Context:

According to the study, published recently in PNAS Nexus, pigs may serve as a transmission route for a strain of the hepatitis E virus (HEV) associated with rats, known as Rocahepevirus Ratti or "rat HEV." 

More on the News:

• The first human case was reported in a person with a suppressed immune system in Hong Kong in 2018, at least 20 total human cases have been reported, including in people with normal immune function. 
• Since then, the potential link between pork consumption and rat HEV infection has become a focal point of investigation, as many infected individuals did not report direct exposure to rats.
• A hepatitis E strain linked to human disease, called LCK-3110, was cloned from its viral sequence and shown to replicate in human and animal cells, including pigs, showing the virus spread through the fecal-oral route.

About Hepatitis E

• Hepatitis E is inflammation of the liver caused by the hepatitis E virus (HEV). 
• The virus has at least 4 different types: genotypes 1, 2, 3 and 4. 
• Genotypes 1 and 2 have been found only in humans. 
• Genotypes 3 and 4 circulate in several animals including pigs, wild boars and deer without causing any disease, and occasionally infect humans.

Current Status of HEV

• Approximately 20 million HEV infections occur worldwide each year, leading to an estimated 3.3 million symptomatic cases of hepatitis E.
• The World Health Organisation (WHO)  also organise the annual World Hepatitis Day (28 July) campaign to raise awareness and understanding of viral hepatitis.
• WHO estimates that hepatitis E caused approximately 44 000 deaths in 2015 (accounting for 3.3% of the mortality due to viral hepatitis).

Transmission:

• The virus is transmitted by the fecal-oral route, primarily through contaminated water.
• Hepatitis E is found worldwide, but the disease is most common in East and South Asia countries with poor sanitation.
• In areas with better sanitation, hepatitis E cases are rare and primarily result from genotype 3, usually due to eating undercooked animal meat.

Symptoms: 

• The incubation period following exposure to HEV ranges from 2 to 10 weeks, with an average of 5 to 6 weeks.
• Common signs include mild fever, nausea, reduced appetite, abdominal pain, and jaundice (yellowing of the skin). Infected individuals may also experience dark urine, pale stools, and a tender, enlarged liver. 
• Severe cases can lead to acute liver failure, fetal loss and mortality.

Treatment:

• There is no specific treatment for acute hepatitis E. 
• Chronic hepatitis E in immunosuppressed individuals can be treated with ribavirin.
• A vaccine (Hecolin) to prevent hepatitis E virus infection has been developed and is licensed in China but is not yet available elsewhere.