13 deaths so far this year! Coughing is not good, beware of whooping cough

Recently, topics such as "whooping cough reappears" and "whooping cough has killed 13 people this year" have attracted attention. The incidence of whooping cough in adolescents and adults has increased significantly. This disease, which was previously thought to be only contracted by infants and young children, is gradually becoming "aged".

According to the "National Notifiable Infectious Diseases Overview" report regularly released by the National Center for Disease Control and Prevention, 32,380 cases of whooping cough were reported nationwide in the first two months of 2024, far higher than the number of cases reported in the same period last year (1,421). In addition, 13 of the whooping cough cases in January-February 2024 were fatal.

What is whooping cough? Does whooping cough really last 100 days? Why has the number of cases of whooping cough suddenly increased when it has long been in a low-prevalence state? This issue of "Health Focus" explains it for you.

What is whooping cough?

Whooping cough is an acute respiratory infectious disease caused by Bordetella pertussis.

China's statutory infectious diseases are divided into three categories: A, B, and C. Category B includes whooping cough , novel coronavirus infection, monkeypox, AIDS, tuberculosis, rabies, viral hepatitis, etc. Category B infectious diseases are strictly managed infectious diseases , and the management content includes three aspects of measures: managing the source of infection, cutting off the transmission route, and protecting susceptible populations.

Source of infection : Patients and carriers are the main sources of infection. The incubation period of pertussis is 5-21 days, generally 7-14 days. The patient is contagious from the beginning of the incubation period to 6 weeks after onset of the disease, and is most contagious from the end of the incubation period to 2-3 weeks after the onset of cough symptoms.

Transmission route : Mainly through respiratory droplets (coughing, talking, sneezing), and can also be transmitted through close contact.

Susceptible population : People are generally susceptible to whooping cough, but infants and young children are more sensitive. Before the large-scale application of vaccines, whooping cough was one of the most common childhood diseases and one of the major causes of death among infants and young children worldwide.

What are the typical symptoms of whooping cough?

Typical whooping cough goes through three stages: catarrhal stage, spasmodic stage, and recovery stage.

Catarrhal stage : symptoms of upper respiratory tract infection include runny nose, sneezing, tearing, sore throat, paroxysmal cough, etc. There is usually no fever, or a transient fever in the early stage. The amount of bacteria excreted reaches its peak during this stage, and it is highly contagious. It usually lasts 1-2 weeks.

Spasmodic cough stage : manifested by paroxysmal spasmodic coughs, accompanied by high-pitched cock-like roars, repeated many times until sticky phlegm is coughed up, lighter during the day and heavier at night. The spasmodic cough is more prominent during sleep, affecting sleep.

The frequency of spasmodic coughing increases with the progression of the disease. Vomiting often occurs after coughing, which can cause tongue frenulum ulcers, facial and eyelid swelling, conjunctival hemorrhage, nose bleeding, and intracranial hemorrhage in severe cases.

In newborns and infants under 6 months old, coughing often causes cyanosis, apnea, convulsions, bradycardia or cardiac arrest. This period generally lasts 2-6 weeks, but can also last more than 2 months.

Adolescents or adults with pertussis often do not have typical spasmodic coughs, but instead experience alternating paroxysmal coughs and temporary relief, which lasts for 2-3 weeks.

There is usually no fever during the spasmodic cough phase. If there is a high fever, there may be a secondary infection. The most common complication is pneumonia, which is the main cause of death in whooping cough patients.

Recovery period : The spasmodic cough gradually eases, the cough intensity weakens, the number of attacks decreases, and the cock-like roar gradually disappears. The symptoms of paroxysmal spasmodic cough may last for weeks or months.

Why has the incidence of whooping cough increased sharply?

Regarding the rising incidence of whooping cough, Dou Zhifang, deputy director and chief physician of the Department of Respiratory and Critical Care Medicine at the Air Force General Hospital, said in an interview with the media that there are two main reasons.

First, the vaccine's immune effect is not long-lasting. The human body can acquire immunity to whooping cough through natural infection or vaccination, but the immunity acquired through these two methods cannot last a lifetime.

Second, in recent years, the diagnostic standards have been continuously improved and the monitoring system has been improved. Compared with the previous bacterial culture and PT antibody testing, the diagnosis of pertussis now also includes nucleic acid testing, and the number of hospitals or institutions with the conditions for diagnosis has increased significantly, which may have led to an increase in the number of cases to a certain extent.

How to treat and prevent whooping cough?

treat

In general, hospitalization is recommended for infants under 4 months of age or patients with severe symptoms or complications; oral medications can be considered for mild cases.

For the treatment of whooping cough, macrolide antibiotics such as azithromycin, erythromycin, roxithromycin or clarithromycin are recommended. Children and adults over 2 months old who have contraindications to the use of macrolides, cannot tolerate macrolides or are infected with macrolide-resistant strains can use trimethoprim-sulfamethoxazole . During medication, pay attention to adverse reactions such as kidney damage, crystalluria, and rash.

Because each person's symptoms, physical condition, and history of combined medication are different, when treating whooping cough, the medication should be mainly based on the doctor's guidance.

prevention

Isolation : Whooping cough is a Class B infectious disease and must be isolated as a respiratory infectious disease. The isolation period must last at least 5 days after effective antibiotic treatment. For patients who are not given effective antibiotic treatment in time, the isolation period must last 21 days after whooping cough.

Post-exposure prevention : For family members and close contacts of confirmed patients, as well as exposed persons with a higher risk of developing severe illness or complications, it is recommended to give them post-exposure antibiotics for prevention. The drug selection, dosage, and course of treatment are the same as those for treatment (use under the guidance of a doctor).

Vaccination : The vaccine currently used in China is a triple vaccine made from a mixture of pertussis vaccine, diphtheria toxoid and tetanus toxoid - the diphtheria, pertussis and tetanus vaccine.

According to relevant research, the protective efficacy of the DTP vaccine in preventing typical whooping cough is 85%.

However, usually the level of protective antibodies decreases 3-5 years after vaccination, and the antibodies almost disappear after 12 years, which means there is a risk of reinfection. Therefore, in addition to vaccination, everyone should also strengthen their awareness of protection.

Wearing a mask is an important measure to prevent respiratory infectious diseases. During the peak season of whooping cough, try to avoid crowded gatherings, exercise appropriately, and enhance your own resistance.

References:

[1] Whooping cough
https://www.chinacdc.cn/jkzt/crb/zl/brk/

[2] 13 deaths so far this year! Why is whooping cough so prevalent?
https://www.chinanews.com.cn/gsztc/2024/04-01/10190825.shtml

[3] Overview of the national epidemic situation of notifiable infectious diseases in January 2024 https://www.ndcpa.gov.cn/jbkzzx/yqxxxw/common/content/content_1759464021993402368.html

[4] Overview of the national epidemic situation of notifiable infectious diseases in February 2024
https://www.ndcpa.gov.cn/jbkzzx/yqxxxw/common/content/content_1769981713455947776.html