Despite insecurity challenges in Somalia, key indicators for acute flaccid paralysis (AFP) surveillance have met recommended targets. However, recent outbreaks of vaccine-derived polioviruses have raised concerns about possible gaps. We analyzed nonpolio enterovirus (NPEV) and Sabin poliovirus isolation rates to investigate whether comparing these rates can inform about the integrity of stool specimens from inaccessible areas and the likelihood of detecting circulating polioviruses.
Using logistic regression, we analyzed case-based AFP surveillance data for 1348 cases with onset during 2014-2017. We assessed the adjusted impacts of variables including age, accessibility, and Sabin-like virus isolation on NPEV detection.
NPEVs were more likely to be isolated from AFP case patients reported from inaccessible areas than accessible areas (23% vs 15%; = .01). In a multivariable model, inaccessibility and detection of Sabin-like virus were positively associated with NPEV detection (adjusted odds ratio [AOR], 1.75; 95% confidence interval [CI], 1.14-2.65; and AOR, 1.79; 95% CI, 1.07-2.90; respectively), while being aged ≥5 years was negatively associated (AOR, 0.42; 95% CI, 0.20-0.85).
Rates of NPEV and Sabin poliovirus detection in inaccessible areas suggest that the integrity of fecal specimens tested for AFP surveillance in Somalia can generate useful AFP data, but uncertainties remain about surveillance system quality.
Published by Oxford University Press on behalf of Infectious Diseases Society of America 2020.
About The Expert
Amen Ben Hamida
Kamil Mohamed Ali
Rennatus Mdodo
Abdinoor Mohamed
Kumlachew Mengistu
Rosemary M Nzunza
Noha H Farag
Derek T Ehrhardt
Eltayeb Elfakki
Chukwuma Mbaeyi
References
PubMed