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Adding to the stampede of MERS-CoV in Camel studies coming out in recent months (see mBio: MERS-CoV In Saudi Arabian Camels & The Lancet: Identification Of MERS Virus In Camels), today we have a new Dispatch from the CDC’s EID Journal that relates the finding of a 99% match to the MERS coronavirus in Egyptian camels.
While just 4 (3.6%) of nasal swabs (out of 110 tested) were positive for the MERS-CoV virus (via RT-PCR testing) – suggesting current or active infection - 48 (92.3%) of 52 dromedary serum samples revealed titers from between 20 to >640, indicating prior infection.
Serological testing of 179 camel abattoir workers, however, revealed no signs of previous MERS infection. Leading the researchers to conclude that while MERS infection in camels is common in Egypt, thus far it is rarely transmitted on to humans.
I’ve only excerpted the Abstract & Conclusions below. Follow the link to read the entire study.
Daniel K.W. Chu1, Leo L.M. Poon1, Mokhtar M. Gomaa, Mahmoud M. Shehata, Ranawaka A.P.M. Perera, Dina Abu Zeid, Amira S. El Rifay, Lewis Y. Siu, Yi Guan, Richard J. Webby, Mohamed A. Ali, Malik Peiris , and Ghazi Kayali
We identified the near-full-genome sequence (29,908 nt, >99%) of Middle East respiratory syndrome coronavirus (MERS-CoV) from a nasal swab specimen from a dromedary camel in Egypt. We found that viruses genetically very similar to human MERS-CoV are infecting dromedaries beyond the Arabian Peninsula, where human MERS-CoV infections have not yet been detected.
Our findings confirm that MERS-CoV infects dromedary camels and that this virus is genetically very similar to a MERS-CoV that is infecting humans. The detection of MERS-CoV in nasal swab specimens of camels in 2 of 12 sampling occasions in abattoirs, taken together with the high seropositivity to MERS-CoV in dromedaries previously reported, supports the contention that MERS-CoV infection is common in dromedaries.
Studies of dromedaries within camel herds and through the animal marketing system supplying abattoirs are needed to define the epidemiology of the infection. Our findings strengthen the plausibility that dromedaries may be a potential source of human infection and emphasize the need for detailed epidemiologic investigation of the exposure histories of humans with MERS.
However, the lack of serologic evidence of infection of humans working in these abattoirs suggests that transmission of this virus to humans is uncommon. The detection of MERS-CoV in dromedaries in Egypt, in animals imported from Sudan and Ethiopia, suggests that cases may occur in humans beyond the Arabian Peninsula. MERS CoV diagnostic tests should be considered for all patients with unexplained severe pneumonia in Egypt, northeastern Africa, and beyond.