Fatal pertussis in infancy, Italy

Pertussis Toxin Promotes Pulmonary Hypertension in an Infant Mouse Model of Bordetella pertussis Infection

Pertussis, caused by Bordetella pertussis, is a reemerging disease that can produce severe disease manifestations in infants, including pulmonary hypertension (PH). B. pertussis-induced PH is a major risk factor for infection-induced death, but the molecular mechanisms promoting PH are unknown and there is no effective treatment. We examined B. pertussis-induced PH in infant and adult mouse models of pertussis by Fulton index, right heart catheterization, or Doppler echocardiogram. Our results demonstrate that B. pertussis-induced PH is age related and dependent on the expression of pertussis toxin by the bacterium. Hence, pertussis toxin-targeting treatments may ameliorate PH and fatal infant infection.

Pertussis in Italy: how to protect the "unprotectable"?

Whooping cough continues to be an important public health issue despite high levels of vaccination coverage with acellular pertussis vaccine. Young unimmunized infants represent the most vulnerable group with the highest rates of complications and death. As infant-specific pertussis epidemiologic data, especially among neonates, in Italy were limited, a retrospective observational study of hospitalizations for whooping cough in Italian infants aged <12 months between 2007 and 2018 was conducted to address this knowledge gap. The temporal trend of rates, also stratified for age classes according to the expected age for the administration of vaccine doses, were analyzed by the slope of the regression line. The mean age at the time of admission was 92 d (±64). A clear seasonal pattern in the occurrence of pertussis hospitalizations with a summer peak was observed. Infants younger than 3 months old had the highest hospitalization rates (169 x 100000 infants on average), with a significant rising trend of 9 x 100000 infants on average per year. Limiting the analysis to Bordetella pertussis-related hospitalizations such trend was even more evident. In the other age classes, hospitalization rates were considerably lower and gradually decreased with increasing age. This study demonstrated that pediatric populations, too young to be protected by vaccination, had a greater risk of contracting pertussis. Thus, it is necessary to promote additional immunization strategies besides one booster dose in adolescents, including vaccination during pregnancy.

Insights and expectations for Tdap vaccination of pregnant women in Italy

BACKGROUND

Pertussis is a widespread vaccine-preventable disease, associated with an increasing trend to hospitalization among newborns. Pertussis in newborns can be fatal, and the most effective way to prevent it is maternal immunization (MI) with a reduced antigen content tetanus, diphtheria, and acellular pertussis vaccine (Tdap). In Italy, the National Immunization Plan (NIP) 2017-2019 introduced de novo Tdap vaccination during each pregnancy at no cost for the recipient. Despite this, vaccination coverage is suboptimal. This survey of pregnant women across Italy was conducted to investigate their knowledge and expectations of Tdap.

METHODS

A cross-sectional survey was conducted. Pregnant women up to 28th gestational weeks were interviewed by Telephone using a questionnaire with 16 questions. Statistics were descriptive.

RESULTS

The final sample recruited 600 respondents evenly distributed across Italy. The average duration of pregnancy at the time of the interview was 20.8 weeks (standard deviation [SD] 6.0). Most women (60.7%) were between 30 and 40 years of age. About half were aware of the risks of pertussis for newborns (54.5%) and the increased risk of hospitalization (59.8%); 47.2% were aware that Tdap MI was offered free of charge under the NIP. Safety information regarding the mother and newborn was considered the most important information in deciding whether to be vaccinated (47.4%), followed by safety information related only to the newborn (29.5%). About half (52.2%) stated that they would "certainly" accept MI, and 25.3% would like to receive more information. Gynecologists were the preferred healthcare providers (HCPs) for the provision of MI information (34.3%), followed by pediatricians (25.5%). Two-thirds of the respondents would prefer to be informed about MI before getting pregnant (66.0%). Vaccines investigated specifically for use in pregnancy were preferred by respondents. Overall, no relevant differences were observed between women pregnant for the first time and those with more than one pregnancy, nor between geographical regions.

CONCLUSIONS

The results show room for improving the awareness and understanding of the risks of pertussis for infants and the protective role of MI. The pregnant women preferred to receive advice on MI from an HCP, primarily their gynecologist. They were most interested in information on the safety profile of Tdap during pregnancy, on the mother, fetus, and newborn. The potential impact of this study to support clinical practice of Healthcare Providers is highlighted in the Focus on the Patient section. [Formula: see text].