Research Project: Viral Ecology of Henipaviruses in Endemic Settings and Intervention Strategies to Prevent their Spread to Domestic Animals

Location: Zoonotic and Emerging Disease Research

Project Number: 3022-32000-027-000-D
Project Type: In-House Appropriated

Start Date: Jun 22, 2022
End Date: Jun 21, 2027

Objective:
Objective 1. Characterize the ecology of henipahviruses with a focus on the One-Health concept. - Conduct the molecular characterization of new and emerging henipahviruses, including phylogenetics, and network analysis. - Examine known or emerging henipahviruses that may have an impact on animal agriculture, including their potential impact on public health. Objective 2. Elucidate the host-pathogen interactions of henipahviruses infections. - Investigate virus-specific factors and viral molecular markers associated with infectivity, pathogenicity and transmissibility of henipahviruses in susceptible animal species including virus tissue tropism and replication. - Investigate host-specific factors associated with the infectivity, pathogenicity and transmissibility in different animal species. - Characterize the innate and adaptive immune response to henipahviruses infections in animal models that are either susceptible, tolerant, or resistant to infection. Objective 3. Develop surveillance strategies and early warning systems for henipahviruses. - Improve surveillance strategies to detect henipaviruses in high-risk countries. - Establish a formal laboratory network for henipavirus surveillance that includes standardized specimen collection, laboratory testing scheme, quality control, specimen referral and accreditation.

Approach:
Henipahviruses are members of the family Paramyxoviridae, order Mononegavirales. The name henipavirus was recommended for the genus of both Hendra virus and Nipah virus. Henipaviruses have a large host range, unlike other members of the Paramyxoviridae, which generally have a very narrow host range. The cell attachment protein, unlike many other members for the paramyxovirus subfamily, does not have haemagglutinating activity and as a consequence does not bind sialic acid on the surface of cells. The natural reservoir of the henipaviruses are fruit bats mainly from the genus Pteropus (flying foxes). Nucleic acid and antibody signatures of exposure to Nipah virus or Nipah-like viruses has been documented in a diversity of bat species across the globe. The threat for a natural introduction of henipaviruses in the United States is low, but there is significant concern that henipaviruses could be used for nefarious purposes to harm agriculture and people. Both Hendra virus and Nipah virus are on the HHS and USDA list of overlap Select Agents and Toxins. Henipaviruses are listed as APHIS Tier 3 high-consequence foreign animal diseases and pests. Henipaviruses are promiscuous in their ability to cause severe morbidity in several animal species, including people, and human infections result in a very high mortality rate. The mortality rate associated with Nipah virus infections in pigs has been reported to be approximately 2.5% in adult pigs – high morbidity, but low mortality. Mortality rates in humans however are significantly higher and range from 40% (Malaysia) to 75% (up to 100%) in Bangladesh. The animal reservoir includes several species of bats, and henipaviruses may thus be readily available in these wildlife reservoirs.