Analyzing Strategies for Containing Avian Influenza.

In this paper, we couple a general-purpose infectious disease theory with a computational modeling framework to analyze strategies for avian influenza containment. We focus on virus transmission among domestic poultry populations to optimize and evaluate the effectiveness of three containment strategies and their combinations: reducing the contact rate among domestic birds, reducing the population of infected birds, and reducing the transportation of infected birds. We illustrate their usage during a two-wave avian flu outbreak in Nigeria. Our findings show that reducing contacts by 20% via cluster isolation early in the first wave can achieve containment rapidly. It also helps avert the second wave. Slaughtering infected birds is not as effective, requiring scheduled killings of over 80% of the poultry while failing to avert the second wave. This practice also risks damaging the local economy and potential secondary infections from the carcasses of infected birds. Reducing transportation between northern and southern Nigeria does not offer good containment since the disease spread began in both regions simultaneously. Reducing transportation has an impact when applied to neighboring regions and cities, or when the initial incidence of the disease is localized. Combination strategies prove to be the most practical and cost-effective to implement. The use of 3D-effectiveness visualized plots allows policymakers to evaluate multiple combination strategies and choose the one that optimizes containment while also adhering to budget constraints, resource availability, and management preference. The generalized mathematical theory and modeling framework is highly flexible and can be applied to other diseases, including those with multiple hosts, multiple species involvement, and across a broad array of heterogeneous regions.

Fasciola hepatica infection in water buffalo Bubalus bubalis in three provinces of the Nile Delta, Egypt: a cross-sectional study.

A cross-sectional study was conducted to estimate the prevalence of Fasciola hepatica (F. hepatica) infection in water buffalo (Bubalus bubalis) in Alexandria, Beheira, and Kafr el-Sheikh governorates (provinces) of the Nile Delta in Egypt and to identify the underlying risk factors associated with the infection. A total of 29 farms (10 in Alexandria, 10 in Beheira, and 9 in Kafr el-Sheikh) were randomly selected and all the buffaloes that resided on these farms from 21 February 2015 to 20 February 2016 were included in the study. The sampling approach was target-based where all the buffaloes were examined and screened for clinical signs of Fasciola infection. All suspected buffaloes were then subjected to fecal examination, and those positive for Fasciola eggs underwent antibody testing using indirect hemagglutination test. Consequently, data on 3,356 buffaloes from 29 farms in these governorates was analyzed using a multiple logistic regression model. The final model showed that the age and body condition score of the buffalo, location and type of the farm, application of prophylactic treatment, and temperature and relative humidity of the farm's location significantly affected the rate of infection. The highest prevalence was observed in buffaloes from Alexandria governorate (19.6%), followed by Beheira and Kafr el-Sheikh governorates (15.5 and 9.1%, respectively).

Epidemiology of bovine fascioliasis in the Nile Delta region of Egypt: Its prevalence, evaluation of risk factors, and its economic significance.

AIM: This study focuses on the risk factors associated with the prevalence of Fasciola affecting cattle population in three provinces belonging to the Nile Delta of Egypt and to estimate the economic losses as a result of fascioliasis. MATERIALS AND METHODS: From January 2015 to end of December 2015, records of 21 farms (4976 cattle) were analyzed to screen the prevalence of fascioliasis among cattle farms, to identify its associated risk factors and its economic impacts on Nile Delta region of Egypt. RESULTS: The overall prevalence of fascioliasis in the Nile Delta region of Egypt was 9.77%. The prevalence of fascioliasis was found to be statistically significantly associated with age, sex, breed, and type of farms. The highest prevalence was observed in <2 age group (10.91%), and the lowest was >3 age groups (8.35%). In terms of body condition scores, cattle with medium and poor conditions were associated with fascioliasis more than those with good body condition. Besides, cattle raised in organic farms were associated with lower risk of fascioliasis than those in conventional farms. The prevalence of fascioliasis was noted more prominent in districts with moderate temperatures and with relative humidity (>60%). The annual overall costs for fascioliasis were estimated to be 221.2 USD/cow due to the significant reduction in body weight, reduction in milk production, and the treatment costs for fascioliasis. CONCLUSION: The results provided could be helpful for improving the control and preventive strategies.

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.

Live bird market (LBM) is integral component in the perpetuation of HPAI H5N1, while biosecurity is crucial and key to the prevention and control of infectious diseases. Biosecurity compliance level and risk factor assessments in 155LBMs was evaluated in Nigeria and Egypt through the administration of a 68-item biosecurity checklist, scored based on the modifications of previous qualitative data, and analysed for degree of compliance. LBMs were scored as "complied with a biosecurity item" if they had good-very good scores (4). All scores were coded and analysed using descriptive statistics and risk or protective factors were determined using univariable and multivariable logistic regression at p≤0.05. Trading of wild birds and other animal in the LBMs (Odd Ratio (OR)=34.90; p=0.01) and claims of hand disinfection after slaughter (OR=31.16; p=0.03) were significant risk factors while mandatory routine disinfection of markets (OR=0.13; p≤0.00), fencing and gates for live bird market (OR=0.02; p≤0.01) and hand washing after slaughter (OR=0.41; p≤0.05) were protective factors for and against the infection of Nigerian and Egyptian LBMs with the HPAI H5N1 virus. Almost all the LBMs complied poorly with most of the variables in the checklist (p≤0.05), but pathways to improved biosecurity in the LBMs existed. We concluded that the LBM operators play a critical role in the disruption of transmission of H5N1 virus infection through improved biosecurity and participatory epidemiology and multidisciplinary approach is needed.