NAME: Enterovirus 70
CHARACTERISTICS: Enterovirus 70 is a small (~ 30 nm in diameter), non-enveloped virus with a single-stranded positive-sense RNA genome (~7.4 kb) enclosed within an icosahedral capsid. It belongs to the species human enterovirus D in the genus Enterovirus and family Picornaviridae Footnote 1, Footnote 3. It replicates optimally at 36oC Footnote 1.
PATHOGENICITY/TOXICITY: Enterovirus 70 causes acute hemorrhagic conjunctivitis Footnote 3. The symptoms of the disease include eye pain, photophobia, swelling of eye lid and varying redness of the conjunctiva (from subconjunctival petechiae to hemorrhages) Footnote 3, Footnote 4. Disease resolves in less than 10 days. Transient corneal involvement may occur in some cases Footnote 3. Acute hemorrhagic conjunctivitis can also cause non-ophthalmic symptoms, such as neurologic dysfunction, respiratory and gastrointestinal disturbances Footnote 4. Furthermore, permanent polio-like paralysis has been reported in individuals infected with enterovirus 70 Footnote 4.
EPIDEMIOLOGY: The first pandemic of acute hemorrhagic conjunctivitis, affecting hundreds of millions of people, occurred in 1969 in Africa Footnote 4. Since then the virus has been associated with large outbreaks, mainly in tropical areas Footnote 3.
HOST RANGE: Humans Footnote 1.
INFECTIOUS DOSE: Unknown.
INCUBATION PERIOD: 24 to 48 hours Footnote 4.
COMMUNICABILITY: Highly contagious Footnote 3.
RESERVOIR: Humans Footnote 1.
DRUG SUSCEPTIBILITY: Pleconaril has shown antiviral activity against several enterovirus strains in vitro Footnote 6.
SUSCEPTIBILITY TO DISINFECTANTS: Enterovirus 70 is susceptible to a solution of 500 p.p.m. sodium hypochlorite with a contact time of 2 minutes. Enterovirus 70 is resistant to phenyl mercuric borate and isopropyl alcohol Footnote 7.
SURVIVAL OUTSIDE HOST: Enterovirus 70 can survive at least 24 hours on inanimate surfaces under high humidity conditions Footnote 5. Enteroviruses are also stable in liquid environments and can survive for many weeks in water, body fluids, and sewage Footnote 1.
SURVEILLANCE: Diagnosis is based on detection of EV 70 virus in clinical specimens with molecular biology methods such as RT-PCR, real-time RT-PCR, and Nucleic Acid Sequence Based Amplification (NASBA). Isolation of EV70 virus from patients with acute hemorrhagic conjunctivitis is very difficult Footnote 2, Footnote 4.
Note: All diagnostic methods are not necessarily available in all countries.
FIRST AID/TREATMENT: Most cases are self-limiting and recover with supportive care. No antiviral therapy is available Footnote 3.
LABORATORY-ACQUIRED INFECTIONS: Laboratory acquired infections have been reported from 2 laboratories, where virological studies were being conducted on EV70 Footnote 2.
PRIMARY HAZARDS: Contact of infectious agent with eye membrane Footnote 2.
SPECIAL HAZARDS: None.
RISK GROUP CLASSIFICATION: Risk group 2 Footnote 8.
CONTAINMENT REQUIREMENTS: Containment Level 2 facilities, equipment, and operational practices for work involving infectious or potentially infectious materials, animals, or cultures Footnote 9.
PROTECTIVE CLOTHING: Lab coat. Gloves when direct skin contact with infected materials or animals is unavoidable. Eye protection must be used where there is a known or potential risk of exposure to splashes Footnote 9.
OTHER PRECAUTIONS: All procedures that may produce aerosols, or involve high concentrations or large volumes should be conducted in a biological safety cabinet (BSC). The use of needles, syringes, and other sharp objects should be strictly limited. Additional precautions should be considered with work involving animals or large scale activities Footnote 9.
SPILLS: Allow aerosols to settle and, wearing protective clothing, gently cover the spill with absorbent paper towels and apply an appropriate disinfectant, starting at the perimeter and working towards the center. Allow sufficient contact time before clean up.
DISPOSAL: Decontaminate all wastes that contain or have come in contact with the infectious organism by autoclave, chemical disinfection, gamma irradiation, or incineration before disposing.
STORAGE: The infectious agent should be stored in leak-proof containers that are appropriately labelled.
REGULATORY INFORMATION: The import, transport, and use of pathogens in Canada is regulated under many regulatory bodies, including the Public Health Agency of Canada, Health Canada, Canadian Food Inspection Agency, Environment Canada, and Transport Canada. Users are responsible for ensuring they are compliant with all relevant acts, regulations, guidelines, and standards.
UPDATED: October 2010
PREPARED BY: Pathogen Regulation Directorate, Public Health Agency of Canada.
Although the information, opinions and recommendations contained in this Pathogen Safety Data Sheet are compiled from sources believed to be reliable, we accept no responsibility for the accuracy, sufficiency, or reliability or for any loss or injury resulting from the use of the information. Newly discovered hazards are frequent and this information may not be completely up to date.
Public Health Agency of Canada, 2010