Emergency surveillance for novel influenza A(H7N9) virus in domestic poultry, feral pigeons and other wild birds in Bhutan

Following the March 2013 outbreak of novel avian influenza A(H7N9) virus in humans and the subsequent isolation of the virus from chickens, ducks and pigeons in the People's Republic of China, concerns were raised that the H7N9 virus would spread beyond China through the poultry value chain linking to a number of bordering countries. For this reason, a rapid emergency surveillance exercise took place in Bhutan between May and July 2013 with the objective of determining whether influenza A(H7N9) virus was silently circulating in domestic poultryandwild birds in Bhutan.Atotal of 1716 oropharyngeal,tracheal and cloacal swabs together with faecal droppings were collected from poultry, wild birds and feral pigeons throughout the country; these samples included 150 that had been previously collected for surveillance of influenza A(H5N1) virus. Overall, 733 of the samples were tested. A QIAamp Viral RNA Mini K it was used to extract viral RNA from a mix of oropharyngeal, tracheal and cloacal swabs and faecal droppings. The matrix gene of avian influenza type A virus was detected using a specific real-time quantitative reverse-transcription polymerase chain reaction (RT-PCR) assay, and positive samples were further tested in RT-PCR for simultaneous detection of the H7 and N9 genes. Among the 733 samples tested, 46 (26 prospective, 20 retrospective) were confirmed positive for influenza A, a prevalence of 6.3% (95% CI: 4.6 to 8.3). The influenza A-positive samples were from areas in the south of Bhutan that had experienced previous outbreaks of highly pathogenic influenza A(H5N1). None of the samples tested positive for H7N9 strains, providing evidence that influenza A(H7N9) virus was not present in the sampled population. A risk-based approach for surveillance of influenza A(H7N9) and H5N1 is recommended in Bhutan, based on the epidemiology of the disease in China and other countries in South and Southeast Asia.T. Tenzin, S. Tenzin, D. Tshering, K. Lhamo, P.B. Rai, N. Dahal, K. Dukp

The effects of age and environment on the expression of inbreeding depression in Eucalyptus globulus

Inbreeding adversely affects fitness traits in many plant and animal species, and the magnitude, stability and genetic basis of inbreeding depression (ID) will have short- and long-term evolutionary consequences. The effects of four degrees of inbreeding (selfing, f=50% full- and half-sib matings, f=25 and 12.5% and unrelated outcrosses, f=0%) on survival and growth of an island population of Eucalyptus globulus were studied at two sites for over 14 years. For selfs, ID in survival increased over time, reaching a maximum of 49% by age 14 years. However, their inbreeding depression for stem diameter remained relatively stable with age, and ranged from 28 to 36% across years and sites. ID for survival was markedly greater on the more productive site, possibly due to greater and earlier onset of inter-tree competition, but was similar on both sites for the diameter of survivors. The deleterious trait response to increasing inbreeding coefficients was linear for survival and diameter. Non-significant quadratic effects suggested that epistasis did not contribute considerably to the observed ID at the population level. Among- and within-family coefficients of variation for diameter increased with inbreeding degree, and the variance among the outcrossed families was significant only on the more productive site. The performance of self-families for diameter was highly stable between sites. This suggests that, for species with mixed mating systems, environmentally stable inbreeding effects in open-pollinated progenies may tend to mask the additive genotype-by-environment interaction for fitness traits and the adaptive response to the environment