Bordetella pertussis-specific antibodies can be detected by enzyme-linked immunosorbent assays (ELISAs) or multiplex immunoassays. Assays use purified or mixed antigens, and only pertussis toxin (PT) is specific for B. pertussis. The interpretation of results can be based on dual-sample or single-sample serology using one or two cut-offs. The EU Pertstrain group recommends that: (i) ELISAs and multiplex immunoassays should use purified non-detoxified PT as an antigen, that they should have a broad linear range and that they should express results quantitatively in International Units per millilitre (IU/ml); (ii) a single or dual diagnostic cut-off for single-serum serology using IgG-anti-PT between 50 and 120 IU/ml should be used, and diagnostic serology cannot be validly interpreted for one year after vaccination with acellular pertussis (aP) vaccines; (iii) IgA-anti-PT should only be used with indeterminate IgG-anti-PT levels or when a second sample cannot be obtained. This group discourages using: (i) other antigens in routine diagnostics, as they are not specific; (ii) micro-agglutination, due to its lack of sensitivity; (iii) immunoblots for pertussis serodiagnosis, as results cannot be quantified; (iv) other methods, such as complement fixation or indirect immunofluorescence, due to their low sensitivity and/or specificity.

Pertussis is re-emerging in vaccinated populations, and to gain insight into the reasons for this development population-based studies are necessary. Unfortunately, various techniques are used to study Bordetella pertussis populations, hampering comparison between studies. A standard methodology for epidemiological typing of Bordetella pertussis isolates is proposed which is based on serotyping, pulsed-field gel electrophoresis and gene typing. Such a standard approach will allow comparisons between studies performed in different laboratories. Comparisons may reveal whether the epidemiological differences observed between countries are due for instance to different Bordetella pertussis populations or different vaccines used.

Existing clinical case definitions of pertussis are decades old and based largely on clinical presentation in infants and children, yet an increasing burden is borne by adolescents and adults who may manifest distinct signs/symptoms. Therefore, a “one-size-fits-all” clinical case definition is no longer appropriate. Seeking to improve pertussis diagnosis, the Global Pertussis Initiative (GPI) developed an algorithm that delineates the signs/symptoms of pertussis most common to 3 age groups: 0–3 months, 4 months to 9 years, and ≥10 years. These case definitions are based on clinical presentation alone, but do include recommendations on laboratory diagnostics. Until pertussis can be accurately diagnosed, its burden will remain underestimated, making the introduction of epidemiologically appropriate preventive strategies difficult. The proposed definitions are intended to be widely applicable and to encourage the expanded use of laboratory diagnostics. Determination of their utility and their sensitivity and/or specificity versus existing case definitions is required.

A polyphasic taxonomic study that included DNA-rRNA hybridizations, DNA-DNA hybridizations, DNA base ratio determinations, whole-cell protein and fatty acid analyses, and an examination of classical phenotypic characteristics was performed in order to classify human and veterinary isolates that resemble Burdeteh avium. Twelve poultry isolates and two human isolates were assigned to a new species, for which we propose the name BordeteZliz hinzii. The position of this organism in the family Akaligenuceae and various genotypic, phenotypic, and chemotaxonomic characteristics are described.Members of the genus Bordetella are well-known pathogens of humans and animals (39). The significance of Bordetella pertussis, Bordetella parapertussis, and Bordetella bronchiseptica as respiratory tract invaders, with whooping cough as the most important infection, is well-known (39). A less familiar member of the genus, Bordetella avium, causes respiratory infections in poultry (22). These infections result in high levels of morbidity and are responsible for significant losses in both the turkey and chicken industries (3, 6, 17, 28, 32, 33). Strains of another taxon, which has been referred to as B. avium-like, Alcaligenes faecalis type 11, TC (turkey coryza) bacterium type 11, or Alcaligenes sp. strain C2T2, have also been isolated from respiratory tracts of chickens and turkeys in various parts of the world (1,3,19,20,31). Although these strains are often isolated from diseased birds, the information available does not provide strong evidence that they are pathogenic (3,19).In this study, we performed a polyphasic taxonomic study in order to clarify the taxonomic position of the B. avium-like taxon. Below, we show that 12 poultry isolates and 2 human isolates of the B. avium-like taxon constitute a novel Bordetella species, for which we propose the name Bordetella hinzii sp. nov. MATERIALS AND METHODSBacterial strains and growth conditions. All of the strains which we studied and their sources are listed in Table 1. Bacteriological purity was checked by plating and examining living cells, using phase-contrast microscopy and Gramstained cells.B. pertussis strains were grown as described by Stainer and Scholte (34). All other strains were grown on Trypticase soy agar (catalog no. 11768; BBL, Becton Dickinson Microbiology Systems, Cockeysville, Md.) and were incubated aerobically at 36 to 37°C unless indicated otherwise.PAGE of whole-cell proteins. After incubation for 48 h, whole-cell protein extracts were prepared, and sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) was performed as described previously (30). A densitometric analysis, normalization and interpolation of the protein profiles, and a numerical analysis were performed by using the GelCompar software package (Applied Maths, Kortrijk, Belgium).Fatty acid methyl ester analysis. After incubation for 48 h, a loopful of well-grown cells was harvested, and fatty acid methyl esters were prepared, separated, and identified by using the Microbial Identif...

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The Global Pertussis Initiative (GPI) is an expert scientific forum addressing the worldwide burden of pertussis, which remains a serious health issue, especially in infants. This age cohort is at risk for developing pertussis by transmission from those in close proximity. Risk is increased in infants aged 0 to 6 weeks, as they are too young to be vaccinated. Older infants are at risk when their vaccination schedules are incomplete. Infants also bear the greatest disease burden owing to their high risk for pertussis-related complications and death; therefore, protecting them is a high priority. Two vaccine strategies have been proposed to protect infants. The first involves vaccinating pregnant women, which directly protects through the passive transfer of pertussis antibodies. The second strategy, cocooning, involves vaccinating parents, caregivers, and other close contacts, which indirectly protects infants from transmission by preventing disease in those in close proximity. The goal of this review was to present and discuss evidence on these 2 strategies. Based on available data, the GPI recommends vaccination during pregnancy as the primary strategy, given its efficacy, safety, and logistic advantages over a cocoon approach. If vaccination during pregnancy is not feasible, then all individuals having close contact with infants ,6 months old should be immunized consistent with local health authority guidelines. These efforts are anticipated to minimize pertussis transmission to vulnerable infants, although real-world effectiveness data are limited. Countries should educate lay and medical communities on pertussis and introduce robust surveillance practices while implementing these protective strategies.