CDC tweaks MERS guidance; WHO notes fewer exported cases

Mecca pilgrims
Mecca pilgrims

The WHO noted that, despite many pilgrims traveling to Saudi Arabia during Ramadan, no exported MERS cases have yet to be reported., iStockphoto

The US Centers for Disease Control and Prevention (CDC) yesterday issued updated its guidance to clinicians on evaluating patients for Middle East respiratory syndrome coronavirus (MERS-CoV).

In a Health Alert Notice (HAN), the CDC said it has changed its criteria on which patients should be evaluated for the disease.

In earlier guidance the agency did not advise testing for those whose illnesses could be explained by another cause. But in new recommendations issued Aug 9, the CDC said patients who meet certain clinical and epidemiologic criteria can be tested for MERS-CoV and other pathogens at the same time. It also added that diagnosis with another respiratory pathogen doesn't necessarily rule out testing for MERS-CoV.

The CDC's revised guidance also contains a clarification about investigating clusters of severe acute respiratory illnesses that don't have an apparent link to a MERS case. It said clusters should be evaluated for common pathogens and reported to local and state health departments, with MERS-CoV testing considered if the infections are still unexplained.

Updates from WHO, ECDC

In related developments, two global health groups have updated their information about the disease. The World Health Organization (WHO), in an update today, reviewed the most recent published MERS studies, along with recent outbreak developments.

It said though new cases continue to be reported from the Arabian Peninsula, no exported infections have occurred since June, despite a surge of pilgrims traveling to Saudi Arabia during Ramadan. The agency also added that Saudi Arabia's health ministry enhanced its surveillance during that time and found no MERS-CoV infections among pilgrims.

The WHO noted, however, that Ramadan ended on Aug 8, and the disease's incubation can be 10 days or more, and it urged countries to remain vigilant. "It is notable that only one previously reported case became ill after a pilgrimage," the WHO said.

The European Centre for Disease Prevention and Control (ECDC) yesterday issued a statement on a recent study that identified antibodies to MERS-CoV or a closely related virus in camels from Oman and Spain.

It said the finding are intriguing but aren't definitive proof that camels are the source of the virus. Though earlier studies have shown that coronaviruses can infect a variety of animals and can cause severe symptoms in newborn camels, the study doesn't exclude the possibility of cross reactions with viruses similar to MERS-CoV, the ECDC said.

It noted that investigations have ruled out direct animal contact for most patients and that few had contact with camels. The ECDC said more studies are needed to pin down the reservoir or potential intermediate animal hosts.

See also:

Aug 12 CDC HAN update

Aug 9 CDC interim guidance for evaluating patients for MERS-CoV

Aug 13 WHO MERS-CoV summary

Aug 12 ECDC statement

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