Changes in the Dutch Bordetella pertussis population in the first 20 years after the introduction of whole-cell vaccines

Genomic interrogation of ancestral Mycobacterium tuberculosis from south India

“…In the largest BCG trial conducted in the same region earlier, BCG did not afford any protection. It is known that genetic variation of the strains is a method of vaccine escape and has been demonstrated in several bacterial species (Van Loo et al, 2002, Mbelle et al, 1999. Further investigation in this line would be helpful to ascertain the role of these highly prevalent strains on the host immunity.…”

An outbreak of pertussis in Bloemfontein, South Africa, 2008–2009

“…10 • The emergence of new bacterial toxin variants. 11,12 It is estimated that 71% of the global burden of pertussis occurs in developing countries. 2 However, no accurate figures are available for Africa, Asia or Latin America.…”

“…This child was initially admitted to the general ward with a diagnosis of Pneumocystis pneumonia, possible pertussis. His total white cell count at admission was 57.99 x 10 9 /l (normal for five weeks [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19].50 x 10 9 /l), and his lactate dehydrogenase levels (LDH) were 733 U/l (normal range 180-430 U/l). Cyanotic spells were noted after five days of hospitalisation.…”

“…However, it would be useful to culture existing circulating Bordetella organisms to type the strain for surveillance, as well as for future vaccine manufacturing. 11,12 Laboratory confirmation of pertussis is recommended and is probably cost-effective. A definitive diagnosis always influenced the management of the children in this series, and was helpful in limiting further investigations.…”

Resurgence of pertussis calls for re-evaluation of pertussis animal models

“…In The Netherlands, a country with an overall high vaccination coverage of more than 95%, the rise in pertussis notifications in the 1990s concurred highly with the switch in the Ptx promoter (ptxP) region from the ptxP1 allele to the ptxP3 allele [41]. Earlier antigenic drift from the Ptx S1 subunit PtxA2 to PtxA1, and from Prn1 to Prn2, had no significant effects on the pertussis incidence, but could have contributed to the reduced long-term effectiveness of the WCV in use [41,42]. To date, the most prominent circulating strains are typed PtxA1/Prn2/Fim2-2 or -/Fim3-2, as opposed to those in the prevaccination era that were predominantly PtxA2/Prn1/Fim2-1 or -/Fim3-1 and are still the base for our first-and second-generation vaccines (Figure 1) [31,32,40,43,44].…”