Natural reservoir

Early research suggested the virus is related to one found in the Egyptian tomb bat. In September 2012 Ron Fouchier speculated that the virus might have originated in bats.Work by epidemiologist Ian Lipkin of Columbia University in New York showed that the virus isolated from a bat looked to be a match to the virus found in humans.2c betacoronaviruses were detected in Nycteris bats in Ghana and Pipistrellus bats in Europe that are phylogenetically related to the MERS-CoV virus.

Recent work links camels to the virus. An ahead-of-print dispatch for the journal Emerging Infectious Diseases records research showing the coronavirus infection in dromedary camel calves and adults, 99.9% matching to the genomes of human clade B MERS-CoV.

At least one person who has fallen sick with MERS was known to have come into contact with camels or recently drank camel milk.

On 9 August 2013, a report in the journal The Lancet Infectious Diseases showed that 50 out of 50 (100%) blood serum from Omani camels and 15 of 105 (14%) from Spanish camels had protein-specific antibodies against the MERS-CoV spike protein. Blood serum from European sheep, goats, cattle, and other camelids had no such antibodies.^]Countries like Saudi Arabia and the United Arab Emirates produce and consume large amounts of camel meat. The possibility exists that African or Australian bats harbor the virus and transmit it to camels. Imported camels from these regions might have carried the virus to the Middle East.

In 2013 MERS-CoV was identified in three members of a dromedary camel herd held in a Qatar barn, which was linked to two confirmed human cases who have since recovered. The presence of MERS-CoV in the camels was confirmed by the National Institute of Public Health and Environment (RIVM) of the Ministry of Health and the Erasmus Medical Center (WHO Collaborating Center), the Netherlands. None of the camels showed any sign of disease when the samples were collected. The Qatar Supreme Council of Health advised in November 2013 that people with underlying health conditions, such as heart disease, diabetes, kidney disease, respiratory disease, the immunosuppressed, and the elderly, avoid any close animal contacts when visiting farms and markets, and to practice good hygiene, such as washing hands.

A further study on dromedary camels from Saudi Arabia published in December 2013 revealed the presence of MERS-CoV in 90% of the evaluated dromedary camels (310), suggesting that dromedary camels not only could be the main reservoir of MERS-CoV, but also the animal source of MERS.^[46]

According to the 27 March 2014 MERS-CoV summary update, recent studies support that camels serve as the primary source of the MERS-CoV infecting humans, while bats may be the ultimate reservoir of the virus. Evidence includes the frequency with which the virus has been found in camels to which human cases have been exposed, seriological data which shows widespread transmission in camels, and the similarity of the camel CoV to the human CoV.

On 6 June 2014, the Arab News

 newspaper highlighted the latest research findings in the New England Journal of Medicine in which a 44-year-old Saudi man who kept a herd of nine camels died of MERS in November 2013. His friends said they witnessed him applying a topical medicine to the nose of one of his ill camels—four of them reportedly sick with nasal discharge—seven days before he himself became stricken with MERS. Researchers sequenced the virus found in one of the sick camels and the virus that killed the man, and found that their genomes were identical. In that same article, the Arab News reported that as of 6 June 2014, there have been 689 cases of MERS reported within the Kingdom of Saudi Arabia with 283 deaths.