Assessment of safety and efficacy against Bordetella pertussis of a new tetanus-reduced dose diphtheria-acellular pertussis vaccine in a murine model.

BACKGROUND: Tetanus-reduced dose diphtheria-acellular pertussis (Tdap) vaccination during adolescence was introduced in response to the resurgence of pertussis in various countries. A new Tdap vaccine was manufactured in Korea as a countermeasure against a predicted Tdap vaccine shortage. This study was performed to evaluate the immunogenicity, safety, and protection efficacy against Bordetella pertussis of the new Tdap vaccine in a murine model. METHODS: Four-week-old BABL/c mice were used for assessment of immunogenicity and protection efficacy. A single dose of primary diphtheria-tetanus-acellular pertussis (DTaP) vaccine was administered, followed by a single dose of Tdap booster vaccine after a 12-week interval. Anti-pertussis toxin (PT), anti-filamentous hemagglutinin (FHA), and anti-pertactin (PRN) IgG titers were measured before primary vaccination, and before and after booster vaccination. An intranasal challenge test was performed after booster vaccination to determine protection efficacy. To assess safety, mouse weight gain test and leukocytosis promotion test were performed using 4-week-old ddY female mice. RESULTS: Anti-PT and anti-FHA IgG titers after booster vaccination were significantly higher than those before booster vaccination with either the new vaccine or a commercially available Tdap vaccine (P = 0.01 for all occasions). After booster vaccination, no significant difference was observed between the two vaccines in antibody titers against pertussis antigens (P = 0.53 for anti-PT IgG, P = 0.91 for anti-FHA IgG, P = 0.39 for anti-PRN IgG). In the intranasal challenge test, inoculated B. pertussis was eradicated 7 days after infection. On days 4 and 7 after infection, colony counts of B. pertussis were not significantly different between the new and positive control vaccine groups (P = 1.00). Mean body weight changes and leukocyte counts of the new vaccine, positive control, and negative control groups were not significantly different 7 days after vaccination (P = 0.87 and P = 0.37, respectively). All leukocyte counts in the new vaccine group were within a mean ± 3 standard deviations range. CONCLUSIONS: A murine model involving a single dose primary DTaP vaccination followed by a single dose Tdap booster vaccination can be used for non-clinical studies of Tdap vaccines. The new Tdap vaccine manufactured in Korea exhibited comparable immunogenicity, protection efficacy, and safety with a commercially available Tdap vaccine.

Causes of resident lapses in professional conduct during the training: A qualitative study on the perspectives of residents.

BACKGROUND: The residency is a critical period for doctors to establish their professional identity and ethical standards, and yet during this time, residents are susceptible to engage in a diverse range of unprofessional behaviors. To prevent the misconduct of residents, it is critical to have a thorough understanding of the contributing factors or circumstances. METHODS: We conducted a qualitative study on 20 residents at one Korean university-affiliated tertiary hospital. During in-depth interviews, residents were asked to reveal their experiences or observations of misconduct, and describe their perceptions on the attributes of professional lapses. RESULTS: Diverse unethical and unprofessional behaviors were extracted from the transcripts and reported in a previous paper. In the current paper, the attributes that residents regarded as the causes of their unprofessional behaviors were identified within four categories: (1) inadequate systems within training hospitals; (2) lack of professionalism education; (3) strong hierarchical structure; and (4) poor character of individuals. The residents tended to perceive their misconduct as situation-sensitive, and emphasized the importance of systematic and cultural changes. CONCLUSIONS: To enhance medical professionalism among residents, the results of this study suggest the need of systematic and structured training programs, adequate professionalism education with clear codes of conduct, and active monitoring and feedback systems.

Asthma as a risk factor for zoster in adults: A population-based case-control study.

BACKGROUND: We recently reported an increased risk of herpes zoster (shingles or zoster) in children with asthma, but little is known about whether the same is true for adults with asthma. OBJECTIVE: We determined whether asthma is associated with an increased risk of zoster in adults. METHODS: This study was designed as a population-based case-control study. Zoster cases during the study period were identified among adults (aged ≥50 years) who resided in Olmsted County, Minnesota. We compared the frequency of asthma between zoster cases and birthday- and sex-matched control subjects (1:2 matching) without a history of zoster. Asthma status was ascertained based on predetermined criteria. A conditional logistic regression model was used to assess the association of asthma with risk of zoster. RESULTS: A total of 371 zoster cases and their 742 matched control subjects were enrolled. Of the 371 cases, 246 (66%) were female, 348 (94%) were white, and the mean ± SD age was 66.8 ± 10.7 years. Twenty-three percent (n = 87) of zoster cases had a history of asthma compared with 15% (n = 114) of control subjects. Controlling for pertinent covariates and confounders, there was a significant association between a history of asthma and risk of zoster (adjusted odds ratio, 1.70; 95% CI, 1.20-2.42; P = .003). The population attributable risk percentage for asthma was about 10%. CONCLUSIONS: Asthma is an unrecognized risk factor for zoster in adults. Consideration should be given to immunizing adults with asthma aged more than 50 years as a target group.

Asthma and risk of breakthrough varicella infection in children.

BACKGROUND: We recently reported a more rapid waning of vaccine-induced humoral immunity (measles vaccine) in children with asthma. It is unknown if asthma affects susceptibility to vaccine-preventable diseases. OBJECTIVE: To determine whether asthma is associated with an increased risk of vaccine-preventable disease, e.g., breakthrough varicella infection. METHODS: This was a retrospective population-based case-control study that examined cases of breakthrough varicella among children between 2005 and 2011. Children with a diagnosis of breakthrough varicella infection in Olmsted County, Minnesota (infection of >42 days after vaccination) between 2005 and 2011 and two age- and sex-matched controls were enrolled for each case. Asthma status was determined by using predetermined criteria. Conditional logistic regression models were used to calculate matched odds ratios (OR) and their corresponding 95% confidence intervals (CI). RESULTS: Of the 165 cases and their 330 matched controls, 48% were boys and the mean (standard deviation) age at the index date was 6.6 ± 3.5 years for both cases and controls. Of the 330 controls, 80 (24%) had two doses of the varicella vaccine compared with only 23 (14%) of the 165 cases (OR 0.29 [95% CI, 0.14-0.61]; p = 0.001). Children with a history of asthma ever had a higher risk of developing breakthrough varicella compared with those without a history of asthma (adjusted OR 1.63 [95% CI, 1.04-2.55]; p = 0.032) when adjusting for elapsed time since the first varicella vaccination and the number of varicella vaccine doses. CONCLUSIONS: A history of asthma might be an unrecognized risk factor for breakthrough varicella infection. Children with asthma should follow the two-dose varicella vaccine policy.

The Immunogenicity and Safety of the Live-attenuated SA 14-14-2 Japanese Encephalitis Vaccine Given with a Two-dose Primary Schedule in Children.

Effective and tolerable vaccination is an essential strategy to prevent Japanese encephalitis (JE) in endemic areas. Although the live attenuated SA 14-14-2 JE vaccine (LAJEV) has been widely used since its introduction, the systemic data of LAJEV was very rarely available in Korea. We conducted the open-label, prospective cohort study to assess the immunogenicity and safety of this vaccine. Ninety subjects were enrolled, and LAJEV in a 2-dose primary series was given with a 12-month interval. Neutralizing antibody titers were measured before and after each vaccination, and active monitoring for adverse events was performed. After the first dose, 91.1% of subjects had seroprotection with a geometric mean titer (GMT) of 40.9. Seroprotection rate after the second dose was 97%, and GMT showed an increase of 6.5-fold. Most adverse events following immunization were self-limited, and no serious adverse events were reported until 42 days after each dose. The 2-dose administration of LAJEV in the primary immunization schedule appeared to be highly immunogenic and safe.

Investigation of Unethical and Unprofessional Behavior in Korean Residency Training.

UNLABELLED: PHENOMENON: Medical ethics and professionalism are fundamental competencies for all physicians, and resident physicians have to develop these competencies during their training. Although Korea has a reputation for having the highest quality medical practice in East Asia, improvements in the technological aspects of care have outpaced the developments in institutional systems and education needed to fulfill social responsibility. Enhancing professionalism education during postgraduate training requires thorough exposition of this situation. APPROACH: Twenty residents from 17 clinical departments at 1 Korean tertiary university-affiliated hospital were recruited, and in-depth interviews were conducted in person by an interviewer who was a fellow resident with participants. Interviewees recalled and described personal experiences or observations of misbehaviors that had occurred during their residency training. Researchers recorded and transcribed all interviews, and 4 researchers conducted a thematic analysis. FINDINGS: Authors extracted 48 descriptors representing 8 categories of unethical and unprofessional behaviors from the transcripts: (a) substandard practice, (b) violation of work ethics, (c) misconduct related to conflict of interest, (d) dishonesty with patients, (e) violation of patient confidentiality, (f) lack of respect for patients, (g) lack of respect for colleagues, and (h) misconduct in research. Each of the interviewees mentioned between 3 and 18 descriptors. "Not fulfilling basic duties for patient care" was the most frequently mentioned misconduct, followed by "fabricating patient medical status or test results to meet preoperative criteria for anesthesia" and "verbal or physical abuse of junior doctors." INSIGHTS: Residents reported a diverse variety of unethical and unprofessional behaviors throughout their training and described the ethical distress they suffered in the real clinical situations. The results of this study support the notion that reinforcing ethics and professionalism education during postgraduate medical training in a practical and authentic way will help trainees manage the ethical conflicts or dilemmas they will inevitably encounter.

Clinical manifestations of respiratory adenoviral infection among hospitalized children in Korea.

BACKGROUND: The objective of our study was to understand the epidemiological and clinical features of respiratory adenoviral infections among children at a single institution over the course of several years. METHODS: From January 2005 to April 2009, 1836 children (≤15 years old) who had been admitted to Korea University Ansan Hospital were tested for acute respiratory infection. The patients who were positive for an adenovirus infection were enrolled in this study, and their medical records were retrospectively reviewed. RESULTS: Adenoviruses were isolated from 310 patients. The male to female ratio was 1.6:1 and mean age was 32 ± 24 months. Children under 5 years of age had the highest prevalence. In 2007, adenovirus infections occurred endemically throughout the year. The clinical diagnoses were primarily upper respiratory tract infections (45.4%), lower respiratory tract infections (48.1%), and neurologic disease (5.2%). Associated symptoms, signs and laboratory findings included fever (91.9%), cough (83.9%), pharyngeal injection (62.3%), rale (32.6%) and elevated C-reactive protein (93.9%). The most common radiologic findings were perihilar and peribronchial infiltrates (42.6%). Co-infections were observed in 29 cases. The mean durations of hospitalization and fever were 6.2 ± 6.5 and 4.8 ± 3.1 days, respectively. The lengths of hospitalization were similar for patients admitted for upper respiratory tract infections with severe morbidity and those admitted for lower respiratory tract infections. No children in the study died. CONCLUSION: Our study demonstrates that respiratory adenovirus infections are an important cause of hospitalization in young children, and contribute to a significant morbidity.

Life-threatening scrub typhus with hemophagocytosis and acute respiratory distress syndrome in an infant.

Scrub typhus is a rickettsial disease, caused by Orientia tsutsugamushi, which is transmitted via the bite of a chigger. This disease is one of the most important infectious diseases in the Asia-Pacific area; however, a severe infant case has not yet been reported. Here, we present the case of an 8-month-old boy with scrub typhus accompanied by hemophagocytic lymphohistiocytosis (HLH). His rapid course was complicated by acute respiratory distress syndrome (ARDS), status epilepticus and disseminated intravascular coagulation (DIC). He recovered after clarithromycin therapy and intensive supportive care. Although being extremely rare, scrub typhus can be life-threatening in an infant; therefore, physicians in endemic countries should be aware of the necessity for early recognition and prompt treatment of suspected cases.

Educational implications of assessing learning outcomes with multiple choice questions and short essay questions.

PURPOSE: This study investigates the characteristics of different item types to assess learning outcomes and explore the educational implications that can be obtained from the results of learning outcome assessments. METHODS: Forty-five second-year premedical students participated in this study. Multiple choice question (MCQ) and short essay question (SEQ) scores and pass rates for 10 learning outcomes were analyzed. Descriptive statistics and correlation analysis were used to analyze the data. RESULTS: The correlation analysis indicated that there was a significant correlation between SEQs and pass rate but there was no significant correlation between MCQs and pass rate. Some students with identical scores on the MCQs had different scores on the SEQs or on the learning outcomes. CONCLUSION: This study showed that students' achievement of learning outcomes can be assessed using various types of questions in outcome-based education.

Specialty impact on residents' perceived quality of life, stress, and job satisfaction: a comparative study.

Purpose: Specialty choice in residency training has a significant impact on an individual's career and satisfaction, as well as the supply-demand imbalance in the healthcare system. The current study aimed to investigate the quality of life (QOL), stress, self-confidence, and job satisfaction of residents, and to explore factors associated with such variables, including postgraduate year, sex, and especially specialty, through a cross-sectional survey. Methods: An online survey was administered to residents at 2 affiliated teaching hospitals. The survey had a total of 46 items encompassing overall residency life such as workload, QOL, stress, confidence, relationship, harassment, and satisfaction. Related survey items were then reconstructed into 4 key categories through exploratory factor analysis for comparison according to group classification. Results: The weekly work hours of residents in vital and other specialties were similar, but residents in vital specialties had significantly more on-call days per month. Residents in vital specialties had significantly lower scores for QOL and satisfaction. Specifically, vital-surgical residents had significantly lower QOL scores and higher stress scores than the other specialty groups. Satisfaction scores were also lowest among vital-surgical residents, with a marginal difference from vital-medical, and a significant difference from other-surgical residents. Female residents had significantly lower satisfaction scores than their male counterparts. Conclusion: Residents in vital specialties, particularly vital-surgical specialties, experience significantly worse working conditions across multiple dimensions. It is necessary to improve not only the quantity but also the quality of the system in terms of resource allocation and prioritization.

Severe osteomyelitis as a complication of Tokyo-172 BCG vaccination.

The bacilli Calmette-Guérin (BCG) Tokyo-172 strain was considered to exhibit good protective efficacy with a low rate of unfavorable side effects. However, we describe a rare case of BCG osteomyelitis developed in an immunocompetent host who was given with BCG Tokyo-172 vaccine on the left upper arm by multipuncture method. A 9-month-old girl presented with progressive inability to move her right elbow and had radiographic evidence of septic elbow combined with osteomyelitis of right distal humerus. A biopsy from the site revealed chronic caseating granulomatous inflammation, positive for BCG Tokyo-172 strain on the multiplex polymerase chain reaction. The child had to undergo second surgical debridements and oral antituberculosis chemotherapy. There were no sequelae after 2 yr of follow-up. This complication, although uncommon, should be considered in the appropriate clinical setting.

Infant pertussis and household transmission in Korea.

A recent resurgence of pertussis has raised public health concerns even in developed countries with high vaccination coverage. The aim of this study was to describe the clinical characteristics of infant pertussis, and to determine the relative importance of household transmission in Korea. The multicenter study was prospectively conducted from January 2009 to September 2011. We identified the demographic and clinical data from these patients and performed the diagnostic tests for pertussis in their household contacts. Twenty-one patients with confirmed pertussis were included in the analysis. All infections occurred in infants younger than 6 months of age (mean age, 2.5 months) who had not completed the primary DTaP vaccination except for one patient. Infants without immunization history had a significant higher lymphocytosis and longer duration of hospital stay compared to those with immunization. All were diagnosed with PCR (100%), however, culture tests showed the lowest sensitivity (42.9%). Presumed source of infection in household contacts was documented in 85.7%, mainly parents (52.6%). Pertussis had a major morbidity in young infants who were not fully immunized. Household members were responsible for pertussis transmission of infants in whom a source could be identified. The control of pertussis through booster vaccination with Tdap in family who is taking care of young infants is necessary in Korea.

Assessment of serologic immunity to diphtheria-tetanus-pertussis after treatment of Korean pediatric hematology and oncology patients.

The aim of this study was to investigate the diphtheria-tetanus-pertussis antibody titers after antineoplastic treatment and to suggest an appropriate vaccination approach for pediatric hemato-oncologic patients. A total of 146 children with either malignancy in remission after cessation of therapy or bone marrow failure were recruited. All children had received routine immunization including diphtheria-tetanus-acellular pertussis vaccination before diagnosis of cancer. The serologic immunity to diphtheria, tetanus and pertussis was classified as: completely protective, partially protective, or non-protective. Non-protective serum antibody titer for diphtheria, tetanus and pertussis was detected in 6.2%, 11.6%, and 62.3% of patients, respectively, and partial protective serum antibody titer for diphtheria, tetanus and pertussis was seen in 37%, 28.1%, and 8.9% of patients. There was no significant correlation between the severity of immune defect and age, gender or underlying disease. Revaccination after antineoplastic therapy showed significantly higher levels of antibody for each vaccine antigen. Our data indicates that a large proportion of children lacked protective serum concentrations of antibodies against diphtheria, tetanus, and pertussis. This suggests that reimmunization of these patients is necessary after completion of antineoplastic treatment. Also, prospective studies should be undertaken with the aim of devising a common strategy of revaccination.

Influences of etiology and endoscopic appearance on the long-term outcomes of gastric antral vascular ectasia.

BACKGROUND: Gastric antral vascular ectasia (GAVE) has diverse associations and presumed causes, which include liver cirrhosis, chronic kidney disease, and autoimmune disease. This heterogeneity of underlying disorders suggests that the pathogenesis of GAVE may be variable. AIM: To compare the clinical features and long-term outcomes of GAVE according to endoscopic patterns and etiologies. METHODS: The medical records and endoscopic images of 23 consecutive patients diagnosed with GAVE by endoscopy at Yeungnam University Hospital from January 2006 to December 2020 were retrospectively reviewed. Patients were allocated to cirrhosis (16 patients) and non-cirrhosis groups (7 patients). GAVE subtypes, as determined by endoscopy, were categorized as punctate (a diffuse, honeycomb-like appearance, 17 patients) or striped (a linear, watermelon-like appearance, 6 patients). RESULTS: All GAVE patients with cirrhosis (16/16, 100%) had a punctate pattern by endoscopy, whereas the majority of patients (6/7, 85.7%) without cirrhosis had a striped pattern (P < 0.001). Overt GAVE bleeding (10/23, 43%) was significantly more common in the non-cirrhosis group than in the cirrhosis group (6/7, 85.7% vs 4/16, 25.0%; P = 0.019), and more common in the striped group than in the punctate group (5/6, 83.3% vs 5/17, 29.4%; P = 0.052). However, mean numbers of admissions due to GAVE bleeding and argon plasma coagulation (APC) sessions to address overt bleeding were similar in the cirrhosis and non-cirrhosis groups and in the punctate and striped groups. All patients with GAVE bleeding were successfully treated by APC, and no patient died from GAVE-related blood loss during a median follow-up of 24 mo. CONCLUSION: Punctate-type GAVE is strongly associated with liver cirrhosis, and GAVE patients without cirrhosis tend to be more prone to overt bleeding. However, the presence of cirrhosis and endoscopic patterns did not influence long-term clinical courses or outcomes in cases of overt bleeding.

The protective effect of Leucosporidium-derived ice-binding protein (LeIBP) on bovine oocytes and embryos during vitrification.

Ice-binding proteins (IBPs) facilitate organism survival under extreme conditions by inhibiting thermal hysteresis and ice recrystallization. IBPs have been widely used as cryoprotectants to cryopreserve mammalian gametes and embryos. In the present study, we evaluated the protective effects of an Arctic yeast, Leucosporidium sp. AY30 derived ice-binding protein (LeIBP), on the vitrification of bovine metaphase II (MII) oocytes and embryos. When oocytes and embryos were frozen using the two-step vitrification method, the survival rate was significantly increased in the presence of LeIBP. The LeIBP supplementation decreased the levels of intracellular reactive oxygen species (ROS) and enhanced mitochondrial functions in the vitrified-warmed oocytes. Furthermore, LeIBP improved the developmental potential and suppressed apoptosis of the embryos derived from vitrified-warmed oocytes. Collectively, these data indicate that LeIBP can be used as a promising cryoprotectant to prevent cryoinjury during vitrification in bovine oocytes.

Development an instrument assessing residents' attitude towards professionalism lapses in training.

PURPOSE: Medical professionalism is a fundamental competency for all physicians and continuous development of professionalism during residency training is crucial. The purpose of this study was to develop an instrument assessing residents' attitudes toward unprofessional behaviors. METHODS: A questionnaire survey was conducted in cooperation with the Korea Resident Association from May to July 2013. A total of 317 residents from seven university-affiliated hospitals in South Korea participated in the survey. RESULTS: In the exploratory factor analysis, seven factors were extracted from the data; factor loadings of the 44 items ranged between 0.40 and 0.89. Through iterative discussion, three items below 0.45 were deleted and one additional item was removed due to its irrelevance. Twelve items included in Factor 1 were divided into two different categories. A final version of the questionnaire containing 40 items in eight categories was assessed using confirmatory factor analysis. It was deemed to have a good fit; the root mean square error of approximation and comparative fit index were 0.07 and 0.9, respectively. The reliability (Cronbach's α) of the inventory was 0.97. CONCLUSION: The items of this instrument encompass a broad range of residents' behaviors in clinical practice, research, and publication. In addition, it includes some types of misconduct that can be considered unique features of the authors' cultural backgrounds. We recommend this instrument as an assessment tool to diagnose residents' perceptions and attitudes towards professionalism lapses and to provide insight regarding potential improvement in professionalism education.

Additive interactions between PRKAA1 polymorphisms and Helicobacter pylori CagA infection associated with gastric cancer risk in Koreans.

Although several studies reported genetic polymorphisms in protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) and their associations with gastric cancer risk, few have evaluated associations between Helicobacter pylori infection and PRKAA1 gene-environment interactions. Here, we evaluated the effects of interactions between H. pylori infection and PRKAA1 polymorphisms on gastric cancer risk in Koreans. In this hospital-based case-control study, PRKAA1 genotypes were analyzed and H. pylori infection and CagA status were examined using a serologic method in 846 pairs of gastric cancer patients and controls matched for age and sex. H. pylori seropositivity was associated with a 1.43-fold [95% confidence interval: 1.12-1.81] increase in the risk of gastric cancer, and CagA low-positive titers during H. pylori infection increased the risk by 1.85-fold (95% confidence interval, 1.38-2.48). Significant positive interaction between the PRKAA1 rs13361707 genotype and H. pylori infection was verified on an additive scale [relative excess risk due to interaction, 0.55; 95% confidence interval, 0.05-1.04; P = 0.030], and the gene-environment interaction between PRKAA1 rs13361707 and CagA status was also statistically significant (relative excess risk due to interaction, 0.50; 95% confidence interval, 0.30-0.70; P < 0.001). Our results indicated that H. pylori infection, CagA status, and PRKAA1 polymorphisms were risk factors for gastric cancer in Koreans, and that the combination of two of these factors rather than their independent effects synergistically increased the risk.

[Needs assessment of a core curriculum for residency training].

PURPOSE: The core curriculum in graduate medical education (GME) is an educational program that covers the minimum body of knowledge and skills that is required of all residents, regardless of their specialty. This study examined the opinions of stakeholders in GME regarding the core curriculum. METHODS: A questionnaire was administered at three tertiary hospitals that were affiliated with one university; 192 residents and 61 faculty members and attending physicians participated in the survey. The questionnaire comprised six items on physician competency and the needs for a core curriculum. Questions on subjects or topics and adequate training years for each topics were asked only to residents. RESULTS: Most residents (78.6%) and faculty members (86.9%) chose "medical expertise" as the "doctor's role in the 21st century." In contrast, communicator, manager, and collaborator were recognized by less than 30% of all participants. Most residents (74.1%) responded that a core curriculum is "necessary but not feasible," whereas 68.3% of faculty members answered that it is "absolutely needed." Regarding subjects that should be included in the core curriculum, residents and faculty members had disparate preferences- residents preferred more "management of a private clinic" and "financial management," whereas faculty members desired "medical ethics" and "communication skills." CONCLUSION: Residents and faculty members agree that residents should develop a wide range of competencies in their training. However, the perception of the feasibility and opinions on the contents of the core curriculum differed between groups. Further studies with larger samples should be conducted to define the roles and professional competencies of physicians and the needs for a core curriculum in GME.

Pertussis Accompanying Recent Mycoplasma Infection in a 10-Year-Old Girl.

Recently, the incidence of pertussis has been increasing; however, reports on mixed infection of pertussis with other respiratory pathogens are rare in highly immunized populations. We report the case of a 10-year-old girl who presented with cough, post-tussive emesis, and fever. She was subsequently diagnosed with bronchopneumonia. Although she had received five doses of diphtheria-tetanus-acellular pertussis vaccine, polymerase chain reaction of her nasopharyngeal aspirate confirmed Bordetella pertussis infection. In addition, serologic testing for Mycoplasma pneumoniae was also positive. The patient was treated with roxithromycin without any complications. This is the first report of mixed B. pertussis and M. pneumoniae infection in Korea. To avoid under-diagnosis, pertussis should be considered in patients with chronic cough even when other respiratory pathogens have been documented.