Western area surge for controlling Ebola hemorrhagic fever outbreak in Sierra Leone and evaluation of its effect / 中华预防医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the Western Area Surge (WAS) program in the Ebola outbreak of Sierra Leone, and to analyze its implementing effect.</p><p><b>METHODS</b>The subject of this study was 3,813 laboratory confirmed Ebola hemorrhagic fever (EHF) cases reported in Sierra Leone from November 19, 2014 through January 27, 2015, a period before and after the implementation of the WAS program. To analyze and make conclusions according to the working experience of China Mobile Laboratory Reponses Team in the fight of Ebola outbreak, using WHO published EHF case definition to make diagnosis and compare the number of bed numbers, confirmed EHF cases, samples tested, and positive rates before and after implementation of WAS program.</p><p><b>RESULTS</b>From the implementation of WAS program on 17th December 2014 to half a month later, the total numbers of Ebola holding and treatment centers increased from 640 to 960, six additional laboratories were established. On January, 2015, another two laboratories from America and The Netherlands were established. The numbers of samples tested one month before and after WAS program were 7,891 and 9,783, respectively, with an increase of 24.0 percent, while the positive rate of Ebola virus decreased from 22.2% (1,752/7,891) to 11.0% (1,077/9,783). The positive rate of blood samples decreased from 39.6% (248/626) in the month before WAS program to 27.4% (131/478) (χ2=17.93, P<0.001) in the mother after WAS program, the positive rate of blood samples 22.7% (103/454) to 10% (62/609) (χ2=31.03, P<0.001), accordingly. After 3 weeks of WAS program, in addition to Western Area, another four hotspots in Sierra Leone had also reported a significant decrease of the numbers of confirmed EVD cases. Forty-two days after implementation of WAS program, the daily number of laboratory confirmed EHF cases decreased from 63 to 10.</p><p><b>CONCLUSION</b>WAS program played a vital role in controlling the EHF outbreak rapidly in Sierra Leone. It could also provide guidance for the control similar large infectious diseases outbreak in the future.</p>