What is new in pertussis?

Despite high vaccination coverage, over the last fifteen years there has been a worldwide resurgence of B. pertussis infection. While classical pertussis in the prevaccine era was primarily a childhood disease, today with widespread vaccination, there has been a shift in the incidence of disease to adolescents and adults. Centers of Disease Control and Prevention (CDC) data from 2004 reveal a nearly 19-fold increase in the number of cases in individuals 10–19 years and a 16-fold increase in persons over 20 years. Indeed adolescent and adults play a significant role in the transmission of pertussis to neonates and infants who are vulnerable to substantial morbidity and mortality from pertussis infection. Several explanations have been proposed to explain the increasing incidence of disease, with waning immunity after natural infection or immunization being widely cited as a significant factor. Improving molecular biology diagnostic techniques, namely PCR assays, also accounts for the increasing laboratory diagnosis of pertussis. Expanding vaccination strategies including universal immunization of adolescents, targeted immunization of adults, and in particular, healthcare workers, childcare providers and parents of newborns, will likely improve pertussis control. With pertussis continuing to pose a serious threat to infants, and greatly affecting adolescents and adults, there remains a need to: (a) increase the awareness of physicians as to the growing pertussis problem, (b) standardize diagnostic techniques, and (c) implement various new vaccine strategies to enhance its control.     

Transmission of Bordetella pertussis to young infants

BACKGROUND: Pertussis vaccination has reduced the number of notified cases in industrialized countries from peak years by more than 95%. The effect of recently recommended adult and adolescent vaccination strategies on infant pertussis depends, in part, on the proportion of infants infected by adults and adolescents. This proportion, however, remains unclear, because studies have not been able to determine the source case for 47%-60% of infant cases. METHODS: A prospective international multicenter study was conducted of laboratory confirmed infant pertussis cases (aged 相似文献   

Pertussis bei Jugendlichen und Erwachsenen

Pertussis is usually considered a typical childhood infection. However, in recent years numerous epidemiological studies have documented and case reports its occurrence in adolescents and adults. After the introduction of acellular pertussis vaccines in 1995 pertussis vaccination take-up for children rose sharply, and it is now estimated at around 90% in Germany. As in other populations with a high infant vaccination rate, an increasing number of adolescents and adults with pertussis have been observed in the last few years. The spectrum of clinical presentation is wide, ranging from a mild cough to severe coughing with rare, but potentially severe complications. Adult pertussis also has an important role in the transmission of B. pertussis to nonimmune individuals, e.g. unvaccinated newborns. Current vaccination strategies include a pertussis booster vaccination for all adolescents in Germany and, especially, for all adults who come in contact with newborn infants; ideally, in fact, adults should receive their boosters 1 month before the birth of any newborn they expect to be in contact with. Boosters are also recommended for healthcare workers in pediatric departments and for child care workers. The introduction of an additional booster for preschool children is currently under discussion in the new länder, as a means of improving protection for schoolchildren and strengthening immunity in the overall population, since take-up of the vaccination recommended for adolescents is rather low at present.     

Whooping cough: biological diagnosis]

Whooping cough is a respiratory infection particularly severe for infants. The agents of the disease are the bacteria Bordetella pertussis and B. parapertussis. Before vaccination, the disease affected majority of the children. Due to the high circulation of the bacteria, adolescents and adults were regularly in contact with the bacteria and had natural boosters. Forty years after generalized vaccination in some countries, a change in the transmission of the disease is observed. Children between 2 and 5-10 years of age are not infected (depending of the vaccine used and the vaccine calendar) because they were vaccinated in their infancy. However, adolescents and adults are becoming susceptible because they do not receive any vaccinal or natural boosters. They can be infected and contaminated infants are too young to be vaccinated. Clinical symptoms in adolescents and adults, previously vaccinated or infected, are very variable and for this reason biological diagnosis are now necessary to confirm the infection. These diagnostics are culture, PCR and serology.     

Action to be taken when facing one or more cases of whooping-cough]

The evolution of the epidemiology of pertussis, new licensed macrolides and vaccines, new recommendations for vaccination among adolescents and adults need an update of the French guidelines for prevention of the disease around one or grouped cases of the disease. A particular attention should be raised to the diagnosis of whooping cough in adults who are presently the main reservoir of Bordetella pertussis. Whooping cough in adults presents as an unexplained prolonged cough with nocturnal exacerbation witch accounts for most of the contaminations of young infants. A bacteriological confirmation of pertussis should be provided before implementation of preventive measures: culture and PCR are presently the gold standard for the diagnosis of pertussis in infants, children and even adults who have been coughing for less than 20 days. Later on, serology (Elisa, immuno-empreinte) is the only technique available, but cannot be interpreted if the patient has been vaccinated less than one year ago. Infants under three months should be admitted to hospital and every case submitted to respiratory isolation. Eviction from the community should be pronounced within the five first days following the onset of an effective antibiotic treatment. New macrolides should be favoured: clarithromycin for seven days or azithromycin for five days. Household contacts should be given the same prophylactic antibiotic treatment: children and adolescent not correctly immunized, parents of the index case as adults parents of not or not completely immunized infants. The vaccination program of the household should be updated. The same measures should be applied in case of grouped cases (at least two contemporary or consecutive cases in the same area). In that case, the Public Health System doctors should be involved in the investigation and the classification of the cases. The close contacts not or not completely immunized should be prescribed and antibiotic prophylaxis and an update of their vaccination program. Among the occasional contacts, high-risk people only should be treated. In the day care centres an antibiotic prophylaxis should be given to children who have received less than four vaccine shots against pertussis and to the personnel contact to the cases as well. In the schools, the antibiotic prophylaxis should be prescribed to all children of the classroom(s) not completely vaccinated and to the teacher(s) as well. In the boarding schools and institutions with handicapped children, antibiotic prophylaxis could be applied to every member if the pertussis vaccine coverage is at less than 50%. In hospitals, coughing personnel should wear masks and investigations towards pertussis should be performed in people with a more than seven day unexplained cough. Preventive measures should be applied in case of confirmation of pertussis.     

Pertussis in infants, children, and adolescents: diagnosis, treatment, and prevention

Pertussis, or "whooping cough," caused by the gram-negative pleomorphic bacillus Bordetella pertussis, is a highly contagious, potentially life-threatening respiratory tract illness that has re-emerged worldwide as a cause of substantial morbidity and mortality in infants, children, and adolescents, despite high vaccination rates. Increased awareness and reporting, in addition to the availability of better diagnostic tests, partially explain the recent resurgence of pertussis. However, waning immunity after childhood immunization has resulted in a growing pool of susceptible adolescents and adults who are capable of transmitting pertussis to vulnerable unvaccinated or incompletely vaccinated infants. An acellular pertussis vaccine booster for adolescents has been recommended in the United States and other industrialized countries. Active immunization and early diagnosis are crucial in the management of pertussis.     

The epidemiology of pertussis: a comparison of the epidemiology of the disease pertussis with the epidemiology of Bordetella pertussis infection

In the prevaccine era pertussis epidemics followed a cyclic pattern, with peaks every 2 to 5 years. With the marked reduction of pertussis by vaccination, the same cyclic pattern still occurs. Studies relating to reported pertussis and Bordetella pertussis infection have been reviewed and analyzed. The increase in reported pertussis over the last 2 decades is mainly due to a greater awareness of pertussis and perhaps to the use of several less efficacious vaccines. Studies of prolonged cough illnesses in adolescents and adults reveal that 13% to 20% are a result of B pertussis infection. Serologic studies suggest that the rate of B pertussis infection in adolescents and adults is approximately 2.0% per year. The rate of cough illnesses (pertussis) caused by B pertussis infection in adolescents and adults is between 370 and 1500 per 100,000 population. These data suggest that there are between approximately 800,000 and 3.3 million cases per year in the United States. The coming availability of adolescent- and adult-formulated diphtheria and tetanus toxoids and acellular pertussis vaccines for adolescents and adults and their widespread use should reduce the reservoir of B pertussis disease. It is suggested that a universal program of adolescent and adult boosters would decrease the circulation of B pertussis in these age groups and possibly could lead to the elimination of the organism from the population.     

Impact of a pertussis booster vaccination program in adolescents and adults on the epidemiology of pertussis in Austria

BACKGROUND: A resurgence of pertussis has been observed in several countries; however, inconsistent data are available for Europe. In Austria, routine pertussis vaccination for babies is administered at 3, 4, and 5 months, and in the second year of life. Since 2002, regular boosters for all persons >6 years of age (including adults) are recommended. This study was undertaken to analyze epidemiologic trends of laboratory-reported pertussis to evaluate current vaccination strategy in Austria. METHODS: Epidemiologic surveillance of laboratory-reported pertussis was conducted from January 1, 2000, to December 31, 2005. Infection was confirmed by positive serology, by positive culture of Bordetella pertussis, or by detection of sequences of the pertussis toxin gene by real-time polymerase chain reaction (RT-PCR). Data were assessed by age, hospitalization rate, seasonality, and incidence rate. RESULTS: During the observation period 4395 reported cases of pertussis were eligible for analysis. The mean annual incidence increased from 6.4 per 100,000 population in 2000 to 11.1 cases per 100,000 population in 2005. Incidence rates were highest among children less than 1 year of age. Decreasing rates were observed for children and adolescents <16 years of age, whereas increasing rates were detected for persons 16 years of age and older. The mean age of reported pertussis cases increased from 30 years (+/-25.9 SD) in 2000 to approximately 44 years (+/-23.7 SD) in 2005. Hospitalization rates were highest in infants <6 months (86%) and lowest in those 10 to <50 years of age (17%), followed by an increase to 80% in persons 85 years of age and older. In general, no seasonal occurrence of disease was apparent. CONCLUSIONS: Pertussis incidence remains high among adults implying that coverage rates regarding booster vaccinations for adolescents and adults still are too low. Reinforced application of the current booster strategy is needed.     

婴儿百日咳的流行病学意义及其临床特点

婴儿百日咳是社区百日咳持续传播的明确证据。婴儿是百日咳健康威胁最严重的群体,也是百日咳社区网状传播的重要节点,预防婴儿百日咳是疫苗免疫等防控措施的核心。目前国内报道百日咳虽然以婴儿百日咳病例为主,但实际发生的婴儿百日咳病例更多,临床上还需提高警惕和加强认识,普及相关实验室检测。在重视识别婴儿百日咳的基础上,及时诊治、随访观察和规范管理百日咳患儿的密切接触者,才能减少和阻断百日咳的社区传播。[中国当代儿科杂志,2022,24 (9):955-959]     

百日咳再现及其原因研究进展

百日咳再现原因复杂,与疫苗免疫效力持久性不足、疫苗接种策略差异、流行病学特征改变、抗生素耐药、百日咳鲍特菌的变异、诊断标准的改进及监测系统的完善度等因素均有关。疫苗接种后,由于自然感染病例减少,导致当前百日咳流行规律已经发生改变。由于人群群体免疫水平下降,经母体胎传给新生儿的血清抗体滴度降低,导致未接种疫苗的婴儿早期免疫水平不足,1岁以下的婴儿易出现重症病例。由于疫苗免疫效力并不持久,儿童、青少年也是百日咳的易感人群,感染后表现以慢性咳嗽较为常见,成人病例可因症状不典型或隐匿性感染难以引起重视,成为婴儿感染的传染源。为了加强百日咳的诊治能力,有必要改进诊断标准、关注细菌变异与耐药、加强百日咳的监测、寻求更为优化的免疫接种策略及进行新疫苗的开发。现就当前百日咳再现原因进行综述,以期为国内百日咳防控提供参考。     

Adolescent and adult pertussis: disease burden and prevention

PURPOSE OF REVIEW: According to surveillance data provided by the Centers for Disease Control and Prevention, the rates of pertussis disease in adolescents and adults have been increasing. This is likely due to increased recognition and waning vaccine-induced immunity. RECENT FINDINGS: The presentation of pertussis in adolescents and adults is generally a persistent cough, but more serious complications have been reported. In addition, adolescents and adults often serve as sources of pertussis infection in infants and young children. SUMMARY: Acellular pertussis vaccines combined with diphtheria and tetanus toxoids have proven to be well tolerated, immunogenic and effective in reducing pertussis disease in adolescents and adults. These vaccines are currently being recommended to replace the booster diphtheria and tetanus toxoid vaccines in adolescents. Recommendations for the use of these vaccines in adults are still being formulated.     

Rationale for use of Tdap booster vaccines for adolescent immunization: overview of efficacy, safety, and clinical use

Pertussis is one of the only vaccine-preventable diseases with increasing incidence in the United States. The incidence of pertussis infection in adolescents is a growing concern; it can be a severe disease that may lead to significant morbidity and mortality when transmitted to susceptible populations (eg, infants). Experts have conceded that booster vaccination of adolescents may considerably decrease the incidence of pertussis infections in previously immunized, partially immunized, and nonimmunized populations. Studies in 2 tetanus, diphtheria, and acellular pertussis (Tdap) booster vaccines licensed by the Food and Drug Administration (FDA) have shown efficacy against pertussis disease and have demonstrated a safety profile comparable to tetanus and diphtheria vaccine (Td) in adolescents. Immunization schedules now include use of Tdap vaccines for preadolescent and adolescent populations to counter the increase in pertussis outbreaks. Challenges for clinicians include prompt recognition of pertussis symptoms, proper diagnosis using appropriate tools, and timely reporting of pertussis infections to surveillance bodies. Additional studies are needed to monitor trends of pertussis incidence after implementing the new vaccination schedule for adolescents.     

Enquête sur le statut vaccinal des parents de jeunes nourrissons

Since 2004, in France, pertussis booster is recommended in parents of young infants and adults likely to become parents. This recommendation adds to others such as rubella vaccination in unvaccinated or seronegative women and decennial dT-IPV booster. The objective of this study is to evaluate the impact of these recommendations in parents of young infants. Pediatricians had to include parents of infants at the first well-baby visit after birth. Vaccination data were secondary recorded from parent's health record or called upon their memory. Between June and October 2006, 41 pediatricians included parents of 400 infants (median age: 36 days). dT-IPV booster was recorded or recalled in 37.4% within the 10 previous years and 17.7% within the 3 previous years. Among this last group, only 11.8% had received a combination including pertussis. Rubella serology was declared as positive by 94% of the mothers, but the physicians obtained the information of a previous rubella vaccination in only 71.7% of the mothers. Among the 9 seronegative mothers during pregnancy, only 3 were vaccinated in postpartum. Adults' immunization guidelines are not well known and poorly applied in France. The unavailability of monovalent pertussis vaccine reduces the eligible population. Two years after the launch of the pertussis cocoon strategy, the coverage of eligible young parents remains low and many opportunities are too frequently missed on the opportunity of decenial dTPolio booster. Rubella catch up strategy should be improved. Adults' vaccination strategies and guidelines need to be better broadcasted to health care professionals and also families.     

National study of infants hospitalized with pertussis in the acellular vaccine era

BACKGROUND: In Australia in 1999 acellular pertussis vaccine (DTPa) replaced locally manufactured whole cell vaccine given at 2, 4 and 6 months of age with coverage of about 95% by 12 months of age. Few data are available on pertussis hospitalizations or sources of infection in countries exclusively using DTPa. METHODS: In 2001 national active monthly surveillance of infant hospitalizations for pertussis was conducted through the Australian Pediatric Surveillance Unit, which surveys all child health specialists monthly. A standard questionnaire was completed for notified cases. RESULTS: There were 140 infants reported (median age at diagnosis, 8 weeks). The rate of hospitalization in indigenous infants was significantly higher than in nonindigenous infants (P < 0.01). Of 97 (69%) infants who had not been vaccinated for pertussis, 63 (65%) were <8 weeks old (before the first scheduled dose of DTPa vaccine). Of 76 infants age > or =8 weeks, only 28 (37%) were appropriately immunized for age. Of 68 coughing contacts whose ages were known, 46 (68%) were adults, usually one of the infant's parents. Of 32 child contacts 16 (50%) were siblings. Four infants <6 weeks old died. CONCLUSION: Despite universal vaccination with DTPa in Australia, pertussis remains an important cause of hospitalization, morbidity and death in infants, most of whom were too young to be vaccinated or had missed vaccinations. The most common source of infection was a parent. Strategies to improve pertussis control in countries with high DTPa coverage could include adult-formulated booster pertussis vaccines for adolescents and recent parents and/or accelerated pertussis vaccine schedules for infants.     

Pertussis outbreak in an elementary school with high vaccination coverage.

BACKGROUND: An outbreak of pertussis in a US elementary school with high vaccination coverage was investigated to evaluate vaccine effectiveness and to identify potential contributing factors. METHODS: Survey and cohort study of all 215 students of an elementary school (including 36 case patients) and 16 secondary cases among contacts. RESULTS: Fifty-two pertussis cases were identified (attack rate among students, 17%). Receipt of <3 doses of pertussis-containing-vaccine compared with receipt of complete vaccination series was a significant risk factor for pertussis [relative risk, 5.1; 95% confidence interval (CI), 3 to 8.6]. The effectiveness of the complete vaccination series was 80% (95% CI 66 to 88). No evidence of waning immunity among students was found. The following contributing factors for the outbreak were identified: multiple introductions of pertussis from the community; delays in identification and treatment of early cases; and high contact rates among students. Antimicrobial treatment initiated >14 days after cough onset was associated with increased risk of further transmission of pertussis (relative risk, 10.1; 95% CI 1.5 to 70.3) compared with treatment within 14 days of onset. CONCLUSIONS: This investigation demonstrated the potential for pertussis outbreaks to occur in well-vaccinated elementary school populations. Aggressive efforts to identify cases and contacts and timely antimicrobial treatment can limit spread of pertussis in similar settings. High vaccination coverage should be maintained, because vaccination significantly reduces the risk of the disease throughout the elementary school years, and to ensure timely diagnosis and treatment health care providers should maintain a high index of suspicion for pertussis among elementary school age children.     

百日咳的临床研究进展

百日咳是一种传染性极强的呼吸道传染病。近20年来,许多疫苗高覆盖率的国家出现了“百日咳再现”。百日咳发病率上升的同时,出现了新的流行特征,即年长儿和成人百日咳患病率逐渐上升,他们往往缺乏典型的临床表现,按照现有的百日咳临床诊断标准必定会漏诊大部分患者。该综述就百日咳的流行病学、临床特点、病原学、诊断、治疗、预防现状进行总结,强调对年长儿和成人百日咳患者的识别,提高百日咳的防治水平。     

Prospective multinational study of pertussis infection in hospitalized infants and their household contacts

BACKGROUND: Increased incidence of pertussis has been noted among infants too young to be immunized. We studied the disease burden of pertussis in pediatric intensive care units and the source of infection in several Asian, European and Latin American countries. METHODS: The study was conducted in 7 countries from September 2001 to January 2004. Children <1 year of age were enrolled from pediatric intensive care units (PICU) and pediatric wards if they presented with respiratory failure, apnea, bradycardia, or cough accompanied by paroxysms, vomiting, whoop or cyanosis. Household members of pertussis-positive index cases were asked to answer a questionnaire and provide diagnostic specimens. RESULTS: Pertussis was confirmed in 99 infants (12%) of 823 infants included in the analysis: 10 of 90 (11%) in Brazil, 9 of 88 (10%) in Costa Rica, 11 of 145 (8%) in Germany, 13 of 147 (9%) in Singapore, 29 of 67 (43%) in Spain, 2 of 86 (2%) in Taiwan and 25 of 200 (13%) in Uruguay. However, sensitivity analysis indicated that these figures were conservative. The mean (+/- SD) average age of infection was 2.6 +/- 2.2 months. Pertussis was found among 96 of 269 (36%) of household contacts investigated. At least one household contact was identified as the source of infection in 24 of 88 (27%) of the PICU cases and mothers were identified as being the most frequent source of infection. CONCLUSION: Although regional differences exist, severe pertussis represents a considerable global disease burden. Since most infants are infected before vaccination and concomitant protection is completed, household contacts should be targeted for booster vaccination to reduce the pertussis reservoir.     

Update on adolescent immunization: review of pertussis and the efficacy, safety, and clinical use of vaccines that contain tetanus-diphtheria-acellular pertussis.

Adolescents, who comprise 14% of the US population, are historically resistant to receiving health care. As a result, adolescents have low immunization rates and are becoming more susceptible to diseases that are preventable by vaccine, such as pertussis. The incidence of pertussis has increased during the past 25 years, with a notable shift in incidence from young children to adolescents and young adults. New vaccines that provide protection against pertussis for use in adolescents have been proven to be safe, effective, and cost-beneficial. Regional epidemics among infants and other vulnerable populations can be reduced or eliminated with improved immunity in adolescents.     

Case-control study of vaccination history in relation to pertussis risk during an outbreak among school students

BACKGROUND: Between September and December 2003, an outbreak of pertussis occurred in Cass County, MO, mostly among adolescent school children. METHODS: We conducted a 1:2 matched case-control study among school children and used conditional logistic regression to evaluate risk factors for pertussis, including the total number of vaccine doses received, age at administration of each dose of vaccine and the type of vaccine (whole cell or acellular). RESULTS: Of all 127 pertussis cases reported in this outbreak, the majority were adolescents (10-19 years of age, 50%) and adults (20 years or older, 22%); only 10% were infants and children less than 5 years of age. Because the focus of our investigation was on school-aged children, we enrolled 237 students (79 cases and 158 controls) in our study. Students missing at least one dose of the vaccine had higher risk for pertussis than those who received all 5 doses (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.17-4.77). Early administration of the fifth dose of the vaccine at age 4 years was significantly associated with risk for pertussis compared with vaccination at age 5 years (adjusted OR, 2.45; 95% CI, 1.16-5.16). A short time interval (<36 months) between the fourth and fifth doses of the vaccine also tended to increase the risk for pertussis, although this association was not statistically significant. The type of vaccine was not a significant risk factor. CONCLUSION: Administering all 5 doses of pertussis vaccine and the fifth dose at age 5 years with at least 36 months between the fourth and fifth doses provided the best protection against pertussis among children and adolescents in this outbreak.     

Infant pertussis: who was the source?

BACKGROUND: In the United States in the 1990s, the incidence of reported pertussis in adults, adolescents and infants increased; infants younger than 1 year of age had the highest reported incidence. METHODS: In 4 states with Enhanced Pertussis Surveillance, we examined the epidemiology of reported pertussis cases to determine the source of pertussis among infants. A source was defined as a person with an acute cough illness who had contact with the case-infant 7-20 days before the infant's onset of cough. RESULTS: The average annual pertussis incidence per 100,000 infants younger than 1 year of age varied by state: 22.9 in Georgia; 42.1 in Illinois; 93.0 in Minnesota; and 35.8 in Massachusetts. Family members of 616 (80%) of 774 reported case-infants were interviewed; a source was identified for 264 (43%) of the 616 case-infants. Among the 264 case-infants, mothers were the source for 84 (32%) and another family member was the source for 113 (43%). Of the 219 source-persons with known age, 38 (17%) were age 0-4 years, 16 (7%) were age 5-9 years, 43 (20%) were age 10-19 years, 45 (21%) were age 20-29 years and 77 (35%) were age > or =30 years. CONCLUSIONS: The variation in reported pertussis incidence in the 4 states might have resulted from differences in awareness of pertussis among health care providers, diagnostic capacity and case classification. Among case-infants with an identifiable source, family members (at any age) were the main source of pertussis. Understanding the source of pertussis transmission to infants may provide new approaches to prevent pertussis in the most vulnerable infants.