Spike in Bacterial Infections With Swine Flu

CDC: Rise in Life-Threatening Bacterial Infections Linked to H1N1 Swine Flu

Medically Reviewed by Brunilda Nazario, MD on November 25, 2009
From the WebMD Archives

Nov. 25, 2009 -- "A worrisome spike" in severe bacterial infections is complicating H1N1 swine flu cases, the CDC warned today.

Denver and nine other cities where CDC conducts intensive surveillance are seeing a tripling of cases of severe, life-threatening bacterial infections -- including pneumonia and blood infections -- linked to H1N1 swine flu.

Most cases of severe bacterial pneumonia occur in the elderly. But the cases being reported to the CDC are mostly in young adults aged 20 to 49, an age group particularly vulnerable to H1N1 swine flu.

"The H1N1 pandemic puts us at risk not just for flu but for bacterial pneumonia," Anne Schuchat, MD, CDC director of immunization and respiratory diseases, said today at a news conference.

The bacteria causing most of the infections is pneumococcus. A pneumococcal vaccine is available and is recommended for adults and children at risk of serious bacterial infections. This is a larger than usual risk group. It includes people with immune deficiency and chronic health conditions, anyone with asthma -- and anyone who smokes cigarettes.

Despite the CDC's efforts, only 25% of people at risk of pneumococcal disease get vaccinated. The vaccine is not being distributed by the government as part of the H1N1 swine flu vaccination effort, but is readily available at doctors' offices, health clinics, and retail pharmacies.

Because so few people at risk have received the vaccine, the CDC is not now recommending the pneumococcal vaccine for healthy adults -- even though some of the severe cases reported to the CDC have been in people without pneumococcal risk factors.

Unfortunately, not all of the bacterial infections complicating H1N1 swine flu are vaccine preventable. Although not as common as pneumococcal infections, the CDC is also seeing a number of staph infections -- including difficult to treat MRSA infections -- complicating flu cases.

H1N1 Swine Flu Vaccine Safe So Far

The CDC has received its first report on the safety of the H1N1 swine flu vaccine -- and the news is "reassuring," Schuchat said.

More than 90% of adverse-event reports have been minor things like sore arms and redness at the site of injection.

There have been 10 reports of the rare neurological condition called Guillain-Barre syndrome (GBS) in people who receive the H1N1 swine flu vaccine. These are just reports -- they have not yet been confirmed as GBS or confirmed to have occurred within the six-week time frame in which vaccine-related GBS occurs.

Schuchat noted that the number of these GBS reports are very much what would be expected with seasonal flu vaccine. GBS is not always linked to vaccination. Schuchat noted that 80 to 160 people get GBS every week even though they did not receive any kind of vaccine.