Swine flu patients benefited from taking Tamiflu, says study

September 29, 2010

Healthy people who caught swine flu during the 2009 pandemic may have been protected against developing radiographically (x-ray) confirmed pneumonia by taking the antiviral drug oseltamivir (Tamiflu), concludes a study of cases in China published in the British Medical Journal today.

The researchers also show that oseltamivir treatment was associated with shorter duration of fever and viral RNA shedding (the period when a virus is contagious), although they stress that their findings should be interpreted with caution.

In 2009, A (H1N1) virus spread rapidly, resulting in millions of cases and over 18,000 deaths in over 200 countries.

Trials carried out on seasonal flu viruses have shown that taking antiviral drugs within 48 hours of symptom onset can reduce the severity and duration of symptoms, and possibly the risk of complications.

However, the extent to which antivirals may benefit otherwise healthy individuals with mild 2009 H1N1 infection, remains unknown.

So researchers reviewed the medical records of 1,291 patients in China with laboratory confirmed mild H1N1 infection during the 2009 pandemic.

The average age of patients was 20 years. Three quarters (76%) were treated with oseltamivir from a median of the third day of symptoms. Of 920 patients who had a chest x-ray, a minority (12%) had abnormal findings consistent with pneumonia.

No patients required admission or mechanical ventilation.

Using statistical modelling of the patients' data, the researchers ruled out the effects of age, sex, influenza vaccination, and treatment with antibiotics on the main study outcomes: getting pneumonia, having prolonged high fever, and viral RNA shedding. Oseltamivir treatment was then identified as a significant protective factor against subsequent development of pneumonia, confirmed by a chest x-ray. This protective effect was seen in all patients including those who started treatment more than two days after onset of symptoms.

Oseltamivir treatment started within two days of symptom onset also reduced the duration of fever and viral RNA shedding, they add. They also found that 2009 H1N1 might be shed longer than seasonal influenza virus.

These findings are consistent with patients with the 2009 H1N1 benefiting from use of oseltamivir, conclude the authors. However, they stress that their finding that treatment protected against subsequent radiographic pneumonia should be interpreted with caution, given the retrospective design of this work and the fact that not all patients underwent a chest x-ray.

They call for continued investigation into the effectiveness of antiviral treatment "to allow for improvement both in clinical treatment and public health guidance."

Related Stories

Recommended for you

H7N9 influenza is both lethal and transmissible in animal model for flu

October 19, 2017
In 2013, an influenza virus that had never before been detected began circulating among poultry in China. It caused several waves of human infection and in late 2016, the number of people to become sick from the H7N9 virus ...

Flu simulations suggest pandemics more likely in spring, early summer

October 19, 2017
New statistical simulations suggest that Northern Hemisphere flu pandemics are most likely to emerge in late spring or early summer at the tail end of the normal flu season, according to a new study published in PLOS Computational ...

Migraines may be the brain's way of dealing with oxidative stress

October 19, 2017
A new perspective article highlights a compelling theory about migraine attacks: that they are an integrated mechanism by which the brain protects and repairs itself. Recent insightful findings and potential ways to use them ...

New insights into herpes virus could inform vaccine development

October 18, 2017
A team of scientists has discovered new insights into the mechanisms of Epstein-Barr virus (EBV) infection, as well as two antibodies that block the virus' entry into cells. The findings, published in Proceedings of the National ...

Pair of discoveries illuminate new paths to flu and anthrax treatments

October 17, 2017
Two recent studies led by biologists at the University of California San Diego have set the research groundwork for new avenues to treat influenza and anthrax poisoning.

Portable 3-D scanner assesses patients with elephantiasis

October 17, 2017
An estimated 120 million people worldwide are infected with lymphatic filariasis, a parasitic, mosquito-borne disease that can cause major swelling and deformity of the legs, a condition known as elephantiasis. Health-care ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.