ABSTRACT
Background & objectives: Leptospirosis, a spirochetal zoonosis, is underreported from the northern States of India. This study reports results of a 10-year retrospective sero-epidemiological survey of leptospirosis conducted in a tertiary care hospital in New Delhi, India. Method: A total of 1453 patients clinically suspected for leptospirosis were included and investigated initially by IgM ELISA. A proportion of these were subjected to culture, microscopic agglutination test (MAT) and polymerase chain reaction (PCR). Results: Of the 1453 patients, 391 (26.90%) were positive serologically by IgM ELISA. Seropositive and seronegative patients revealed no significant difference in clinical features and laboratory parameters. Amongst the IgM seropositive cases, culture for leptospires was positive in 5 of 192 (2.6%), MAT in 50 of 138 (36.23%), PCR from blood and urine in 10 of 115 (8.7%) and 10 of 38 (26.31%) cases, respectively. In Leptospira spp. positive patients co-infections with viral hepatitis E, malaria and dengue fever were diagnosed in 27 cases. Interpretation & conclusions: The overall seropositivity for leptospirosis was 26.9 per cent in our study. A decreasing trend in seropositivity was observed in recent years. Co-infections with malaria, dengue, hepatitis A and E were also seen. Since leptospirosis is a treatable disease, correct and rapid diagnosis may help in effective management of patients.
ABSTRACT
During the post monsoon season of 1996 an outbreak of human Salmonellosis caused by Salmonella serovar-paratyphi A occurred in New Delhi and had continued for over 2 months. A total of 36 clinically diagnosed enteric-fever cases were reported during this outbreak. The isolates were compared following their characterisation by biotyping, antibiogram-analysis, plasmid-profiling and IS200 probing, to study the relatedness in order to delineate a common source. The study included representative strains from both outbreak (15) and sporadic (7) cases for comparative analysis. Biotyping, antibiogram, whole cell protein-analysis and plasmid-profiling could not discriminate sporadic cases from outbreak strains, suggesting that a single clone/type (PT-1) may be prevalent in our region. In contrast, molecular-typing using IS200-probing revealed 2 clonally related strains circulating during the outbreak, as compared to the unrelated sporadic strains which exhibited considerable genetic diversity. Molecular analysis by IS200-probing, helped to assign an index case which provided a history of later outbreaks, since paratyphi A was repeatedly cultured in later outbreaks also. The study also suggests that genetic rearrangements can occur during the emergence of outbreaks. It reaffirmed the usefulness of IS200-probing in epidemiological investigations of Salmonella enterica serovars.