Newcastle disease (ND) is one of the most important and widespread avian pests. In Africa, backyard poultry production systems are an important source of protein and cash for poor rural livelihoods. ND mortality in these production systems is important and seriously disrupts benefits derived from it. This study undertook an African continental approach of ND epidemiology in backyard poultry. After a systematic literature review of studies published from 1980 to 2009, a meta-analysis of spatio-temporal patterns of serological prevalence and outbreak occurrence was performed. Average ND serological prevalence was estimated at 0·67 [95% confidence interval (CI) 0·58–0·75] in regions characterized by humid ecosystems, high human and poultry densities and low altitudes; 0·36 (95% CI 0·30–0·41) in dry ecosystems at intermediate altitude where human and poultry densities are low and 0·27 (95% CI 0·19–0·38) in mountain ecosystems where human and poultry densities are intermediate. In terms of seasonality, ND outbreaks occur mostly during the dry seasons in Africa, when environmental conditions are likely to be harshest for backyard poultry. In addition, a phylogeographical analysis revealed the regionalization of ND virus strains, their potential to evolve towards a higher pathogenicity from the local viral pool and suggests a risk for vaccine strains to provide new wild strains. These results present for the first time a continent-wide approach to ND epidemiology in Africa. More emphasis is needed for ND management and control in rural African poultry production systems.

Despite a number of risk-factor studies in different countries, the epidemiology of Campylobacter colonization in broilers, particularly spatial dependencies, is still not well understood. A series of analyses (visualization and exploratory) were therefore conducted in order to obtain a better understanding of the spatial and temporal distribution of Campylobacter in the Danish broiler population. In this study, we observed a non-random temporal occurrence of Campylobacter, with high prevalence during summer and low during winter. Significant spatio-temporal clusters were identified in the same areas in the summer months from 2007 to 2009. Range of influence between broiler farms were estimated at distances of 9·6 km and 13·5 km in different years. Identification of areas and time with greater risk indicates variable presence of risk factors with space and time. Implementation of safety measures on farms within high-risk clusters during summer could have an impact in reducing prevalence.

The Argentine shortfin squid (Illex argentinus) is a common neritic species occurring in waters off Brazil, Uruguay, Argentina, and the Falkland/Malvinas Islands in the southwest Atlantic. Illex argentinus is the most important fished cephalopod species in the area and plays a significant role in the ecosystem. It is object of major fisheries using both trawlers (mostly from European countries) and jigging vessels (mainly from Asian countries) and estimated total annual average catch for the last 15 years (1988-2003) is about 700 000 tons. The present paper aims to develop predictive models of squid abundance in relation to physical and environmental conditions, models that could ultimately be applied to fishery forecasting. Fishery and biological data collected by scientific observers aboard commercial trawlers between 1988 and 2003 were analysed in relation to physical and environmental factors to establish the spatio-temporal pattern of the species' distribution and quantify the influence of environmental variables (e.g. SST, depth) on local abundance. The data included 26 168 fishing haul records, of which 11 103 were positive for Illex. CPUE (Catch Per Unit Effort, kg h−1) was used as abundance index. The analyses were based on time-series maps created using Geographical Information Systems (GIS). GIS maps showed that highest CPUE values were recorded during the first four months of the year (the Austral summer-autumn), with peak values higher than 5000 kg h−1 mainly located within 42° S, 46° S and MN (North part of Malvinas/Falkland) areas. Generalised additive models (GAMs) were used to describe variation in Illex argentinus abundance in relation to geographical and environmental variables. The presence/absence (PA) of Illex and its abundance (CPUE) in areas of presence were modelled separately. Predictors retained in the optimal models included SST, latitude, longitude, month, average fishing depth and year. Both models suggest a clear seasonal effect: maximum catchability was found during March (PA model) and the maximum abundances were found during the first quarter of the year (CPUE model). GAM models also demonstrated that higher catches and maturity of squid were related, in general terms, to warmer and deeper water.