiene, sanitation and health services. Other ways include:

• Through contaminated water- by infected faeces
• Through undercooked meats

Early warning signs of a hepatitis E outbreak^2,3

The incubation period after exposure to HEV is known to be from two to ten weeks. The infected people restart to transmit the virus beginning from just a few days before to three to four weeks after the onset of the infection. 

Increased cases of acute hepatitis symptoms

In most cases, the infected people are between the ages of 15-40 years, but it can also happen to young children, it does go undiagnosed. The symptoms experienced include:

• Mild fever
• Reduced appetite (anorexia)
• Nausea
• Vomiting
• Abdominal pain
• Itching
• Skin rash 
• Joint pain
• Jaundice
• Dark urine
• Pale stools 
• Tender liver- slightly enlarged - hepatomegaly

Epidemiological indicators of an outbreak^1,4

Hepatitis E occurs worldwide, mostly found in regions where sanitation is poor, such as developing countries in Central America, Asia and Africa. The HEV spreads by consuming the sewage-contaminated faeces shed from infected animals or people into food and or water. 

In developed countries, the virus can spread from animals to humans by consuming undercooked or raw pig, game meat, processed meats and shellfish. 

Back in the day, hepatitis E used to be known as a travel-associated infection and it was often underdiagnosed. However, the number of hepatitis E cases has increased significantly between 2010 and 2016. 

Higher infection rates in at-risk populations

Those who have pre-existing liver conditions and are immunocompromised individuals are more prone to hepatitis E. In parts of Asia and Africa, pregnant women are at a higher risk of infections. 

Environmental and social indicators^1,2,6

So, how do we know there could be a rise in hepatitis E? Well, there are many factors, including:

• Poor water and sanitation 
• Breakdown in public health infrastructure- sewage, sanitation, and drinking water systems
• Communities not having adequate access to clean water
• Outbreaks often occur in areas of poverty, overcrowding, or refugee camps
• High mobility of affected populations - migration

Laboratory confirmation^2,5

In most cases, the infection is diagnosed based on the symptoms and blood tests, such as:

• Blood tests - these can detect antibodies IgM and IgG specifically
• PCR tests - detecting for HEV RNA 

Public health and community response indicators²

Currently, the World Health Organisation (WHO) is working with researchers and experts to develop a generic protocol for HEV vaccination as an outbreak response. Other ways include:

• Creating public warnings about water quality, hygiene, and food safety
• Recommendation for boiling water 
• Avoiding certain types of foods

Conclusion

Hepatitis E is an infection that is caused by the HEV virus and it causes symptoms such as jaundice and abdominal pain. It is transmitted to someone by contamination of water by faeces of infected animals and mainly by undercooked meats, such as pork meat and deli meats. It is important to recognise the disease as there has been an upsurge of cases worldwide. Campaigns and education should be provided in low-income areas.