[Children's pertussis immunization strategy in China]

Risk factors and prediction model of severe pertussis in infants < 12 months of age in Tianjin, China

Background

To identify risk factors associated with the prognosis of pertussis in infants (< 12 months).

Methods

A retrospective study on infants hospitalized with pertussis January 2017 to June 2019. The infants were divided into two groups according to the severity of disease: severe pertussis and non-severe pertussis groups. We collected all case data from medical records including socio-demographics, clinical manifestations, and auxiliary examinations. Univariate analysis and Logistic regression were used.

Results

Finally, a total of 84 infants with severe pertussis and 586 infants with non-severe pertussis were admitted. The data of 75% of the cases (severe pertussis group, n = 63; non-severe pertussis group, n = 189) were randomly selected for univariate and multivariate logistic regression analysis. The results showed rural area [P = 0.002, OR = 6.831, 95% CI (2.013–23.175)], hospital stay (days) [P = 0.002, OR = 1.304, 95% CI (1.107–1.536)], fever [P = 0.040, OR = 2.965, 95% CI (1.050–8.375)], cyanosis [P = 0.008, OR = 3.799, 95% CI (1.419–10.174)], pulmonary rales [P = 0.021, OR = 4.022, 95% CI (1.228–13.168)], breathing heavily [P = 0.001, OR = 58.811, 95% CI (5.503–628.507)] and abnormal liver function [P < 0.001, OR = 9.164, 95% CI (2.840–29.565)] were independent risk factors, and higher birth weight [P = 0.006, OR = 0.380, 95% CI (0.191–0.755)] was protective factor for severe pertussis in infants. The sensitivity and specificity of logistic regression model for remaining 25% data of severe group and common group were 76.2% and 81.0%, respectively, and the consistency rate was 79.8%.

Conclusions

The findings indicated risk factor prediction models may be useful for the early identification of severe pertussis in infants.

Mortality risk factors among hospitalized children with severe pertussis

BACKGROUND

Some children hospitalized for severe pertussis need intensive care; moreover, some children die because of deterioration alone or in combination with other complications. The purpose of this study was to identify the mortality risk factors among hospitalized children with severe pertussis.

METHODS

This study evaluated the medical records of 144 hospitalized children with severe pertussis at the Guangzhou Women and Children's Medical Centre between January 2016 and December 2019.

RESULTS

The median age of patients was 2 months (IQR 1-4 months), with 90.3% of the patients aged < 6 months and 56.9% of the patients aged < 3 months. A total of 38 patients were admitted to intensive care unit (ICU), 13 patients died, and the mortality of severe pertussis was 34.2%, with patients younger than 6 weeks accounting for 76.9% of the deaths. On the multivariate analysis, the independent risk factors for death were WBC > 70.0 × 10⁹/L (odds ratio [OR], 230.66; 95% confidence interval [CI], 5.16-10,319.09 P = 0.005) and pulmonary hypertension (PH) (OR 323.29; 95% CI 16.01-6529.42; P < 0.001).

CONCLUSION

Severe pertussis mainly occurred in children aged < 3 months. The mortality of severe pertussis was 34.2%, with patients younger than 6 weeks accounting for the majority of the deaths. We recommend the first dose of diphtheria-tetanus-pertussis (DTP) should be advanced to the age of 2 months or even 6 weeks. The presence of a WBC > 70.0 × 10⁹/L and PH were the prognostic independent variables associated with death.

Intention to accept pertussis vaccination among Chinese people older than age 5

Background: The intention of Chinese people older than age 5 to accept the pertussis vaccination is unknown, which is important for the future design of an effective pertussis vaccination program in China.Method: We conducted a cross-sectional survey among people older than age 5 in China. A 24-item questionnaire was used to explore the determinants of intention to accept a pertussis vaccination, and for children and adolescents (≦15 years old), their guardian was required to help answer the questionnaire on their behalf. Univariate and multivariate logistic regression was used to analyze the influencing factors of intention.Results: A total of 3,041 individuals participated in our survey and 3025 completed the questionnaire, among which 1938 (64.07%) reported a positive intention to be vaccinated. A multiple logistic regression analysis revealed that the main positive factors for the intention to accept pertussis vaccination were younger age (Odd ratio [OR] 0.838, P < .001), higher educational attainment (OR 1.171, P = .002), no hospitalization because of the most recent cough (OR 2.468, P < .001), awareness about pertussis (OR 1.958, P < .001), and consideration of pertussis vaccination to be safe (OR 1.450, P = .026).Conclusion: There is a relatively high level of intention to receive the pertussis vaccine among people older than age 5 in China. Future pertussis vaccination strategies geared at them should consider focusing on middle-aged and older individuals and those with a low education as well as strengthen the promotion of disease characteristics, vaccine effectiveness, and safety.

[Effect of pertussis vaccination on clinical manifestations of infants and young children with pertussis]

OBJECTIVE

To study the effect of pertussis vaccination on the clinical manifestations of infants and young children with pertussis.

METHODS

A retrospective analysis was performed to investigate the differences in clinical manifestations and peripheral blood cell levels between pertussis children with different pertussis vaccination status.

RESULTS

A total of 1 083 children with pertussisat at age of < 3 years were enrolled, with 551 children in the unvaccinated group and 532 in the vaccinated group. Of all the children, 392 had an age of onset of < 3 months (372 were unvaccinated and 20 were vaccinated) and 691 children had an age of onset of ≥ 3 months (179 were unvaccinated and 512 were vaccinated). Compared with the vaccinated group, the unvaccinated group had a longer length of hospital stay and a higher incidence rate of respiratory failure (P < 0.05). Among the children ≥ 3 months of age, the incidence of severe pneumonia in the unvaccinated group was higher than that in the vaccinated group (P < 0.05), and the incidence of severe pneumonia was the highest in the unvaccinated group (10.6%) and the lowest in the 4-dose vaccination group (1.2%). Among the 101 patients with severe pneumonia, 80 (79.2%) were observed in the unvaccinated group and only 21 (20.8%) in the four different doses vaccination groups. For the children with an age of onset of ≥ 3 months, the unvaccinated group had higher white blood cell count, absolute value of lymphocytes, and platelet count than the vaccinated group (P < 0.05).

CONCLUSIONS

Pertussis vaccination can reduce the incidence of severe pneumonia and respiratory failure and alleviate the severity of respiratory complications in infants and young children with pertussis.