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MERS-CoV in Upper RespiratoryTract and Lungs of DromedaryCamels, Saudi Arabia, 2013–2014Abdelmalik I. Khalafalla, Xiaoyan Lu, Abdullah I.A. Al-Mubarak,Abdul Hafeed S. Dalab, Khalid A.S. Al-Busadah, Dean D. ErdmanTo assess the temporal dynamics of Middle East respiratorysyndrome coronavirus (MERS-CoV) infection in dromedarycamels, specimens were collected at 1–2 month intervalsfrom 2 independent groups of animals during April 2013–May 2014 in Al-Ahsa Province, Saudi Arabia, and tested forMERS-CoV RNA by reverse transcription PCR. Of 96 livecamels, 28 (29.2%) nasal swab samples were positive; of91 camel carcasses, 56 (61.5%) lung tissue samples werepositive. Positive samples were more commonly foundamong young animals (4years of age). The proportions of positive samples varied bymonth for both groups; detection peaked during November2013 and January 2014 and declined in March and May2014. These findings further our understanding of MERS-CoV infection in dromedary camels and may help informintervention strategies to reduce zoonotic infections.Middle East respiratory syndrome coronavirus(MERS-CoV) is an emerging pathogen associatedwith severe respiratory symptoms and renal failure ininfected persons (1,2). Saudi Arabia is the country mostseverely affected by the virus and is where the first recognizedcase was identified in 2012. The origin of MERS-CoV remains a mystery. Bats seem to be the reservoirhost of the virus (3) but are probably not the source ofthe ongoing MERS-CoV outbreak because of limitedcontact with humans in the Arabian Peninsula. Early observationsthat some MERS-CoV–infected persons hadbeen exposed to camels suggested a possible role of theseanimals as intermediate reservoir hosts (2,4). Serologicsurveys subsequently conducted in several countries inthe Arabian Peninsula and Africa identified high ratesof MERS-CoV–specific antibodies in dromedary camels(5–12). Furthermore, MERS-CoV infection in dromedarycamels was definitively proven by the detection of virusand virus sequences in respiratory specimens, feces, andAuthor affiliations: King Faisal University, Al-Ahsa, Saudi Arabia(A.I. Khalafalla, A.I.A. Al-Mubarak, A.H.S. Dalab, K.A.S. Al-Busada);Centers for Disease Control and Prevention, Atlanta, Georgia,USA (X. Lu, D.D. Erdman)DOI: http://dx.doi.org/10.3201/eid2107.150070milk collected from camels in Qatar (9,13), Oman (14),Saudi Arabia (5,15,16), and Egypt (17).The few published studies that looked for MERS-CoVin the respiratory tract of naturally infected dromedarycamels examined nasal or ocular swab samples but notsamples from the lower respiratory tract. Moreover, severalstudies relied on only a few specimens or collected specimensat only 1 time point (9,13–15). To address these limitationsand to clarify the dynamics of MERS-CoV infectionin these animals, we conducted a year-round study in whichwe collected a large number of specimens from the upperrespiratory tracts of live dromedary camels and from thelungs of dromedary camel carcasses.Materials and MethodsSample CollectionThis study was approved by the Institutional Review Boardof the Camel Research Center, King Faisal University,Al-Ahsa, Saudi Arabia. Respiratory specimens were collectedfrom 2 independent groups of mixed-age dromedarycamels (Camelus dromedaruis). The first collection wasobtained during April 2013–May 2014 at the Al OmranAbattoir, Al Omran City, in Al-Ahsa Province in the easternregion of Saudi Arabia. Livestock slaughtered at thisabattoir include cattle, goats, sheep, and camels originatingfrom Al-Ahsa and neighboring provinces. Animals selectedfor slaughter were mainly from the livestock market andfrom herds located around Al-Ahsa Province. At the livestockmarket in Al-Ahsa, dromedary camels are housed insmall groups (10–15 animals), where they may stay for nomore than 4 days. They are then transported in vehicles tothe abattoir, where they are kept for no more than 24 hoursbefore slaughter.Samples were taken from slaughtered dromedary camelson 8 occasions (every 1–2 months). On each particularcollection date, tissue specimens were collected from thelungs of all slaughtered dromedary camels. A total of 91animal carcasses were sampled; 28 had been young animals(4 years of age).Lung lobes that showed pulmonary lesions were sampled;if both lobes showed lesions or if no lesions were visible,Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 21, No. 7, July 2015 1153