While it’s still very early in this year’s influenza season, reports on the first cases of the season are beginning to emerge from health officials in states such as New Mexico, where doctors have confirmed two cases of the flu.
According to the Centers for Disease Control and Prevention
(CDC), influenza activity in the United States often begins in October and November. It peaks between December and March, and can go on into May. Influenza surveillance
from a network of state health departments and outpatient healthcare providers helps the CDC track cases around the country of people experiencing influenza-like illnesses. This monitoring looks for patients exhibiting flu symptoms
such as fever, cough, sore throat, runny nose, or body aches. Health officials weigh the percentage of patients reporting flu symptoms each week on the basis of state population against a national baseline of flu activity. While many regions of the United States continue to report influenza cases below the national baseline, this is the time of year where those start to go up.
New Mexico is one of 36 states currently reporting sporadic flu activity, according to the CDC
, and has just released its first flu report
of the season. While 103 patients in the state have experienced symptoms of the flu, the New Mexico Department of Health has announced only two laboratory-confirmed cases so far. The two patients
are both 64 years old, with one residing in Bernalillo County and the other in Valencia County. For health officials in the state, while the toll so far has been minimal, the flu season is young and early cases serve as a reminder of the importance of getting the influenza vaccine
The North American flu vaccine for the 2016-2017
season contains three virus components – A/California/7/2009 (H1N1) pdm09-like virus, A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (B/Victoria lineage). In additional to those three components, this season’s quadrivalent vaccine also contains a B/Phuket/3073/2013-like virus. These are the viruses that health officials expect to dominate the flu season, based on national surveillance data, which track the forms of the flu virus in circulation. Over time, the virus goes through gradual change called antigenic drift
, which health experts can monitor to help develop appropriate vaccines for each season. It is when the virus goes through a more sudden antigenic shift that big and unexpected changes happen quickly, defying the process of surveillance, and making it harder to anticipate which viral components to include in the flu vaccine. The last big shift occurred in 2009 in an H1N1 virus
first found in California, causing a pandemic that the CDC
says resulted in 60.8 million cases, 274,304 hospitalizations, and 12,469 deaths in the United States.
CDC Director Tom Frieden, MD, MPH, says it’s important for individuals to get the flu shot
by the end of October to protect themselves during this year’s flu season. Complications, hospitalizations, and deaths from influenza are most common in adults ages 65 and older, though the CDC emphasizes the importance of the flu vaccine for the following groups
- Children between the ages of 6 months and 4 years
- Individuals 50 years of age and older
- Those with chronic pulmonary (including asthma), cardiovascular (except hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus)
- Those who are immunosuppressed (including immunosuppression caused by medications or by Human Immunodeficiency Virus)
- Women who are or will be pregnant during the influenza season and women up to two weeks after delivery
- Those between the ages of 6 months through 18 years who are also receiving long-term aspirin therapy and who therefore might be at risk for experiencing Reye syndrome after influenza virus infection
- Residents of nursing homes and other chronic-care facilities
- American Indians/Alaska Natives
- Those with extreme obesity (body-mass index is 40 or greater)
- Health care personnel
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