House crows (Corvus splendens): the carrier of pathogenic viruses or the misunderstood bird?

Abstract

The house crow (Corvus splendens) is globally recognised as a pest. It is an invasive species that can populate Malaysia's urban landscape and urban coastal areas. C. splendens was imported from Sri Lanka to Klang, Malaysia, in the 1890s to control caterpillars on coffee plantations. After a few decades, crows are able to adapt and co-exist with humans as a result of significant growth in the human population and urbanization. These urban pests are important due to the large volume of faecal droppings on buildings and near human dwellings. In other parts of the world, house crows can transmit pathogens and diseases such as chlamydiosis, salmonellosis, colibacillosis, and avian tuberculosis. They also carry human pathogens such as Salmonella spp., Shigella serotypes, Vibrionaceae spp., Newcastle disease virus (NDV), avian influenza virus (AIV) and West Nile virus (WNV) that can be transmitted to humans through their faeces. The first AIV transmission from birds to humans that caused a pandemic was alarming because of the risk of AIV and other avian virus transmission from birds. This prompted investigations into crow populations in urban centres. This review details the potential of C. splendens to spread AIV, NDV and WNV in Malaysia's highly urbanized areas.

Keywords

• Crows
• avian influenza
• West Nile virus
• Newcastle disease virus
• urban