Influenza Agent Information Sheet

Boston University
Research Occupational Health Program (ROHP)
617-358-7647

Agent

Influenza virus is a segmented negative-sense RNA virus, which belongs to influenzavirus genus in the Orthomyxoviridae family.  The virus particle is 80-120 nm in diameter and consists of a central RNA core wrapped by two large glycoproteins (Hemagglutinin or HA and neuraminidase or NA) within an envelope.  These HA and NA glycoproteins are the virulence factors responsible for causing infectious disease.

Disease/Infection

The influenza virus may cause influenza or the “flu”, a contagious respiratory illness.  It can cause mild to severe illness, and at times can lead to death due to pulmonary complications.

Pathogenicity

Three genera or types predominate: A, B, and C.  New subtypes or strains of influenza can result from re-assortment of human and avian influenza virus genes (antigenic shift) and have the potential to result in epidemics or pandemics.  Antigenic changes within a type or subtype (antigenic drift) of A and B viruses are ongoing processes that are responsible for frequent epidemics and regional and seasonal outbreaks and make the annual reformulation of influenza vaccine necessary.  The morbidity and mortality from influenza is dependent on the strain and on the host.

• Special Populations at Risk:
  Pregnant women, young children, the elderly, those with compromised immune systems, or the chronically ill are at a greater risk of developing complications, and experience more severe illness.

Biosafety Information

Risk Group/BSL
Risk Group 2
Biosafety level:  BSL2/ABSL2

Modes of Transmission

Host Range/Reservoir
Influenza A viruses are found in many different lab animals, including chickens, pigs, horses, and cats.  Influenza B viruses circulate widely among humans.

Symptoms
Symptoms vary but consist of an acute viral disease of the respiratory tract, fever, headache, lack of energy, myalgia, sore throat, cough, nasal congestion, and possibly runny nose.  In rare, cases myositis or rhabdomyolosis  (muscle inflammation), cardiac and central nervous system manifestations have also been reported.  Many patients with influenza pneumonia may also be at risk for secondary bacterial pneumonia.

Incubation Period
The period of communicable disease is usually 3-5 days from clinical symptom onset in adults and up to 7 days in young children.

Viability
Influenza viruses are killed by heat above 167 degrees Fahrenheit (75 degrees Celsius) and by products containing chlorine, hydrogen peroxide, detergents (soaps), iodophors (iodine-based antiseptics), and alcohols.  Sterilization of reusable instruments and decontamination of surfaces should be performed in accordance with recommendations described by the CDC (www.cdc.gov) and the WHO infection control guidelines (www.who.int/en/).

Survival Outside Host
Influenza viruses are capable of surviving on hard surfaces for up to 24-48 hours and on tissues for only 15 minutes.  Influenza can remain on the unwashed fingertips for up to 30 minutes and cause indirect transmission.  Good hand hygiene is recommended.

Information for Lab Workers

Laboratory PPE

Lab coat, gloves, and eye protection when direct skin contact with infected materials or animals is unavoidable.  Eye protection must be used when there is a known or potential risk of exposure to splashes.  Extreme care must be taken to avoid accidental autoinoculation or other parenteral inoculations of infectious tissues and fluids.

Containment

BSL-2 practices, containment equipment, and facilities are recommended for activities using clinical materials and diagnostic quantities of infectious material.

In Case of Exposure/Disease

• For injuries in the lab which are major medical emergencies (heart attacks, seizures, etc…):
  • Medical Campus: call or have a coworker call the Control Center at 617-414–4144.
  • Charles River Campus: call or have a coworker call campus security at 617-353-2121.
    You will be referred to or transported to the appropriate health care location by the emergency response team.
• For lab exposures (needle sticks, bite, cut, scratch, splash, etc…) involving animals or infectious agents, or for unexplained symptoms or illness call the ROHP 24/7 hour number (1-617-358-ROHP (7647); or, 8-ROHP (7647) if calling from an on-campus location) to be connected with the BU Research Occupational Health Program (ROHP) medical officer. ROHP will refer you to the appropriate health care location.
• Under any of these scenarios, always inform the physician of your work in the laboratory and the agent(s) that you work with.
• Provide the wallet-size agent ID card to the physician.

Vaccination

An annual seasonal influenza vaccination is the best way to protect oneself from influenza.  Antibodies develop in the body approximately two weeks after vaccination.

Information for First Responders/Medical Personnel

Public Health Issues

Unlike annual epidemics, individuals have virtually no immunity against a pandemic influenza strain, leading to widespread person-to-person transmission.  Suspected pandemics should be reported to the Massachusetts Department of Public Health (phone: 617-983-6800 and ask for the Epidemiologist On-call).  Health care providers should immediately report to the local board of health (BPHC) where the diagnosis was made.

Diagnosis/Surveillance

Monitor for clinical signs.  Influenza can be diagnosed with rapid influenza diagnostic tests or rapid molecular assays from a nose or throat swab within 10-20 minutes.

First Aid/Post Exposure Prophylaxis

Perform one of the following actions:

Then call ROHP for prophylaxis for splash or mucus membrane exposure:

1.  Oseltamivir (NA inhibitor), 75 mg, daily for 10 days
2.  If seasonal influenza vaccine was not received, influenza vaccination will be offered

Treatment

Care is mainly supportive since most illness is mild.  On a case-by-case basis, high risk groups or severe illness may be treated with antiviral drugs to prevent complications and shorten the period of illness.  Patients should practice respiratory etiquette and good hand hygiene to limit the transmission of the disease to others.

References

Biosafety in Microbiological and Biomedical Laboratories; Deborah E. Wilson, DrPH, CBSP  Director Division of Occupational Health and Safety National Institutes of Health  Bethesda, Maryland L. Casey Chosewood, M.D. Director Office of Health and Safety  Centers for Disease Control and Prevention Atlanta, Georgia; US Government Printing Office, Washington DC.  5^th Edition; 2007

Control of Communicable Diseases Manual. David L. Heymann. Washington DC, USA: American Public Health Association Press, 19th edition, 2008

https://www.cdc.gov/smallpox/index.html

Interim Guidance for State and Local Health Departments for Reporting Influenza-Associated Hospitalizations and Deaths for the 2009-2010 Season  http://www.cdc.gov/H1N1flu/hospitalreporting.htm

HHS Pandemic Influenza Plan Supplement 2 Laboratory Diagnostics; https://www.cdc.gov/flu/pdf/professionals/hhspandemicinfluenzaplan.pdf

Survival of influenza virus on human fingers Y Thomas et al Clinical Microbiology and Infection 2014; 20; O58-O64