INVESTIGADORES
BIANCO Maria Isabel
congresos y reuniones científicas
Título:
Prevalence of Clostridium botulinum spores in soil of Catamarca, Argentina, and infant botulism incidence
Autor/es:
DE JONG LIT, CICCARELLI AS, FERNÁNDEZ RA, DEGARBO SM, CABALLERO PA, BIANCO MI, LÚQUEZ C, CICCARELLI MA.
Lugar:
Mendoza
Reunión:
Otro; XXI Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2003
Resumen:
The high incidence of infant botulism (IB) in exclusively breast milk-fed infants in Mendoza, Argentina (26.31%=75/285), suggests soil as an important source if infection. Environmental dust can be considered a vector for IB transmission in arid regions. Hence, frequency of soil samples positive for Clostridium botulinum (Cb) and spore load are two important variables. Soil samples from Catamarca (n=38) were processed for detection of Cb, typing of BoNT and estimation of Cb viable spore concentration (VSC) with the most probable number (MPN) method. As Mendoza province has the highest IB incidence, its figures were used to define minimal expected incidence (MEI) of IB in a 10-year period. Positive results were obtained in 18/38 samples (47.36%). In 20/38 (52.63%), VSC in MPN spores per g of soil (95% confidence limits between parentheses) was less than 0.12 (0.04-0.41). In 3/38 (7.89%) VSC was 0.12 (0.04-0.41). The highest value was 1.15 (0.35-3.81) in 7.89% (3/38). BoNT types were: A 88.33% (15/18), B 5.55% (1/18), and unidentified 11.11% (2/18). IB incidence in Catamarca (2 cases per decade 1994-2003) is significantly lower than its MEI estimate (9.4 cases/10 yr). Although Catamarca exhibits a higher prevalence of Cb spores in soil than Mendoza (39.47%=30/76), its VSC is substantially lower. This might explain its low IB incidence, while another factor might be underdiagnosis.