Differences in H7N9 infection in men and women – treatment practice

H7N9 avian influenza: gender differences in disease progression

Almost 20 years ago, the occurrence of a low-pathogenic species for birds was first reported bird flu virus A (H7N9) at people reported. Since then, thousands of people around the world have become infected with this pathogen. Scientists now report that such infections gender differences them the course of the disease they are.

An international research team has shown for the first time that infection with the H7N9 bird flu virus attacks the hormonal axis in men, but not in women. And low testosterone is associated with serious or even fatal conditions in men. The results of the study were published in the journal Nature Communications.

More infections in men

As explained in a statement by the Leibniz Institute for Virology (LIV), avian influenza viruses of the H7N9 subtype (H7N9 avian influenza viruses) have great epidemic and pandemic potential.

In March 2013, H7N9 bird flu viruses first appeared species barriers he skipped and went from birds to humans. Men were affected more often than women. In the five epidemic waves that followed, the incidence of H7N9 was higher in men than in women.

An interdisciplinary team from LIV Hamburg, China National Influenza Center, China Centers for Disease Control and Prevention (China CDC), and Sun Yat School of Public Health (Shenzhen), unraveled the mechanisms behind these gender-specific differences. – dream University data of laboratory-confirmed patients H7N9 infection and compared them to close contacts with H7N9 and people with seasonal flu.

H7N9 infection leads to low testosterone levels

The researchers show that H7N9 infection specifically attacks the hormonal axis in men, but not in women. In men, H7N9 infection leads to low testosterone levels, which is associated with severe and even fatal outcome correlated.

In contrast, seasonal influenza H1N1 or H3N2 had no significant impact on influenza hormonal axis in patients.

In mouse models, scientists confirm a causal relationship between H7N9 infection and Testosterone deficiency in men. They also show that the H7N9 bird flu virus replicates in the testes of mice and causes local and systemic inflammation that likely affects testosterone production.

Avian influenza viruses continue to require high vigilance

According to experts, very little is known about the molecular mechanisms that lead to this gender specific Disease progression in respiratory virus infections.

The current study could serve as a blueprint for studying gender differences in others respiratory infection including SARS-CoV-2 as seen in the current pandemic.

“Bird flu viruses continue to pose a high epidemic and pandemic risk. The 2021/2022 season was the biggest Bird flu epidemicrecorded worldwide including Europe”says prof. Gülşah Gabriel, Head of Research Unit LIV Viral Zoonoses – One Health and Professor at the University of Veterinary Medicine in Hannover.

Therefore, according to the researcher, understanding molecular mechanismswhich mediate the gender-specific course of the disease, are of fundamental importance for the individual management of the patient.

“Strict surveillance and massive vaccination of poultry has so far prevented the further spread of the H7N9 virus to humans. But bird flu viruses evolve and require high levels vigilance, said Professor Yuelong Shu, former director of the China National Influenza Center at the China CDC. (advertisement)

Author and source information

This text meets the requirements of the medical literature, medical guidelines and current studies and has been reviewed by health professionals.


  • Leibniz Institute for Virology (LIV): H7N9 avian influenza in humans: gender differences in the course of the disease, (Accessed: 16 November 2022), Leibniz Institute for Virology (LIV)
  • Tian Bai, Yongkun Chen, Sebastian Beck, Stephanie Stanelle-Bertram, Nancy Kouassi Mounogou, Tao Chen, Jie Dong, Bettina Schneider, Tingting Jia, Jing Yang, Lijie Wang, Andreas Meinhardt, Antonia Zapf, Lothar Kreienbrock, Dayan Wang, Yuelong & Gülsah Gabriel: H7N9 avian influenza infection in men is associated with testosterone depletion; in: Nature Communications, (veröffentlicht: 14.11.2022), Nature Communications

Important note:
This article contains general advice only and should not be used for self-diagnosis or treatment. It cannot replace a doctor’s visit.

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