August 10, 2012
From: Lisa B. Hernandez, MD, MPH Kristy Michie, MS
Interim Health Officer 831-755-4585 Supervising Epidemiologist 831-755-4503
To date, no cases of H3N2v have been detected in California.
Since July 2011, a number of U.S. residents were found to be infected with a new variant of influenza virus, H3N2v, which includes a swine component (M gene) from the influenza A (H1N1)pdm09 virus. From July 12, 2012, through August 9, 2012, a total of 153 cases have been reported nationwide. States with confirmed cases in this timeframe include Indiana (120 cases), Ohio (31), Hawaii (1), and Illinois (1). All individuals except for the one from Hawaii reported direct or indirect exposure to swine, the majority at agricultural fairs. Cases were also detected in Iowa, Maine, Pennsylvania, Utah, and West Virginia prior to July 2012.
H3N2v has not been detected in Monterey County or California at this time.
The Centers for Disease Control and Prevention (CDC) released an evaluation of rapid influenza diagnostics tests’ ability to detected seven different H3N2v strain designations. Results are below:
- Directigen, Sofia, Veritor, and Xpect detected 7 out of 7 strains
- BinaxNOW detected 5 out of 7 strains
- QuickVue detected 3 out of 7 strains
- FluAlert detected 1 out of 7 strains
Until more information is available, it is unclear how much protection, if any, the seasonal influenza vaccine will provide against H3N2v. H3N2v virus is related to human viruses from the 1990s. Adults may have some protection against H2N3v, but young children probably do not. Early steps to make a vaccine against H3N2v have been taken, but no decision to mass produce such a vaccine has been made. This should not deter physicians from administering the seasonal influenza vaccine because strains included in this year’s influenza vaccine are predicted to circulate this fall.
There is no indication that either the H3N2 or H3N2v strains are resistant to neuraminidase inhibitors.
Recommendations for Healthcare Providers
- Consider the possibility of influenza virus infection for individuals presenting with fever and 1) cough or 2) sore throat, irrespective of vaccination status.
- Ask suspected influenza cases about possible exposure to swine.
- Encourage immunization against seasonal influenza when the vaccine becomes available.
- Follow the standard seasonal influenza testing, treatment, and prophylaxis guidelines when managing all suspected influenza cases (summary below).
- Laboratories should submit the following to the Monterey County Public Health Department:
- Positive specimens for influenza A from local hospital laboratories (inpatient and outpatient).
- All specimens (positive or negative) from individuals who report contact with swine (inpatient or outpatient).
- All specimens (positive or negative) from severe or fatal cases of respiratory illness.
- Educate your patients about everyday preventative actions:
- Cover your nose and mouth with a tissue or your elbow when you cough or sneeze.
- Wash your hands often with soap and water, especially after you cough or sneeze. If soap and water are not available, an alcohol-based hand rub may be used.
- Avoid touching your eyes, nose, or mouth.
- Try to avoid close contact with sick people.
- If you are sick, stay home from work or school until you have been symptom-free for 24 hours.
- Counsel your patients with possible exposure to swine:
- Wash your hands frequently with soap and running water before and after exposure to animals.
- Never eat, drink, or put things in your mouth in animal areas.
- Children younger than 5 years, people 65 years and older, pregnant women, and people with certain chronic medical conditions (like asthma, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions) are at high risk from serious complications if they get influenza. These people should consider avoiding exposure to pigs and swine barns this summer, especially if sick pigs have been identified.
- If you have animals – including swine – watch them for signs of illness and call a veterinarian if you suspect they might be sick.
- Avoid close contact with animals that look or act ill, when possible.
- Avoid contact with pigs if you are experiencing flu-like symptoms.
- Promptly report cases of:
- severe influenza (fatal and/or admitted to the ICU), and
- laboratory confirmed influenza who report swine exposure (inpatient and outpatient)
to the Health Department’s Communicable Disease Unit (phone: 831-755-4521; fax: 831-754-6682).
Recommendations will be updated as information becomes available.
For additional information about influenza, please contact the Communicable Disease Unit at 831‑755‑4521. For information about influenza testing at the Monterey County Public Health Lab, call 831‑755‑4516.