Constructing Rigorous and Broad Biosurveillance Networks for Detecting Emerging Zoonotic Outbreaks

Abstract

Determining optimal surveillance networks for an emerging pathogen is difficult since it is not known beforehand what the characteristics of a pathogen will be or where it will emerge. The resources for surveillance of infectious diseases in animals and wildlife are often limited and mathematical modeling can play a supporting role in examining a wide range of scenarios of pathogen spread. We demonstrate how a hierarchy of mathematical and statistical tools can be used in surveillance planning help guide successful surveillance and mitigation policies for a wide range of zoonotic pathogens. The model forecasts can help clarify the complexities of potential scenarios, and optimize biosurveillance programs for rapidly detecting infectious diseases. Using the highly pathogenic zoonotic H5N1 avian influenza 2006-2007 epidemic in Nigeria as an example, we determined the risk for infection for localized areas in an outbreak and designed biosurveillance stations that are effective for different pathogen strains and a range of possible outbreak locations. We created a general multi-scale, multi-host stochastic SEIR epidemiological network model, with both short and long-range movement, to simulate the spread of an infectious disease through Nigerian human, poultry, backyard duck, and wild bird populations. We chose parameter ranges specific to avian influenza (but not to a particular strain) and used a Latin hypercube sample experimental design to investigate epidemic predictions in a thousand simulations. We ranked the risk of local regions by the number of times they became infected in the ensemble of simulations. These spatial statistics were then complied into a potential risk map of infection. Finally, we validated the results with a known outbreak, using spatial analysis of all the simulation runs to show the progression matched closely with the observed location of the farms infected in the 2006-2007 epidemic.

An evaluation of biosecurity compliance levels and assessment of associated risk factors for highly pathogenic avian influenza H5N1 infection of live-bird-markets, Nigeria and Egypt

“…Highly pathogenic avian influenza (HPAI) H5N1 remains an emerging zoonotic disease with significant economic, food security and human health impacts (Brown et al, 2015). The first outbreak of HPAI H5N1 in Africa was in Kaduna, Nigeria in February 2006(Joanis et al, 2006, with consequent destruction of millions of poultry and approximately US$ 5.4 million paid in compensation by the Government of Nigeria.…”

Systematic review and meta-analyses of cases and deaths associated with highly pathogenic avian influenza H5N1 in humans and poultry.

“…However, we tried to filter all data, remove duplicates and validate records based on laboratory-confirmed cases before including data in the evaluation. A CFR in the range determined by Li et al [28] (14-33%) is high enough to warrant the attention of health authorities in case of an epidemic in humans and for an effective control to be implemented [6,9]. Although the virus is yet to adapt effectively to infect and transmit between humans, it and other forms of influenza viruses continue to threaten humans and livestock [29][30][31][32].…”

“…For instance, the outbreaks in Cote d'Ivoire in 2006 primarily occurred in Abidjan, but in 2015, multiple outbreaks occurred in many localities within about a 5-h drive from Abidjan. Rivas et al [25] confirmed that such distances can play a role in the dissemination of outbreaks to new locations, and Brown et al [9] stated that multiple empirically-dispersed disease surveillance and detection centres in each country will assist in facilitating rapid and effective controls of outbreaks. The spatio-temporal dynamics of policy decisions on diseases may have influenced the outcomes of HPAI H5N1 infections in Africa.…”

“…As of September 2015, a total of 844 confirmed cases with 449 deaths (cumulative proportion of fatal cases: 53.2%) of H5N1-infected patients had been reported to the World Health Organization from 16 countries [7]. Routine surveillance, either passive or active, is an integral part of the means for detecting cases of HPAI H5N1 outbreak as early as possible [8,9]. However, it is unlikely that continuous and sustained surveillance is practiced in parts of Africa where competition for limited resources is great and priorities are often weighed in favour of other competing interests apart from animal health and welfare.…”

Risk perceptions and preventive preparedness towards avian influenza (H5N1) at live bird markets in North-central Nigeria: Public health implications

“…Highly pathogenic avian influenza (HPAI) H5N1 is an emerging and re-emerging zoonotic disease with significant economic, food security and human health implications (Brown et al, 2015). The wide genetic diversity of avian influenza viruses and the potential for recombination with human influenza strains continue to pose major public health challenges (Li et al, 2010;Fournié et al, 2011).…”