[Research progress on the mechanism of -lactam resistance in group A Streptococci in vivo]. / Aæ—é“¾çƒèŒä½“å† è€å—-å† é °èƒºç±»è¯ç‰©çš„æœºåˆ¶ç ”ç©¶è¿›å±•.

-lactams, including penicillin, have been used for over 80 years in the treatment of group A Streptococcus (GAS) infections. Although -lactam-resistant GAS strains have not been identified in vitro tests, clinical treatment failures have been reported since the 1950s. The mechanism underlying the clinical failure of -lactam treatment in GAS infections remains unclear. Previous research has suggested that -lactam resistance in GAS in vivo is associated with reduced drug susceptibility of strains, bacterial inoculation effects, biofilm formation, the effect of coexisting bacteria, bacterial persistence, and bacterial internalization into host cells. This article reviews the main reports on -lactam treatment failure in GAS infections and analyzes the possible mechanisms of -lactam resistance in vivo. The findings aim to contribute to future research and clinical approaches in the field.

[Recent research on the epidemiology and preventive strategies of neonatal group B Streptococcus infection in the latest decade]. / 新生儿Bæ—é“¾çƒèŒæ„ŸæŸ“æµè¡Œç— å­¦å’Œé¢„é˜²ç­–ç•¥è¿‘åå¹´æ¥çš„ç ”ç©¶è¿›å±•.

Currently, the main strategy for preventing neonatal group B Streptococcus (GBS) infection is prenatal screening combined with intrapartum antibiotic prophylaxis, which has effectively reduced the incidence of neonatal GBS early-onset disease. However, the burden of GBS infection is still significant. The intrapartum antibiotic prophylaxis strategy has limitations such as inducing antibiotic resistance and inability to effectively prevent GBS late-onset disease. It is crucial to develop and evaluate other prevention strategies, while paying close attention to assessing penicillin allergy in pregnant women and how to prevent GBS infection in neonates with negative maternal GBS screening. In recent years, there has been some progress in GBS vaccines and related immunological research, and the use of specific vaccines is expected to significantly reduce GBS infection in neonates.

[Paying attention to the epidemic of group A Streptococcus infections in multiple European and American countries]. / å ³æ³¨æ¬§ç¾Žå¤šå›½Aæ—é“¾çƒèŒæ„ŸæŸ“ç–«æƒ .

At the end of 2022, the World Health Organization reported an increase in group A Streptococcus (GAS) infections, such as scarlet fever, in multiple countries. The outbreak primarily affected children under 10 years old, and the number of deaths was higher than anticipated, causing international concern. This paper reviews the current state of the GAS disease outbreak, its causes, and response measures. The authors aim to draw attention from clinical workers in China and increase their awareness and vigilance regarding this epidemic. Healthcare workers should be aware of the potential epidemiological changes in infectious diseases that may arise after the optimization of control measures for coronavirus disease 2019 to ensure children's health.

Clinical characteristics, antimicrobial resistance, and risk factors for mortality in paediatric invasive pneumococcal disease in Beijing, 2012-2017.

BACKGROUND: To analyse clinical characteristics, antibiotic susceptibility, and risk factors for mortality in paediatric invasive pneumococcal disease (IPD) in Beijing. METHODS: Paediatric IPD patients in our hospital were retrospectively collected from 2012 to 2017. Clinical manifestations, laboratory tests, antimicrobial susceptibility and serotype of isolates, and risk factors for mortality of IPD were analysed. RESULTS: Overall, 186 IPD cases were enrolled. The major manifestations were meningitis (76), pneumonia with bacteraemia (60), bacteraemia without focus (21), and pneumonia with empyaema (22). Of 72 cases with underlying diseases, leukaemia (18.0%), congenital heart disease (15.3%), primary immunodeficiency disease (12.5%), nephrotic syndrome (12.5%), and cerebrospinal fluid leakage (12.5%) were most common. In total 96.9% of isolates would have been covered by the pneumococcal conjugate vaccine (PCV13), including 19F (32.8%), 19A (23.4%), 4 (17.2%), and 23F (9.4%). Nonsusceptibility rates of penicillin, cefotaxime, and cefepime among nonmeningitis patients increased between 2012 and 2017; The mortality rate was 21.5%. Meningitis, respiratory failure, multiple organ failure, and white blood cell count < 4000 cells/µL were independent risk factors for mortality. CONCLUSION: Meningitis was the most common clinical manifestation of IPD, and was frequently associated with death. Strains in the PCV13 vaccine would cover most of the cases, and so wider use of PCV13 should be considered.

Identification and molecular epidemiology of routinely determined Streptococcus pneumoniae with negative Quellung reaction results.

BACKGROUND: Some streptococci strains identified as Streptococcus pneumoniae (S. pneumoniae) by routine clinical methods exhibiting negative Quellung reaction results may belong to other species of viridans group streptococci or non-typeable S. pneumoniae. The purpose of this study was to investigate the identification and molecular characteristics of S. pneumoniae with negative Quellung reaction results. METHODS: One hundred and five isolates identified as S. pneumoniae using routine microbiological methods with negative Quellung reaction results were included. Multilocus sequence analysis (MLSA) was used as a gold standard in species identification, and the capacity of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) in identification was evaluated. Capsular genes and sequence types of S. pneumoniae isolates were determined by sequential multiplex PCR and multilocus sequence typing. Antimicrobial susceptibility patterns were determined via broth microdilution with a commercialized 96-well plate. RESULTS: Among the isolates, 81 were identified as S. pneumoniae and 24 were S. pseudopneumoniae by MLSA. MALDI-TOF MS misidentified six S. pneumoniae isolates as S. pseudopneumoniae and nine S. pseudopneumoniae isolates as S. pneumoniae or S. mitis/S. oralis. Thirty-one sequence types (STs) were detected for these 81 S. pneumoniae isolates, and the dominant ST was ST-bj12 (16, 19.8%). The non-susceptibility rates of S. pseudopneumoniae were comparable to those of NESp strains. CONCLUSIONS: Some S. pneumoniae isolates identified by routine methods were S. pseudopneumoniae. Most NESp strains have a different genetic background compared with capsulated S. pneumoniae strains. The resistance patterns of S. pseudopneumoniae against common antibiotics were comparable to those of NESp.

[Learning from the past: the history of human monkeypox and the atypical multi-country outbreak in 2022]. / çŸ¥å¾€é‰´ä»Šï¼šäººæ„ŸæŸ“çŒ´ç—˜å²åŠå ¶éžåŒå¯»å¸¸çš„2022å¹´å¤šå›½æš´å‘ç–«æƒ .

In 2022, the outbreak of human monkeypox (HMPX) occurred in many non-endemic countries. World Health Organization (WHO) assesses that this outbreak is "atypical". The history of monkeypox and HMPX must be reviewed to clearly recognize the "typical" outbreaks to fully understand this comment. Therefore, this paper reviews the epidemiological history of monkeypox, especially HMPX, and discusses and analyzes the atypical manifestations and the possible causes of the present outbreak based on the recent views of WHO, other organizations/institutions, and experts. The text describes the thought-provoking history of the interaction between the monkeypox virus and the human being in the past 64 years, and provides various information and views on the outbreak of HMPX, which is helpful to understand risk assessment and the potential impact of this outbreak on clinical and public health in future.

[Interpretation of "Clinical Considerations for Monkeypox in Children and Adolescents" released by the US Centers for Disease Control and Prevention]. / ç¾Žå›½ç–¾ç— é¢„é˜²å’ŒæŽ§åˆ¶ä¸­å¿ƒå‘å¸ƒçš„ã€Šå„¿ç«¥å’Œé’å°‘å¹´çŒ´ç—˜çš„ä¸´åºŠæ³¨æ„äº‹é¡¹ã€‹è§£è¯».

In order to cope with monkeypox in children and adolescents, the US Centers for Disease Control and Prevention released "Clinical Considerations for Monkeypox in Children and Adolescents", which is specially written for pediatric health workers serving children and adolescents under the age of 18 years to standardize the clinical management of children and adolescents with exposure to monkeypox (human monkeypox or animal monkeypox) or with suspected or confirmed monkeypox. This document highlights the characteristics of children and adolescents and gives some valuable suggestions to the special issues in pediatric clinical practice, and it is worth studying by pediatric health workers who are preparing for a possible epidemic of monkeypox.

[The investigation on the acute, severe hepatitis of unknown origin in children]. / å„¿ç«¥ä¸æ˜ŽåŽŸå› æ€¥æ€§ä¸¥é‡è‚ç‚Žç— ä¾‹è°ƒæŸ¥è¿›å±•.

In April 2022, the United Kingdom notified the World Health Organization (WHO) of an unexpected increase of acute hepatitis of unknown origin in children. Subsequent investigations have found more than 400 cases in more than 20 countries and regions around the world. Although the potential role of adenovirus type 41 in the pathogenesis of these cases is one hypothesis, but it is probably not the only pathogenic factor, and other infectious and non-infectious causes cannot be completely ruled out. For hepatitis caused by non-hepatitis A, B, C, D and E viruses, there is a lack of systematic monitoring and research, and many unknowns still exist. According to the current etiology speculation and epidemiological characteristics of adenovirus in China, cases of acute hepatitis with unknown origin may be found in China in the future. There is also a risk of imported cases. This article systematically sorts out the reports and studies on child acute hepatitis of unknown origin, hoping to attract the attention of pediatric clinicians in China, raise awareness and vigilance, and calmly prepare for possible abnormal situations.

Clinical characteristics and epidemiological significance of coronavirus disease 2019 in children and adolescents. / 儿童和青少年2019å† çŠ¶ç— æ¯’ç— çš„ä¸´åºŠè¡¨çŽ°åŠæµè¡Œç— å­¦æ„ä¹‰.

The epidemic of coronavirus disease 2019 (COVID-19) started in late December 2019, and spread rapidly throughout the world. In March 2020, the World Health Organization (WHO) declared global epidemic of COVID-19. According to the American Academy of Pediatrics, nearly 13 million children have been diagnosed with COVID-19 since the outbreak. In general, children and teens have milder symptoms and fewer deaths from COVID-19 than adults. Understanding the symptoms, infectivity, and transmission patterns of COVID-19 in children and adolescents is of great significance for timely identifying suspected patients and developing effective control measures. Considering that some children will not be vaccinated for quite some time in the future, it is more important to improve the understanding of the clinical and epidemiological significance of COVID-19 in children and adolescents. This article summarizes the current understanding of the clinical manifestations and epidemiological significance of COVID-19 in children and adolescents to provide a reference for clinical diagnosis and treatment and the formulation of epidemic prevention and control strategies in children's gathering institutions such as kindergartens and schools.

[Clinical features and epidemiological significance of pertussis in infants]. / å©´å„¿ç™¾æ—¥å’³çš„æµè¡Œç— å­¦æ„ä¹‰åŠå ¶ä¸´åºŠç‰¹ç‚¹.

Infantile pertussis is clear evidence for the persistent transmission of pertussis in communities. Infants are the most vulnerable population for pertussis infection and are also important nodes in pertussis transmission networks in communities, and therefore, the prevention of infantile pertussis is the core of prevention and control measures against pertussis including vaccine immunization. Although the cases of pertussis reported in China are mainly infants with pertussis, the actual number of infants with pertussis might be higher than the reported number. It is necessary in clinical practice to improve the awareness of this disease and promote related laboratory tests. On the basis of emphasizing the identification of pertussis in infants, timely diagnosis and treatment, follow-up visits, and standard management of the close contacts of infants with pertussis should be performed to reduce and block the community transmission of pertussis.

[Diagnosis and treatment of human monkeypox]. / 人感染猴痘的诊断和治疗.

The guideline for the diagnosis and treatment of monkeypox (2022 edition) issued by National Health Commission of the People's Republic of China introduces the key knowledge of the diagnosis and treatment of human monkeypox (HMPX) and does not systematically introduce the sampling methods and requirements of specimens for HMPX etiology testing and the discrepancy in diagnostic criteria between China and overseas. However, the doctors who are not engaged in dermatology lack understanding of the sampling methods and requirements of specimens for laboratory diagnosis of HMPX, and there are few relevant references available. This article collects the information on the diagnosis and treatment of HMPX, so as to provide a reference for learning, understanding, and application of this guideline.

Molecular characteristics of the new emerging global clone ST1193 among clinical isolates of Escherichia coli from neonatal invasive infections in China.

Sequence type 1193 (ST1193) constitutes an emerging fluoroquinolone-resistant Escherichia coli clone in several countries. However, reports of such isolates in neonatal invasive diseases are limited. Here, we assessed the antimicrobial resistance and molecular characteristics of E. coli ST1193 isolates causing neonatal bloodstream infections and meningitis in China. A total of 56 E. coli isolates were collected from neonatal blood and cerebrospinal fluid between September 2009 and June 2015. Antimicrobial susceptibility was evaluated using E-test methods. Polymerase chain reaction amplification was used to detect antibiotic resistance genes including blaTEM, blaSHV, and blaCTX-M groups. Molecular typing was performed via multi-locus sequence typing. Among 56 E. coli isolates, 17 (17/56, 30.4%) were extended-spectrum ß-lactamase (ESBL) producers, and 37(37/56, 66.1%) were multidrug-resistant. The most frequent sequence types were ST1193 (12/56), followed by ST95 and ST62. ST1193 isolates exhibited a 91.7% resistance rate to ciprofloxacin, amoxicillin, and sulfonamides, and 83.3% resistance rate to tetracycline. A total of 4 (33.3%) among the 12 ST1193 isolates were ESBL producers, of which three carried both blaCTX-M-15 and blaTEM genes with the remaining isolate harboring blaCTX-M-27 and blaTEM genes. Additionally, 1 of the 3 ST1193 isolates obtained from cerebrospinal fluid was an ESBL producer that carried both blaCTX-M-15 and blaTEM genes. This study revealed for the first time the molecular characteristics of E. coli ST1193 causing neonatal invasive diseases in China. Notably, we found that ST1193 isolates were multidrug-resistant. Further multicenter studies are needed to assess the molecular epidemiology of ST1193 in China to control its spread.

Clinical characteristics and serotype distribution of invasive pneumococcal disease in pediatric patients from Beijing, China.

Invasive pneumococcal disease (IPD) is associated with significant morbidity and mortality. However, limited studies have reported clinical features of IPD cases among Chinese children. This study aimed to evaluate clinical characteristics as well as serotype distribution of hospitalized IPD children in Beijing, China. Children with confirmed IPD were retrospectively recruited from January 2014 to December 2019. Clinical data were gathered from medical records, and serotypes of Streptococcus pneumoniae isolates were detected. Clinical differences between deaths and survivors were also compared, and risk factors associated with death were determined. Of sixty-eight children diagnosed with IPD, 58 (85.3%) were < 5 years. 19F was the predominant serotype (23, 33.8%), followed by 19A (14, 20.6%), 14 (12, 17.6%), 23F (5, 7.4%), and non-vaccine serotype (NVT) 15A (3, 4.4%). The coverage rate of 13-valent pneumococcal conjugate vaccine (PCV) was 92.6% (63). After introduction of PCV-13, there was a significant increase of IPD due to NVTs (p = 0.047). Sixteen (23.5%) children died, and diagnoses of 11 (68.8%) were meningitis. Risk factors for death were < 2 years (odds ratio [OR] [95% confidence interval {CI}]: 6.64 [1.14-32.10]; p = 0.019), altered mental status (OR [95%CI]: 10.10 [2.11-48.31]; p = 0.004), and septic shock (OR [95%CI]: 6.61 [1.11-39.50]; p = 0.038). This study revealed that the case fatality rate of hospitalized IPD children was high in this hospital. Fatal cases were more likely to be children < 2 years, presented with changed mental status and septic shock. Notably, we found that NVTs increased after PCV13 availability in China.

[Research advances in the treatment strategies for severe pertussis in children].

At present, effective antibiotics and comprehensive symptomatic/supportive treatment as early as possible are mainly used for the treatment of severe pertussis in clinical practice. However, some children with severe pertussis have unsatisfactory response to commonly used drugs and treatment measures in the intensive care unit and thus have a high risk of death. Studies have shown that certain treatment measures given in the early stage, such as exchange transfusion, may help reduce deaths, but there is still a lack of uniform implementation norms. How to determine the treatment regimen for severe pertussis and improve treatment ability remains a difficult issue in clinical practice. This article reviews the advances in the treatment of severe pertussis, in order to provide a reference for clinical treatment and research.

Abundance of the nasopharyngeal microbiome effects pertussis diagnosis and explains the sensitivity difference between bacterial culture and real-time PCR.

Quantitative real time PCR (qPCR)is used for pertussis diagnosis. The positive rate of qPCR is generally much higher than that of bacterial culture, which may cause confusion. The current study utilized the 16S ribosomal RNA (16S rRNA) sequencing to assess the correlation between conventional culture and qPCR and to explore the value of 16S rRNA in diagnosing pertussis. Nasopharyngeal swabs, collected from 102 children meeting clinical diagnostic criteria for pertussis, were subjected to Bordetella pertussis culture and qPCR. Bioinformatic microbiota analysis was based on 16S rRNA V3-V4 gene sequencing. Among 102 samples, 14 (13.7%) were culture-positive for Bordetella pertussis, while 61 (59.8%) were qPCR positive. Genus Bordetella was identified in 68 (66.7%) samples via 16S rRNA sequencing. When the relative abundance of Bordetella genus exceeded 0.70%, both qPCR and culture results were positive. Samples with a relative abundance of less than 0.20% exhibited positive qPCR and negative culture results. Samples with a low Bordetella abundance are the key factors underlying poor correlation between culture and qPCR results in laboratory tests.

Widespread of non-typeable Haemophilus influenzae with high genetic diversity after two decades use of Hib vaccine in China.

BACKGROUND: The aim of this study was to analyze the microbiological characteristics of nasopharyngeal carriage Haemophilus influenzae isolates collected from children with respiratory infections in Beijing hospital and Youyang Hospital of China. METHODS: The serotypes of all isolates were determined using latex agglutinated antisera (a-f). The minimum inhibitory concentrations (MICs) of 11 antibiotics were determined using E-test strips. For the beta-lactamase-negative ampicillin-resistant (BLNAR) isolates, ftsI gene was sequenced based on fragments amplified by PCR. STs of H influenzae isolates were determined by multi-locus sequence typing. RESULTS: The overall carriage rate of H influenzae in the study population was 9.1% (362/3984). One hundred and ninety H influenzae isolates which were selected in our study were non-typeable (NTHi) and 44 (23.2%) of them were positive for ß-lactamase. All isolates were susceptible to ceftriaxone and levofloxacin. Susceptibility rates to erythromycin and sulfamethoxazole-trimethoprim in Beijing were significantly higher than Youyang (P < .05). Thirty-six BLNAR isolates were identified. The MLST analysis showed 108 STs in 190 isolates, the most common of which were ST408 (11, 5.8%), ST914 (10, 5.3%), ST57 (9, 4.7%), and ST834 (6, 3.2%). Twelve STs were detected in both of the study sites, which covered 63 isolates. CONCLUSIONS: All isolates in the present study were NTHi, which suggested widespread of this type in China. The BLNAR isolates were detected more frequently than before. Because high genetic diversity of NTHi isolates of H influenzae exists worldwide, it is important to continuously monitor these bacteria in the future.

[A comparative analysis of the Chinese and English descriptions of typical pertussis manifestations and recommendations for the diagnosis of pertussis-like or pertussis syndrome].

The Chinese and English names of pertussis or whooping cough show the important clinical features of the disease in terms of its course and cough characteristics respectively. In the clinical description of typical pertussis, the meanings of the Chinese and English words are not completely consistent, such as spastic cough versus paroxysmal cough, spasmodic stage/phase versus paroxysmal stage/phase, and "back-hook" versus whoop, and some descriptions in English are not seen in Chinese. This article aims to provide more comprehensive information for the understanding of pertussis by comparing the descriptions of typical clinical manifestations of pertussis in Chinese and English literatures and to put forward suggestions for the diagnosis of pertussis syndrome based on typical clinical manifestations.

High Prevalence of Macrolide-Resistant Bordetella pertussis and ptxP1 Genotype, Mainland China, 2014-2016.

According to the government of China, reported cases of pertussis have increased remarkably and are still increasing. To determine the genetic relatedness of Bordetella pertussis strains, we compared multilocus variable-number tandem-repeat analysis (MLVA) results for isolates from China with those from Western countries. Among 335 isolates from China, the most common virulence-associated genotype was ptxA1/ptxC1/ptxP1/prn1/fim2-1/fim3A/tcfA2, which was more frequent among isolates from northern than southern China. Isolates of this genotype were highly resistant to erythromycin. We identified 36 ptxP3 strains mainly harboring ptxA1 and prn2 (35/36); ptxP3 strains were sensitive to erythromycin and were less frequently from northern China. For all isolates, the sulfamethoxazole/trimethoprim MIC was low, indicating that this drug should be recommended for patients infected with erythromycin-resistant B. pertussis. MLVA of 150 clinical isolates identified 13 MLVA types, including 3 predominant types. Our results show that isolates circulating in China differ from those in Western countries.

Accessory gene regulator (agr) dysfunction was unusual in Staphylococcus aureus isolated from Chinese children.

BACKGROUND: Staphylococcus aureus (S. aureus) with accessory gene regulator (agr) dysfunction occurs in health care settings. This study evaluated the prevalence and the molecular and drug resistance characteristics of S. aureus with dysfunctional agr in a pediatric population in Beijing, China. RESULTS: A total of 269 nonduplicate S. aureus clinical isolates were isolated from Beijing Children's Hospital, including 211 methicillin-resistant S. aureus (MRSA) from September 2010-2017 and 58 methicillin-sensitive S. aureus (MSSA) from February 2016-2017. Only 8 MRSA and 2 MSSA isolates were identified as agr dysfunction, and the overall prevalence rate was 3.7%. For MRSA isolates, ST59-SCCmec IV and ST239-SCCmec III were the most common clones, and the prevalence rate of agr dysfunction in ST239-SCCmec III isolates (17.39%) was significantly higher than in ST59-SCCmec IV (1.69%) and other genotype strains (P = 0.006). Among the agr dysfunctional isolates, only one MRSA ST59 isolate and one MSSA ST22 isolate harbored pvl. No significant difference was detected between agr dysfunction and agr functional isolates regarding the biofilm formation ability (P = 0.4972); however, 9/10 agr dysfunctional isolates could effectuate strong biofilm formation and multidrug resistance. Among MRSA, the non-susceptibility rates to ciprofloxacin, gentamicin, and trimethoprim-sulfamethoxazole were significantly higher in agr dysfunctional isolates than in isolates with functional agr (P < 0.05). Two isolates belonging to ST239 had no mutations in agr locus, but a synonymous mutation was found in agrA in another ST239 isolate. The inactivating mutations were detected in other seven agr dysfunctional isolates. The variants were characterized by non-synonymous changes (n = 5) and frameshift mutations (insertions, n = 2), which mainly occurred in agrC and agrA. CONCLUSIONS: The results showed that agr dysfunctional S. aureus was not common in Chinese children, and ST59-SCCmec IV was associated with lower prevalence of agr dysfunction as compared to ST239-SCCmec III isolates. The agr dysfunctional isolates were healthcare-associated, multidrug resistant and form strong biofilm, which suggested that agr dysfunction might offer potential advantages for S. aureus to survive in a medical environment.

The maternal antibody against diphtheria, tetanus and pertussis showed distinct regional difference in China.

BACKGROUND: Passive transferred antibodies to the fetus play an essential role on protecting neonates and young infants until infant vaccination is more efficacious. However, very little is known about the discrepancy of DTP vaccine associated antibodies level in neonates from different economic areas in China. METHODS: In 2018, 200 neonates hospitalized in Shunyi Women and Children's Hospital in Beijing, and 238 neonates hospitalized in Qianjiang Central Hospital located in the southwestern mountainous areas were included in this study. Antibodies specific for the antigens covered by DTP vaccine were determined using ELISA Kits (Euroimmun, Lübeck, Germany). The cut off value of ≥0.1 IU/ml (anti-diphtheria, anti-Dtx), > 0.1 IU/ml (anti-tetanus, anti-Ttx) and > 40 IU/ml (anti-pertussis toxin, anti-Ptx) were used to assess the percentage of protected neonates, respectively. RESULTS: The antibody levels in the neonates from Qianjiang (0.04 IU/ml for anti-Dtx IgG and 0.07 IU/ml for anti-Ttx IgG) were significantly lower than those from Shunyi (0.12 IU/ml for anti-Dtx IgG and 0.18 IU/ml for anti-Ttx IgG). The prevalence of protective anti-Dtx and anti-Ttx IgG were lower in the neonates from Qianjiang (7.1% for anti-Dtx IgG and 7.6% for anti-Ttx IgG) than in those from Shunyi (30.5% for anti-Dtx and 38.5% for anti-Ttx). The neonates from Qianjiang also had lower detectable rate of anti-Dtx (57.5%) and anti-Ttx IgG (55.8%) than neonates from Shunyi (97.5% for anti-Dtx and 71.0% for anti-Ttx). However, the detectable rate of anti-Ptx IgG in neonates from Qianjiang (39.9%) was higher significantly than in those from Shunyi (30.5%). Two neonates from Qianjiang have anti-PT IgG ≥100.0 IU/ml, which suggested that their mothers have a recent pertussis course. CONCLUSIONS: The regional discrepancy of the protective antibody rates might be caused by different vaccine coverage and pertussis exposure, which suggested the importance of Tdap booster immunization for pregnant women or women at childbearing age, those living undeveloped areas in particular.