A young child recovered from a rare reassortant virus, highlighting the importance of livestock surveillance and advanced genetic testing.
RT’s Three Key Takeaways:
- Zoonotic Transmission Risk: Investigators identified a likely transmission from domestic pigs to a child in a rural setting, reinforcing the need for physical separation between livestock and living areas.
- Advanced Diagnostic Tools: The case demonstrated the utility of next-generation sequencing in identifying viral pathogens when routine polymerase chain reaction testing yields negative results.
- Surveillance and Coordination: Researchers emphasized the clinical importance of screening patients for swine exposure and improving coordination between human and animal healthcare systems.
Researchers have identified the first human case of swine influenza A(H1N2)v in mainland China, a finding that underscores the ongoing risk of zoonotic disease transmission, according to a report in Frontiers in Public Health.
The infection occurred in a previously healthy boy, aged 2 years and 10 months, who presented with a recurrent fever and paroxysmal cough. After his condition progressed to bronchopneumonia, he was hospitalized for treatment. Clinical testing on admission identified influenza A and a concurrent Haemophilus influenzae infection. A chest computed tomography (CT) scan revealed increased and blurred pulmonary markings.
The patient was treated with cefoperazone–sulbactam, oseltamivir, ambroxol, and nebulized budesonide. His respiratory symptoms improved, and he was discharged following a full recovery, the study authors said.
While initial reverse transcription polymerase chain reaction (PCR) testing of specimens was negative, investigators recovered the complete viral genome using next-generation sequencing on an oropharyngeal swab. Genomic analysis revealed a reassortant virus derived from swine H1N1, H1N2, and H3N2 lineages circulating in China.
The discrepancy between the sequencing and PCR results may have been caused by a low viral load, early specimen collection, or inadequate recovery of infected cells, the researchers said. The case highlights how genetic sequencing can assist in diagnosis when routine testing is negative but clinical and epidemiological suspicion remains high.
Epidemiological investigations found the child lived in a rural compound where pigs, chickens, and pigeons were kept near residential and cooking areas. A pig owned by a relative died shortly after the child became ill, and two other pigs developed cough and diarrhea. Testing of the deceased pig confirmed the presence of influenza A.
Although a specific transmission route was not confirmed, investigators identified the deceased pig as a plausible source of the infection. Monitoring of 30 close contacts revealed no secondary infections or evidence of human-to-human transmission.
The study authors said the findings reinforce the importance of asking patients with influenza-like illness about recent exposure to swine. The researchers also called for sustained influenza surveillance and better coordination between human and animal healthcare systems.
Reference
Zhao D et al. First report of human infection caused by swine-origin influenza A(H1N2)v virus in mainland China: a confirmed case identified through influenza-like illness surveillance, Kunming (Yunnan), 2025. Front Public Health. 2026;14:1893536. https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2026.1893536/full
This article was originally published by AMJ and was made available under the terms of the Creative Commons Attribution-Non Commercial 4.0 License. Author: Anaya Malik
