MERS-COV (62): ANIMAL RESERVOIR, CAMELS, FAO, OIE, WHO

Posted on 02ND OCT 2017
tagged MERS-CoV, Worldwide

A ProMED-mail post
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International Society for Infectious Diseases
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Date: Sun 1 Oct 2017 7:09 PM CEST
Source: Reuters [edited]
https://in.reuters.com/article/us-health-mers/health-experts-zero-in-on-...

The fight against the deadly Middle East respiratory syndrome (MERS), which has killed at least 722 people over the past 5 years, is honing in on its target: camels.

MERS coronavirus (MERS-CoV), a member of a virus family ranging from the common cold to severe acute respiratory syndrome, appears to have emerged in humans in Saudi Arabia in 2012, but has now been traced back in camels to at least 1983.

Almost all the outbreaks so far originated in the Arabian Gulf, but MERS-CoV could infect humans wherever there are one-humped dromedary camels -- 2-humped bactrians are not affected.

That means people across a swathe of Africa, the Middle East, Pakistan, and South Asia are potentially at risk. So the hunt is on for vaccinations -- both for humans, and camels.

"The virus is in camels everywhere. The virus is in Qatar, it's in United Arab Emirates, it's wherever we look," said Maria Van Kerkhove, a disease outbreak expert at the World Health Organization (WHO), where 130 experts gathered last week [26-27 Sep 2017] to collaborate for the 1st time on tackling the disease. "I know so much more about camels than I ever thought I would," she said.

People have probably caught MERS in Africa but the absence of outbreaks recorded there may be due to poor disease surveillance, less contact with camels, or lower rates of underlying conditions like obesity and heart problems that make MERS more severe.

Saudi Arabia has been heavily criticized for not being transparent about MERS, but Van Kerkhove said that had totally changed. It is now testing 70 000 human samples a year and generating a vast amount of research.

MERS is hard to spot, and far more deadly than other acute respiratory infections, killing one in three sufferers. It has a habit of infiltrating Saudi hospitals via patients visiting for regular dialysis or cardiac appointments, causing outbreaks that have killed patients and health workers alike.

Hospitals are raising their game. "One hospital even has a drive-thru. Literally a drive-thru in their emergency department," said Van Kerkhove, explaining how patients are vetted before being allowed in. "You drive up in the car to the person in the booth and they ask you 3 questions. It takes less than 13 seconds."

A dozen human vaccines are in development, with vaccine coalition CEPI [Coalition for Epidemic Preparedness Innovations] expected to announce soon which it will fund.

But the key to stopping human deaths is controlling MERS in camels. 2 camel vaccines have been developed, but only one, developed by the Jenner Institute [Oxford, England], is in field trials.

The other, developed at the Erasmus Medical Centre [Rotterdam, Netherlands], is still seeking funding. The WHO MERS program is also under-funded, Van Kerkhove said.

At last week's meeting, hosted by the WHO, animal health body OIE, and the UN Food and Agriculture Organization [FAO], Saudi and Qatari experts were "happy to talk to each other" despite their governments' diplomatic friction, she said.

Collaboration is vital, because camels must be diagnosed, quarantined, and vaccinated as they enter the Gulf from the Horn of Africa. The virus must be tracked like bird flu is in birds, Van Kerkhove said.

But there is a long road ahead. "I've never seen a really good map showing where camels move," she said.

[Byline: Tom Miles]

--
Communicated by:
ProMED-mail Rapporteur Mary Marshall

[Press releases addressing the global MERS-CoV meeting mentioned above, convened in Geneva on 26-27 Sep 2017, were published by OIE and WHO. The WHO press release was included in archive no. 20171001.5353977.

FAO maintains an exhaustive continuous MERS-CoV situation report, which is updated every month. The recent report was updated on 27 Sep 2017. It includes detailed information on the evolvement of the disease in humans since its initial detection in 2012 and epidemiological information collected from camels globally, including tables, maps, and multiple links, commendably available at http://www.fao.org/ag/againfo/programmes/en/empres/mers/situation_update....

MERS-CoV does not cause a serious disease in camels; rather, it is mild or subclinical. In such a situation, the implementation of control measures in camels -- essentially, to prevent human infection -- requiring the active cooperation of camel holders, becomes a complex issue.

During the last, 85th annual General Session of the OIE, Paris, 21-26 May 2017, a case definition for MERS-CoV in camels was discussed, as reported in the event's final report (art 146). The definition was meant to provide information that would help member countries to differentiate confirmed and suspected MERS-CoV cases in camels and to report to the OIE in accordance with the 'emerging disease provisions' of the Code's Article 1.1.4. Based on new scientific information, the following case definition had been finalised and agreed by the OIE ad hoc Group on Camelid Diseases and MERS-CoV experts: "A dromedary camel with laboratory confirmation of MERS-CoV infection, with or without clinical signs." The said definition was presented to the Scientific Commission which recommended that the updated case definition be published on the OIE website and that the OIE question and answer document on MERS-CoV be updated with the latest scientific information to include the new case definition.

Accordingly, on 27 Sep 2017 the following text addressing the new case definition was published on OIE's website (see http://www.oie.int/scientific-expertise/specific-information-and-recomme...):

"Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Case definition for reporting to OIE (Update: May 2017)

1. Introduction
Dromedary camels have been confirmed by several studies to be the reservoir of the MERS-CoV infection in humans. Zoonotic transmissions of MERS-CoV from dromedary camels to humans were reported in multiple occasions. MERS-CoV has never been reported as a disease in camels though in experimental infections MERS-CoV has been associated with mild upper respiratory signs. Positive PCR results for MERS-CoV or isolation of the virus from camels is notifiable to the OIE because MERS is an emerging disease with a significant public health impact.

2. Confirmed case
A dromedary camel with laboratory confirmation (*1) of MERS-CoV infection, with or without clinical signs.

3. Suspected case
- observed clinical signs of mild respiratory infection (rhinitis in young dromedaries); and
- direct epidemiologic link (*2) with a confirmed human or camel MERS-CoV case; and
- testing for MERS-CoV is unavailable, negative or inconclusive (*4) on a single inadequate specimen (*3).

Notes
*1. A case may be laboratory confirmed by virus isolation or detection of viral nucleic acid. The presence of viral nucleic acid can be confirmed by 1) a positive RT-PCR result on at least 2 specific genomic targets; 2) a single positive target with sequencing of a 2nd target; or 3) a single positive target with positive result in a rapid MERS-CoV Ag test. Serological investigations are of little value as high percentage of tested dromedaries possess antibodies to MERS-CoV.

*2. A direct epidemiological link with a confirmed MERS-CoV dromedary camel may include living or traveling together in close proximity or sharing the same environment with individual dromedaries infected with MERS-CoV.

*3. An inadequate specimen would include a specimen that has had improper handling, is judged to be of poor quality by the testing laboratory, or was taken too late in the course of illness.

*4. Inconclusive tests may include a positive screening test on a single rRT-PCR target without further confirmation. Animals with an inconclusive initial test should undergo additional sampling and testing to determine if the animal can be classified as a confirmed MERS-CoV case. At herd level, having positive single target PCRs in more than one animal could constitute confirmation. Preference should be a repeat nasopharyngeal specimen. Other types of clinical specimens could also be considered for molecular testing if necessary, including blood/serum, and stool/rectal swab. These generally have lower titers of virus than respiratory tract specimens but have been used to confirm cases when other specimens were inadequate or unobtainable."

The case definition above and, in particular, the section addressing suspected MERS-CoV cases in camels, is rather complex. It remains to be seen if the reporting to the OIE, and the level of control upon international movement and trade in dromedary camels, are improving. What measures are anticipated from a country detecting a suspected case? The development of a high-potent vaccine and its compulsory, preferably free-of-charge application in camels may become the only feasible measure to prevent human infection.

As remarked by Dr Van Kerkhove, "a really good map showing where camels move" may not readily become available; nomad routes and timetable, within and across national boundaries, are a serious challenge for the national veterinary authorities. - Mod.AS]

See Also
MERS-CoV (61): Saudi Arabia 20171001.5353977
MERS-CoV (40): animal reservoir, camels, review, FAO 20170619.5115999
MERS-CoV (29): Qatar, animal reservoir, camels 20170527.5066519
MERS-CoV (28): Qatar, Saudi Arabia (HA) 20170524.5059234
MERS-CoV (23): Saudi Arabia (AS) animal reservoir, human contact, OIE, RFI 20170421.4986081
MERS-CoV (21): Egypt, animal reservoir, camel, ex Sudan, control, RFI 20170405.4948727
MERS-CoV (18): Africa, animal reservoir, camels, 2015, research 20170331.4939980
2016
----
MERS-CoV (87): Jordan, animal reservoir, camelids, OIE 20160802.4385317
MERS-CoV (66): Saudi Arabia, animal reservoir, camelids, OIE, RFI 20160618.4294807
MERS-CoV (59): animal reservoir, review 20160610.4275921
MERS-CoV (40): Egypt, animal reservoir, camel, ex Sudan, susp. 20160316.4097730
MERS-CoV (21): Saudi Arabia, animal reservoir, camel, comment 20160216.4023772
MERS-CoV (19): Saudi Arabia, animal reservoir, camel, prevention, RFI 20160204.3995194
MERS-CoV (18): Saudi Arabia, animal reservoir, camel, vaccination, comment 20160203.3990284
MERS-CoV (16): Saudi Arabia (MK) animal reservoir, OIE, RFI 20160201.3985175
MERS-CoV (11): Saudi Arabia, animal reservoir, camel, vaccination, comment 20160126.3966528
MERS-CoV (09): Saudi Arabia, animal reservoir, camel, vaccination considered 20160125.3963370
2015
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MERS-CoV (163): Saudi Arabia, animal reservoir, camel, research, vaccine 20151219.3873486
MERS-CoV (155): animal reservoir, camel, research, RFI 20151110.3781744
MERS-CoV (104): Saudi Arabia, animal reservoir, camel debate 20150810.3569207
MERS-CoV (63): animal reservoir, bat 20150612.3432410
MERS-CoV (48): UAE (Dubai) animal reservoir, camel 20150527.3386738
MERS-CoV (27): Saudi Arabia, animal reservoir, camel 20150302.3200502
MERS-CoV (12): animal reservoir, camels debated, case-control study, RFI 20150122.3109335
MERS-CoV (09): Saudi Arabia, animal reservoir, camels debated 20150117.3098294
2014
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MERS-CoV (67): Iran (SB) animal reservoir, camel, ex Pakistan, RFI 20141219.3039497
MERS-CoV (49): Iran (SB), animal reservoir, camel conf, OIE 20141029.2912385
MERS-CoV (40): animal reservoir, camel, milk susp, RFI 20141022.2889778
MERS-CoV (24): animal reservoir, camel, experimental infection 20140929.2813981
MERS-CoV (09): animal reservoir, update, OIE, WHO 20140818.2700879
MERS-CoV (07): animal reservoir, camel, bat 20140720.2623848
MERS-CoV - Eastern Mediterranean (79): Qatar (OIE) Kuwait (susp) animal res, RFI 20140611.2533756
MERS-CoV - Eastern Mediterranean (77): S Arabia, Qatar, animal res, control, RFI 20140607.2525113
MERS-CoV - Eastern Mediterranean (75): Animal res, camel, zoonotic aspects 20140604.2518134
MERS-CoV - Eastern Mediterranean (66): Oman (SH), camel conf, OIE 20140523.2493556
MERS-CoV - Eastern Mediterranean (10): camel, Sudan, Ethiopia 20140228.2307254
MERS-CoV - Eastern Mediterranean (09): animal reservoir, camel, Saudi Arabia 20140227.2303420
MERS-CoV - Eastern Mediterranean (02): animal reservoir, camel, UAE, serology 20140104.2151807
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