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H1N1 (Swine) Flu, Flu Vaccine and Pregnancy

H1N1 flu (a.k.a. swine flu) has affected many pregnant and non-pregnant women and the management of such cases including vaccination has created concerns and confusion in the general population. Swine flu is most commonly caused by swine influenza virus A and one of its subtypes called H1N1. It is relatively common in pigs and was possibly associated with human flu in the early 1910s for the first time when both pigs and humans had flu at the same time as a pandemic. The current virus appears to carry genes that are very similar to the typical swine flu. Flu viruses change their genetic structure every year and this is the reason flu vaccines have to be prepared from the viral strains from the previous flu season each year. Swine flu appears to have followed a similar path and changed its “appearance” over the years.

Current pandemic of swine flu has affected millions worldwide and the most susceptible are reported to be pregnant women and children. The symptoms are similar to the seasonal flu and include sore throat, runny nose, fever, chills, body aches, fatigue, headaches and coughing. The virus is transmitted the same way seasonal flu is spread, which is through the respiratory tract. Unfortunately, deaths have been reported with the viral infection and have been mainly due to respiratory failure, severe dehydration, lung and generalized infection called sepsis.

The diagnosis of swine flu is made by clinical evaluation and in some cases by laboratory testing. The rapid influenza tests offer results in less than an hour, but the reliability is quite variable and thus not recommended routinely. The most reliable method is by using the PCR method to detect the virus, but such a test is expensive, needs to be done at special labs and the results may take a few days to obtain, possibly delaying treatment. Therefore, the diagnosis of swine flu is currently made by the clinician and in severe cases patients are admitted to the hospital, tested, monitored and treated appropriately. In mild cases of swine flu, treatment may not be necessary because the natural immune system will overcome the viral infection. In others with moderate symptoms, outpatient treatment is recommended with anti-viral drugs. In individuals with compromised immune systems, older population and in those with medical problems hospitalization is indicated.

The two anti-viral drugs commonly prescribed for swine flu are Tamiflu (Oseltamivir), and Relenza (Zanamivir). Tamiflu should not be confused with Theraflu which is an over the counter flu medication that relieves symptoms, but does not have any anti-viral effects. Oseltamivir is prescribed as 75mg tablets to be taken twice a day for five days and Zanamivir as two 5mg inhalations twice a day. In severe cases, treatment may be prolonged by a physician as an outpatient or inpatient.

The best treatment in medicine is prevention of the disease, but this is not possible all the time. Therefore, preventative measures should be taken whenever possible which include frequent hand washing, avoiding close interactions with people known or suspected of having the flu or with flu-like symptoms, and vaccinization for both swine and seasonal flu. Vaccines include the common flu as well as the swine flu vaccines that are manufactured separately in 2009, which may be combined in 2010. The nasal spray and injectible forms are the two types that are available. The nasal spray is the attenuated form and the injectible is the inactive form of the vaccine and both types are equally effective in preventing the flu.

Pregnancy and Treatment of Swine Flu:

In pregnant patients with flu symptoms, either Oseltamivir or Zanamivir can be used to treat both swine and common flu. These drugs are both category C drugs, which means there are no clinical studies assessing the safety of these drugs during pregnancy. Nevertheless, pregnancy is not considered a contraindication for use of either of these medications. Current medical data suggests prompt diagnosis and treatment of flu in pregnancy due to the high risk nature of having complications in such a state. The injectible form of the vaccine is recommended for pregnant patients because it contains the inactivated virus, compared to the nasal form which has the live-attenuated form of the virus.

The injectible type of the vaccine is recommended to all individuals above the age of 6 months, including pregnant women, healthy individuals and people with medical conditions. The nasal type of the vaccine is recommended to people between ages 2-50, except pregnant women because it’s a live-attenuated type of viral vaccine. You can contact your health care provider to have access to these vaccines and most patients tolerate them well.

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