A prospective study of phage types & biotypes of Salmonella enterica serotype Typhi isolated from hospitalized children in Kolkata, India.

BACKGROUND & OBJECTIVES: Kolkata and its suburbs in eastern India faced an epidemic of typhoid fever in 1990. A prospective, hospital and laboratory based study over a period of 12 yr (1990-2001), on the phage typing and biotyping pattern of Salmonella enterica serotype Typhi was carried out, to see if there has been a change. METHODS: A total of 338 S. enterica serotype Typhi isolates from 1491 blood samples were phage typed and biotyped. The mean age of isolation was calculated. RESULTS: The age distribution of subjects (neonates to 12 yr) has been analysed. Of the 338 (22.7%) isolates obtained, eight different S. enterica serotype Typhi phage types were detected. Biotype I (95.8%) was more prevalent as compared to biotype II (4.1%). Phage type E1 was the commonest phage type in Kolkata and its suburbs. INTERPRETATION & CONCLUSION: The mean age at isolation was found to be 6.7 +/- 3.3 yr. Biotype I was predominant and it was of interest that all strains of phage type E1 belonged to biotype I.

Decreasing trend in the occurrence of Salmonella enterica serotype Typhi amongst hospitalised children in Kolkata, India during 1990-2000.

In a prospective hospital based surveillance, 1454 children clinically diagnosed as typhoid fever were enrolled during the period between 1990 to 2000. Of them 336 (23.1%) children were positive for Salmonella enterica serotype Typhi by blood culture. A declining trend of hospitalization and identification of the pathogen was observed from 1992 to 2000 as compared to 1990-1991. A declining trend of resistance to the commonly used anti-typhoid drugs was seen in the S. enterica serotype Typhi isolates. Recently in 2000, nine strains were detected as ciprofloxacin resistant. Misuse and overuse of ciprofloxacin for the treatment of typhoid fever influenced the development of ciprofloxacin resistant strains of S. enterica serotype Typhi in and around Kolkata.

Isolation of Salmonella enterica serotypes from children with diarrhoea in Calcutta, India.

The prevalence of Salmonella enterica serotypes, antimicrobial susceptibility, and phage typing of serovers were studied. Clinical presentations of the infected cases were also examined. The study was carried out during August 1993-September 1996 in and around Calcutta, India. In total, 1,025 faecal samples from hospitalized diarrhoeal children were screened for enteropathogens. Four S. enterica serotypes were identified in 157 (15.3%) cases as a single pathogen. S. enterica serotype Typhimurium was detected in 110 (70%) cases. S. Seftenberg, S. Infantis, and S. Virchow were detected in 28 (17.8%), 14 (8.9%), and 5 (3.2%) cases respectively. S. Typhimurium was isolated from 11 (3.2%) non-diarrhoeal control children. All of these children had acute watery diarrhoea, and 5% of them had severe dehydration, 40% had some dehydration, and 55% had no dehydration. Vomiting, fever, and diffused pain in abdomen were the associated presentations of these children. Most (95%) of them recovered with oral rehydration therapy only and without any antibiotics. In-vitro susceptibility testing showed that 120 of the 121 S. Typhimurium strains isolated from cases and controls were resistant to the commonly-used drugs. Thirteen of the 121 strains were phage-typeable and belonged to the phage type 193. However, no clinical or epidemiological significance could be established with these typeable strains. The findings of the study indicate that diarrhoeagenic Salmonella is one of the major pathogens causing diarrhoeal diseases in eastern India.

Ceftriaxone therapy in ciprofloxacin treatment failure typhoid fever in children.

BACKGROUND & OBJECTIVES: The rapid spread of multidrug resistant (MDR) typhoid fever has posed a great challenge for the treatment of these cases the world over. After the emergence of chloramphenicol resistant Salmonella typhi strains, ciprofloxacin has become the drug of choice for the treatment of typhoid fever even in the paediatric age group. This study evaluated the role of ceftriaxone therapy in bacteriologically confirmed MDR typhoid cases who did not respond to 12-14 days of ciprofloxacin therapy. Attempts have also been made to investigate the in vitro susceptibility of isolated S. typhi strains to chloramphenicol, ciprofloxacin and ceftriaxone. METHODS: A total of 140 children, aged 3-10 yr, clinically diagnosed as having typhoid fever, without any clinical response after 12-14 days of ciprofloxacin therapy were screened for S. typhi by blood culture. In the bacteriologically positive children the treatment was changed to intravenous ceftriaxone for 14 days. The isolated strains of S. typhi were tested for in vitro antimicrobial susceptibility. RESULTS: Clinical and bacteriological cure was observed with intravenous ceftriaxone therapy in all the 32 bacteriologically positive patients. All isolated S. typhi strains were uniformly (100%) susceptible to ciprofloxacin and ceftriaxone but 50 per cent of the strains were resistant to chloramphenicol. The MIC values of chloramphenicol, ciprofloxacin and ceftriaxone ranged between 125-500, 0.0625-0.5 and < 0.0625 microgram/ml respectively. INTERPRETATION & CONCLUSION: The study indicates that although the S. typhi strains were susceptible to ciprofloxacin in vitro, the patients did not respond clinically and bacteriologically to ciprofloxacin therapy. Hence, ciprofloxacin may not represent a reliable and useful option for treating MDR typhoid fever; ceftriaxone may be an effective alternative for the treatment of such cases.

Enteroaggregative Klebsiella pneumoniae in association with childhood diarrhoea.

A total of 19 strains of Klebsiella pneumoniae isolated as sole pathogen from children with diarrhoea were used to study their virulence mechanism using different assays. Eith strains of K. pneumoniae exhibited aggregative adherence that was distinct from the stacked brick enteroaggregative pattern shown by Escherichia coli. The study suggests the presence of a new virulence mechanism in the pathogenesis of Klebsiella-associated diarrhoea.

Multi-drug resistant typhoid fever with diarrhea.

OBJECTIVE: To provide information about the characteristics of diarrheal stool in multi-drug resistant typhoid fever and observe the clinical course after treatment with furazolidone or ciprofloxacin. SETTING: Hospital based. SUBJECTS AND METHODS: Twenty one male children who were positive for multi-drug resistant S. typhi by blood and stool cultures, having diarrhea at the time of hospitalization comprised the subjects. Serum and stool electrolytes were estimated. Stool samples were also processed to detect established enteropathogens, leukocytes and red blood cells. Children were treated either with furazolidone or ciprofloxacin and evaluated till recovery. RESULTS: Mean (+/- SD) pre-admission duration of fever and diarrhea of these cases were 19.1 (+/- 5.6) and 15.8 (+/- 4.6) days, respectively. Stool character in 81% of the patients was watery with mean (+/- SD) volume of stool 51.4 (+/- 25.1) ml per kg body weight in the first 24 hours of observation. Leukocyte count varied between 20-49 per high power field in 66.7% stool samples. Occult blood was present in only 19% cases. Fecal red blood cells in high power field were detected in 52.4% cases. Mean fecal electrolytes (mmol/liter) were as follows: sodium-53.8, potassium-51.4, chloride-41.6 and total CO2-24.3. Most of the children (71.4%) had no dehydration and had normal serum electrolytes. The isolated strains of S. typhi were multi-drug resistant. These children were treated successfully either with furazolidone or ciprofloxacin. CONCLUSION: The stools of multi-drug resistant typhoid fever patients were watery with little blood. Their electrolyte contents were more similar to the diarrheal stool seen in shigellosis rather than cholera. Uncontrolled observations revealed that children recovered with furazolidone or ciprofloxacin therapy.

Association of enterotoxigenic Bacteroides fragilis with childhood diarrhoea.

This study was conducted in a hospital setting to determine whether enterotoxigenic strains of Bacteroides fragilis (ETBF) were associated with childhood diarrhoea. ETBF was isolated from 6 (2.6%) of 226 patients and 3 (1.7%) of 172 controls and was found mostly in children between 1-5 yr of age. The syndrome associated with ETBF was secretory in nature with watery diarrhoea and of mild severity. ETBF may be associated with diarrhoeal illness in children but is not a major problem in this part of the country.

Assessing the cause of in-patients pediatric diarrheal deaths: an analysis of hospital records.

Records of all the diarrheal patients up to the age of 5 years who were admitted to and died in Dr. B.C. Roy Memorial Hospital for Children, Calcutta, between January and December 1990 were analyzed. The records were reviewed to assess the relative importance of three clinical types of diarrhea (acute watery diarrhea, acute dysentery and persistent diarrhea) as the causes of mortality. Annual hospital death rates of children suffering from acute watery diarrhea, dysentery and persistent diarrhea were 13.6%, 18.2% and 25.9%, respectively. Overall death rates in dysentery (p = 0.03) and persistent diarrhea groups (p < .00001) were significantly higher than watery diarrhea group. Maximum deaths occurred among children aged between 7 and 36 months in all categories of diarrhea. Shigella infected children had higher case fatality rate. In acute watery diarrhea, 30.9% cases were assigned to associated causes of death whereas the same could be assigned to 92.6% and 93.2% cases in dysentery and persistent diarrhea group, respectively. Deaths occurred in most of the cases who had bronchopneumonia as underlying cause, septicemia as immediate cause and protein calorie malnutrition as associated cause and these were most frequently associated in patients suffering from dysentery and persistent diarrhea. Only 2.0% children suffering from acute watery diarrhea had dehydration at the time of death. Significantly, a high percentage of deaths occurred among malnourished children who suffered from dysentery (54.4%) and persistent diarrhea. These data suggest that Diarrheal Disease Control Programme should also give emphasis on management of non watery, non-dehydrating type of diarrhea with complications.

Comparative efficacy of furazolidone and nalidixic acid in the empirical treatment of acute invasive diarrhea: randomized clinical trial.

Efficacy of furazolidone and nalidixic acid was compared in a randomized trial involving 72 children with acute invasive diarrhea. Thirty six children received furazolidone (7.5 mg/kg/day) and 36 children received nalidixic acid (55 mg/kg/day). Clinical characteristics of the two treatment groups were comparable on admission. Of these, 34 children in furazolidone treated group and 29 children in nalidixic acid treated group completed the full course of treatment and were analyzed finally for clinical efficacy. Clinical cure was observed in 29(85.3%) children treated with furazolidone and 29(100.0%) children treated with nalidixic acid. Nalidixic acid treated group had statistically significantly higher cure rate (p = 0.039) as compared to furazolidone treated group. However, 85% cure rate in furazolidone treated group may be potentially useful for the treatment of acute invasive diarrhea because of decreasing efficacy of nalidixic acid against shigellosis in many countries.

Clostridium difficile in antibiotic associated pediatric diarrhea.

A case control study was carried out at the medical wards of Dr. B.C. Roy Memorial Hospital for Children, Calcutta, between January and September 1989. One hundred eleven hospitalized children up to the age of 5 years, receiving antibiotics for different medical problems, developed antibiotic associated diarrhea. Isolation of Clostridium difficile as sole pathogen was very low (3.6%) from these patients. Fecal samples of 111 case matched control children were also screened for C.difficile. Only 2.7% fecal samples of control children were positive for C.difficile. All the strains of C.difficile isolated from antibiotic associated diarrhea cases showed neutralisable cytotoxin in in vitro test. In contrast none of the strains isolated from control children showed cytotoxicity. This study suggests that C.difficile is not an important pathogen related to antibiotic associated diarrhea in children at this hospital.

Acute diarrhoea caused by Vibrio mimicus in Calcutta.

Out of 539 acute diarrhoea cases studied, Vibrio mimicus was isolated as a sole pathogen in the faeces of 7 (1.3%) cases. The chief clinical presentations of the seven cases were watery diarrhoea and vomiting. Bloody diarrhoea was observed in 2 (28.5%), abdominal pain in 2 (28.57%) and fever in one (14.29) cases. All cases could be effectively treated with ORS except 3 (42.85%) cases who required IV Ringer's lactate. All V. mimicus strains isolated in the study were uniformly susceptible to tetracycline, chloramphenicol, norfloxacin and ciprofloxacin.

Value of a single Widal test in the diagnosis of typhoid fever.

Results of a single Widal test in patients with bacteriologically confirmed typhoid fever (116), clinically suggestive but culture negative fever (170) and non-typhoidal febrile illness (98) and in normal control children (54) were analysed. Positive Widal test (antibody titre against S. typhi O antigen of 1:160) was recorded in 61.2 per cent of patients with bacteriologically confirmed typhoid fever and in 58.8 per cent with culture negative but clinically suggestive typhoid fever. In contrast, the same titre was observed in 10.2 per cent patients with other febrile illnesses of known etiology and in 1.8 per cent of normal children. Differences in the positivity of Widal test in patients with bacteriologically confirmed typhoid fever and clinically suggestive but culture negative fever were highly significant (P < 0.000001) when compared to that of patients with non-typhoidal febrile illnesses and normal controls. High specificity and positive predictive value in 1:160 dilution makes the Widal test acceptable as a diagnostic tool.

Prospective study of nosocomial enteric infections in a pediatric hospital, Calcutta.

Hospital acquired enteric infections were investigated by studying 3138 children under 5 years of age who were admitted without diarrhea in nine medical words of a pediatric hospital, Calcutta during the period between March and September 1987. Three hundred and twenty (10.2%) children developed nosocomial diarrhea during their hospital stay. Fecal samples from 178 nosocomial diarrhea, 345 hospitalized diarrhea cases, 178 hospital controls and 200 outpatient controls were collected for detection of established enteropathogens. There were no statistically significant differences in the detection of most of the enteropathogens from fecal samples of nosocomial diarrhea, hospitalized diarrhea and hospital controls. Enteric pathogens were detected at a higher frequency (statistically significant) from fecal samples of nosocomial diarrhea cases as compared to outpatient controls. This study highlights the importance of most of the enteropathogens like Shigella, Salmonella, rotavirus, enteropathogenic E. coli as the cause of hospital cross infection. This study reinforces the importance of developing preventive measures in order to reduce the frequency of illness.

Influence of admission weight on neonatal mortality amongst hospitalised neonates in Calcutta.

The study was conducted on 785 neonates aged up to 28 days to evaluate the influence of admission weight on mortality. It was observed that there were 200 (25.5%) cases of septicaemia, 134(17.1%) of diarrhoea, 120(15.3%) each of prematurity related conditions and neonatal jaundice, 117(14.9%) of respiratory diseases and 94 (11.9%) cases of convulsion. There were total 182(23.18%) deaths comprising 70(38.5%) from prematurity related conditions, 40(22%) from diarrhoea, 35(19.2%) from respiratory diseases, 26(14.3%) from septicaemia, 8(4.4%) from neonatal jaundice and 3(1.6%) deaths from convulsion. The incidence of deaths among neonates weighing less than 2500 g on admission was 59.2% in diarrhoeal diseases, 53.4% in respiratory diseases and 44.6% in other conditions compared to those of 10%, 8.2% and 7.1% respectively in neonates having admission weight more than 2500 g. The findings are statistically significant. The results of the study indicate that low admission weight should be considered as a predictor of mortality among neonates.