This page is intended for use by health care providers and laboratories.
Please contact Teresa Frankovich, M.D., M.P.H. at 906-482-7382, if you have questions.
H1N1 Flu Key Points: Winter 2009
(Summary of guidance from CDC and MDCH)
Testing:
· The rapid flu tests currently used in offices and local hospitals were not designed to test for H1N1, they were designed to test for seasonal influenza A and B
· That being said, H1N1 is a type of “A” virus and some of the time, the rapid flu test will pick up H1N1 and give a positive result. The problem is that much of the time it will not pick up H1N1.
· So, when faced with a patient who has flu symptoms, you have two options:
1) Do not do a rapid flu test and make a treatment decision based on the clinical diagnosis, severity of symptoms and whether the patient is at high risk for complications
2) Do a rapid flu test. If it is positive for “A,” it is likely the patient has H1N1 (since 99% of influenza circulating in the US right now is H1N1). If the test is negative, it is still very possible that the patient has H1N1, and a treatment decision should be made based on that possibility, the severity of symptoms and whether the patient is at high risk for complications.
In other words…a negative rapid flu test does not rule out H1N1 as a diagnosis.
· The state lab is no longer doing diagnostic testing for H1N1. It is only doing testing for surveillance purposes and will test specimens in the following situations: severely ill hospitalized patients (ICU), seriously ill pregnant women, facility outbreaks, unusual presentations (ex. encephalitis in patient suspected of having flu), and deaths. Right now, the only test specific for H1N1 is a PCR test.
· Some commercial labs are approved to offer H1N1 PCR testing. You can find these by going to the MDCH Bureau of Labs section regarding H1N1. Turn-around time is typically several days and the test is expensive.
Treatment:
· Tamiflu or Relenza may be used for treatment of H1N1
· Treatment is most effective when started within the first 48 hours of illness but can be used at any time during the illness, as clinically indicated.
· Not all patients suspected of having H1N1 require treatment with anti-virals.
· Patients who should be treated include those who are hospitalized, pregnant or at high risk of complications based on their age or underlying medical condition.
· Clinicians should use CDC guidelines and clinical judgement to make individual treatment decisions. Please read the full guidance at cdc.gov/h1n1
Prophylaxis:
· Tamiflu and Relenza may be used for prophylaxis of H1N1
· Few people are expected to need prophylaxis
· The CDC suggests that in many cases, prophylaxis may be replaced with observation and rapid treatment (at least in high risk individuals), if symptoms develop. If this approach is used, high risk patients must be instructed to monitor for symptoms and contact the provider right away with symptom onset.
· Again, the CDC defers to clinical judgement in individual cases
Vaccine:
· Both nasal (LAIV) and injectable vaccine will be available this year
· Children under 10 years will need two doses of H1N1 vaccine this year, given at least 4 weeks apart. Children 10 years and older and adults, will need only one dose of H1N1 vaccine.
· Nasal vaccine may be used in healthy people age 2 years - 49 years, who are not pregnant. Please see the MDCH or CDC guidance on exclusions for LAIV.
· LAIV may be given to healthcare workers and household contacts of high risk individuals. The only exception to this is for people working with or in close contact with severely immune-compromised individuals who require a protected environment (positive pressure and special air filtering rooms, ex. a bone marrow transplant unit)
· Injectable Seasonal and H1N1 vaccine may be given at the same time (in different locations) or at any interval to each other.
· If a patient wishes to get both seasonal and H1N1 vaccine in the nasal form, they must wait 4 weeks between the doses.
· In a patient receiving both seasonal and H1N1 vaccine, if the patient receives one vaccine in the injectable form and one in the nasal form, they may be given at any interval to each other.
· Thimerasol-free H1N1 vaccine, packaged as single dose units, will be available this season for those concerned about thimerasol. It is not yet known when shipments of this vaccine will arrive locally.
Vaccine Safety:
· Seasonal flu vaccine is changed frequently to include the strains of flu most likely to be circulating each year (based on global surveillance)
· Every year about 100 million doses of seasonal flu vaccine are given. The vaccine has an excellent safety track record
· The H1N1 vaccine is simply a “strain change” in the usual flu shot recipe and is expected to be similar in terms of safety. Clinical trial data to date, supports this expectation.
The best way to keep up with changing recommendations is to check the www.CDC.gov/h1n1 website regularly, particularly the “What’s New” tab in the green box on the upper left portion of the screen or the “Information for Specific Groups” tab in the same green box (this tab will lead you to a page where you may select “clinician” and review guidance on a variety of clinical H1N1 topics. An H1N1 vaccine provider toolkit is available at the MDCH website: www.michigan.gov/flu