Evaluation of Laboratory Component of Highly Pathogenic Avian Influenza Surveillance - Nigeria, 2006 to 2009

Background: In 2006, Nigeria reported Highly Pathogenic Avian Influenza (HPAI) in poultry. In 2007, the first human case was detected linked to poultry from a Live Bird Market (LBM). The West and Central African Regional Laboratory for Avian Influenza in Nigeria is responsible for investigating specimens from birds meeting the case definition of HPAI (passive surveillance) and for specimens collected routinely from LBMs and high risk areas (active HPAI surveillance). We evaluated the laboratory component of the surveillance systems to determine whether it meets their objectives of early detection and response.

Methods: We used CDC’s updated guidelines for evaluating public health surveillance systems, conducted six key informant interviews, reviewed laboratory reports and analyzed HPAI surveillance data from 2006-2009.

Results: The active system employed a simple case definition with timely submission of specimens. Laboratory results were available within 48 hours for positive cases. The positive predictive value was 99.9%.The system has been adapted for surveillance of Newcastle Disease diagnosis. Strategies for control, depopulation of poultry and biosecurity were based on data from the passive system. Of 25,763 samples analyzed, 300 (1.2%) were confirmed for HPAI in 2006 and 2007 including 12 positive cases in 26 States with reported outbreaks where LBM surveillance was done. Active surveillance in 11 States with no previous outbreaks yielded two positive cases in 2008. No positive case was detected in 2009.

Conclusions: The laboratory component of the HPAI surveillance is acceptable, timely, and flexible. It was useful in the control of HPAI since laboratory results were available within 48 hours allowing culling to be done on time at the affected poultry; hence the laboratory surveillance is meeting its objectives. 

Author (s): 

Mabel K. Aworh, T. Joannis, P. Okewole, C. Meseko, E. Okolocha, P. Ekong, G. Poggensee, P. Nguku

Presenter (s): 
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