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Parasites have the potential to severely reduce host reproductive success. However, the effects of endoparasites on reproductive success have not received the same amount of attention as the effects of parasites on host survival. We investigated the relationship between an avian endoparasite (gapeworm, Syngamus trachea) and both current and future reproductive success of female house sparrows (Passer domesticus) in a population on the coast of Helgeland, northern Norway. We found that the proportion of eggs in a nest that failed to develop into fledglings increased as the faecal parasitic egg count of the mothers increased. We also found that juvenile females with high numbers of parasitic eggs in their faeces had lower lifetime reproductive success as adults. However, we did not find a relationship between maternal parasite infection and clutch size or recruitment rate of offspring. To our knowledge this is the first study to find a relationship between reproductive success of an avian host and faecal egg count of an endoparasite. The present study indicates that infection by an endoparasite may be associated with lower individual reproductive success in both the short-term and long-term in a wild population of hosts. [ABSTRACT FROM AUTHOR]

Parasitic salmon lice are potentially harmful to salmonid hosts and farm produced lice pose a threat to wild salmonids. To control salmon lice infections in Norwegian salmonid farming, numbers of lice are regularly counted and lice abundance is reported from all salmonid farms every month. We have developed a stochastic space-time model where monthly lice abundance is modelled simultaneously for all farms. The set of farms is regarded as a network where the degree of contact between farms depends on their seaway distance. The expected lice abundance at each farm is modelled as a function of i) lice abundance in previous months at the same farm, ii) at neighbourhood farms, and iii) other, unspecified sources. In addition, the model includes explanatory variables such as seawater temperature and farm-numbers of fish. The model gives insight into factors that affect salmon lice abundance and contributing sources of infection. New findings in this study were that 66% of the expected salmon lice abundance was attributed to infection within farms, 28% was attributed to infection from neighbourhood farms and 6% to non-specified sources of infection. Furthermore, we present the relative risk of infection between neighbourhood farms as a function of seaway distance, which can be viewed as a between farm transmission kernel for salmon lice. The present modelling framework lays the foundation for development of future scenario simulation tools for examining the spread and abundance of salmon lice on farmed salmonids under different control regimes. [ABSTRACT FROM AUTHOR]

Abstract: Faecal samples collected from lambs on 6 Norwegian farms on 2 separate occasions during spring/summer 2008 (approximately 550 samples collected at each occasion) were examined for Cryptosporidium oocysts and Giardia cysts by immunofluorescent antibody test. Overall prevalence at the first sampling was approximately 23% for Giardia and 15% for Cryptosporidium, and at the second sampling approximately 31% for Giardia and 24% for Cryptosporidium, with substantial between-farm variation on each sampling occasion. To assess the potential public health significance of these infections, molecular analyses were conducted on 42 Giardia isolates and 42 Cryptosporidium isolates, with PCR targeted at one or both of two genes (Giardia: glutamate dehydrogenase and β-giardin genes; Cryptosporidium: SSU rRNA and actin genes) for each parasite. Of the Giardia isolates, 41 were Assemblage E (non-zoonotic) and 1 was Assemblage B (zoonotic). Of the Cryptosporidium isolates, 35 were cervine genotype (potentially zoonotic) and 7 C. xiaoi (non-zoonotic). These results suggest that sheep in Norway are unlikely to be an important reservoir of zoonotic Giardia in Norway, but might have some public health significance with respect to Cryptosporidium. [Copyright &y& Elsevier]

Abstract: The aims of this study were to estimate the national herd prevalence and the general spatial distribution of Neospora caninum infection in Norwegian dairy cattle. Bulk milk samples from 1657 randomly selected dairy herds were analysed by iscom ELISA for the presence of N. caninum specific antibodies. The national herd prevalence was estimated to be 0.7% (95% CI: 0.3–1.2%), which is the lowest national herd prevalence reported in Europe. In addition, we included a subpopulation study in which all 400 herds in the Oslo, Akershus and Østfold counties were sampled, and we found a herd prevalence of 1.8%. In the national herd study, a significant cluster of N. caninum infected herds was identified in Jæren, on the south west coast of Norway. Jæren has the highest density of farm animals in the country as well as climatic conditions that favour parasite survival. Dairy herds in this region had a 52 times higher relative risk of being N. caninum positive than dairy herds in other parts of Norway. This indicates that even though N. caninum infection is of minor importance in Norway, infection might cause abortion problems in high risk areas. [Copyright &y& Elsevier]