Since the beginning of this year, the viral fever syndrome has been widespread across provinces in Northern Vietnam. According to reports from the Central Institute of Hygiene and Epidemiology, the number of cases has reached tens of thousands.
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| Image of influenza virus (Photo: TTO) |
The Central Institute of Hygiene and Epidemiology, along with provincial preventive health centers, has promptly taken action. Many samples have been tested, confirming positive results for influenza B virus, a type of influenza virus that causes the common flu but can be dangerous for individuals with chronic diseases, the elderly, malnourished children, and pregnant women if timely preventive measures are not taken.
How Does Influenza B Virus Affect Health?
According to Assoc. Prof. Dr. Pham Ngoc Dinh, Deputy Director of the Central Institute of Hygiene and Epidemiology, influenza B virus is a type of influenza virus capable of causing flu in humans. However, unlike influenza A virus, this virus has less antigenic variation, only causing sporadic flu cases, typical flu, and mild progression, possibly leading to outbreaks either on its own or in combination with other respiratory viruses.
This is a benign virus, transmitted through respiratory droplets, with an incubation period of 1-3 days and a disease duration of 3-5 days. The susceptible population includes everyone, particularly children under 5, the elderly, immunocompromised individuals, and those with other chronic illnesses.
Upon entering the body, influenza B virus causes symptoms such as fever (which can be high and sudden), inflammation of the upper respiratory tract, cough, and sore throat. Rarely, symptoms of lower respiratory tract infections like pneumonia or bronchitis may appear, which could indicate complications or co-infection with other viruses.
Influenza B is a self-limiting disease that usually requires no treatment. After infection, the immunity period is short, lasting only a few years, and patients can be re-infected. As the disease is viral, there is no preventive antibiotic treatment. However, it can significantly impact fetuses in the first trimester (potentially causing deformities), malnourished children, and individuals with chronic diseases.
The Current Weather Conditions Favor the Spread of Influenza B Virus
According to the Central Institute of Hygiene and Epidemiology, since the beginning of the year, the number of people diagnosed with viral fever syndrome has reached tens of thousands. Provinces with high patient numbers (over 1,000 cases) include Vinh Phuc, Yen Bai, Bac Giang, Lao Cai, Nam Dinh, Lang Son, Hung Yen, and Quang Ninh, with Yen Bai having the highest recorded cases: 5,155 individuals (as of March 23, 2006). In the five provinces experiencing outbreaks, the institute has investigated and collected samples from 98 individuals exhibiting fever for 3-5 days, with 50 out of 98 testing positive for influenza B.
Epidemiological experts indicate that influenza B circulates in Vietnam year-round, with the late winter and early spring typically being conducive conditions for disease outbreaks, especially in areas with poor sanitary conditions and low public awareness of disease prevention and treatment, such as among ethnic minorities in mountainous and remote regions. Given the current situation, the influenza B outbreak is likely to escalate if the public does not take proactive measures in collaboration with the health sector to control the disease.
Preventing Disease to Limit Outbreaks and Prevent the Combination of Influenza B with H5N1 Influenza Virus
Since the H5N1 influenza virus has been fatal to humans, health experts have been concerned about the potential for a global influenza pandemic if it becomes transmissible from person to person, with the greatest risk being the combination of H5N1 with other common flu strains (like influenza B). Therefore, implementing measures to prevent the current outbreak of influenza B is crucial.
To limit the spread of disease, isolation measures should be taken when children are infected, such as not sending them to school or daycare while ill to prevent spreading the virus to others. Everyone must pay attention to personal hygiene and food safety. In outbreak areas, individuals should wear masks when interacting with patients or when out in public. If severe complications arise, patients should be taken to healthcare facilities.
Currently, there is a vaccine available for influenza B, which is part of the trivalent vaccine that includes H3N2, H1N1, and influenza B. This vaccine is updated and recommended annually by the World Health Organization, and if possible, it should be administered as a booster every year since immunity lasts only from 6 months to 2 years. The best time for vaccination is in August or September.
