Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in Calcutta, India, was initiated in January 1994. The incidence of cases of V. parahaemolyticus infection suddenly increased in February 1996 and has remained high since then. One hundred thirty-four strains of V. parahaemolyticus isolated from January 1994 to August 1996 were examined for serovar, the presence of the thermostable direct hemolysin gene (tdh) and tdh-related hemolysin genes (trh1 and trh2), production of urease, and antibiogram. Strains of the O3:K6 serovar appeared for the first time in February 1996. The O3:K6 serovar strains accounted for 50 to 80% of the strains isolated during the high-incidence period (February to August 1996). All of the serovar O3:K6 strains carried the tdh gene but not the trh genes and did not produce urease. All of the isolates except two were sensitive to all of the antibiotics tested. These and the results of analysis by an arbitrarily primed PCR method indicated that the O3:K6 serovar strains belong to a unique clone. When the O3:K6 serovar strains, isolated from travelers arriving in Japan from Southeast Asian countries, were compared by the arbitrarily primed PCR method, the strains isolated between 1982 and 1993 were distinct from Calcutta O3:K6 while the strains isolated in 1995 and 1996 were indistinguishable from the Calcutta O3:K6 strains. The results suggest that this unique O3:K6 clone may have become prevalent not only in Calcutta but also in Southeast Asian countries very recently. Not only the O3:K6 strains but also the non-O3:K6, tdh-bearing strains isolated in 1996 produced thermostable direct hemolysin at high levels, and thus the level of hemolysin produced does not appear to have influenced the high incidence of serovar O3:K6 strains.

Sixty-one clinical strains of Vibrio cholerae O1 El Tor isolated in Calcutta before, during, and after the V. cholerae O139 Bengal outbreak were examined to see if the O1 strains of the post-O139 period were different from those in existence before. Comparison of the restriction fragment length polymorphism of the rRNA genes (ribotyping) and the CTX genetic element revealed that all "before" strains except 1 belonged to a single known ribotype, whereas all "after" strains except 2 belonged to a hitherto undescribed ribotype. Also, 23 of 25 "before" strains harbored two or more copies of CTX in tandem and also a "free" RS1 element away from CTX, whereas 19 of 21 "after" strains had a single copy of CTX and no free RS1 element. CTX occupied different chromosomal locations in "before" and "after" strains. These studies clearly showed that El Tor O1 strains, which displaced V. cholerae O139 in Calcutta, belonged to a new clone and suggested that there is a continuous genetic reassortment among El Tor strains of V. cholerae O1.

This study presents results of a surveillance on cholera conducted with hospitalized patients admitted to the Infectious Diseases Hospital, Calcutta, India, from January 1993 to December 1995. The O139 serogroup of Vibrio cholerae dominated in 1993 but was replaced by O1 as the dominant serogroup in 1994 and 1995. The isolation rate of V. cholerae non-O1 non-O139 did not exceed 4.9% throughout the study period, while the isolation rate of the O139 serogroup in 1994 and 1995 was below 9%. No temporal clustering of any non-O1 non-O139 serogroup was observed. With the exception of 1 strain, none of the 64 strains belonging to the non-O1 non-O139 serogroup hybridized with ctx, zot, and ace gene probes, while 97.3 and 97.7% of the O139 and O1 strains, respectively, hybridized with all the three probes. Multiplex PCR studies revealed that all the O1 strains belonged to the ElTor biotype. There was a progressive increase in the cytotoxic response on CHO and HeLa cells evoked by culture supernatants of strains of V. cholerae non-O1 non-O139 isolated during 1994 and 1995 compared with the response evoked by those isolated in 1993. Dramatic shifts in patterns of resistance to antibiotics between strains of V. cholerae belonging to different serogroups and within strains of a serogroup isolated during different time periods were observed. There was a discernible increase in the incidence of multidrug-resistant strains of V. cholerae O1 isolated in 1994 and 1995 compared with that in 1993. On the basis of the results of this study, we predict the possibility of newer variants of V. cholerae emerging in the future.

This study investigated age and sex variations in height and weight, levels of stunting, underweight and wasting among 533 (254 boys; 279 girls) 3- to 5-year-old rural children of Bengalee ethnicity at 11 Integrated Child Development Services centres of Nadia District, West Bengal, India. Height-for-age, weight-for-age and weight-for-height < -2 z-scores were used to evaluate stunting, underweight and wasting, respectively, following the National Center for Health Statistics (NCHS) Guidelines. Results revealed that boys were significantly heavier than girls at age 3 years. Significant age differences existed in mean height and weight in both sexes. Mean z-scores of height-for-age, weight-for-age and weight-for-height were lower than those of NCHS for both sexes at all ages. The overall (age and sex combined) rates of stunting, underweight and wasting were 23.9%, 31.0% and 9.4%, respectively. The rate of underweight and wasting was higher among girls (underweight = 35.1%, wasting = 12.2%) compared with boys (underweight = 26.5%, wasting = 6.3%). In general, the frequency of stunting increased with increasing age in both sexes. Based on the World Health Organization classification of severity of malnutrition, the overall prevalence of underweight was very high (>or=30%). The prevalence rates of stunting (20-29%) and wasting (5-9%) were medium. In conclusion, the nutritional status of the subjects is unsatisfactory. There is scope for improvement in the form of enhanced supplementary nutrition.

We studied the restriction fragment length polymorphism of the rRNA gene and CTX genetic element in Vibrio cholerae O139 Bengal, which resurged in Calcutta in September 1996 after a gap of 32 months. While the strains from this resurgence were indistinguishable from the earlier strains by ribotyping, the structure of the CTX genetic element present in the current O139 strains was found to be unconventional. Vibrio cholerae O139, the second etiological serogroup of cholera, came into being dramatically in September 1992 in Southern India and thereafter spread explosively to all areas of cholera endemicity in India (11) and to neighboring countries (12). Inexplicably, towards the end of 1993 the incidence of V. cholerae O139 declined in Calcutta, India (10), and in other parts of the subcontinent (3), and the O139 serogroup was replaced by a new clone of V. cholerae O1 biotype El Tor (4, 18, 21). However, in September 1996, V. cholerae O139 staged a resurgence. Phenotypically, the reemerged V. cholerae O139 strains were different from those that appeared in late 1992 and 1993 in that the current O139 strains were sensitive to cotrimoxazole (9). However, like the O139 strains isolated in 1992 to 1993 (16), the O139 strains that resurged were resistant to ampicillin, furazolidone, neomycin, and streptomycin (9). Toxigenic strains of V. cholerae contain a compound transposon-like structure known as the CTX genetic element, which comprises a 4.5-kb central core region that contains the ctxAB, zot, ace, orfU, and cep genes and has one or more copies of a 2.7-kb repetitive sequence (designated RS1) flanking it (14, 19). The number and arrangement of the CTX element are known to vary in different strains of toxigenic V. cholerae (20) and have formed a useful basis for the study of the clonality of strains. We embarked on a study to characterize the ribotype, organization, and chromosomal location of the CTX genetic element of the current O139 strains to assess the extent of genotypic variations in these compared to the strains isolated in 1992 to 1993. A total of 10 strains of V. cholerae O139, namely, AS207, AS209, AS210, AS212, AS213, AS231, AS233, AS258, AS259, and AS260, isolated from hospitalized patients with cholera from the Infectious Diseases Hospital, Calcutta, India, between 21 August and 20 September 1996 were selected randomly by blinding the date of isolation from the person who selected the strains. MO1, a serotype O1 strain which could be a progenitor strain of V. cholerae O139 (12), and AP1, an O139 strain which appeared in late 1992, were also included in the study for comparison (13). Chromosomal DNA was prepared (1), restricted with a va

f Analysis of 1,180 diarrheal stool samples in Zanzibar detected 247 Vibrio cholerae O1, Ogawa strains in 2009. Phenotypic traits and PCR-based detection of rstR, rtxC, and tcpA alleles showed that they belonged to the El Tor biotype. Genetic analysis of ctxB of these strains revealed that they were classical type, and production of classical cholera toxin B (CTB) was confirmed by Western blotting. These strains produced more CT than the prototype El Tor and formed a separate cluster by pulsed-field gel electrophoresis (PFGE) analysis.

A cross-sectional study was undertaken to determine the anthropometric profile and nutritional status of adult Kora Mudis, a tribal population of Bankura District, West Bengal, India, based on their body mass index (BMI). A total of 500 adult (18.0 < age ≤ 65.0 years) Kora Mudis from two villages (Phulberia and Siromonipur, approximately 160 km from Kolkata) were studied. Anthropometric measurements, including height, weight, circumferences, and skinfolds, were measured using standard protocols. BMI was calculated and utilized as a measure of nutritional status. The extent of undernutrition (BMI < 18.5) was found to be very high (52.2%). The frequency of undernutrition was higher in women (56.4%) than men (48.0%), although this difference was not statistically significant. Using the World Health Organization criterion, the prevalence of undernutrition is classified as 'very high'. In order to fully understand the causes and consequences of adult undernutrition, further research is needed not only among this ethnic group but also on the other tribal populations of India.

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