Saudi Arabia reported three more Middle East respiratory syndrome coronavirus (MERS-CoV) cases today, while a serologic study of 268 children and men in eastern Saudi Arabia found that none had antibodies suggesting past exposure to the virus.
The Saudi Ministry of Health (MOH) said the three new cases involve an 87-year-old woman, a 53-year-old woman, and a 63-year-old man, all of them Saudi citizens and all being treated in hospital intensive care units. The statement was dated Sep 27 but was posted online today.
The MOH said all three patients had other diseases—chronic in two cases—before they were found to have MERS. The statement did not list their home cities or give any other details. The MOH now shows a national total of 114 MERS-CoV cases, with 49 deaths.
The serologic study, released Sep 27 by Emerging Infectious Diseases, suggests that the virus was not widespread among men in Saudi Arabia's Eastern province late last year. However, an expert who was not involved in the study noted that no serologic tests for the virus have been fully validated, leaving some uncertainty about the findings.
Few MERS-CoV seroprevalence studies have been conducted, leaving it unclear whether many infections have gone undetected because they caused no or only mild symptoms.
In the study, German and Saudi researchers analyzed samples collected from two sets of patients at King Fahd Hospital of the University of Alkhobar, Saudi Arabia: children hospitalized for lower respiratory infections from May 2010 through May 2011, and men who donated blood in December 2012. Collection of samples from the children predated the emergence of MERS-CoV in April 2012.
The children had a mean age of 11.6 months (range, 7.3 months to 9 years), while the men's median age was 28 years (range, 19 to 52).
The test used was a lentivirus vector that incorporates the spike (S) protein of MERS-CoV. The test "mimics key aspects of MERS-CoV cellular entry and enables sensitive and quantitative detection of neutralizing antibodies," the report says.
By examining the lentivirus vector's effect on target cells, the researchers determined that none of the samples contained neutralizing antibodies against MERS-S.