Pertussis FAQ

Pertussis FAQ

pertussis is an old and highly contagious acute respiratory infectious disease caused by Bordetella pertussis (BP), which belongs to class B infectious diseases in China. It is ancient because it has a long history and is not a new disease, as early as the seventh century AD, Sui Dynasty period, China's medical monograph has been recorded.

According to the official data released by China's Center for Disease Control and Prevention, since November 2023, China's reported cases of pertussis have shown a significant upward trend. In the first quarter of 2024, the number of pertussis cases reported nationwide was 59,458, while the number of cases reported nationwide was only 2242 in the same period last year. The number of cases of pertussis in China this year is as high as 26.5 times of the same period in previous years. Pertussis was once a major cause of childhood morbidity and death, but since 1978, pertussis vaccine has been included in the national immunization program, and the vaccination has greatly reduced the incidence and mortality of pertussis, especially in infants and young children. But according to the latest data in China, whooping cough is now making a comeback, causing panic and anxiety among parents.

In view of the current clinical parents are more concerned about pertussis drug resistance, antibiotic treatment course, persistent cough after pertussis treatment and prevention and isolation and other problems, today to answer for you one by one.

1. How to treat macrolide resistant pertussis?

For macrolide sensitive pertussis, after 7 days of treatment, the bacterial clearance rate of macrolides is better than that of βlactam drugs, so it is recommended to choose macrolides, such as erythromycin, azithromycin, clarithromycin. According to the Chinese Guidelines for the Diagnosis, Treatment and Prevention of pertussis (2024 edition), azithromycin is recommended as a priority. However, the resistance rate of bordetella pertussis strains isolated from pertussis patients in China to macrolides has reached 70% to 100%. In vitro drug sensitivity tests showed that compound sulfamethoxazole, β-lactam and other drugs were more sensitive to pertussis, and the bacterial clearance rate of β-lactam was better than that of macrolides after 14 days of treatment. Therefore, for patients with pertussis who were resistant to macrolides or who failed empirical treatment of macrolides, compound sulfamethoxazole was the first choice for children over 2 months of age. Beta-lactam drugs such as cefoperazone sulbactam or piperacillin tazobactam are recommended for infants 2 months of age and younger.

2. What should I pay attention to when using compound sulfamethoxazole, cefoperazone and sulbactam?

Compound sulfamethoxazole can cause liver and kidney function damage. During or after treatment, monitor urine routine and liver and kidney function. Drink more water during medication to prevent the occurrence of crystallized urine. Compound sulfamethoxazole is prohibited for infants <2 months old and those with severe liver and kidney damage. Use with caution in patients with glucose-6-phosphate dehydrogenase deficiency, large doses may induce hemolysis; When using cefoperazone and sulbactam in infants under the age of 2 months, pay attention to rechecking the coagulation function. This drug can inhibit the production of vitamin K by intestinal flora, interfere with the circulation of vitamin K in the body, and hinder prothrombin synthesis.

3. Does pertussis treatment require 2-3 sessions?

The duration of pertussis antibiotics that are sensitive to macrolids varies slightly depending on the drug selected. Azithromycin is used for 1 course for 5 days, erythromycin is used for 1 course for 14 days, and clarithromycin is used for 7 days. For children with poor effect after one course of treatment with macrolides, the possibility of resistance to macrolides should be considered, and it is recommended to adjust to compound sulfamethoxazole in time, with 14 days as one course of treatment. In general, the course of treatment should not exceed 14 days. The vast majority of patients can be treated for 1 course of treatment, for children who are not significantly improved after 1 course of treatment, a comprehensive assessment should be carried out in time, and the next course of treatment should be continued if necessary, and the total course of treatment is generally not more than 2 to 3 courses of treatment.

4. Must pertussis nucleic acid turn negative before discharge?

At present, rapid clinical diagnosis of pertussis mainly means of nasopharyngeal swab or nasopharyngeal wash specimen positive pertussis Baute nucleic acid test, similar to the novel coronavirus epidemic during the collection of nucleic acid. The main factor to evaluate the outcome of pertussis treatment is the clinical outcome of the patient. When the patient has passed the acute episode, the clinical cough symptoms have improved, and there is no other serious complications such as hypoxemia, the patient can be discharged from the hospital and take medicine home to continue oral treatment, and there is no need to wait until the pertussis nucleic acid has turned negative, unless the child urgently needs to go back to school, in which case, from the perspective of infectious disease prevention and control, It is recommended that pertussis nucleic acid test should be negative before returning to school.

5. Pertussis long cough bad how to do? Do you need antibiotics?

Bordeta pertussis expresses a variety of virulence factors and produces a large number of toxins and bioactive products. The most important virulence factor is pertussis toxin (PT), which can stimulate the peripheral respiratory tract nerves and pass into the medullary cough center, reflexively causing continuous spastic cough until the secretion is discharged, causing inflammatory damage to the airway and causing high airway response. The main symptomatic treatments for pertussis include glucocorticoids, bronchodilators, antihistamines and leukotriene receptor antagonists. The 2024 version of the pertussis guideline recommends that in the period of paroxysmal spasmodic cough or accompanied by repeated asphyxia episodes, a short course of systemic hormone therapy can be received for no more than 7 to 10 days. Local atomized budesonide and terbutaline can also effectively relieve cough symptoms during spasmodic cough. The therapeutic effect of other symptomatic antitussive and expectorant drugs is not certain, and there is no unified recommendation at present. Intravenous pertussis immunoglobulin can effectively relieve cough, but it is currently not available in the domestic market. In addition to the cough caused by pertussis itself, if the cough does not improve for a long time, it is also necessary to conduct a timely assessment of the condition to determine whether there is a possibility of secondary bacterial infection, and if there is a bacterial infection, other antibiotics can be added.

6. Does whooping cough have to last 100 days?

Pertussis does not necessarily last for 100 days, and varies from person to person, with the total duration of illness ranging from weeks to months. The typical course of pertussis includes catarrine period (1 to 2 weeks), convulsive cough period (2 to 8 weeks) and recovery period (2 to 3 weeks or longer), if the patient is not treated in time into the convulsive cough period, it will lead to a longer total course of pertussis, if the treatment is actively performed in the catarrine period, it may be improved in 1 to 2 weeks, and will not enter the convulsive cough period, the total course of disease is relatively short.

7. How long should I stay away from whooping cough before I can go to school?

According to the domestic pertussis guidelines, it is recommended to isolate at least 5 days after effective antibacterial treatment, and for patients who do not give effective antibacterial treatment in time, the isolation period is 21 days after spasmolysis.

8. Should I use antimicrobial prophylactic therapy after pertussis exposure?

In the following cases, close contacts of confirmed cases should receive drug prophylaxis within 21 days after exposure (1 to 2 weeks after exposure if possible), with the same drug selection, dose, and course of treatment:

(1) Family members;

(2) Infants who have not completed 3 doses of basic immunization vaccine;

(3) Children in childcare institutions who are not fully immunized;

(4) Medical personnel in medical institutions and neonatal care institutions responsible for the care of infants under 3 months of age;

(5) Staff of child care institutions;

(6) Close contacts involved in clusters or outbreak sites.

9. Is it necessary for preschool children to receive 1 dose of pertussis vaccine?

Vaccination is the most effective way to prevent pertussis. At present, China's immunization program vaccines are diphtheria toxoid, acellular pertussis vaccine, tetanus toxoid (DTaP) triple vaccine, which is vaccinated at 3 months of age, 4 months of age, 5 months of age, and 1 dose of each at 18 months of age. However, protective antibody levels decreased after 3 to 5 years of vaccination, and antibodies almost disappeared after 12 years. Therefore, the guidelines recommend that preschool children aged 4 to 6 years receive one dose of DTaP vaccine.

10. Can special groups receive pertussis vaccine?

Although the routine vaccination time of pertussis in China starts from 3 months of age, considering that newborns generally lack protective antibodies against pertussis and infants are high-risk groups of pertussis infection, once the hospitalization rate and mortality rate are high, the first dose of pertussis vaccine can be advanced to 2 months of age, which can protect children earlier. Therefore, the 2024 pertussis Guidelines recommend that infants at 2 months of age can begin receiving their first dose of pertussis vaccine; For preterm infants, it is recommended to start the first dose of pertussis vaccine according to the actual age; Children with neurological diseases can be routinely vaccinated with vaccines containing pertussis components under stable disease control or during the recovery period, and neurological diseases are not contraindications for vaccination.