Scientists have isolated the source that is responsible for 26,000 piglets becoming sick and dying during the last couple of years in China. The source for the virus turned out to be another animal living the area, the horseshoe bat.

Piglets began dying in 2016 and at first, scientists thought they knew what was causing the deaths.

Swine Acute Diarrhea Syndrome

Researchers released a study in the journal Nature showing how coronavirus transmission could go from bats to domestic animals to humans. They found that China is one of the hot spots for the transmission of these viruses.

Newborn piglets began to get sick in October 2016 in Guangdong Province in China. At first, officials believe that the cause of the illnesses was porcine epidemic diarrhea virus (PEDV). Piglets tested positive for the disease then around January 2017, they stopped testing positive for PEDV.

While looking for the cause of the disease, they inspected the PEDV and the severe acute respiratory syndrome (SARS) that emerged in 2002 from Foshan, which was 60 miles away. Scientists found that the new virus was in the same family but was a completely different disease. This disease is called swine acute diarrhea syndrome (SADS).

They are all a type of coronavirus. These types of viruses can cause mild to moderate infections. Another virus in this family is Middle East respiratory syndrome (MERS). These viruses are easy to spread because they are airborne.

SADS latched on to the piglets during the outbreak of PEDV then replaced it. By the time it was identified, the virus had killed more than 24,000 in the region.

The Main Culprits Were Bats

Scientists were able to trace the origin of the outbreak to bats. They were able to compare SADS to samples that were taken from bat caves the year before. Samples of the virus from bats came from their butts. These samples led to scientists determining that 9.8 percent of horseshoe bats had a similar virus.

Researchers of the study single out bats as one of the most important reservoirs for emerging viruses. A study from 2017 named bats as one of the major reservoir for coronaviruses in the world.

While bats are known to carry coronaviruses, scientists do know which viruses will actually affect humans. SADS is one of the coronaviruses that couldn't be transmitted to humans. Unlike SADS, zoonotic viruses — diseases that are transmissible between humans and animals — happen when humans and domesticated animals come into contact with previously isolated wildlife.