Last data update: May 20, 2024. (Total: 46824 publications since 2009)
Records 1-17 (of 17 Records) |
Query Trace: Pawloski LC [original query] |
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Assessing the impact of the 2020 Council of State and Territorial Epidemiologists case definition for pertussis on reported pertussis cases
Rubis AB , Cole M , Tondella ML , Pawloski LC , Youngkin E , Firmender P , Aden V , Cruz V , Stanislawski E , Wester R , Cieslak PR , Acosta AM , Skoff TH . Clin Infect Dis 2024 BACKGROUND: In 2020, the Council of State and Territorial Epidemiologists (CSTE) pertussis case definition was modified; the main change was classifying PCR-positive cases as confirmed, regardless of cough duration. Pertussis data reported through Enhanced Pertussis Surveillance (EPS) in seven sites and the National Notifiable Diseases Surveillance System (NNDSS) were used to evaluate the impact of the new case definition. METHODS: We compared the number of EPS cases with cough onset in 2020 to the number that would have been reported based on the prior (2014) CSTE case definition. To assess the impact of the change nationally, the proportion of EPS cases newly reportable under the 2020 CSTE case definition was applied to 2020 NNDSS data to estimate how many additional cases were captured nationally. RESULTS: Among 442 confirmed and probable cases reported to EPS states in 2020, 42 (9.5%) were newly reportable according to the 2020 case definition. Applying this proportion to the 6,124 confirmed and probable cases reported nationally in 2020, we estimated that the new definition added 582 cases. Had the case definition not changed, reported cases in 2020 would have decreased by 70% from 2019; the observed decrease was 67%. CONCLUSIONS: Despite a substantial decrease in reported pertussis cases in the setting of COVID-19, our data show that the 2020 pertussis case definition change resulted in additional case reporting compared with the previous case definition, providing greater opportunities for public health interventions such as prophylaxis of close contacts. |
Genome-based prediction of cross-protective, HLA-DR-presented epitopes as putative vaccine antigens for multiple Bordetella species
Natrajan MS , Hall JM , Weigand MR , Peng Y , Williams MM , Momin M , Damron FH , Dubey P , Tondella ML , Pawloski LC . Microbiol Spectr 2023 e0352723 Pertussis, caused by Bordetella pertussis, can cause debilitating respiratory symptoms, so whole-cell pertussis vaccines (wPVs) were introduced in the 1940s. However, reactogenicity of wPV necessitated the development of acellular pertussis vaccines (aPVs) that were introduced in the 1990s. Since then, until the COVID-19 pandemic began, reported pertussis incidence was increasing, suggesting that aPVs do not induce long-lasting immunity and may not effectively prevent transmission. Additionally, aPVs do not provide protection against other Bordetella species that are observed during outbreaks. The significance of this work is in determining potential new vaccine antigens for multiple Bordetella species that are predicted to elicit long-term immune responses. Genome-based approaches have aided the development of novel vaccines; here, these methods identified Bordetella vaccine candidates that may be cross-protective and predicted to induce strong memory responses. These targets can lead to an improved vaccine with a strong safety profile while also strengthening the longevity of the immune response. |
Genomic characterization of cocirculating Corynebacterium diphtheriae and non-diphtheritic Corynebacterium species among forcibly displaced Myanmar nationals, 2017-2019
Xiaoli L , Peng Y , Williams MM , Lawrence M , Cassiday PK , Aneke JS , Pawloski LC , Shil SR , Rashid MO , Bhowmik P , Weil LM , Acosta AM , Shirin T , Habib ZH , Tondella ML , Weigand MR . Microb Genom 2023 9 (9) Respiratory diphtheria is a serious infection caused by toxigenic Corynebacterium diphtheriae, and disease transmission mainly occurs through respiratory droplets. Between 2017 and 2019, a large diphtheria outbreak among forcibly displaced Myanmar nationals densely settled in Bangladesh was investigated. Here we utilized whole-genome sequencing (WGS) to characterize recovered isolates of C. diphtheriae and two co-circulating non-diphtheritic Corynebacterium (NDC) species - C. pseudodiphtheriticum and C. propinquum. C. diphtheriae isolates recovered from all 53 positive cases in this study were identified as toxigenic biovar mitis, exhibiting intermediate resistance to penicillin, and formed four phylogenetic clusters circulating among multiple refugee camps. Additional sequenced isolates collected from two patients showed co-colonization with non-toxigenic C. diphtheriae biovar gravis, one of which exhibited decreased susceptibility to the first-line antibiotics and harboured a novel 23-kb multidrug resistance plasmid. Results of phylogenetic reconstruction and virulence-related gene contents of the recovered NDC isolates indicated they were likely commensal organisms, though 80.4 %(45/56) were not susceptible to erythromycin, and most showed high minimum inhibition concentrations against azithromycin. These results demonstrate the high resolution with which WGS can aid molecular investigation of diphtheria outbreaks, through the quantification of bacterial genetic relatedness, as well as the detection of virulence factors and antibiotic resistance markers among case isolates. |
Detection of SARS-CoV-2 on Surfaces in Households of Persons with COVID-19.
Marcenac P , Park GW , Duca LM , Lewis NM , Dietrich EA , Barclay L , Tamin A , Harcourt JL , Thornburg NJ , Rispens J , Matanock A , Kiphibane T , Christensen K , Pawloski LC , Fry AM , Hall AJ , Tate JE , Vinjé J , Kirking HL , Pevzner E . Int J Environ Res Public Health 2021 18 (15) SARS-CoV-2 transmission from contaminated surfaces, or fomites, has been a concern during the COVID-19 pandemic. Households have been important sites of transmission throughout the COVID-19 pandemic, but there is limited information on SARS-CoV-2 contamination of surfaces in these settings. We describe environmental detection of SARS-CoV-2 in households of persons with COVID-19 to better characterize the potential risks of fomite transmission. Ten households with ≥1 person with laboratory-confirmed COVID-19 and with ≥2 members total were enrolled in Utah, U.S.A. Nasopharyngeal and anterior nasal swabs were collected from members and tested for the presence of SARS-CoV-2 by RT-PCR. Fifteen surfaces were sampled in each household and tested for presence and viability of SARS-CoV-2. SARS-CoV-2 RNA was detected in 23 (15%) of 150 environmental swab samples, most frequently on nightstands (4/6; 67%), pillows (4/23; 17%), and light switches (3/21; 14%). Viable SARS-CoV-2 was cultured from one sample. All households with SARS-CoV-2-positive surfaces had ≥1 person who first tested positive for SARS-CoV-2 ≤ 6 days prior to environmental sampling. SARS-CoV-2 surface contamination occurred early in the course of infection when respiratory transmission is most likely, notably on surfaces in close, prolonged contact with persons with COVID-19. While fomite transmission might be possible, risk is low. |
Effect of maternal Tdap on infant antibody response to a primary vaccination series with whole cell pertussis vaccine in So Paulo, Brazil
Vaz-de-Lima LRA , Sato APS , Pawloski LC , Fernandes EG , Rajam G , Sato HK , Patel D , Li H , de Castilho EA , Tondella ML , Schiffer J . Vaccine: X 2021 7 100087 Background: Maternal Tetanus, diphtheria, and acellular pertussis (Tdap) vaccination provides antibody transfer to newborn infants and may affect their antibody response to the primary vaccination series. This study aimed to assess the effect of Tdap vaccination during pregnancy on infant antibody response to the whole cell pertussis (DTwP) primary series. Methods: Plasma from 318 pregnant women (243 Tdap-vaccinated and 75 unvaccinated) and their infants (cord blood) was collected at delivery; infant blood was again collected at 2 and 7 months, before and after their primary DTwP series. Anti-pertussis toxin (PT), pertactin (PRN), filamentous hemagglutinin (FHA), fimbriae 2/3 (FIM) and adenylate cyclase toxin (ACT) IgG antibodies were quantified by a microsphere-based multiplex antibody capture assay and anti-PT neutralizing antibodies by the Real Time Cell analysis system. Results: Infant geometric mean concentrations (GMCs) of IgG anti-Tdap antigens were significantly higher (p < 0.001) among the Tdap-vaccinated (PT: 57.22 IU/mL; PRN: 464.86 IU/mL; FHA: 424.0 IU/mL), versus the unvaccinated group (4 IU/mL, 15.43 IU/mL, 31.99 IU/mL, respectively) at delivery. Anti-FIM and ACT GMCs were similar between the two groups. At 2 months of age, anti-PT, PRN, and FHA GMCs remained higher (p < 0.001) in the Tdap-vaccinated group (12.64 IU/mL; 108.76 IU/mL; 87.41 IU/mL, respectively) than the unvaccinated group (1.02 IU/mL; 4.46 IU/mL; 6.89 IU/mL). However, at 7 months, after receiving the third DTwP dose, the anti-PT GMC was higher (p = 0.016) in the unvaccinated group (7.91 IU/mL) compared to the vaccinated group (2.27 IU/mL), but without differences for anti-PRN, FHA, FIM and ACT GMCs. Conclusion: Elevated antibody levels suggest that maternal Tdap vaccination might protect infants until 2 months of age. Reduced anti-PT levels at 7 months indicate potential blunting of immune response in infants. Surveillance would help determine if blunting alters vaccine immunity and impacts pertussis prevention in infants. © 2021 The Authors |
Notes from the field: Conjunctivitis caused by toxigenic Corynebacterium ulcerans - Missouri, 2018
Weil LM , Butler C , Howell KR , Sharr S , Paley GL , Huang AJW , Maamari RN , Pawloski LC , Cassiday PK , Acosta AM , Hariri S , Tiwari TSP . MMWR Morb Mortal Wkly Rep 2019 68 (27) 615-616 On December 12, 2018, an immunocompromised man with non-Hodgkin’s lymphoma, aged 73 years, was evaluated by an ophthalmologist for left eyelid redness, swelling, and eye discharge and received a diagnosis of ligneous (pseudomembranous) conjunctivitis. The pseudomembrane was debrided and sent for culture, and the patient was prescribed oral amoxicillin clavulanate and moxifloxacin eye drops, with topical loteprednol and cyclosporine to decrease the robust inflammatory response. Corynebacterium ulcerans, one of three species of Corynebacterium (in addition to C. diphtheriae and C. psuedotuberculosis) that can harbor the diphtheria toxin–producing gene was initially identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry performed on an isolate obtained from culture of the pseudomembrane at a Missouri hospital on December 13. The Missouri Department of Health and Senior Services (MDHSS) laboratory-confirmed C. ulcerans by culture and forwarded the isolate to CDC for toxin testing. On December 28, CDC confirmed toxin-producing C. ulcerans. The patient had no systemic symptoms, was not hospitalized, and did not receive diphtheria antitoxin. On January 11, 2019, following multiple membrane removals and no residual membrane; cultures of conjunctival swabs tested by the hospital were negative for C. ulcerans. The patient was not up-to-date for tetanus-diphtheria (Td) vaccine and had postponed vaccination because of his ongoing cancer treatment. |
Association between the timing of maternal vaccination and newborns' anti-pertussis toxin antibody levels
Vaz-de-Lima LRA , Sato HK , Fernandes EG , Sato APS , Pawloski LC , Tondella ML , de Brito CA , Luna EJA , Carvalhanas Trmp , de Castilho EA . Vaccine 2019 37 (36) 5474-5480 BACKGROUND: Pertussis remains an important global public health concern, despite the presence of extensive immunization programs. Incidence and severity of pertussis are typically higher in neonates and young infants. As a strategy to protect these young infants, maternal vaccination with Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis) has been recommended in Brazil. The objective of this study was to evaluate the effects of Tdap vaccination during pregnancy on the anti-pertussis toxin (PT) IgG response in mothers and their infants at birth. MATERIAL AND METHODS: Maternal and cord blood samples were collected from vaccinated (n=243) and unvaccinated (n=75) pregnant women, at the time of delivery, from July 2015 to August 2016 in Sao Paulo, Brazil. Anti-PT IgG antibodies were quantified by Enzyme-Linked Immunosorbent Assay (ELISA) and geometric mean concentrations (GMC) were calculated. Relationship between timing of vaccination and antibody concentrations were evaluated. RESULTS: Maternal and cord blood GMCs among the vaccinated group were 5.4 and 5.6 fold higher [66.5 International Units (IU)/mL and 89.8IU/mL] compared to the unvaccinated group (12.4IU/mL and 16.1IU/mL), respectively (p<0.001). Higher anti-PT IgG GMCs were observed when vaccination occurred >/=60days before delivery compared to <60days, suggesting that vaccination early in the third trimester may be more effective than later in pregnancy. CONCLUSION: Tdap maternal vaccination results in significantly higher anti-PT IgG in newborn infants and supports the current recommendation of the Brazilian Immunization Program. |
Genomic Survey of Bordetella pertussis Diversity, United States, 2000-2013.
Weigand MR , Williams MM , Peng Y , Kania D , Pawloski LC , Tondella ML . Emerg Infect Dis 2019 25 (4) 780-783 We characterized 170 complete genome assemblies from clinical Bordetella pertussis isolates representing geographic and temporal diversity in the United States. These data capture genotypic shifts, including increased pertactin deficiency, occurring amid the current pertussis disease resurgence and provide a foundation for needed research to direct future public health control strategies. |
Clinical evaluation and validation of laboratory methods for the diagnosis of Bordetella pertussis infection: Culture, polymerase chain reaction (PCR) and anti-pertussis toxin IgG serology (IgG-PT)
Lee AD , Cassiday PK , Pawloski LC , Tatti KM , Martin MD , Briere EC , Tondella ML , Martin SW . PLoS One 2018 13 (4) e0195979 INTRODUCTION: The appropriate use of clinically accurate diagnostic tests is essential for the detection of pertussis, a poorly controlled vaccine-preventable disease. The purpose of this study was to estimate the sensitivity and specificity of different diagnostic criteria including culture, multi-target polymerase chain reaction (PCR), anti-pertussis toxin IgG (IgG-PT) serology, and the use of a clinical case definition. An additional objective was to describe the optimal timing of specimen collection for the various tests. METHODS: Clinical specimens were collected from patients with cough illness at seven locations across the United States between 2007 and 2011. Nasopharyngeal and blood specimens were collected from each patient during the enrollment visit. Patients who had been coughing for </= 2 weeks were asked to return in 2-4 weeks for collection of a second, convalescent blood specimen. Sensitivity and specificity of each diagnostic test were estimated using three methods-pertussis culture as the "gold standard," composite reference standard analysis (CRS), and latent class analysis (LCA). RESULTS: Overall, 868 patients were enrolled and 13.6% were B. pertussis positive by at least one diagnostic test. In a sample of 545 participants with non-missing data on all four diagnostic criteria, culture was 64.0% sensitive, PCR was 90.6% sensitive, and both were 100% specific by LCA. CRS and LCA methods increased the sensitivity estimates for convalescent serology and the clinical case definition over the culture-based estimates. Culture and PCR were most sensitive when performed during the first two weeks of cough; serology was optimally sensitive after the second week of cough. CONCLUSIONS: Timing of specimen collection in relation to onset of illness should be considered when ordering diagnostic tests for pertussis. Consideration should be given to including IgG-PT serology as a confirmatory test in the Council of State and Territorial Epidemiologists (CSTE) case definition for pertussis. |
Screening and genomic characterization of filamentous hemagglutinin-deficient Bordetella pertussis.
Weigand MR , Pawloski LC , Peng Y , Ju H , Burroughs M , Cassiday PK , Davis JK , DuVall M , Johnson T , Juieng P , Knipe K , Loparev VN , Mathis MH , Rowe LA , Sheth M , Williams MM , Tondella ML . Infect Immun 2018 86 (4) Despite high vaccine coverage, pertussis cases in the United States (US) have increased over the last decade. Growing evidence suggests that disease resurgence results, in part, from genetic divergence of circulating strain populations away from vaccine references. The US exclusively employs acellular vaccines and current Bordetella pertussis isolates are predominantly deficient in at least one immunogen, pertactin (Prn). First detected in the US retrospectively in a 1994 isolate, the rapid spread of Prn deficiency is likely vaccine driven, raising concerns about whether other acellular vaccine immunogens experience similar pressures as further antigenic changes could potentially threaten vaccine efficacy. We developed an electrochemiluminescent antibody capture assay to monitor production of the acellular vaccine immunogen filamentous hemagglutinin (Fha). Screening 722 US surveillance isolates collected from 2010-2016 identified two that were both Prn- and Fha-deficient. Three additional Fha-deficient laboratory strains were also identified from a historic collection of 65 isolates dating back to 1935. Whole-genome sequencing of deficient isolates revealed putative, underlying genetic changes. Only four isolates harbored mutation to known genes involved in Fha production, highlighting the complexity of its regulation. The chromosomes of two Fha-deficient isolates included unexpected structural variation that did not appear to influence Fha production. Furthermore, insertion sequence disruption of fhaB was also detected in a previously identified pertussis toxin-deficient isolate that still produced normal levels of Fha. These results demonstrate the genetic potential for additional vaccine immunogen deficiency and underscore the importance of continued surveillance of circulating B. pertussis evolution in response to vaccine pressure. |
Risk Factors Associated With Bordetella pertussis Among Infants ≤4 Months of Age in the Pre-Tdap Era: United States, 2002-2005
Curtis CR , Baughman AL , DeBolt C , Goodykoontz S , Kenyon C , Watson B , Cassiday PK , Miller C , Pawloski LC , Tondella MC , Bisgard KM . Pediatr Infect Dis J 2016 36 (8) 726-735 BACKGROUND: In the United States, infants have the highest reported pertussis incidence and death rates. Improved understanding of infant risk factors is needed to optimize prevention strategies. METHODS: We prospectively enrolled infants ≤4 months of age with incident-confirmed pertussis from 4 sites during 2002-2005 (preceding pertussis-antigen-containing vaccination recommendations for adolescents/adults); each case-patient was age- and site-matched with 2 control subjects. Caregivers completed structured interviews. Infants and their contacts ≥11 years of age were offered serologic testing for IgG; being seropositive was defined as ≥94 anti-pertussis toxin IgG enzyme-linked immunosorbent assay units/mL. RESULTS: Enrolled subjects (115 case-patients; 230 control subjects) had 4,396 contacts during incubation periods; 83 (72%) case-patients had ≥1 contact with prolonged (≥5 days) new cough in primary or secondary households. In multivariable analysis, the odds for pertussis were higher for infants with primary/secondary household contacts who had a prolonged new cough, compared with infants who did not. These contacts included mother (adjusted matched odds ratio [aMOR] 43.8; 95% confidence interval [CI], 6.45-298.0) and ≥1 nonmother contact (aMOR, 20.1; 95% CI, 6.48-62.7). Infants receiving breast milk with 0-1 formula feedings daily had decreased pertussis odds (aMOR, 0.27; 95% CI, 0.08-0.89), compared with those receiving more formula. Of 41 tested case-patients, 37 (90%) were seropositive. CONCLUSIONS: Pertussis in infants was associated with prolonged new cough (≥5 days) in infants' household contacts. Findings suggest breastfeeding protects against pertussis, and warrants recommendation with pertussis prevention strategies, which currently include pertussis vaccination of pregnant mothers and infants' close contacts. |
Evaluation of commercial assays for single-point diagnosis of pertussis in the US
Pawloski LC , Plikaytis BD , Martin MD , Martin SW , Prince HE , Lape-Nixon M , Tondella ML . J Pediatric Infect Dis Soc 2016 6 (3) e15-e21 BACKGROUND: Pertussis serodiagnosis is increasingly being used in the United States despite the lack of a US Food and Drug Administration-approved, commercially available assay. To better understand the utility of these assays in diagnosing pertussis, serology assays were evaluated for analytical parameters and clinical accuracy. METHODS: Forty-three antigen-antibody combinations were evaluated for single-point diagnosis of pertussis. Serum panels included sera from laboratory-confirmed cases, an international reference standard, and healthy donors. Phase I panel (n = 20) of sera was used to assess precision, linearity, and accuracy; Phase II panel (n = 226) followed with positive percent agreement (PPA) and negative percent agreement (NPA) estimates. Analytical analyses included coefficients of variation (CV) and concordance correlation coefficients (rc). RESULTS: Intra-analyst variability was found to be relatively low among samples per assay, with only 6% (78 of 1240) having CV >20%, primarily with the highly concentrated immunoglobulin (Ig)G anti-pertussis toxin (PT) specimens and IgM assays. The rc measurements to assess linearity ranged between 0.282 and 0.994, 0.332 and 0.999, and -0.056 and 0.482 for IgA, IgG, and IgM, respectively. Analytical accuracy for calibrated IgG anti-PT assays was 86%-115%. The PPA and NPA varied greatly for all assays; PPA/NPA ranges for IgA, IgG, and IgM assays, with culture and/or polymerase chain reaction positivity as control, were 29-90/13-100, 26-96/27-100, and 0-73/42-100, respectively. In IgG assays, mixing filamentous hemagglutinin antigen with PT increased PPA but decreased NPA. CONCLUSIONS: Seroassays varied substantially under both analytical and clinical parameters; however, those that were calibrated to a reference standard were highly accurate. Our findings support incorporation of calibrated pertussis seroassays to the pertussis case definition for improved diagnosis and surveillance. |
Serodiagnosis as adjunct assay for pertussis infection in Sao Paulo, Brazil
Vaz-de-Lima LR , Martin MD , Pawloski LC , Leite D , Rocha KC , de Brito CA , Vaz TM , Martins LM , Alvarenga DP , Ribeiro AF , Carvalhanas TR , Nakasaki RM , Oliveira SS , Waldman EA , Tondella ML . Clin Vaccine Immunol 2014 21 (5) 636-40 Pertussis remains an important public health problem in many countries despite extensive immunization. Cultures and real-time PCR (RT-PCR) assays are the recommended pertussis diagnostic tests, but they lack sensitivity at the later stage of the disease. This study introduces the IgG anti-pertussis toxin enzyme-linked immunosorbent assay (PT ELISA) in our routine diagnosis to improve disease burden estimation. Serum samples and nasopharyngeal swabs (n = 503) were collected at the same time from patients presenting with cough illness suspected of being pertussis and tested by the PT ELISA and culture and/or RT-PCR, respectively. Patients were separated into three age groups: group 1, <1 year (n = 260; mean age, 3 months), group 2, 1 to 6 years (n = 81; mean age, 3 years), and group 3, ≥7 years (n = 162; mean age, 26 years). The times (means) from cough onset to specimen collection were 16, 24, and 26 days, respectively. In group 1, 83 (82.2%) of 101 positive cases were positive for pertussis by culture/RT-PCR, while 40 (39.6%) tested positive by PT ELISA. In group 2, 6 (19.4%) of 31 positive cases were culture/RT-PCR positive, and 29 (93.6%) were seropositive. In group 3, 13 (13.8%) of 94 positive cases were positive by culture/RT-PCR and 91 (96.8%) were positive by serology. Culture/RT-PCR detected more cases of pertussis in infants (P < 0.0001), whereas the PT ELISA detected more cases in adolescents and adults (P < 0.0001). The timing between cough onset and specimen collection or recent vaccination may have partially affected our results. Serology is a suitable, cost-effective, and complementary pertussis diagnostic tool, especially among older children, adolescents, and adults during the later disease phase. |
Prevalence and molecular characterization of pertactin-deficient Bordetella pertussis in the United States.
Pawloski LC , Queenan AM , Cassiday PK , Lynch AS , Harrison M , Shang W , Williams MM , Bowden KE , Burgos-Rivera B , Qin X , Messonnier N , Tondella ML . Clin Vaccine Immunol 2013 21 (2) 119-25 Pertussis has made a striking resurgence in the US, returning to record numbers of reported cases last observed in the 1950s. Bordetella pertussis isolates lacking pertactin, a key antigen component of the acellular pertussis vaccine, have been observed, suggesting that B. pertussis is losing pertactin in response to vaccine immunity. Screening of 1300 isolates from outbreak and surveillance studies (historical isolates collected from 1935 up to 2009, the 2010 California pertussis outbreak, US isolates from routine surveillance between 2010-2012, and the 2012 Washington pertussis outbreak) by conventional PCR and later by Western blot and prn sequencing analyses ultimately identified 306 pertactin-deficient isolates. Of these pertactin-deficient strains, 276 were identified as having an IS481 in the prn gene (prnIS481-positive). The first prnIS481-positive isolate was found in 1994, with the next prnIS481-positive isolates not detected until 2010. Pertactin-deficient isolates increased substantially to over 50% in 2012. Sequence analysis of pertactin-deficient isolates revealed various types of mutations in the prn gene, including two deletions, single nucleotide substitutions resulting in a stop codon, an inversion in the promoter, and a single nucleotide insertion resulting in a frame shift mutation. All but one mutation type were found in prn2 alleles. CDC013 was a predominant PFGE profile in the pertactin-positive isolates (203/994), but was found in only 5% (16/306) of the pertactin-deficient isolates. Interestingly, PFGE profiles CDC002 and CDC237 represented 55% (167/306) of the identified pertactin-deficient isolates. These results indicate that there has been a recent, dramatic increase in pertactin-deficient B. pertussis isolates throughout the US. |
Does Tdap vaccination interfere with serodiagnosis of pertussis infection?
Pawloski LC , Kirkland KB , Baughman AL , Martin MD , Talbot EA , Messonnier NE , Tondella ML . Clin Vaccine Immunol 2012 19 (6) 875-80 BACKGROUND: An IgG anti-pertussis toxin (PT) enzyme-linked immunosorbent assay (ELISA) was analytically validated for diagnosis of pertussis, using the cut-off of 94 ELISA Units (EU)/mL. Little was known about the performance of this ELISA for diagnosis in adults recently vaccinated with tetanus-diphtheria-acellular pertussis (Tdap), which contains PT. The goal of this study was to determine when the assay can be used following Tdap vaccination. METHODS: A cohort of 102 asymptomatic health care personnel (HCP) vaccinated with Tdap (Adacel, Sanofi Pasteur) were aged 19 to 79 years (median 47 years) at vaccination. For each HCP, specimens were available for evaluation at 2-10 time points (pre-vaccination to 24 months post-vaccination), and geometric mean concentrations (GMC) for the cohort were calculated at each time point. Among 97 HCP who responded to vaccination, a mixed model analysis with prediction and tolerance intervals was performed to estimate the time at which serodiagnosis can be used following vaccination. RESULTS: The GMC was 8, 21, and 9 EU/mL at pre-vaccination, four, and 12 months post-vaccination, respectively. Eight of 102 (8%) HCP reached antibody titers ≥ 94 EU/mL during their peak response but none had these titers by six months post-vaccination. Calculated prediction and tolerance intervals were < 94 EU/mL by 45 and 75 days post-vaccination, respectively. CONCLUSIONS: Tdap vaccination six months prior to testing did not confound result interpretation. This seroassay remains a valuable diagnostic tool for adult pertussis. |
Pertussis Pseudo-outbreak linked to specimens contaminated by Bordetella pertussis DNA From clinic surfaces.
Mandal S , Tatti KM , Woods-Stout D , Cassiday PK , Faulkner AE , Griffith MM , Jackson ML , Pawloski LC , Wagner B , Barnes M , Cohn AC , Gershman KA , Messonnier NE , Clark TA , Tondella ML , Martin SW . Pediatrics 2012 129 (2) e424-30 BACKGROUND AND OBJECTIVES: We investigated a pertussis outbreak characterized by atypical cases, confirmed by polymerase chain reaction (PCR) alone at a single laboratory, which persisted despite high vaccine coverage and routine control measures. We aimed to determine whether Bordetella pertussis was the causative agent and advise on control interventions. METHODS: We conducted case ascertainment, confirmatory testing for pertussis and other pathogens, and an assessment for possible sources of specimen contamination, including a survey of clinic practices, sampling clinics for B pertussis DNA, and review of laboratory quality indicators. RESULTS: Between November 28, 2008, and September 4, 2009, 125 cases were reported, of which 92 (74%) were PCR positive. Cases occurring after April 2009 (n = 79; 63%) had fewer classic pertussis symptoms (63% vs 98%; P < .01), smaller amounts of B pertussis DNA (mean PCR cycle threshold value: 40.9 vs 33.1; P < .01), and a greater proportion of PCR-positive results (34% vs 6%; P < .01). Cultures and serology for B pertussis were negative. Other common respiratory pathogens were detected. We identified factors that likely resulted in specimen contamination at the point of collection: environmentally present B pertussis DNA in clinics from vaccine, clinic standard specimen collection practices, use of liquid transport medium, and lack of clinically relevant PCR cutoffs. CONCLUSIONS: A summer pertussis pseudo-outbreak, multifactorial in cause, likely occurred. Recommendations beyond standard practice were made to providers on specimen collection and environmental cleaning, and to laboratories on standardizing PCR protocols and reporting results, to minimize false-positive results from contaminated clinical specimens. |
Novel Corynebacterium diphtheriae in domestic cats
Hall AJ , Cassiday PK , Bernard KA , Bolt F , Steigerwalt AG , Bixler D , Pawloski LC , Whitney AM , Iwaki M , Baldwin A , Dowson CG , Komiya T , Takahashi M , Hinrikson HP , Tondella ML . Emerg Infect Dis 2010 16 (4) 688-91 Novel nontoxigenic Corynebacterium diphtheriae was isolated from a domestic cat with severe otitis. Contact investigation and carrier study of human and animal contacts yielded 3 additional, identical isolates from cats, although no evidence of zoonotic transmission was identified. Molecular methods distinguished the feline isolates from known C. diphtheriae. |
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