Surveillance for avian influenza in Nepal 2004-2005.

Highly pathogenic avian influenza has not been reported in Nepal to date. Surveillance for the presence of avian influenza viruses was conducted in 16 districts of Nepal from February 2004 to December 2005. Four hundred forty-six serum samples were collected from ducks, chickens, and pigeons and tested for antibodies to all influenza A viruses by competitive enzyme-linked immunosorbent assay (C-ELISA). Any sera positive by C-ELISA were tested for antibodies to H5, H7, and H9 influenza viruses by hemagglutination inhibition tests. One hundred and thirty-five cloacal swabs from healthy ducks and chickens were tested by commercial avian influenza antigen detection kits. A further 13 tissue samples from diseased birds were tested for the presence of virus by virus isolation in eggs, cell culture, and immunohistochemistry. No influenza viruses were detected in any of the tissues or swabs. All serum samples collected before October 2005 were negative for antibodies. The first sera positive for antibodies were collected on October 13, 2005, which were determined to be of the H9N2 subtype. This is the first report of serologic evidence of an avian influenza virus infection in Nepal.

A serological survey of pigs, horses, and ducks in Nepal for evidence of infection with Japanese encephalitis virus.

Japanese encephalitis (JE) is an emerging disease of animals and humans in Nepal. A serological study for antibody to JE virus was conducted in Nepal from September 2003 to August 2004 by collecting 280 sera from pigs, ducks, and horses covering 10 districts of the country. These sera were tested by performing competitive enzyme-linked immunosorbent assay for the detection of antibodies against JE virus. The total number of tested sera was 280, of which 43.92% were found positive for the presence of antibodies against JE virus infection in Nepal. Sero-prevalence of JE in pigs, ducks, and horses was 48.11%, 26.79%, and 50.0%, respectively.

Emergence or improved detection of Japanese encephalitis virus in the Himalayan highlands?

The emergence of Japanese encephalitis virus (JEV) in the Himalayan highlands is of significant veterinary and public health concern and may be related to climate warming and anthropogenic landscape change, or simply improved surveillance. To investigate this phenomenon, a One Health approach focusing on the phylogeography of JEV, the distribution and abundance of the mosquito vectors, and seroprevalence in humans and animal reservoirs would be useful to understand the epidemiology of Japanese encephalitis in highland areas.

Recent emergence and spread of an Arctic-related phylogenetic lineage of rabies virus in Nepal.

Rabies is a zoonotic disease that is endemic in many parts of the developing world, especially in Africa and Asia. However its epidemiology remains largely unappreciated in much of these regions, such as in Nepal, where limited information is available about the spatiotemporal dynamics of the main etiological agent, the rabies virus (RABV). In this study, we describe for the first time the phylogenetic diversity and evolution of RABV circulating in Nepal, as well as their geographical relationships within the broader region. A total of 24 new isolates obtained from Nepal and collected from 2003 to 2011 were full-length sequenced for both the nucleoprotein and the glycoprotein genes, and analysed using neighbour-joining and maximum-likelihood phylogenetic methods with representative viruses from all over the world, including new related RABV strains from neighbouring or more distant countries (Afghanistan, Greenland, Iran, Russia and USA). Despite Nepal's limited land surface and its particular geographical position within the Indian subcontinent, our study revealed the presence of a surprising wide genetic diversity of RABV, with the co-existence of three different phylogenetic groups: an Indian subcontinent clade and two different Arctic-like sub-clades within the Arctic-related clade. This observation suggests at least two independent episodes of rabies introduction from neighbouring countries. In addition, specific phylogenetic and temporal evolution analysis of viruses within the Arctic-related clade has identified a new recently emerged RABV lineage we named as the Arctic-like 3 (AL-3) sub-clade that is already widely spread in Nepal.