Epidemiological shift, seasonal variation and antimicrobial susceptibility patterns among enteric fever pathogens in South India.

Between January 2005 and December 2006, a higher incidence of paratyphoid fever (53.8%) compared to typhoid fever (44.9%) has been observed at a tertiary hospital in South India. A definite seasonal pattern of incidence is seen in paratyphoid fever (peak incidence during October-December, i.e., post monsoon period) but not in typhoid fever. Decreased fluoroquinolone susceptibility is much higher in S. Paratyphi A (98.8%) as compared to S. Typhi (46.5%). These findings are of importance in therapeutic decision making, development of vaccination strategies and implementing public health measures for disease control.