Many swine flu deaths linked with second infection

[hawkeye]

Many swine flu deaths linked with second infection
Wed Sep 30, 2009 3:32pm EDT

WASHINGTON (Reuters) - Many people who have died of H1N1 swine flu in the United States have also had bacterial infections, health officials reported on Wednesday.

A study of 77 patients who died of the new pandemic H1N1 virus showed 29 percent of them had so called bacterial co-infections, the U.S. Centers for Disease Control and Prevention reported.

About half of these had Streptococcus pneumoniae, which can be prevented with a vaccine, the CDC said. It said doctors may be missing these infections in people severely ill with flu.

The CDC has already reported that H1N1, declared a pandemic in June, has become more active as weather cools and schools reopened after summer breaks. Cases are reported in all 50 states and it is still circulating globally.

H1N1 is not any more deadly than seasonal influenza so far but it attacks a younger age group than seasonal flu does and because virtually the entire population lacks immunity, it can infect far more people at once than seasonal flu usually does.

"The findings in this report indicate that, as during previous influenza pandemics, bacterial pneumonia is contributing to deaths associated with pandemic H1N1," the team of experts at the CDC and state health departments reported.

"Our influenza season is off to a fast start and unfortunately there will be more cases of bacterial infections in people suffering from influenza," CDC epidemiologist Dr. Matthew Moore, who helped organize the study, added in a statement.

The report noted in previous pandemics -- in 1968, 1957 and 1918 -- many of the patients who died were also infected with S. pneumoniae, Haemophilus influenzae, Staphylococcus aureus and group A Streptococcus, which causes rheumatic fever and "strep throat".

The CDC team noted that at first it did not appear that people who were seriously ill with swine flu or who died of it had secondary infections but doctors may have missed them.

"Routine clinical tests used to identify bacterial infections among patients with pneumonia do not detect many of these infections," the CDC team reported.

Five of the patients who died, including a 9-year-old and an 11-year-old, had infections with the so-called superbug methicillin-resistant S. aureus or MRSA. None of the seven children who died had reported medical conditions that should put them at special risk of flu complications, although one was obese and one had Down syndrome.

The researchers cautioned that the patients whose cases were studied may not represent the nation as a whole. But like most of the victims of swine flu, they were young, with a median age of 31 and ranging from 2 months to 56 years.

Moore said people getting flu vaccinations should also ask about getting a pneumococcal vaccine.

Wyeth's Prevnar is part of the routine series of immunizations that children should get, and Merck and Co. makes a vaccine against so-called pneumococcal bacteria that is available for adults, mostly those over 65. Merck also makes an Hib vaccine, although there is no vaccine to prevent group A streptococcal infections or MRSA.

(Editing by Bill Trott)

 

[Gert van der Hoek]

Re: Many swine flu deaths linked with second infectio

Re: Many swine flu deaths linked with second infectio

Bacteria were the real killers in 1918 flu pandemic

14:02 04 August 2008 by Ewen Callaway

Medical and scientific experts now agree that bacteria, not influenza viruses, were the greatest cause of death during the 1918 flu pandemic.

Government efforts to gird for the next influenza pandemic - bird flu or otherwise - ought to take notice and stock up on antibiotics, says John Brundage, a medical microbiologist at the Armed Forces Health Surveillance Center in Silver Spring, Maryland.

Brundage's team culled first-hand accounts, medical records and infection patterns from 1918 and 1919. Although a nasty strain of flu virus swept around the world, bacterial pneumonia that came on the heels of mostly mild cases of flu killed the majority of the 20 to 100 million victims of the so-called Spanish flu, they conclude.

"We agree completely that bacterial pneumonia played a major role in the mortality of the 1918 pandemic," says Anthony Fauci, director of National Institute for Allergy and Infectious Disease in Bethesda, Maryland, and author of another journal article out next month that comes to a similar conclusion.

Double whammy

That pneumonia causes most deaths in an influenza outbreak is well known. Late 19th century physicians recognised pneumonia as the cause of death of most flu victims. While doctors limited fatalities in other 20th-century outbreaks with antibiotics such as penicillin, which was discovered in 1928, but did not see use in patients until 1942.

This is not to say that flu viruses do nothing, says Jonathan McCullers, an expert on influenza-bacteria co-infections at St Jude Children's Research Hospital in Memphis, Tennessee.

McCullers' research suggests that influenza kills cells in the respiratory tract, providing food and a home for invading bacteria. On top of this, an overstressed immune system makes it easier for the bacteria to get a foothold.

However, the sheer carnage of 1918 caused many microbiologists to reconsider the role of bacteria, and some pointed their fingers firmly at the virus.

'Unique event'

When US government scientists resurrected the 1918 strain in 2005, the virus demolished cells grown in a Petri dish and felled mice by the dozen.

"The 1918 pandemic is considered to be - and clearly is - something unique, and it's widely understood to be the most lethal natural event that has occurred in recent human history," Brundage says.

But to reassess this conclusion, he and co-author Dennis Shanks, of the Australian Army Malaria Institute in Enoggera, Queensland, scoured literature and medical records from 1918 and 1919.

The more they investigated, the more bacteria emerged as the true killers, an idea now supported by most influenza experts.

For instance, had a super virus been responsible for most deaths, one might expect people to die fairly rapidly, or at least for most cases to follow a similar progression. However, Shanks and Brundage found that few people died within three days of showing symptoms, while most people lasted more than a week, some survived two - all hallmarks of pneumonia.

Local bugs

Military health records for barracks and battleships also painted a different picture. New recruits - men unlikely to have been exposed to resident bacteria - died in droves, while soldiers whose immune systems were accustomed to the local bugs survived.

And most compelling, Brundage says, medical experts of the day identified pneumonia as the cause of most deaths.

"The bottom line is we think the influenza virus itself was necessary - but not sufficient - to cause most of the deaths," he says.

As the world's health experts prepare for the next influenza pandemic, many have looked to 1918 as a guide, planning for a deadly super-virus.

The H5N1 bird flu strains jetting around the world seem to kill humans without the aid of bacteria, but those viruses aren't fully adapted to humans, McCullers says. If H5N1 does adapt to humans, bacteria may play a larger role in deaths, he adds.

"Everyone is focused exclusively on the virus, and that's probably not the best idea," he says.

Antibiotics and vaccines against bacterial pneumonia could limit deaths in the next pandemic. And while an effective influenza vaccine should nip an outbreak in the bud, such a vaccine could take months to prepare and distribute.

"The idea of stockpiling [bacterial] vaccines and antibiotics is under serious consideration," says Fauci, who is on a US government taskforce to prepare for the next flu pandemic.

At a recent summit on pandemic influenza, McCullers said health authorities were increasingly interested in the role bacteria might play, but there had been little action taken.

"There's no preparation yet. They are just starting to get to the recognition stage," he says. "There's this collective amnesia about 1918."

Journal reference: Emerging Infectious Disease (DOI: 10.3201/eid1408.071313)

http://www.newscientist.com/article/dn14458-bacteria-were-the-real-killers-in-1918-flu-pandemic.html

thanks to Kassy

 

[kent nickell]

Re: Many swine flu deaths linked with second infection

Yes, the relationship between MRSA and influenza probably deserves special mention... It is a very important secondary bacterial infection to consider when an ILI patient starts to have a worsening course. There is both HA (hospital acquired) and CA (community acquired) MRSA. However, CA-MRSA is also now becoming more common as a nosocomial infection so that distinction is becoming somewhat blurred.... However the two groups of bacteria are different and have different genetic profiles with CA-MRSA tending to be more virulent but also being susceptible to a wider range of antibiotics...

So it is important for treating physicians to know the MRSA profile of their local community... The MRSA profile of New York City will likely be different from that of Kearny, Nebraska... Ideally it is best to isolate the particular bacteria in the particular patient and do the antibiotic susceptibility profile.. But practically speaking treatment often needs to be started before this can be accomplished and a knowledge of the profile of the bugs in your community will help to determine this type of empiric therapy....

 

[Snowy Owl]

Re: Many swine flu deaths linked with second infection

Ain<t it="" the="" time="" to="" consider="" propolis="" and="" yes="" spider="" webs="" as="" an="" alternatives="" ?="">'t it the time to consider as a preventive approach Propolis and yes spider"s Webs.

There anti bacterial effects are well known

Snowy</t>

 

[mixin]

Re: Many swine flu deaths linked with second infection

Kent,
There have been a couple of MMWR reports that have commented on the lack of bacterial co-infections.

However, a number of severe cases have been given antibiotics prior to being admitted into critical care. It would be interesting to know at what point during antibiotic treatment bacterial infections become undetectable.

In the report on 10 Michigan patients: Quote:

As of July 8, none of the 10 patients had evidence of bacterial infection after admission to the SICU or in subsequent blood, bronchoalveolar lavage, or urine cultures. All patients received antibiotic therapy upon admission to the initial hospitals, and broad spectrum antibiotics were continued upon transfer to the SICU.... However, bacterial coinfection in the lung not identified by blood culture or bronchoalveolar lavage cannot be excluded.

And again in the NEJM on Pneumonia and Respiratory Failure:

(Of the 18 study cases) 12 patients had sought medical care at other institutions and were treated with one or more antibiotics: ceftriaxone (five patients), amikacin (three), azithromycin (one), amoxicillin-clavulanate (two) or other macrolides (three), or another agent (two)....concurrent bacterial infection does not appear to be a major contributing factor to the severity of illness in our patients, possibly in part because most received antibiotics before hospitalization.

 

[kent nickell]

Re: Many swine flu deaths linked with second infection

The bacterial co-infection rate seems to stand out when you look at the cases that were fatal.....

http://www.cdc.gov/flu/weekly/

Influenza-Associated Pediatric Mortality

Three influenza-associated pediatric deaths were reported to CDC during week 37 (Texas [2] and Virginia). These deaths were associated with 2009 influenza A (H1N1) virus infection, and occurred between August 30 and September 19, 2009. Since September 28, 2008, CDC has received 117 reports of influenza-associated pediatric deaths that occurred during the current influenza season (25 deaths in children less than 2 years, 12 deaths in children 2-4 years, 35 deaths in children 5-11 years, and 45 deaths in individuals 12-17 years). Forty-nine of the 117 deaths were due to 2009 influenza A (H1N1) virus infections, and four of these have occurred since August 30, 2009.

Of the 50 children who had specimens collected for bacterial culture from normally sterile sites, 19 (38.0%) were positive; Staphylococcus aureus was identified in 13 (68.4%) of the 19 children. Six of the S. aureus isolates were sensitive to methicillin and seven were methicillin resistant. Seventeen (89.5%) of the 19 children with bacterial coinfections were five years of age or older and 12 (63.2%) of the 19 children were 12 years of age or older. Nineteen (38.8%) of the 49 children with confirmed 2009 influenza A (H1N1) infection had a specimen collected from a normally sterile site; five (26.3%) of the 19 children had a positive bacterial culture (methicillin sensitive S. aureus [2], methicillin resistant S. aureus [2], and Streptococcus constellatus).