Experimental inoculation study indicates swine as a potential host for Hendra virus

Area of Science:

• Veterinary Virology
• Zoonotic Disease Research
• Animal Models for Viral Infections

Background:

• Hendra virus (HeV) is a zoonotic paramyxovirus known to cause severe, often fatal, disease in humans and horses.
• The role of pigs as potential hosts or reservoirs for HeV has not been extensively studied, despite their close proximity to humans and livestock.

Purpose of the Study:

• To investigate the susceptibility of pigs to Hendra virus (HeV) infection.
• To characterize the clinical signs, viral shedding, and tissue tropism of HeV in pigs.
• To assess the potential of pigs as intermediate hosts in HeV transmission.

Main Methods:

• Inoculation of Landrace and Gottingen minipigs with HeV.
• Monitoring of clinical signs, including fever, depression, respiratory, and neurological signs.
• Detection of viral RNA in various swab samples using real-time RT-PCR.
• Quantification of virus titers in nasal swabs (TCID50/mL).
• Analysis of viral distribution in tissues through pathological examination and immunohistochemistry.

Main Results:

• Pigs (Landrace and Gottingen minipigs) experimentally infected with HeV exhibited clinical signs such as fever and depression.
• Respiratory signs were observed in both pig breeds, with one Gottingen minipig also showing mild neurological signs.
• Viral RNA was detected in oral, nasal, rectal, and ocular swabs from infected pigs, with high titers in nasal samples.
• Early viral RNA distribution was predominantly in respiratory and lymphoid tissues, confirmed by virus isolation and immunohistochemistry.

Conclusions:

• Pigs are susceptible to Hendra virus infection, developing clinical signs and shedding the virus.
• The observed tissue tropism and viral shedding patterns suggest pigs could serve as an intermediate host in the HeV transmission cycle.
• These findings highlight the importance of considering pigs in HeV surveillance and control strategies to prevent zoonotic transmission to humans.