
==== Front
New Microbes New Infect
New Microbes New Infect
New Microbes and New Infections
2052-2975
Elsevier

S2052-2975(24)00262-2
10.1016/j.nmni.2024.101478
101478
Letter to the Editor
A Rare Encounter: The first documented human infection of avian influenza A(H5N2)
Pokhrel Prakriti prakriti.pokhrel@kmc.edu.np
⁎
Kathmandu Medical College and Teaching Hospital, Kathmandu, Nepal
Verma Amogh amoghverma2000@gmail.com

Rama Medical College Hospital and Research Centre, Hapur, 245304, India
Medicos In Research, Nautanwa, 273164, India
Pant Kumud kumud.pant@geu.ac.in

Department of Biotechnology, Graphic Era (Deemed to be University) Clement Town Dehradun, India
Department of Allied Sciences, Graphic Era Hill University Clement Town Dehradun, India
Khatib Mahalaqua Nazli nazlikhatib@dmiher.edu.in

Division of Evidence Synthesis, Global Consortium of Public Health and Research, Datta Meghe Institute of Higher Education, Wardha, India
Singh Mahendra Pratap msingh.gces@gmail.com

Center for Global Health Research, Saveetha Medical College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, 602117, India
Medical Laboratories Techniques Department, AL-Mustaqbal University, 51001, Hillah, Babil, Iraq
Zahiruddin Quazi Syed zahirquazi@dmiher.edu.in

South Asia Infant Feeding Research Network (SAIFRN), Division of Evidence Synthesis, Global Consortium of Public Health and Research, Datta Meghe Institute of Higher Education, Wardha, India
Rustagi Sarvesh sarveshrustagi@uumail.in

School of Applied and Life Sciences, Uttaranchal University, Dehradun, Uttarakhand, India
Sah Sanjit sanjitsahnepal561@gmail.com

Dr. D. Y. Patil Medical College, Hospital and Research Centre, Dr. D. Y. Patil Vidyapeeth, Pune, 411018, Maharashtra, India
Dr. D. Y. Patil Dental College and Hospital, Dr. D. Y. Patil Vidyapeeth, Pune, 411018, Maharashtra, India
⁎ Corresponding author. Kathmandu Medical College and Teaching Hospital, Kathmandu, Nepal. prakriti.pokhrel@kmc.edu.np
03 9 2024
12 2024
03 9 2024
62 10147814 6 2024
1 7 2024
2 9 2024
© 2024 The Authors. Published by Elsevier Ltd.
2024

https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Keywords

Avian influenza
Human infection
H5N2 virus
Mexico
Zoonotic disease
Handling Editor: Patricia Schlagenhauf
==== Body
pmcThe first human case of avian influenza A(H5N2) virus infection was reported in Mexico in May 2024, marking a significant milestone in the epidemiological landscape [1]. This case involved a 59-year-old resident of the State of Mexico who was hospitalized in Mexico City with no known history of exposure to poultry or other animals. The patient, who had multiple underlying medical conditions, developed acute symptoms and succumbed to complications, making it the first laboratory-confirmed human infection with an influenza A(H5N2) virus globally and the first such infection in Mexico.

The infection was identified on May 23, 2024, and the patient's clinical history revealed that he had been bedridden for three weeks before the onset of symptoms, which included fever, shortness of breath, diarrhea, and general malaise. Despite receiving medical attention, the patient died on the same day due to complications from his underlying conditions. Subsequent genetic analysis by Mexican authorities revealed that the virus had a 99 % similarity to the strain obtained from birds in Texcoco, Mexico, earlier that year.

The emergence of this case prompted an immediate and robust public health response. Local and national health authorities, in collaboration with the Pan American Health Organization (PAHO) and the World Health Organization (WHO), implemented a series of measures to investigate the source of the infection and mitigate further risks [2]. These measures included epidemiological investigations, monitoring and surveillance of healthcare workers and contacts, and extensive training on preparedness and response to zoonotic influenza events.

In the State of Mexico, where the patient resided, authorities identified and tested 17 hospital contacts and 12 community contacts. All tested negative for influenza viruses, including H5N2, indicating no further spread from this case. Additionally, serological samples were collected to enhance the understanding of the virus's transmission dynamics. This comprehensive approach underscores the importance of immediate and coordinated action in response to emerging infectious diseases.

Avian influenza viruses, such as A(H5N2), typically circulate in bird populations but can occasionally infect humans. Human infections often result from direct contact with infected animals or contaminated environments. The clinical manifestations in humans can range from mild respiratory symptoms to severe illness and death. The current understanding of A(H5N2) suggests that while it poses a low risk of sustained human-to-human transmission, it is crucial to maintain vigilance and preparedness [3].

The epidemiological landscape of avian influenza in Mexico has been dynamic. In early 2024, outbreaks of both low and high pathogenicity avian influenza A(H5N2) were reported in poultry in various regions, including Texcoco and Michoacán [4]. These outbreaks in poultry raised concerns about potential human exposure, although no direct link between these outbreaks and the human case has been established. Continuous monitoring and genetic sequencing of the virus in both human and avian populations remain critical for identifying potential transmission pathways and informing public health strategies.

The public health response to this case also included strengthening molecular diagnostic capacities, improving surveillance at the human-animal interface, and conducting risk assessments for transmissibility and severity of zoonotic viruses [5]. These efforts are essential for enhancing global health security and ensuring timely responses to future outbreaks.

Data from similar influenza cases and previous outbreaks provide valuable insights into managing and mitigating risks associated with zoonotic influenza viruses. For instance, the continuous circulation of low pathogenicity avian influenza H5N2 viruses in Mexico and their spread to other countries highlight the need for international cooperation and information sharing [4]. The WHO and PAHO have emphasized the importance of routine surveillance, risk communication, and intersectoral collaboration to strengthen global preparedness and response mechanisms.

In conclusion, the first human infection with avian influenza A(H5N2) in Mexico represents a significant event in the ongoing efforts to monitor and control zoonotic influenza viruses. The swift and comprehensive public health response, coupled with robust epidemiological investigations, underscores the importance of preparedness and collaboration in addressing emerging infectious diseases. Continued vigilance, research, and international cooperation are paramount to safeguarding public health and preventing future outbreaks. The data and insights gained from this case will contribute to the global understanding of zoonotic influenza viruses and inform strategies to mitigate their impact on human health.

Financial support and sponsorship

All the authors declare to have received no financial support or sponsorship for this study.

CRediT authorship contribution statement

Prakriti Pokhrel: Writing – review & editing, Writing – original draft, Supervision, Project administration, Conceptualization. Amogh Verma: Writing – review & editing, Writing – original draft. Kumud Pant: Writing – review & editing, Writing – original draft. Mahalaqua Nazli Khatib: Writing – review & editing, Writing – original draft, Validation. Mahendra Pratap Singh: Writing – review & editing, Writing – original draft, Validation. Quazi Syed Zahiruddin: Writing – review & editing, Writing – original draft. Sarvesh Rustagi: Writing – review & editing, Writing – original draft. Sanjit Sah: Writing – review & editing, Writing – original draft.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

Amogh Verma and Prakriti Pokhrel contributed equally and should be considered as co-first authors.
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References

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2 Strengthening the intersectoral work for Influenza at the Human Animal Interface in the Region of the Americas: Technical Questions and Answers - PAHO/WHO | Pan American Health Organization. www.paho.org. Published May 19, 2023. Accessed June 14, 2024. https://www.paho.org/en/documents/strengthening-intersectoral-work-influenza-human-animal-interface-region-americas.
3 Farahat R.A. Khan S.H. Rabaan A.A. Al-Tawfiq J.A. The resurgence of Avian influenza and human infection: a brief outlook New Microbes New Infect 53 2023 Mar 30 101122 10.1016/j.nmni.2023.101122 PMID: 37090950; PMCID: PMC10113833
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