#13,690
MERS continues to simmer in the Middle East without sparking any large scale community outbreaks - but there remain a number of unanswered questions regarding both its prevalence, and how it is transmitting among humans.
Contact with infected camels is a known risk factor - and no doubt accounts for the continued re-introduction of the virus into the human population - but most community acquired human infections have no known recent contact with camels or camel products.While some of these cases have had contact (usually hospital or household) with a known infected person, most do not. Exactly how, and where they were exposed remains a mystery.
One theory is that a small number of mildly symptomatic (or asymptomatic) individuals may be inefficiently spreading the virus in the community. While unproven at this time, a few recent studies on point include:
mBio: High Prevalence of MERS-CoV Infection in Camel Workers in Saudi Arabia
AJIC:Intermittent Positive Testing For MERS-CoV
JIDC: Atypical Presentation Of MERS-CoV In A Lebanese PatientAnd last August - in Evaluation of a Visual Triage for the Screening of MERS-CoV Patients - we looked at what has been described as a serious flaw in Saudi Arabia's MERS surveillance program.
Because of the difficulties in identifying cases, the WHO continues to advise:
It is not always possible to identify patients with MERS-CoV early because like other respiratory infections, the early symptoms of MERS-CoV are non-specific. Therefore, healthcare workers should always apply standard precautions consistently with all patients, regardless of their diagnosis.
Droplet precautions should be added to the standard precautions when providing care to patients with symptoms of acute respiratory infection; contact precautions and eye protection should be added when caring for probable or confirmed cases of MERS-CoV infection; airborne precautions should be applied when performing aerosol generating procedures.
Today's report from the Saudi MOA adds a second community acquired case in Riyadh City with no known risk exposure this week. Of note, the most recent case is a 29 y.o. female.
The typical primary (community acquired) MERS case is male (2:1), over the age of 50 (see chart below), and often has comorbidities such as smoking, diabetes, or renal disease.
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| Credit WHO EMRO |
While MERS-CoV hasn't embarked on a world tour the way that SARS did 15 years ago, we've seen studies (see A Pandemic Risk Assessment Of MERS-CoV In Saudi Arabia) suggesting the virus doesn't have all that far to evolve before it could pose a genuine global threat.
Earlier this year, in the WHO List Of Blueprint Priority Diseases, we saw MERS-CoV listed among the 8 disease threat in need of urgent accelerated research and development.
List of Blueprint priority diseases
(SNIP)
The second annual review occurred 6-7 February, 2018. Experts consider that given their potential to cause a public health emergency and the absence of efficacious drugs and/or vaccines, there is an urgent need for accelerated research and development for*:
- Crimean-Congo haemorrhagic fever (CCHF)
- Ebola virus disease and Marburg virus disease
- Lassa fever
- Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS)
- Nipah and henipaviral diseases
- Rift Valley fever (RVF)
- Zika
- Disease X
All of which makes gaining a better understanding of how - and how well - the MERS coronavirus continues to spread in the community a high priority.
