Pertussis epidemiology in Argentina: trends over 2004-2007.
OBJECTIVE
Pertussis continues causing significant morbidity and mortality worldwide. Although its epidemiology has been studied in many developed countries, the current pertussis situation in South America is scarcely known. This review summarizes the most important recent data concerning pertussis in a country of South America, Argentina.


METHODS
CDC criteria were used for pertussis diagnosis. Proportion of pertussis cases by age, immunization status, and immunization coverage rate evaluated at the Argentinean National Pertussis Reference Centers was reported. Bordetella pertussis isolates were characterized and compared with vaccine strains.


RESULTS
From 2002 to nowadays, a steady increase of pertussis cases was observed. Most of these cases correspond to patients younger than six months old that received less than three doses of vaccine. However, cases in adolescent and adults have also been detected. For this situation, which is not peculiar to Argentina, several explanations have been proposed. Among them, the inability of current vaccines to induce long-lasting immunity is the most widely accepted as a cause of pertussis resurgence. Furthermore, antigenic divergence between local clinical isolates and vaccine strains may have aggravated the effect of waning immunity.


CONCLUSIONS
Pertussis is an important problem for public health in Argentina. Divergence between vaccine strains and local isolates could contribute to the described pertussis epidemiology.
Hozbor
D
D
Instituto de Biotecnología y Biología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CCT La Plata-CONICET, 1900 La Plata, Argentina. hozbor@biol.unlp.edu.ar
Mooi
F
F
Flores
D
D
Weltman
G
G
Bottero
D
D
Fossati
S
S
Lara
C
C
Gaillard
M E
ME
Pianciola
L
L
Zurita
E
E
Fioriti
A
A
Archuby
D
D
Galas
M
M
Binsztein
N
N
Regueira
M
M
Castuma
C
C
Fingermann
M
M
Graieb
A
A
D000293:Adolescent; D001118:Argentina / Q000453:epidemiology; D001886:Bordetella pertussis / Q000145:classification / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D016172:DNA Fingerprinting; D006801:Humans; D016233:Immunotherapy, Active / Q000706:statistics & numerical data; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D014917:Whooping Cough / Q000175:diagnosis / Q000453:epidemiology*