Earliest known evidence of 1918 influenza pandemic found

Examination of lung tissue and other autopsy material from 68 American soldiers who died of respiratory infections in 1918 has revealed that the influenza virus that eventually killed 50 million people worldwide was circulating in the United States at least four months before the 1918 influenza reached pandemic levels that fall.

The study, using tissues preserved since 1918, was led by Jeffery K. Taubenberger, M.D., Ph.D., of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. The researchers found proteins and 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. These four cases are the earliest 1918 pandemic influenza cases they know to be documented anywhere in the world, the scientists say.

The clinical disease and tissue damage seen in the pre-pandemic cases were indistinguishable from those evident in cases that occurred during the height of the pandemic. This suggests, says Dr. Taubenberger, that over the course of the pandemic, the virus did not undergo a dramatic change that could explain the unusually high mortality it ultimately caused.

In the current study, the autopsy materials showed that the virus replicated not only in the but also the lower respiratory tract, in a pattern very similar to that of the 2009 virus. The team also found evidence that two virus variants were circulating in 1918. In one, a key called hemagglutinin bound well to receptors on human respiratory cells, while the hemagglutinin from the other variant bound less efficiently. Despite this difference in binding ability, both viruses caused similar disease symptoms and replicated in a similar pattern within cells lining the respiratory tract, suggesting that differences in hemagglutinin binding capacity alone do not fully explain the unusually high mortality seen in the 1918 pandemic.

Bacterial co-infections were found in all 68 cases studied, the researchers noted. The role played by bacterial co-infections, such as bacterial pneumonia, in contributing to deaths in the 1918 pandemic was previously described by Dr. Taubenberger and his colleagues in a 2008 study. According to the study authors, the new data underscore the crucial role that bacterial infections can play in conjunction with any , whether historic or future, and the need for public health officials to prepare to prevent, detect and treat bacterial co-infections during future influenza outbreaks.

More information: Z-M Sheng et al. Autopsy series of 68 cases dying before and during the 1918 influenza pandemic peak. Proceedings of the National Academies of Sciences DOI:10.1073/pnas.1111179108 (2011).

Provided by National Institutes of Health

4.7 /5 (9 votes)

Related Stories

Protein enhances lethality of influenza virus

Oct 10, 2007

Often called the most devastating epidemic in the recorded history of the world, the 1918 influenza virus pandemic was responsible for more than 40 million deaths across the globe. The incredible lethality of the 1918 flu ...

Recommended for you

Recorded Ebola deaths top 7,000

3 hours ago

The worst Ebola outbreak on record has now killed more than 7,000 people, with many of the latest deaths reported in Sierra Leone, the World Health Organization said as United Nations Secretary-General Ban ...

Liberia holds Senate vote amid Ebola fears (Update)

7 hours ago

Health workers manned polling stations across Liberia on Saturday as voters cast their ballots in a twice-delayed Senate election that has been criticized for its potential to spread the deadly Ebola disease.

Evidence-based recs issued for systemic care in psoriasis

Dec 19, 2014

(HealthDay)—For appropriately selected patients with psoriasis, combining biologics with other systemic treatments, including phototherapy, oral medications, or other biologic, may result in greater efficacy ...

Bacteria in caramel apples kills at least four in US

Dec 19, 2014

A listeria outbreak believed to originate from commercially packaged caramel apples has killed at least four people in the United States and sickened 28 people since November, officials said Friday.

Steroid-based treatment may answer needs of pediatric EoE patients

Dec 19, 2014

A new formulation of oral budesonide suspension, a steroid-based treatment, is safe and effective in treating pediatric patients with eosinophilic esophagitis (EoE), according to a new study in Clinical Gastroenterology and Hepatology, the official clinical practice journal ...

User 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.