Severe Pertussis Research Articles

Bordetella pertussis infection in infants less than three months: analysis of 59 cases from 2011 to 2015 in a single center

Objective To study the epidemiological and clinical characteristics of pertussis in infants younger than three months. Methods Infants younger than three months were enrolled from January 1, 2011 to December 31, 2015 with one or more of the following symptoms: persistent cough, spasmic cough, cyanosis of unknown causes, asphyxia and apnea. Multiplex polymerase chain reaction(PCR) assay was performed to identifyBordetella pertussisand enzyme-linked immunosorbent assay was used to detect antibody to pertussis toxin. Clinical features, complications, treatments and prognosis of the infants confirmed with pertussis were analyzed. Results Altogether 202 cases were enrolled in the five years, and 59 (29.2%) of which were positive for pertussis confirmed by multiplex PCR. Among the 59 cases, 37 were boys and 22 were girls. The youngest baby was 13 days and the oldest one was 85 days. Length of stay ranged from 7 to 21 days. Twelve cases had a contact history with family members having chronic cough. Symptoms occurred in spring or summer in 46 cases (78.0%), and in autumn or winter in 13 (22.0%) cases. Symptoms of spasmic cough, cyanosis after coughing, vomiting after coughing and conjunctival hemorrhage were respectively found in 41 (69.5%), 36 (61.0%), 39 (66.1%) and 33 (55.9%) cases, while only six (10.2%) presented with inspiratory whooping sound on coughing. Forty-nine cases (83.1%) showed increased lymphocyte count (≥10×109/L). Twenty-eight cases (47.5%) developed severe pertussis. Complications including apnea and bradycardia after coughing, respiratory failure and heart failure, pertussis encephalopathy as well as highly increased leucocyte count (≥60×109/L) occurred in 23 (39.0%), 18 (30.5%), five (8.5%) and four (6.8%) cases, respectively. Twenty-four cases with severe pertussis required respiratory support, of which six received invasive ventilation and 18 received non-invasive ventilation. Fifty-eight infants were recovered and discharged, while one baby died. Conclusions Bordetella pertussisinfection is an important cause of persistent cough in unimmunized infants under three months of age. The symptoms of pertussis in infants are untypical, but the incidence of severe pertussis is high.Thus early diagnosis and timely treatment are necessary. Key words: Whooping cough; Infant; Cough; Incidence

Reduced Severity of Pertussis in Persons With Age-Appropriate Pertussis Vaccination-United States, 2010-2012.

In 2012, >48000 pertussis cases were reported in the United States. Many cases occurred in vaccinated persons, showing that pertussis vaccination does not prevent all pertussis cases. However, pertussis vaccination may have an impact on disease severity. We analyzed data on probable and confirmed pertussis cases reported through Enhanced Pertussis Surveillance (Emerging Infections Program Network) between 2010 and 2012. Surveillance data were collected through physician and patient interview and vaccine registries. We assessed whether having received an age-appropriate number of pertussis vaccines (AAV) (for persons aged ≥3 months) was associated with reduced odds of posttussive vomiting, a marker of more clinically significant illness, or of severe pertussis (seizure, encephalopathy, pneumonia, and/or hospitalization). Adjusted odds ratios were calculated using multivariable logistic regression. Among 9801 pertussis patients aged ≥3 months, 77.6% were AAV. AAV status was associated with a 60% reduction in odds of severe disease in children aged 7 months-6 years in multivariable logistic regression and a 30% reduction in odds of posttussive vomiting in persons aged 19 months-64 years. Serious pertussis symptoms and complications are less common among AAV pertussis patients, demonstrating that the positive impact of pertussis vaccination extends beyond decreasing risk of disease.

An update of the global burden of pertussis in children younger than 5 years: a modelling study

Since the publication in 2003 of a model to estimate the disease burden of pertussis, new evidence of the protective effect of incomplete pertussis vaccination against severe pertussis has been reported. We revised the model to provide new estimates of regional and global pertussis cases and deaths for children younger than 5 years. We developed a revised model with data from 2014 to estimate pertussis cases and deaths. Pertussis cases were defined according to the WHO clinical case definition, as a coughing illness lasting at least 2 weeks with paroxysms of coughing, inspiratory whooping, or post-tussive vomiting. We used UN population estimates and WHO and UNICEF data on national pertussis immunisation coverage. Estimates were made for vaccine effectiveness against pertussis cases and deaths for one, two, and three doses of vaccination, probability of infection in low and high coverage countries, and case fatality ratios in low and high mortality countries in two age groups: infants younger than 1 year and children aged 1-4 years. We did sensitivity analyses with a range of input parameters to assess the effect of uncertainty of the input parameters on the model outputs. We estimated that there were 24·1 million pertussis cases and 160 700 deaths from pertussis in children younger than 5 years in 2014, with the African region contributing the largest proportions (7·8 million [33%] cases and 92 500 [58%] deaths). 5·1 million (21%) estimated pertussis cases and 85 900 (53%) estimated deaths were in infants younger than 1 year. In the sensitivity analyses, the estimated number of cases ranged from 7 million to 40 million and deaths from 38 000 to 670 000. Our estimates suggest that, compared with the 1999 estimates published in 2003 (30·6 million pertussis cases and 390 000 deaths from pertussis in children younger than 5 years), the numbers of cases and deaths of pertussis have fallen substantially. Model sensitivity emphasised the importance of better surveillance to improve country-level decision making and pertussis control. None.

Maternal pertussis immunisation: clinical gains and epidemiological legacy.

The increase in whooping cough (pertussis) incidence in many countries with high routine vaccination coverage is alarming, with incidence in the US reaching almost 50,000 reported cases per year, reflecting incidence levels not seen since the 1950s. While the potential explanations for this resurgence remain debated, we face an urgent need to protect newborns, especially during the time window between birth and the first routine vaccination dose. Maternal immunisation has been proposed as an effective strategy for protecting neonates, who are at higher risk of severe pertussis disease and mortality. However, if maternally derived antibodies adversely affect the immunogenicity of the routine schedule, through blunting effects, we may observe a gradual degradation of herd immunity. ‘Wasted’ vaccines would result in an accumulation of susceptible children in the population, specifically leading to an overall increase in incidence in older age groups. In this Perspective, we discuss potential long-term epidemiological effects of maternal immunisation, as determined by possible immune interference outcomes.

Severe pertussis infection in infants less than 6 months of age: Clinical manifestations and molecular characterization

ABSTRACTWe conducted a study to determine the main traits of pertussis among unimmunized infants less than 6 months of age. From August 2012 to March 2015, 141 nasopharyngeal aspirates (NPAs) were collected from infants with respiratory symptoms attending 2 major hospitals in Rome. Clinical data were recorded and analyzed. Lab-confirmation was performed by culture and realtime PCR. B. pertussis virulence-associated genes (ptxP, ptxA and prn), together with multilocus variable-number tandem repeat analysis (MLVA), were also investigated by the sequence-based analysis on the DNAs extracted from positive samples. Antibiotic susceptibility with Etest was defined on 18 viable B. pertussis isolates. Samples from 73 infants resulted positives for B. pertussis. The median age of the patients was 45 d (range 7–165); 21 infants were treated with macrolides before hospital admission. Cough was reported for a median of 10 d before admission and 18 d after hospital discharge among infected infants, 84% of whom showed paroxysmal cough. No resistance to macrolides was detected. Molecular analysis identified MT27 as the predominant MLVA profile, combined with ptxP3-ptxA1-prn2 associated virulence genes.Although our data may not be generalized to the whole country, they provide evidence of disease severity among infants not vaccinated against pertussis. Moreover, genetically related B. pertussis strains, comprising allelic variants of virulence associated genes, were identified.

Characteristics of Bordetella pertussis infection among infantsand children admitted to paediatric intensive care units in Greece: A multicentre, 11-year study.

To describe children with pertussis who required intensive care. This is a retrospective analysis of pertussis admissions to all (six) national intensive care units in Greece from 2003 to 2013. A total of 31 children were included, 28 of whom were younger than 12 months old. Cough was the most prominent symptom, being present in 27 of 31 (87%) patients, and on admission, only 7 (22.6%) satisfied the case definition. Mechanical ventilation was initiated in 13 (42%) patients. Six patients died because of respiratory failure (two) or multi-organ system failure (four). The patients who died had significantly higher white blood cell counts (WBC) (77 800-31 600, P = 0.031) and neutrophils (29 016-12 795, P = 0021) than those who survived and lower minimum values of serum sodium (125-133, P = 0002). They also had a longer duration of hospitalisation prior to their paediatric intensive care unit admission (6-1 days, P = 0022). Three patients were diagnosed with pulmonary hypertension, and only one of them survived. Age, gender and immunisation status did not differ between survivors and non-survivors. Two patients received exchange blood transfusion, and survival benefit was not apparent. Young infants are at risk of severe pertussis, resulting in serious complications or death. Elevated WBC and low serum sodium are associated with higher mortality. Despite advances in life support and treatment of organ failure in childhood critical illness, pertussis still has substantial mortality.

Durability and Kinetics of Maternal Pertussis Antibodies in Infants of Mothers Immunized with Tdap During Pregnancy

BackgroundInfant protection against severe pertussis requires sufficient maternal pertussis antibodies until infant immunization begins. The kinetics of maternally-derived Tdap-induced antibodies in infants is poorly understood.Methods34 healthy mother-infant pairs were followed prospectively from maternal Tdap immunization to infant age 6 weeks. Blood was collected from women pre-Tdap, 4 weeks post Tdap and at delivery, and from infants at birth, and age 3 and 6 weeks. IgG to pertussis toxin (PT), filamentous hemagglutinin (FHA), fimbrial proteins (FIM) and pertactin (PRN) was quantified by luminex assay (IU/mL). Geometric mean concentrations (GMCs) with 95% confidence intervals (C.I.) for pertussis-specific IgG and half-life of IgG to PT were calculated.ResultsMean maternal age was 31.1 years (range 22.7–39.7); 47% were white, 32% Hispanic and 21% Black. Tdap was administered at a mean gestation of 30.7 weeks (28–32.7). Infants had a mean gestation of 39.1 weeks (36–41.1) and birthweight of 3379g (2580–4584). GMCs (95%C.I.) for maternal pertussis-specific IgG increased significantly 4 weeks post-Tdap (4-fold higher in 59%, 41%, 29% and 44% for PT, FHA, FIM and PRN, respectively) and waned before delivery. Placental transfer was 135% for PT, 141% for FHA, 131% for FIM and 136% for PRN. Maternal antibodies in infants decayed quickly, but at age 6 weeks GMC of infant PT-specific IgG was 21.1IU/mL (14.7–30.2) and 91% had PT ≥ 10 IU/mL. Estimated half-life of PT-specific IgG in infants was 30.9 days. Time PT (IU/mL) FHA (IU/mL) FIM (IU/mL) PRN (IU/mL) Pre-Tdap9.85 (6.71–14.45)32.81 (21.79–49.42)131.55 (81.98–211.15)55.67 (35.75–86.68)Post-Tdap46.8 (34.4–63.68)116.82 (88.9–153.5)440.35 (327.57–591.97)233.02 (179.14–303.04)Maternal Delivery40.78 (29.4–56.53)104.81 (78.27–140.35)384.5 (287.41–514.28)204.41 (155.42–268.84)Infant Cord55.12 (38.65–78.6)147.81 (113.47–192.49)505.36 (366.44–696.95)278.55 (216.57–358.26)Infant 3w30.73 (21.57–43.79)82.49 (63.65–106.93)292.87 (221.11–388.06)167.72 (129.57–217.07)Infant 6w21.1 (14.72–30.23)54.98 (41.97–72.03)210.52 (153.74–288.27)113.03 (86.94–146.99)ConclusionAlthough the half-life of maternal PT- specific antibodies induced by Tdap immunization during the third trimester of pregnancy is shorter than previously thought, this strategy results in levels likely sufficient to protect infants through the start of the immunization series.Disclosures All authors: No reported disclosures.

Ciddi Boğmaca Pnömonisi Olan Bir İnfantta Kan Değişimiyle Tedavi

Ciddi Boğmaca Pnömonisi Olan Bir İnfantta Kan Değişimiyle Tedavi

Pertussis in north-central and northwestern regions of Algeria.

Pertussis outbreaks continue to occur in many countries despite high vaccination coverage. Under-diagnosed cases in adolescents and adults may result in increased transmission to infants, who are at risk of severe pertussis. Additional measures to protect both groups should be considered. Nasopharyngeal samples and sera were collected from patients and household contacts with clinically suspected pertussis. Diagnoses were confirmed by culture, real-time polymerase chain reaction (PCR), and serology. Bordetella pertussis isolates were characterized by antimicrobial sensitivity and fimbrial serotyping. Of 392 participants, 134/248 patients (54%) and 66/144 contacts (45.8%) had confirmed pertussis infections. B. parapertussis was not detected. All B. pertussis isolates were sensitive to the antibiotics tested, and all expressed the Fim3, not the Fim2, fimbrial serotype. Most patients (81.2%) were <6 months (51.8% of whom were <3 months) of age; 77.6% were unvaccinated, and most positive contacts were mothers 20-40 years of age. Despite high vaccination coverage, pertussis is circulating in Algeria. Most infections occur in unvaccinated infants <6 months of age, with mothers as the main source of infection. An adolescent/adult booster should be considered. Adoption of sensitive and specific laboratory tests would improve pertussis diagnosis and surveillance.

Incidence of Severe and Nonsevere Pertussis Among HIV-Exposed and -Unexposed Zambian Infants Through 14 Weeks of Age: Results From the Southern Africa Mother Infant Pertussis Study (SAMIPS), a Longitudinal Birth Cohort Study.

Background. Maternal vaccination with tetanus, reduced-dose diphtheria, and acellular pertussis vaccine (Tdap) could be an effective way of mitigating the high residual burden of infant morbidity and mortality caused by Bordetella pertussis. To better inform such interventions, we conducted a burden-of-disease study to determine the incidence of severe and nonsevere pertussis among a population of Zambian infants.Methods. Mother–infant pairs were enrolled at 1 week of life, and then seen at 2- to 3-week intervals through 14 weeks of age. At each visit, nasopharyngeal (NP) swabs were obtained from both, and symptoms were catalogued. Using polymerase chain reaction (PCR) to identify cases, and a severity scoring system to triage these into severe/nonsevere, we calculated disease incidence using person-time at risk as the denominator.Results. From a population of 1981 infants, we identified 10 with clinical pertussis, for an overall incidence of 2.4 cases (95% confidence interval [CI], 1.2–4.2) per 1000 infant-months and a cumulative incidence of 5.2 cases (95% CI, 2.6–9.0) per 1000 infants. Nine of 10 cases occurred within a 3-month window (May–July 2015), with highest incidence between birth and 6 weeks of age (3.5 cases per 1000 infant-months), concentrated among infants prior to vaccination or among those who had only received 1 dose of Diphtheria Tetanus whole cell Pertussis (DTwP). Maternal human immunodeficiency virus (HIV) modestly increased the risk of infant pertussis (risk ratio, 1.8 [95% CI, .5–6.9]). Only 1 of 10 infant cases qualified as having severe pertussis. The rest presented with the mild and nonspecific symptoms of cough, coryza, and/or tachypnea. Notably, cough durations were long, exceeding 30 days in several cases, with PCRs repeatedly positive over time.Conclusions. Pertussis is circulating freely among this population of Zambian infants but rarely presents with the classical symptoms of paroxysmal cough, whooping, apnea, and cyanosis. Maternal HIV appears to increase the risk, while lack of effective exposure to DTwP increased the risk.

An Assessment of the Cocooning Strategy for Preventing Infant Pertussis-United States, 2011.

Infants are at greatest risk for severe pertussis. In 2006, the Advisory Committee on Immunization Practices recommended that adolescents and adults, especially those with infant contact, receive a single dose of Tdap (tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine). To assess the effectiveness of cocooning, we conducted a case-control evaluation of infant close contacts. Pertussis cases aged <2 months with onset between 1 January 2011 and 31 December 2011 were identified in Emerging Infections Program Network sites. For each case, we recruited 3 controls from birth certificates and interviewed identified adult close contacts (CCs) or parents of CCs aged <18 years. Pertussis vaccination was verified through medical providers and/or immunization registries. Forty-two cases were enrolled, with 154 matched controls. Around enrolled infants, 859 CCs were identified (600 adult and 259 nonadult). An average of 5.4 CCs was identified per case and 4.1 CCs per control. Five hundred fifty-four (64.5%) CCs were enrolled (371 adult and 183 non-adult CCs); 119 (32.1% of enrolled) adult CCs had received Tdap. The proportion of Tdap-vaccinated adult CCs was similar between cases and controls (P = .89). The 600 identified adult CCs comprised 172 potential cocoons; 71 (41.3%) potential cocoons had all identified adult CCs enrolled. Of these, 9 were fully vaccinated and 43.7% contained no Tdap-vaccinated adults. The proportion of fully vaccinated case (4.8%) and control (10.0%) cocoons was similar (P = .43). Low Tdap coverage among adult CCs reinforces the difficulty of implementing the cocooning strategy and the importance of vaccination during pregnancy to prevent infant pertussis.

Effectiveness of Prenatal Tetanus, Diphtheria, and Acellular Pertussis Vaccination on Pertussis Severity in Infants.

All US women are recommended to receive a tetanus, diphtheria, and acellular pertussis (Tdap) vaccine at 27-36 weeks gestation during each pregnancy to reduce the risk of pertussis to their infants. The impact of this strategy on severity of disease among infected infants has not been evaluated. We use a retrospective cohort study design evaluating whether pertussis-infected infants born in 2011-2015 whose mothers received Tdap vaccine during pregnancy had less severe pertussis, resulting in a lower risk of hospitalization or intensive care unit admission compared with infants born to unvaccinated mothers. Infected infants of vaccinated mothers were significantly less likely to be hospitalized and had significantly shorter hospital stays compared with infants born to unvaccinated mothers, after adjustment for chronological and gestational age and receipt of diphtheria and tetanus toxoids and acellular pertussis vaccine. Unadjusted and adjusted vaccine effectiveness for preventing hospitalization among infants with pertussis was 72% (95% confidence interval [CI], 49%-85%) and 58% (95% CI 15%-80%), respectively. No infants born to vaccinated mothers required intubation or died of pertussis. Infants with pertussis whose mothers received Tdap during pregnancy had a significantly lower risk of hospitalization and intensive care unit admission and shorter hospital stays. Prenatal Tdap vaccination is a critical strategy for reducing the morbidity and mortality from pertussis.

Burden and Outcomes of Severe Pertussis Infection in Critically Ill Infants.

Despite World Health Organization endorsed immunization schedules, Bordetella pertussis continues to cause severe infections, predominantly in infants. There is a lack of data on the frequency and outcome of severe pertussis infections in infants requiring ICU admission. We aimed to describe admission rates, severity, mortality, and costs of pertussis infections in critically ill infants. Binational observational multicenter study. Ten PICUs and 19 general ICUs in Australia and New Zealand contributing to the Australian and New Zealand Paediatric Intensive Care Registry. Infants below 1 year of age, requiring intensive care due to pertussis infection in Australia and New Zealand between 2002 and 2014. During the study period, 416 of 42,958 (1.0%) infants admitted to the ICU were diagnosed with pertussis. The estimated population-based ICU admission rate due to pertussis ranged from 2.1/100,000 infants to 18.6/100,000 infants. Admission rates were the highest among infants less than 60 days old (p < 0.0001). Two hundred six infants (49.5%) required mechanical ventilation, including 20 (4.8%) treated with high-frequency oscillatory ventilation, 16 (3.8%) with inhaled nitric oxide, and 7 (1.7%) with extracorporeal membrane oxygenation. Twenty of the 416 children (4.8%) died. The need for mechanical ventilation, high-frequency oscillatory ventilation, nitric oxide, and extracorporeal membrane oxygenation were significantly associated with mortality (p < 0.01). Direct severe pertussis-related hospitalization costs were in excess of USD$1,000,000 per year. Pertussis continues to cause significant morbidity and mortality in infants, in particular during the first months of life. Improved strategies are required to reduce the significant healthcare costs and disease burden of this vaccine-preventable disease.

Bordetella pertussis: new concepts in pathogenesis and treatment.

The purpose of this review is to summarize and discuss recent findings and selected topics of interest in Bordetella pertussis virulence and pathogenesis and treatment of pertussis. It is not intended to cover issues on immune responses to B. pertussis infection or problems with currently used pertussis vaccines. Studies on the activities of various B. pertussis virulence factors include the immunomodulatory activities of filamentous hemagglutinin, fimbriae, and adenylate cyclase toxin. Recently emerging B. pertussis strains show evidence of genetic selection for vaccine escape mutants, with changes in vaccine antigen-expressing genes, some of which may have increased the virulence of this pathogen. Severe and fatal pertussis in young infants continues to be a problem, with several studies highlighting predictors of fatality, including the extreme leukocytosis associated with this infection. Treatments for pertussis are extremely limited, though early antibiotic intervention may be beneficial. Neutralizing pertussis toxin activity may be an effective strategy, as well as targeting two host proteins, pendrin and sphingosine-1-phosphate receptors, as novel potential therapeutic interventions. Pertussis is reemerging as a major public health problem and continued basic research is revealing information on bacterial virulence and disease pathogenesis, as well as potential novel strategies for vaccination and targets for therapeutic intervention.

Differences in Bordetella pertussis DNA load according to clinical and epidemiological characteristics of patients with whooping cough

To identify associations between nasopharyngeal Bordetella pertussis DNA load and clinical and epidemiological characteristics and evaluate DNA load prognostic value in pertussis severity. Prospective observational multi-centre study including nasopharyngeal samples positive to pertussis DNA by real-time PCR collected from children and adult patients in more than 200 health centres of Catalonia (Spain) during 2012-2013. B. pertussis load was inversely correlated with age (rho = -0.32, p < 0.001), time to diagnosis (rho = -0.33, p < 0.001) and number of symptoms (rho = 0.13, p = 0.002). Median bacterial load was significantly higher in inpatients versus outpatients (4.91 vs. 2.55 log10 CFU/mL, p < 0.001), patients with complications versus those without (6.05 vs. 2.82 log10 CFU/mL, p < 0.001), disease incidence in summer and autumn versus spring and winter (3.50 vs. 2.21 log10 CFU/mL, p = 0.002), and unvaccinated-partially vaccinated patients versus vaccinated (4.20 vs. 2.76 log10 CFU/mL, p = 0.004). A logistic regression model including bacterial load and other candidate prognostic factors showed good prediction for hospital care (AUC = 0.94) although only age and unvaccinated status were found to be prognostic factors. We observed strong positive associations of nasopharyngeal bacterial load with severity outcomes of hospitalisation and occurrence of complications. Bacterial load and other independent variables contributed to an accurate prognostic model for hospitalisation.

The relationship between Bordetella pertussis genotype and clinical severity in Australian children with pertussis

Changes in circulating Bordetella pertussis genotypes, including a novel pertussis toxin promoter ptxP3 allele and absence of pertactin (Prn) antigen, have been reported from several countries but limited data on relative severity are available. We compared markers of disease severity in children with B. pertussis infection due to strains of differing genotype. Culture confirmed cases presenting to tertiary paediatric hospitals in three Australian states between 2008 and 2012 were classified as severe if they required a hospital stay greater than seven days, were admitted to intensive care, or if death occurred. Associations between age, vaccination, genotype and severity were assessed. Of 199 pertussis cases, 81 (41%) were <3 months, including 32/39 (82%) of severe cases. The proportion of isolates from these cases that were Prn deficient increased markedly between 2008 and 2012. Of B. pertussis isolates, the proportion considered severe was similar for Prn positive (27/128, 21%) and Prn deficient (12/71, 17%) cases but only 1/22 (4.5%) of non ptxP3 cases were severe versus 38/177 (21.4%) ptxP3 positive. Adjusting for ptxP type, vaccination status and age, disease severity was not significantly associated with Prn status (RRA: 0.95, [0.57-1.56]; p=0.83). In children, we found no relationship between Prn status and markers of severe pertussis. An increased proportion of severe disease in isolates with the ptxP3 allele was observed.

Update on leukoreduction therapies as alternatives for the treatment of severe pertussis

Pertussis is a contagious disease that in patients under 1 year of age may evolve to a highly lethal course characterized by hypoxemia and refractory pulmonary hypertension, being this responsible for cardiovascular collapse. Pulmonary hypertension occurs by direct action of bacteria and its toxins, responsible for the vascular tone alteration associated with hyperviscosity syndrome and arteriolar thrombosis due to hyperleukocytosis. Since 2004, leucodepletion has been proposed as a treatment option; there are currently 18 publications on leucodepletion in patients with severe Pertussis, with a total of 288 patients, 68 cytoreduction procedures and a mortality rate of 28% in those exposed to the mentioned treatment. Published studies have design limitations, so the evidence for using leukoreduction in patients with severe pertussis remains low.

Predictors of severity of pertussis

Journal of Paediatrics and Child HealthVolume 51, Issue 10 p. 1044-1044 Heads UpFree Access Predictors of severity of pertussis First published: 01 October 2015 https://doi.org/10.1111/jpc.13004 edited by Craig Mellis ([email protected]) AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Pertussis continues to cause large epidemics every 3–4 years even in countries like Australia with high levels of childhood immunisation. A multicentre Australian study classified the severity of illness in children admitted to hospital with pertussis during a 2009–2010 pertussis outbreak, using a simple novel clinical scoring system.1 The study enrolled 120 children up to 17 years old, of whom 46 (38.3%) were classified as having severe disease. Logistic regression analysis identified the variables significantly associated with severe pertussis as age <2 months, co-infection with a virus such as rhinovirus or respiratory syncytial virus or with a bacterium, fever >37.5°C (which may be a surrogate for co-infection as pertussis is usually afebrile) and a history of prematurity <37 weeks' gestation. A third of children > 2 months old had not received any pertussis vaccine, but in this study immunisation status did not predict severity, which may be because a single dose of vaccine provides little protection. Strategies that might protect the most vulnerable infants <2 months old include maternal immunisation in late pregnancy and reverting to whole cell pertussis vaccine, at least for the first dose. Reference 1Marshall H, Clarke M, Rasiah K et al. Predictors of disease severity in children hospitalized for pertussis during an epidemic. Pediatr. Infect. Dis. J. 2015; 34: 339– 345. Reviewer: David Isaacs, [email protected], Children's Hospital at Westmead, Sydney Volume51, Issue10October 2015Pages 1044-1044 ReferencesRelatedInformation

Clinical analysis of 247 children with whooping cough and the risk factors of severe cases

To summarize the clinical characteristics of whooping cough in children and analyze the risk factors for severe whooping cough. A retrospective analysis was made on the clinical data of 247 children with whooping cough in Children's Hospital of Chongqing Medical University between Jan 2013 and Dec 2014. Of these patients, 126 were male, 121 were female, the median age was 3.1 months (23 days-4 years and eight months old). The patients were divided into two groups, group 1 had infants less than 3 months of age (n=120) and group 2 had infants and young children older than 3 months (n=127) according to their age. On the other hand, the patients were also divided into two groups according to vaccination status: vaccinated group (received diphtheria toxoid, tetanus toxoid, and acellular pertussis, DTP) (n=31) and unvaccinated group (n=188). Pure Bordetella pertussis infection was seen in 106 cases, and 141 cases had mixed infection. Severe disease was seen in 13 cases, and the other 234 cases had the modest disease. Clinical data were retrospectively analyzed and compared. (1) Bordetella pertussis was identified in 57/680 cases (8.4%) in 2013, and 190/1 856 cases (10.2%) in 2014. The disease could be seen throughout the year, but 182 cases (73.7%) occurred in summer or autumn; 202 cases (81.8%) were less than 6 months. (2) Paroxysmal cough was seen in 238 cases (96.4%) , 61 cases (24.7%) had inspiratory whoop. Infants in group 1 often had episodes of cyanosis, apnea and suffocation (χ² = 19.999, 12.081, 6.508, P<0.05), persistent cough was often seen in group 2 (χ² = 9.885, P<0.05). Complications such as severe pneumonia, pulmonary consolidation and encephalopathy were more common in the group 1 than in group 2 (χ² = 17.340, 6.080, 11.030, 23.545, P<0.05). (3) The length of stay of group 1, and of unvaccinated group was significantly longer than that of group 2 and of vaccinated group (t=19.331, 26.741, P<0.05). (4) Leukocytosis was found in 224 cases (90.7%), 182 cases (73.7%) had predominant lymphocytosis. White blood cell in group 1, unvaccinated group and severe disease group was higher than the corresponding group (t=11.075,13.739,3.469, P<0.05). (5) Patients who had a history of exposure, fever, leukocytosis and pulmonary consolidation or atelectasis on chest imaging were prone to develop into severe pertussis (OR=4.521, 4.900, 1.085, 4.792, 50.400; P<0.05). A total of 244 cases (98.8%) recovered, 3 cases (1.2%) died, they were less than 3 months old and unvaccinated. The number of cases with whooping cough in Chongqing area tends to be rising. The disease occurred mostly in summer and fall. Infants less than 3 months old, unvaccinated with DTP had high susceptibility to pertussis, often had a severe clinical presentation and severe complications, had a high mortality rate.

Severe Neonatal Pertussis Treated by Leukodepletion and Early Extra Corporeal Membrane Oxygenation

We report the case of a 17-day-old infant with severe pertussis for whom the early initiation of veno-arterial extra corporeal membrane oxygenation and leukodepletion strategies (exchange transfusion and leukofiltration) allowed to reduce leukocytosis and pulmonary hypertension, thus leading to survival. These invasive techniques can be considered when severe pulmonary hypertension complicates hyperleukocytosis in neonates.