The rise of pertussis in Malta in 2011 : a case for adolescent and adult pertussis booster vaccination

Notwithstanding the high rates of pertussis infant vaccination coverage in developed countries, Bortedella pertussis infections are manifesting a changing epidemiological pattern of disease. Of notable concern is the rise of pertussis in adolescents and adults. This changing picture is largely attributable to waning immunity after natural infection or vaccination. The belief that pertussis is chiefly a childhood disease is a common misconception. A significant rise of pertussis cases in Malta in older age groups was recorded in 2011. The addition of an adolescent and/or an adult booster dose against pertussis should be strongly considered.peer-reviewe

Differential and Temporal Immunomodulation of alpha4 Integrins on CD4+ Memory Cells by Bordetella pertussis and Bordetella parapertussis

Pertussis, caused by Bordetella pertussis (B. pertussis), is reemerging worldwide due to vaccine inefficacy. The hallmarks of infection are extreme lymphocytosis and delayed recovery, which are partially associated with pertussis toxin. Lymphocytes migrate to infected tissues using trafficking receptors. Specific combinations of these lymphocyte trafficking receptors are identified for skin and gut but are not well established for lung. This study focused on the effect of pertussis toxin on lung-associated trafficking receptors and tested the hypothesis that pertussis toxin alters dendritic cell imprinting of lung trafficking receptors on T cells, thus delaying resolution of the infection. B. pertussis-infected mice were compared with pertussis toxin-deficient strains. Imprinting of trafficking receptors on allogeneic T cells by dendritic cells derived from Bordetella-infected mice was analyzed by flow cytometry. Mice infected with Bordetella strains showed an increase in mature dendritic cells on day 5 post-infection. Despite their mature phenotype, dendritic cells from B. pertussis infection, were compromised in their ability to imprint lung trafficking receptors on allogenic T cells. These results indicated a pertussis toxin-dependent defect in dendritic cell imprinting of lung trafficking receptors on T cells. In conclusion, this study provides important data for future vaccine development against respiratory pathogens

Brain damage following whooping cough vaccination : is it time to lay the myth to rest?

Whooping cough causes significant morbidity and mortality, especially in early infancy. Although an effective vaccine exists, vaccine uptake in Malta was previously disappointing due to the general public’s and the medical community’s doubts regarding vaccine efficacy and safety. The aim of this study was to review population-based studies which have analysed the potential short and long term neurological sequelae following pertussis and pertussis vaccination, to describe vaccine uptake globally and in Malta over the past 15 years, and to analyse the effect of vaccine uptake on pertussis epidemics in Malta. This study found that pertussis vaccine uptake has only become satisfactory in recent years, with a resulting attenuation in the most recent pertussis outbreak. Uptake has increased progressively all over the world, and no study has ever incriminated pertussis vaccination as a cause of permanent neurological disability, both locally and abroad. This should encourage the present continuing trend of pertussis uptake.peer-reviewe

Infants hospitalized for Bordetella pertussis infection commonly have respiratory viral coinfections

Background: Whether viral coinfections cause more severe disease than Bordetella pertussis (B. pertussis) alone remains unclear. We compared clinical disease severity and sought clinical and demographic differences between infants with B. pertussis infection alone and those with respiratory viral coinfections. We also analyzed how respiratory infections were distributed during the 2 years study. Methods: We enrolled 53 infants with pertussis younger than 180 days (median age 58 days, range 17–109 days, 64. 1% boys), hospitalized in the Pediatric Departments at “Sapienza” University Rome and Bambino Gesù Children’s Hospital from August 2012 to November 2014. We tested in naso-pharyngeal washings B. pertussis and 14 respiratory viruses with real-time reverse-transcriptase-polymerase chain reaction. Clinical data were obtained from hospital records and demographic characteristics collected using a structured questionnaire. Results: 28/53 infants had B. pertussis alone and 25 viral coinfection: 10 human rhinovirus (9 alone and 1 in coinfection with parainfluenza virus), 3 human coronavirus, 2 respiratory syncytial virus. No differences were observed in clinical disease severity between infants with B. pertussis infection alone and those with coinfections. Infants with B. pertussis alone were younger than infants with coinfections, and less often breastfeed at admission. Conclusions: In this descriptive study, no associations between clinical severity and pertussis with or without co-infections were found

Increase in pertussis cases along with high prevalence of two emerging genotypes of Bordetella pertussis in Perú, 2012

As has occurred in many regions worldwide, in 2012 the incidence of pertussis increased in Perú. This epidemiologic situation has been associated with a waning vaccine-induced immunity and the adaptation of Bordetella pertussis to vaccine-induced immunity along with improved diagnostic methods. Methods: The study comprised a total of 840 pertussis-suspected cases reported in Perú during 2012. We summarize here the distribution of pertussis cases according to age and immunization status along with the immunization-coverage rate. Laboratory diagnosis was performed by culture test and real-time polymerase-chain reaction (PCR). B. pertussis bacteria recovered from infected patients were characterized by pulsed-field gel electrophoresis (PFGE), and the DNA sequencing of the pertussis-toxin (promoter and subunit A), pertactin, and fimbriae (fim2 and fim3) genes. Results: From the total pertussis-suspected cases, 191 (22.7 %) infections were confirmed by real-time PCR and 18 through cultivation of B. pertussis (2.1 %), while one infection of B. parapertussis (0.11 %) was also detected by culture. Pertussis was significantly higher in patients that had had 0-3 vaccine doses (pentavalent vaccine alone) than in those who had had 4-5 vaccine doses (pentavalent plus DwPT boosters) at 94.3 vs. 5.7 %, respectively (p < 0.00001). The relative risk (RR) for patients with 4-5 doses compared to those with fewer than 4 doses or no dose was 0.23 (95 % Confidence Interval: 0.11-0.44), while the vaccine effectiveness was 77 % and coverage 50.5 %. Genetic analysis of B. pertussis isolates from different Peruvian regions detected two clonal groups as identified by PFGE. Those two groups corresponded to the B. pertussis genotypes emerging worldwide ptxP3-ptxA1-prn2 or 9-fim3-1 and ptxP3-ptxA1-prn2 or 9-fim3-2. Conclusions: Two emerging B. pertussis genotypes similar to isolates involved in worldwide epidemics were detected in Perú. Low vaccine coverage (<50 %) and genetic divergence between the vaccine-producing strain and the local isolates could contribute to this pertussal epidemic.Fil: Bailon, H. Instituto Nacional de Salud; PerúFil: León-Janampa, N. Instituto Nacional de Salud; PerúFil: Padilla, C.. Instituto Nacional de Salud; PerúFil: Hozbor, Daniela Flavia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

Protection against pertussis in humans correlates to elevated serum antibodies and memory B cells

Pertussis is a respiratory infection caused by Bordetella pertussis that may be particularly severe and even lethal in the first months of life when infants are still too young to be vaccinated. Adults and adolescents experience mild symptoms and are the source of infection for neonates. Adoptive maternal immunity does not prevent pertussis in the neonate. We compared the specific immune response of mothers of neonates diagnosed with pertussis and mothers of control children. We show that women have pre-existing pertussis-specific antibodies and memory B cells and react against the infection with a recall response increasing the levels specific serum IgG, milk IgA, and the frequency of memory B cells of all isotypes. Thus, the maternal immune system is activated in response to pertussis and effectively prevents the disease indicating that the low levels of pre-formed serum antibodies are insufficient for protection. For this reason, memory B cells play a major role in the adult defense. The results of this study suggest that new strategies for vaccine design should aim at increasing long-lived plasma cells and their antibodies

Estimation of effective vaccination rate for pertussis in New Zealand as a case study

In some cases vaccination is unreliable. For example vaccination against pertussis has comparatively high level of primary and secondary failures. To evaluate efficiency of vaccination we introduce the idea of effective vaccination rate and suggest an approach to estimate it. We consider pertussis in New Zealand as a case study. The results indicate that the level of immunity failure for pertussis is considerably higher than was anticipated

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

We conducted a study to determine the main traits of pertussis among unimmunized infants less than 6&nbsp;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&nbsp;d (range 7–165); 21 infants were treated with macrolides before hospital admission. Cough was reported for a median of 10&nbsp;d before admission and 18&nbsp;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