Reston Ebolavirus Infection

Reston Ebolavirus (RESTV), belonging to the Filoviridae family, is categorized as a non-pathogenic virus in humans, unlike other highly virulent members of the Ebolavirus genus. Nevertheless, RESTV has been linked to outbreaks of severe and often fatal hemorrhagic fever in non-human primates (NHPs), particularly cynomolgus monkeys from the Philippines. Furthermore, RESTV has been detected in domestic pigs in the Philippines, which raises concerns regarding the possibility of zoonotic transmission. As a leading animal disease diagnostic company, BioVenic continues to deepen its understanding and research on RESTV to provide customers with relevant biological services.

Virology

RESTV was initially identified in Reston, Virginia, USA, in 1989. The discovery occurred when a group of cynomolgus monkeys that had been imported from the Philippines became infected with the virus. Reston Ebolavirus falls under the same classification as other members of the Ebolavirus genus, which includes Ebola (EBOV), Marburg (MARV), Sudan (SUDV), Bundibugyo (BDBV), Ravn (RAVV), and Taï Forest viruses. Nonetheless, RESTV distinguishes itself as an exceptional case given its non-pathogenic behavior in humans. While it primarily infects non-human primates like cynomolgus monkeys, macaques, chimpanzees, and gorillas, it has also been detected in pigs and humans. Bats are recognized as the natural reservoir of RESTV, and transmission to non-human primates and pigs can occur through contact with bat feces or secretions.

Fig. 1 Schematic representation of the RESTV VP35 coiled-coil tetramer.¹

Transmission

Contact transmission is the main transmission route of RESTV. Blood and other body fluids, vomitus, secretions, and excreta (such as urine, and feces) of infected animals are highly contagious. In the case of NHPs, close contact during research settings or wildlife interactions can facilitate transmission. The virus can also be transmitted from domestic pigs to humans.

Signs and Symptoms of Reston Ebolavirus Infection in Pig

In non-human primates, RESTV infection manifests as severe hemorrhagic fever, causing a range of symptoms including fever, internal and external bleeding, organ failure, and ultimately, death.

In the case of pigs, RESTV-infected individuals experience severe respiratory symptoms, including cyanosis, difficulty breathing, and acute interstitial pneumonia, which closely resemble symptoms seen in porcine reproductive and respiratory syndrome virus (PRRSV) infection.

Conversely, RESTV infection in humans is generally asymptomatic or associated with mild respiratory symptoms.

Diagnosis of RESTV

To accurately and timely identify Reston Ebola virus infection, BioVenic develops a variety of diagnostics methods, diagnostics reagents, and even test kits according to customer needs.

• Antibody-based Veterinary Diagnostics Development
  
  • We help customers develop IgM capture ELISA for serum-specific IgM antibodies against RESTV.
  • We develop immunofluorescence assay (IFA) for our customers to detect serum-specific IgG antibodies.
  • We develop virus neutralization assay for our customers that analyze antibody responses.
• Pathogen-based Veterinary Diagnostics Development
  
  • Virus isolation.
  • We utilize ELISA to develop diagnostics solutions for our customers targeting RESTV antigens.
  • We use PCR to develop diagnostics solutions for our customers to detect RESTV nucleic acid substances.

Treatment

Currently, there are no specific antiviral treatments or vaccines approved for Reston Ebolavirus.

As RESTV infections in humans are typically asymptomatic or cause mild respiratory symptoms, supportive care and monitoring are the mainstays of treatment.

However, infected NHPs and pigs should be culled after infection and strict biosecurity measures should be implemented to prevent transmission to humans.

Prevention and Control of Reston Ebolavirus Infection

• It is important to control the exposure of domestic pigs and NHPs to bats.
• Closely monitor the RESTV in NHPs and pigs in the Philippines and other Southeast Asian countries.
• Continue to strictly enforce quarantine and RESTV testing for all exported NHPs.
• Sentinel testing of other NHPs within the Philippines should be considered.
• Testing of domestic pigs for RESTV in areas with a history of disease transmission.
• Raise awareness of RESTV among healthcare professionals, animal keepers, and the general public.

RESTV infection poses unique challenges due to its potential zoonotic transmission. To fully understand its pathogenicity and infection ability, BioVenic believes further research is needed. To reduce the risk of potential outbreaks and protect animals and humans, we develop diagnostics solutions, specific antiviral treatments, and vaccines against RESTV. If you are interested in this, please feel free to contact us.

Reference

1. Zinzula, Luca, et al. "Structures of Ebola and Reston virus VP35 oligomerization domains and comparative biophysical characterization in all ebolavirus species." Structure 27.1 (2019): 39-54.