WHO: New specimen recommendations and longer period of observation in updated MERS-CoV guidelines
The World Health Organization (WHO) recently released revised surveillance recommendations Middle East respiratory syndrome coronavirus (MERS-CoV), which highlight two key areas: Stronger recommendations for lower respiratory specimens and a longer period of observation for contacts of cases.
The WHO states that more evidence suggests that nasopharyngeal swabs aren’t as sensitive as lower respiratory specimens for detecting infections.
The UN health agency says concerning specimens for testing, “It is strongly advised that lower respiratory specimens such as sputum, endotracheal aspirate, or bronchoalveolar lavage should be used when possible until more information is available.
“If patients do not have signs or symptoms of lower respiratory tract infection and lower tract specimens are not possible or clinically indicated, both nasopharyngeal and oropharyngeal specimens should be collected.
“If initial testing of a nasopharyngeal swab is negative in a patient who is strongly suspected to have MERS-CoV infection,
patients should be retested using a lower respiratory specimen or a repeat nasopharyngeal specimen with additional oropharyngeal specimen if lower respiratory specimens are not possible.”
In addition, the WHO says the incubation period for MERS-CoV may be as long as 14 days.
“The incubation period for cases in whom exposure is known or strongly suspected is generally less than one week. However, in at least one case,the known exposure occurred 9 to 12 days prior to onset of illness. Further evidence in cases exposed over a range of time suggest that at least in a minority of cases, incubation period may exceed one week but is less than two weeks.”
Globally, from September 2012 to date, WHO has been informed of a total of 77 laboratory-confirmed cases of infection with MERS-CoV, including 40 deaths.
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