Recent demand for increased understanding of avian infl uenza virus in its natural hosts, together with the development of high-throughput diagnostics, has heralded a new era in wildlife disease surveillance. However, survey design, sampling, and interpretation in the context of host populations still present major challenges. We critically reviewed current surveillance to distill a series of considerations pertinent to avian infl uenza virus surveillance in wild birds, including consideration of what, when, where, and how many to sample in the context of survey objectives. Recognizing that wildlife disease surveillance is logistically and fi nancially constrained, we discuss pragmatic alternatives for achieving probability-based sampling schemes that capture this host–pathogen system. We recommend hypothesis-driven surveillance through standardized, local surveys that are, in turn, strategically compiled over broad geographic areas. Rethinking the use of existing surveillance infrastructure can thereby greatly enhance our global understanding of avian infl uenza and other zoonotic diseases.

Surveillance of Wild Birds for Avian Infl uenza Virus

A current review of avian influenza in pigeons and doves (Columbidae).

Unique systems of breeding and calving management have been developed to allow New Zealand cattle herd owners to maintain seasonally concentrated calving patterns. Improved pastures are used as the sole ration for most beef and dairy cows with limited conservation and no grain feeding. Patterns of calving are described in relation to herd Planned Start of Calving (PSC) dates, calculated as 282 days after the first date of insemination in the preceding seasonal artificial breeding (AB) programme. Corti-costeroids have been systematically used in over 80% of New Zealand dairy herds to induce premature parturition (calving induction) during the third trimester of pregnancy for about 25 years, to condense calving patterns into periods of 6-12 weeks. Widespread use of calving induction has minimised the adverse effects of declining reproductive performance in dairy herds on the sustainability of seasonally concentrated calving. The use of calving induction is now discouraged on animal welfare grounds ...

Advances in bovine theriogenology in New Zealand. 1. Pregnancy, parturition and the postpartum period.

Extract Veterinary interest in New Zealand's indigenous bird species was evident in the first issue of the New Zealand Veterinary Journal when Roach (1952) outlined some of the unusual anatomical features of the kiwi (Apteryx spp), including observations on their behaviour, clinical signs, and population distribution. Some of these anatomical and behavioural adaptations have no doubt helped kiwi survive the human invasion that exterminated New Zealand's other ratites in the early part of the last millennium, but they have also left it prone to certain diseases. Smith et al (1973) were the first to report pneumoconiosis in the kiwi, which was presumably the result of the positioning of external nares at the end of a long beak, an adaptation useful for nocturnal feeding. Egg peritonitis is also now recognised as a common problem in kiwi both in captivity (Boardman 1995) and in the wild (Reed 1997b). The retention of a very large ratite egg in a bird which has adapted to be small enough to nest in l...

Avian wildlife diseases in New Zealand: current issues and achievements.

AIM: To determine if migratory birds arriving in New Zealand in the Southern Hemisphere spring of 2004 were infected with the highly pathogenic avian influenza (AI) virus, H5N1. METHODS: Cloacal and faecal samples were collected from migratory red knots following their arrival in New Zealand in October 2004. Two species of resident sympatric birds, wrybill and mallard duck, were sampled prior to, and following, the arrival of migratory birds. RESULTS: No AI viruses were isolated from migratory or resident shorebirds. Non-pathogenic AI viruses were isolated from six resident mallard ducks, comprising the endemic subtypes H4 (n=2), H7 (non-pathogenic), H10, and H11 (n=2). CONCLUSIONS: Highly pathogenic AI H5N1 virus was not detected in migratory shorebirds or sympatric water birds in the Firth of Thames, New Zealand, in 2004-2005, despite the possible proximity of migratory birds to outbreaks of the disease in East Asia in 2004.

Surveillance for highly pathogenic avian influenza in migratory shorebirds at the terminus of the East Asian-Australasian Flyway

Extract Abstract Avian paramyxoviruses (PMV) and influenza viruses have been readily isolated from free-living birds throughout the world(1) (2) and, in New Zealand, both these viruses have been isolated from wild waterfowls, particularly ducks(3) (4). It is widely known that free-living birds could harbour PMV and influenza viruses and could act as natural reservoirs of these viruses. They have occasionally caused Newcastle disease (PMV-1) and influenza outbreaks in commercial poultry farms throughout the world(5) (6) (7) (8). However, similar outbreaks have not been reported from New Zealand.

C. E. M. Reed

Papers

A survey for avian paramyxoviruses and influenza viruses in feral pigeons and native birds in New Zealand.