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Recent research has shown that poultry and swine workers, especially those with intense exposures, are at increased risk of zoonotic influenza virus infections. In multiple studies, US poultry workers and poultry veterinarians have evidence of previous infections with avian influenza virus. Similarly, US swine workers have strong evidence of previous and acute infections with swine influenza viruses. Mathematical modeling has demonstrated that such workers may accelerate the spread of pandemic viruses in their rural communities. Because these workers may contribute to the novel generation of viruses and serve as a bridging population in the cross-species sharing of influenza viruses, it seems prudent to include poultry and swine workers in influenza preparedness programs. Possible preventive and control interventions include special education programs to increase workers' use of personal protective equipment such as gloves, increased surveillance for influenza viruses among workers and their animals, recommendations that workers seek medical attention should they develop influenza-like illness, and workers' priority receipt of annual and pandemic influenza vaccines.

Avian pneumovirus (APV; officially known as turkey rhinotracheitis virus) is an emergent pathogen of birds in the USA that results in upper respiratory tract disease in turkeys. Six years after the first outbreak in the USA, the disease continues to ravage turkey flocks, primarily in the state of Minnesota. From 1997 to 2000, the industry recorded losses estimated at 15 million US dollars per annum. Researchers have developed sensitive diagnostic techniques, including the enzyme-linked immunosorbent assay and the reverse transcriptase-polymerase chain reaction. which, when used together, are highly sensitive in detecting APV outbreaks in commercial turkey flocks. Phylogenetic analysis of the nucleotide and predicted amino acid sequence of 15 US viruses isolated between 1996 and 2000 demonstrated that the US viruses are relatively homogenous but different from the European APV subgroups A and B, resulting in the classification of US isolates into subgroup C. Infectious APV was isolated from sentinel waterfowls placed close to an infected commercial turkey farm and from wild Canada geese captured in Minnesota, suggesting that free-ranging birds may be involved in the spread of APV. Current efforts to prevent and control the infection include improving management and biosecurity practices and developing attenuated live and deletion mutant vaccines capable of conferring protection.

A pig-borne virus causing viral encephalitis amongst human beings in Malaysia was detected in 1997 by the Ministry of Health. Initially, the disease was considered to be Japanese encephalitis. Subsequently, it was thought to be a Hendra-like viral encephalitis, but on 10th April, 1999 the Minister of Health announced this mysterious and deadly virus to be a new virus named Nipah virus. The virus was characterized at CDC, Atlanta, Georgia. The gene sequencing of the enveloped virus revealed that one of the genes had 21% difference in the nucleotide sequence with about 8% difference in the amino acid sequence from Hendra virus isolated from horses in Australia in 1994. The virus was named after the village Nipah. In all, the Ministry of Health declared 101 human casualties, and 900,000 pigs were culled by April, 1999. The worst affected area in Malaysia was Negri Sembilan. The symptoms, incubation period in human being and pigs, animal to human transmission, threat of disease to other livestock, and control program adopted in Malaysia is described.