A new study published in the Proceedings of the National Academy of Sciences suggests that the flu virus that killed 50 million people worldwide in 1918 “circulated silently” at least four months before the 1918 influenza reached pandemic levels in the fall.1
For the study, researchers examined lung tissue and other autopsy material from 68 American soldiers who died of respiratory infections in 1918. Led by National Institute of Allergy and Infectious Diseases (NIAID) researcher Jeffery K. Taubenberger, M.D., the researchers found proteins and genetic material from the 1918 influenza virus in specimens from 37 of the soldiers, including four who died between May and August 1918, months before the pandemic peaked. Those four cases are the earliest 1918 pandemic influenza cases known to be documented anywhere in the world, according to NIAID.
“We were able to show that the pandemic virus was clearly circulating at least at a low level below the radar for several months before the big outbreak occurred,” Taubenberger told U.S. Medicine. “A lesson for us is that it is likely to be the case in the future and so with surveillance. The good news is that, if a new serious virus was to get into humans and begin to circulate, hopefully, our new surveillance systems would allow us to detect these early cases, which would give us a jumpstart to try to contain the outbreak or get a head start on developing a vaccine.”
Bacterial co-infections were found in all 68 cases studied. Taubenberger said this underscores that most people in 1918 were dying not only from the viral infection but also from secondary bacterial pneumonia.
Taubenberger said this was not unique to 1918: Studies done in the wake of the 2009 H1N1 pandemic also found that the majority of H1N1-infected patients who died succumbed to bacterial pneumonia.
It is important for clinicians and public-health providers to recognize the high bacterial pneumonia risk with flu, especially in people who are immunocompromised or with other underlying diseases such as heart disease, lung disease or cancer, Taubenberger said.
“If they were to get the flu, one needs to carefully follow them and perhaps even think about starting antibiotics early on in their course,” he explained.
The autopsy material from the soldiers for the study came from the National Tissue Repository of the Armed Forces Institute of Pathology (AFIP). While the repository is being maintained, AFIP was closed as part of Base Realignment and Closure (BRAC).
Taubenberger, who previously worked at AFIP, said the tissue specimens from 1918 are a unique source for understanding potential flu pandemics now and in the future.
“The military doctors were doing their best to care for these severely ill soldiers in 1918, but they were dying, and there was nothing they could do about it. … The one thing that is amazing is that they did these autopsies to try to find out what was going on,” he said. “They couldn’t explain the whole picture, but they saved these tissues. They sent them to be archived at this national repository in Washington, DC, and they were dutifully archived for nearly 100 years. Now, using techniques and knowledge that they would have had no idea about, we are using their tissues.”
1. Z-M Sheng et al. Autopsy series of 68 cases dying before and during the 1918 influenza pandemic peak. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1111179108 (2011).
VA Study Finds Higher COPD Mortality in Rural Areas
Patients with COPD living in isolated rural areas of the U.S. seem to be at greater risk for COPD exacerbation–related mortality than those living in urban areas, independent of hospital rurality and volume, a new study concluded.1
For the study, researchers sought to determine whether COPD-related mortality is higher among VA patients living in rural areas and to assess whether hospital characteristics influence any observed associations.
The study authors hypothesized that “rural residence would be associated with increased mortality but that hospital characteristics would attenuate any increase in mortality.”
For the retrospective cohort study, 18,809 patients lived in urban areas, 5,671 in rural areas, and 1,919 in isolated rural areas. The researchers found that mortality was increased in patients living in isolated rural areas, compared with urban areas (5.0% vs. 3.8%; P = 0.002). The increase in mortality associated with living in an isolated rural area persisted after adjustment for patient characteristics and hospital rurality and volume, according to the study.
“We found that patients from isolated rural areas admitted for a COPD exacerbation have an increased risk for 30-day mortality, independent of the characteristics of the admitting hospitals,” the study concluded. “Mortality for patients living in non-isolated rural areas did not differ from that for patients living in urban settings. We believe that work force and policy leaders need to be aware of this difference as a first step toward more equitable distribution of resources shown to be associated with variations in mortality, such as board-certified pulmonary staff and ventilatory support resources.”
1: Abrams TE, Vaughan-Sarrazin M, Fan VS, Kaboli PJ. Geographic isolation and the risk for chronic obstructive pulmonary disease-related mortality: a cohort study. Ann Intern Med. 2011 Jul 19;155(2):80-6. PubMed PMID: 21768581.
VA Study: Smoking’s Effect on Surgical Outcomes
A new study aimed to assess the attributable risk and potential benefit of smoking cessation on surgical outcomes.1
For the study, researchers conducted a retrospective cohort analysis of elective operations from 2002 to 2008 in the Veterans Affairs Surgical Quality Improvement Program for all surgical specialties performed. Patients were stratified by current, prior, and never smokers.
Of 393,794 patients, 135,741 were current smokers, 71,421 prior smokers, and 186,632 had never been smokers. A total of 6,225 pneumonias, 11,431 deep and superficial surgical-site infections, 2,040 thromboembolic events, 1,338 myocardial infarctions, and 4,792 deaths occurred within 30 days of surgery.
“Compared with both never and prior smokers individually and controlled for patient and procedure risk factors, current smokers had significantly more postoperative pneumonia, surgical-site infection and deaths (P < 0.001 for all). There was a dose-dependent increase in pulmonary complications, based on pack-year exposure with greater than 20 pack years leading to a significant increase in smoking-related surgical complications,” the authors wrote in the study abstract.
The authors concluded, “smoking cessation interventions could potentially reduce the occurrence and costs of adverse perioperative events.”
1. Hawn MT, Houston TK, Campagna EJ, Graham LA, Singh J, Bishop M, Henderson WG.
The Attributable Risk of Smoking on Surgical Complications. Ann Surg. 2011 Aug 24.
[Epub ahead of print] PubMed PMID: 21869677.