A new study by researchers at Tohoku University Graduate School of Medicine in Japan show that there is a high prevalence of  hepatitis E (HEV) antibodies in the household-raised pig population in rural areas of the Philippines.

Pig and piglets
Pig and piglets/Agricultural Research Services

The study was published in BMC Veterinary Research Jan. 27. Prior to this there was no epidemiological data available regarding HEV infection among the swine or human population in the Philippines.

Researchers tested molecular characteristics and seroprevalence of HEV among household-raised pigs in San Jose, Tarlac Province, the Philippines.

Serum and rectal swab samples were collected from 299 pigs aged 2–24 months from 155 households in four barangays (villages) between July 2010 and June 2011.

Republic of the Philippines

What they found was half the pigs tested for HEV IgG antibodies and nearly a quarter tested positive for HEV IgM antibodies using Enzyme-linked immunosorbent assay (ELISA) technology.

In addition, HEV RNA was detected in the feces of 22 pigs, or 7 percent of those tested.

Two-thirds of households had at least one pig that tested positive for anti-HEV IgG or IgM or HEV RNA.


Because there was such a high prevalence of HEV antibodies in the household-raised pig population in this Tarlac village, researchers conclude that this indicates the potential risk of HEV infection among local residents.

Hepatitis E is a liver disease caused by the Hepatitis E virus (HEV). HEV infection usually results in a self-limited, acute illness. It is widespread in the developing world.

Hepatitis E is most common in developing countries with inadequate water supply and environmental sanitation. Large hepatitis E epidemics have been reported in Asia, the Middle East, Africa, and Central America.

Hepatitis E virus is usually spread by the fecal-oral route. The most common source of infection is fecally contaminated drinking water. In developed countries sporadic outbreaks have occurred following consumption of uncooked/undercooked pork or deer meat.