Adenovirus Cases Triple, Vietnam's National Children's Hospital Warns of Summer Infection Risk

Vietnam's National Children's Hospital has reported a significant surge in Adenovirus infections, with 2,777 positive cases recorded from the beginning of 2026 until now, a threefold increase compared to the same period last year. The trend indicates a rapid escalation, with 383 new cases identified in the early days of July 2026 alone. Dr. Nguyen Thi Mai Hoan, Head of the General Examination Department at the hospital, noted a recent influx of children presenting with high fever of unknown origin. "The majority of children have experienced continuous fever for 3-5 days. After examination and testing, we observed clear signs of systemic inflammation with elevated white blood cell counts and CRP levels, and Adenovirus tests returning positive," she stated. Dr. Hoan highlighted a shift in the typical presentation of Adenovirus infections. Previously more common in younger children with characteristic symptoms like respiratory illness, conjunctivitis, or digestive disorders, the virus is now increasingly affecting older children. These older children often lack specific symptoms, primarily presenting with prolonged high fever that responds poorly to antipyretics. A concerning incident involved a group of children attending a swimming class at a public pool, where 4 out of 5 children contracted the virus from each other. This underscores public pools as high-risk environments if hygiene and social distancing measures are not adequately maintained. Adenovirus is a common virus that can cause illness year-round but typically peaks during transitional seasons or summer when children engage in more outdoor activities and social interactions. Transmission primarily occurs through the respiratory route (coughing, sneezing, close contact) and the digestive tract. It can also spread through mucous membranes during swimming or contact with unsanitary surfaces and water sources. Outbreaks are common in concentrated child-care settings like schools, extracurricular classes, playgrounds, and public swimming pools. Doctors explain that symptoms are diverse, with high fever, cough, sore throat, conjunctivitis (pink eye), and digestive issues being the most common. Notably, many children, especially older ones, experience persistent high fever that is difficult to manage with standard fever reducers. Without proper monitoring and management, some cases can develop into severe complications like pneumonia, requiring hospitalization. To prevent illness and ensure proper care, experts advise parents to seek immediate medical attention if their child has a persistent high fever, prolonged cough, red eyes, or digestive problems. Early detection, close monitoring, and appropriate treatment are crucial for recovery. Dr. Hoan strongly cautioned against self-medicating with antibiotics or other drugs without a doctor's prescription due to potential adverse effects. Parents are urged to keep children exhibiting symptoms like fever, cough, or digestive upset at home and to temporarily avoid public swimming pools and crowded places to prevent further spread. Facilities hosting large groups of children, such as schools, play areas, and public pools, are advised to conduct regular cleaning and disinfection of water sources and common surfaces, ensure adequate ventilation, and manage crowd density to minimize cross-infection risks within the community.