China News Service, Beijing, April 3 (Shao Meng) Since the beginning of this year, the number of whooping cough cases in our country has increased significantly, and "whooping cough reappears" once became a hot search topic. National epidemic data on notifiable infectious diseases released by the National Bureau of Disease Control and Prevention show that in the first two months of this year, the number of whooping cough cases was 32,380, which is nearly 23 times the number of cases in the same period last year.
This phenomenon has also attracted the attention of disease control departments. "Currently, pertussis prevention and control in my country requires great attention." Shen Hongbing, deputy director of the National Administration of Disease Control and Prevention and director of the Chinese Center for Disease Control and Prevention, said at the "2024 Vaccine and Immunization Conference" held on March 16.
Whooping cough, an “ancient” disease, seems to be making a comeback.
The population is generally susceptible
Whooping cough is an acute respiratory infectious disease caused by Bordetella pertussis and is a legally reportable Class B infectious disease in my country. The course of the disease is long, and a typical case may manifest as a cough that lasts for 2-3 months, so it is called "whooping cough".
Data map: Medical staff inject fluids into children. Photo by Shao Meng
Hu Yang, deputy director of the Department of Respiratory and Critical Care Medicine at Shanghai Pulmonary Hospital, introduced to Sino-Singapore Health that the initial stage of whooping cough infection may present upper respiratory tract infection symptoms such as fever, sneezing, coughing, etc., which are similar to the common cold, which also makes whooping cough more likely to occur. Missed diagnosis. “If your cough persists, especially if the cough symptoms become more and more severe, you must seek medical attention in time,” he reminded.
According to the "Pertussis Diagnosis and Treatment Plan (2023 Edition)" (hereinafter referred to as the "Diagnosis and Treatment Plan") issued by the National Health Commission, the incubation period of whooping cough is generally 7-14 days. It is contagious from the beginning of the incubation period to 6 weeks after the onset of disease, especially in the incubation period. It is most contagious from the end of the period to 2 to 3 weeks after symptoms appear, and the population is generally susceptible.
Hu Yang said that cases of whooping cough infection are more common in children and less in adults. Newborns and infants under 3 months old are high-risk groups. "Their airways are inherently narrow. When spasmodic coughs and rooster-like inhalation roars occur, if treatment is not timely, it may lead to suffocation or even death."
Why has the incidence rate increased significantly?
In fact, the incidence of pertussis is increasing not only in my country but also in many regions around the world. The "Diagnosis and Treatment Plan" points out that due to the weakening of immunity after vaccination and the mutation of Bordetella pertussis, many countries around the world with high vaccine coverage have seen a "reappearance of whooping cough", and the peak age of onset has shifted from infants and young children to adolescents and adults. , teenagers and adults have become the main source of infection for infants whooping cough.
Experts interviewed told Sino-Singapore Health that the incidence of whooping cough is on the rise, which may be affected by various factors such as improved detection technology and the shorter duration of protective effects after vaccination.
Zhao Wei, director of the Biosafety Research Center of the School of Public Health of Southern Medical University, said that whooping cough epidemics occur approximately every 2-5 years. In the past, its spread was seriously underestimated globally. This epidemic is not only related to the entry of whooping cough into the epidemic period, but also may This is related to the significant increase in the incidence of whooping cough under active surveillance. But no matter what the reason is, it needs to attract the attention of relevant departments.
Data map: People queuing up for treatment at the outpatient clinic of a children's hospital. Photo by Zhang Yuhui
In Hu Yang's view, the cause of this situation is not yet clear. Generally speaking, it may be related to strain variation or reduced host immunity against Bordetella pertussis.
Talking about the reasons for the increased incidence of pertussis among teenagers and adults, Zhao Wei analyzed that in the past, healthy adults had strong immunity. Even if they were infected with Bordetella pertussis, they would often have asymptomatic infection or mild symptoms, and it was covertly spread by families. important source of infection. “During the COVID-19 epidemic, as people consciously carried out strict protection of the respiratory tract, the chance of contracting respiratory infectious diseases was reduced, and objectively the specific immunity to Bordetella pertussis was also reduced. Under active surveillance, whooping cough infection will appear in the post-epidemic period. Expansion of the range of people.”
"Consider adjusting immunization planning strategies"
Vaccination with pertussis-containing vaccine remains an effective means of preventing whooping cough. According to the national immunization program, children should receive one dose of pertussis-containing vaccine at 3, 4, 5 months and 18 months of age.
"Neither vaccination nor natural infection can produce lifelong immunity, but vaccination can reduce the risk of severe illness and death." Shen Hongbing said at the "2024 Vaccine and Immunity Conference".
He pointed out that since 2014, the incidence of whooping cough in my country has shown an upward trend. "Pertussis prevention and control needs to be paid attention to. The National Agency for Disease Control and Prevention will hold a special meeting to conduct special studies. Whether our immunization planning policy needs to be adjusted and what changes are needed in the vaccine are worthy of consideration."
Zhao Wei agreed. He believes that my country needs to further strengthen active surveillance of pertussis-like symptoms and promptly identify potential sources of infection among adolescents and adults to effectively block the chain of transmission. Considering that the occurrence of the epidemic may be related to the decline of population-specific immunity, if the epidemic further expands, preschool children at high risk of pertussis infection can be vaccinated for booster vaccination.
In terms of personal protection, Hu Yang said that the vaccine can work most of the time, but it does not mean that it can completely eliminate infection. In addition to vaccination, staying away from infected people, wearing masks as much as possible, washing hands frequently, paying attention to reasonable work and rest and physical exercise are also effective ways to avoid infection. (over)