Eurosurveillance - Volume 19, Issue 36, 11 September 2014

The effective reproduction number, Rt, of Ebola virus disease was estimated using country-specific data reported from Guinea, Liberia and Sierra Leone to the World Health Organization from March to August, 2014. Rt for the three countries lies consistently above 1.0 since June 2014. Country-specific Rt for Liberia and Sierra Leone have lied between 1.0 and 2.0. Rt<2 indicate that control could be attained by preventing over half of the secondary transmissions per primary case.

In some influenza surveillance systems, timely transport to laboratories for reverse transcription-polymerase chain reaction (RT-PCR) testing is challenging. Guidelines suggest that samples can be stored at 4°C for up to 96 hours but the effect of longer storage times has not been systematically evaluated. We collected nasopharyngeal and oropharyngeal specimens from patients in Kenya and stored them in viral transport medium at 2 to 8°C before testing for influenza A and B using real-time RT-PCR. From April 2008 to November 2010, we collected 7,833 samples; 940 (12%) were positive for influenza. In multivariable analysis, specimens stored for six days were less likely to be influenza-positive compared to specimens stored between zero and one day (adjusted odds ratio (aOR): 0.49, 95% confidence interval (CI): 0.27-0.93). There was no statistically significant difference in influenza positivity of specimens stored for five days compared to zero to one day. There was no statistically significant relationship between days in refrigeration and cycle threshold (C_t) values for positive samples (p=0.31). We found that samples could remain in storage for at least five days without affecting the proportion-positive of samples, potentially increasing the feasibility of including influenza surveillance sites in remote areas. .

A vaccine safety signal and association between new onset of narcolepsy and AS03-adjuvanted pandemic influenza A(H1N1) vaccine (Pandemrix, GlaxoSmithKline) in children and young adults has been reported in several European countries. In Ontario, Canada, AS03-adjuvanted pandemic A(H1N1) vaccine (Arepanrix, GlaxoSmithKline) was the primary vaccine administered in 2009/10, with 4.8 million doses distributed. We assessed post-marketing safety surveillance data by extracting adverse events following immunisation (AEFIs) associated with this vaccine from the integrated Public Health Information System. Reports were screened for key terms related to narcolepsy and further limited to children and young adults four to 29 years of age. Of 1,604 AEFIs reported in Ontario, 53 reports met the search criteria. Individual assessment by a nurse consultant for additional context suggestive of narcolepsy yielded five reports for secondary medical review. None of the five reports proved consistent with a possible narcolepsy diagnosis based on the available information. We present the first post-marketing assessment from Canada of narcolepsy reports following receipt of Arepanix. Continued investigation of differences between Arepanrix and Pandemrix and subsequent risk of narcolepsy is indicated. In light of the limitations of passive surveillance to detect a signal in this instance, validation using other data sources is prudent.