The First 2014 MERS Wave Peaked in Late April

About three week ago, I posted a graph that suggested the first wave of Middle East Respiratory Syndrome (MERS) infections in 2014 peaked about April 20th and was starting to decline (Number ofCurrent MERS Infections on the Arabian Peninsula May Be Declining).

Since April 30 almost 200 additional MERS cases have been reported. Extending the graph to include data through May 17, the additional data clearly show that the number of MERS cases (based on the plotting criteria) started to decline about April 20 and has continue to decline since then. The date associated with each individual case varies with the publicly available information. Where possible, the onset date is used. If the onset date is not provided, the date of hospitalization is used or the date of death. If the case is asymptomatic, the date of confirmation is used if available, if not, the date of the official report is used. If no other calendar information is available, the date of the report is used.  Importantly, the distribution of these additional cases by onset date, hospitalization or death date, or date of report, did not appreciably alter the shape of the graph or shift it closer in time. The plotted 5-day central moving average (incorporating all of the additional cases) is almost coincidental with the moving average plotted through April 30 as show on the graph below. 

Since most MERS cases are being reported from Saudi Arabia, the decline in cases is welcome news.  However, the number of exported MERS cases from Saudi Arabia to other countries seems to be increasing and should of concern for public health officials worldwide.