Has Vector-Rodent Relationship Changed in Plague? Experiences of Plague Affected Hilly Terrains of Himachal Pradesh, India.

Background: The present study was conducted with objectives to elucidate the existence of sylvatic cycle of plague and to document the changing pattern of relationship between rodents and fleas. Methods: Collection of samples was done from 15 sites (25 locations) from plague affected areas of Shimla district of Himachal Pradesh, India during 5 visits between June 2011 to July 2012, which were thereafter entomologically investigated in a BSL-3 laboratory Results: 57 fleas (3 species) from 243 rodents (3 species) were collected in domestic (n=16), peridomestic (n=3) and wild (n=6) locations. Rattus rattus (n=197) and Nosopsyllus fascitus (n=43) was most frequently trapped rodent and flea species respectively. Rattus rattus (domestic rodent species) was also trapped from wild areas and Nosopsyllus fascitus (domestic flea species) was also isolated from Rattus norvegicus (wild rodent species). One rare rodent species Cornilurus albipes was also found. Most common rodent-flea association was Rattus norvegicus-Nosopsyllus fascitus. The recovery of rodents and flea was higher in months of June and December respectively. Conclusions: The study concluded that sylvatic cycle persisted in study area and rodent and flea mixing was widely prevalent between domestic and wild area. This demands regular and intensive surveillance in plague prone hilly areas of Himachal Pradesh.

Differential Effect of Paromomycin and Nitazoxanide on Clinical Isolates of Cryptosporidia In Vitro.

Background: Cryptosporidiosis is one of the most difficult protozoan infections to treat, with only two drugs i.e. nitazoxanide and paromomycin known for treatment with variable response in different patients. Human cryptosporidiosis is accounted mainly by C. hominis and C. parvum. These two species or their subtypes are known to differ in clinical manifestations, and may differ in their response to drugs. So, we planned the study to see the effect of nitazoxanide and paromomycin on different isolates of Cryptosporidium in vitro. Methods: MDCK cell lines were used for in vitro growth of parasite and cytotoxicity of drugs to MDCK cells was determined by MTT assay after 3, 12 and 24 hours of drug exposure. Efficacy of non-toxic drug concentrations (<25% cytotoxic) on 12 Cryptosporidium isolates (7 C. hominis and 5 C. parvum) was determined at three different life cycle stages (in vitro growth, invasion and oocyst) by quantitative RT-PCR. Unpaired t-test was used to calculate the difference response of Cryptosporidium isolates to nitazoxanide and paromomycin. Results and conclusions: Cytotoxicity of nitazoxanide and paromomycin increased in dose and time dependent manner. After 24 hours of drug exposure, >25% cytotoxic effect was seen with nitazoxanide and paromomycin at concentrations of more than, 25μg/ml and 6mg/ml, respectively. Nitazoxanide was more effective than paromomycin in decreasing in vitro growth, invasion inhibition and reducing oocyst viability of Cryptosporidium isolates. Drugs effect was higher on growth inhibition followed by invasion inhibition and least in decreasing oocyst viability. Different isolates had variable response to drugs; cumulatively C. parvum isolates were more susceptible at particular drug concentrations than C. hominis isolates.

Isosporiasis in a tertiary care center of North India.

Background: Cystoisospora (Isospora) belli is a coccidian, protozoan parasite that resides in the gastrointestinal tract of humans. It is mainly reported from HIV-positive individuals. However, a few cases have been reported in other immunosuppressed individuals including renal transplant patients, and those with lymphoma and leukemia. Materials and Methods: During a period of 5 years (2008-2012), approximately 1700 stool samples of immunosuppressed patients were screened for the presence of opportunistic parasitic infections by a modifi ed acid fast staining technique. Results: A total of 41 C. belli were reported, out of which 30 were HIV-positive individuals while 11 were HIV negative. The latter individuals were also immunosuppressed due to prolonged use of steroids or other immunosuppressive drugs. Twenty-six out of 30 HIVpositive patients and all the HIV-negative individuals with C. belli infection had diarrhea. Conclusion: All immunosuppressed individuals should be examined for the presence of opportunistic coccidian parasitic infections and treated accordingly and alternatively, isolation of opportunistic parasites should trigger a hunt for immunocompromised state to reduce the morbidity and mortality in such patients.

Anti-Toxoplasma gondii antibody detection in serum and urine samples by enzyme-linked immunosorbent assay in HIV-infected patients.

Background: Toxoplasmosis is a common parasitic infection of man, and reactivation of latent disease in HIV-infected patients can cause fatal encephalitis. Diagnosis depends on demonstration of parasite-specific antibodies in serum. In HIV-infected patients, IgM is often undetectable, whereas IgG remains detectable in the majority. Urine sample is very easily available and has not been evaluated for immunodiagnosis of toxoplasmosis. Aim: The study was an effort to find whether urine sample can be used in place of serum for immunodiagnosis of toxoplasmosis. Materials and Methods: Enzyme-linked immunosorbent assay (ELISA) was carried out in serum and urine samples collected from 100 HIV-infected patients to detect anti-toxoplasma IgG and IgM antibodies and whether positivity correlated with the CD4 T-cell counts of patients. Results: In this study, we observed that there was no significant difference in positivity of anti-toxoplasma IgM and IgG between serum and urine samples of HIV-infected patients by ELISA. There was a negative correlation between CD4 count and seropositivity. Conclusion: Urine sample can be satisfactorily used in place of serum for immunodiagnosis of toxoplasmosis.

Concomitant intestinal parasitism and noncholera vibrio infection.

Concomitant parasitism is not uncommon especially in tropical countries with low socioeconomic status. Here we report an unusual combination of intestinal infection due to Strongyloides stercoralis, Blastomyces hominis and non-cholera Vibrio in a patient suffering from acute gastroenteritis and hypoalbuminemia. Early recognition and accurate treatment of gastrointestinal infections and infestations before the patient develops complications is important.

Intestinal bacterial and parasitic infections among food handlers in a tertiary care hospital of North India.

BACKGROUND: Intestinal infection is still an important public health problem in developing countries like India. Food handlers may be infected by a wide range of enteropathogens and have been implicated in the transmission of many infections to the public in the community and to patients in hospitals. AIM: To study the presence of enteropathogenic bacteria and parasites in food handlers working in the food service establishments of a tertiary care centre in North India. METHOD: The stool samples received from food handlers during January 2001 to December 2006 were examined by wet mount, iodine mount and modified acid fast staining directly and after formol ether concentration technique for parasites. For enteropathogenic bacteria, samples were inoculated onto MacConkey's agar, Deoxycholate Citrate Agar, Xylose Lysine Deoxycholate agar (XLD) as per the WHO protocol. RESULTS: During the years 2001-2006 respectively, 8.75%, 16%, 1.4%, 6.75%, 2.56% and 6.75% food handlers were infected with enteropathogens. The parasitic infections in our study were 1.3 to 7% while the enteropathogenic bacteria were reported from 0% to 13.3% during the years 2001-6. Giardia was the most common parasite while Shigella was the most common bacteria isolated from food handlers. During the year 2001, there was an outbreak of ETEC in the neonatal ICU, Advanced Paediatric Centre, PGIMER, which was traced back to a food handler involved in the preparation of the milk feed. CONCLUSION: Routine screening of food handlers is a valuable tool for prevention of nosocomial food-borne infections.

Prevalence of anti-cysticercus antibodies in slum, rural and urban populations in and around Union territory, Chandigarh.

A comparative analysis for the prevalence of anti-cysticercus antibodies was carried out in urban, rural and slum population in & around Union territory of Chandigarh. Prevalence of anti-cysticercus antibodies in different population groups was found to be 17.3% with highest prevalence (24%) reported from slum areas followed by that of rural areas (20%) and least in the urban organized sectors (8%). Only 8% of the seropositive individuals had history suggestive of neurocysticercosis. Overall, females showed the highest anti-cysticercus response of 20.4%.

Comparative analysis of intestinal parasitic infections in slum, rural and urban populations in and around union Territory, Chandigarh.

A study was conducted in and around the union Territory, Chandigarh, India to estimate the prevalence of intestinal parasitic infections in different population groups. The stool samples from a total of 600 subjects selected by cluster sampling technique were examined by direct microscopy. The prevalence of intestinal parasitic infections was found to be 14.6% with highest prevalence of 19% from the slum area. Children were the most commonly affected group (18%) with those from slums showing the highest prevalence (24.6%). The most common parasite was Giardia (5.5%) followed by H. nana and Ascaris (2.8% and 2.7% respectively).

An outbreak of hospital acquired diarrhea due to Aeromonas sobria.

Six children admitted in a 18 bedded hematology-oncology unit, developed acute diarrhea in a four week period between March and April 2001. Salmonella senftenberg was the additional pathogen in the stool sample of one patient who developed cola colored urine and pneumonia in the course of his illness. All the Aeromonas strains had a similar biotype and antibiogram. The diarrhea subsided spontaneously in two children whilst three responded to antimicrobial therapy. One patient sought discharge and did not return for a follow up. Aeromonas sobria with a similar profile as the isolates from the patients could be isolated from only one of several environmental sites. The outbreak could be contained by appropriate interventional measures.

Antimicrobial resistance in selected bacterial enteropathogens in north India.

BACKGROUND & OBJECTIVES: The resistance of enteropathogenic bacteria to commonly prescribed antibiotics is increasing both in developing as well as in developed countries. Resistance has emerged even to newer, more potent antimicrobial agents. The present study was therefore undertaken to report the current antibiotic resistance in common bacterial enteropathogens isolated in a tertiary care hospital in north India. METHODS: Faecal samples from 1802 patients were cultured for common bacterial enteropathogens and identified by standard methods. Antibiotic susceptibility was done by Stoke's disk diffusion method. The clinical and demographic profile of the patients was noted. RESULTS: Stool specimens from 119 (88 male, 31 female) patients yielded Shigella, Salmonella, Vibrio cholerae or Aeromonas. Fifty two per cent (62/119) of patients were children and 70 per cent were below the age of 5 yr. Twenty seven patients developed hospital acquired diarrhoea. Among all enteropathogens, Shigella spp. was the commonest followed by non-typhoidal Salmonella (27), V. cholerae O1 El tor serotype Ogawa (19), Aeromonas spp. (14), Salmonella Typhi and S. paratyphi A (2 isolates each). Resistance to antimicrobial agents was common among all pathogens. Among shigellae an overall resistance of 63.6, 58.1 and 16.3 per cent was observed for nalidixic acid, cotrimoxazole and furazolidone respectively. Seven isolates of Shigella were resistant to ciprofloxacin, (18.5%) of non-typhoidal salmonellae were resistant to ciprofloxacin. V. cholerae were generally susceptible to tetracycline (only 1 isolate out of 13 resistant) and other drugs except nalidixic acid (89.5% resistance) and cotrimoxazole (77.8% resistance). INTERPRETATION & CONCLUSION: Enteropathogens have developed high level resistance to first line agents used for empiric treatment of diarrhoea. Progressively increasing resistance to ciprofloxacin is a serious cause of concern.

Intestinal parasites and intra familial incidence in a low socio-economic area of Chandigarh (North India).

A total of 550 stool samples were collected from a low socio economic population of Chandigarh (North India) and examined macroscopically and microscopically, to determine the prevalence of intestinal parasitic infections and their familial incidence. The overall prevalence rate was 19.3%. Ascaris lumbricoides and Giardia lamblia were the commonest, affecting 51 (9.3%) and 33 (6.0%), respectively. In 17 (22.7%) families the same parasite was observed to infect multiple family members, which included A.lumbricoides (in 9 families), G. lamblia (in 7 families) and H. nana (in 1 family). The results of present study indicate that there is a high prevalence of parasitic infection in the community where personal hygiene and sanitary conditions are poor and may be one of the contributing factors for transmission within the families. Intervention strategies including health education program should be designed and implemented to control parasitic infections.

Extended spectrum beta-lactamase mediated resistance in urinary tract isolates of family Enterobacteriaceae.

BACKGROUND & OBJECTIVES: Extended spectrum beta-lactamases (ESBL) hydrolyse expanded spectrum cephalosporins like ceftazidime, cefotaxime and monobactam aztreonam. ESBL producing bacteria may not be detectable in the routine disk diffusion susceptibility tests leading to inappropriate use of antibiotics and treatment failures. As information on ESBL producers causing urinary tract infection (UTI) is not available from our country, the occurrence of ESBL producing strains causing UTI was studied as also the differences between the antimicrobial susceptibility patterns of ESBL and non-ESBL producers. METHODS: Urinary isolates (233) were tested for antimicrobial susceptibility by Stoke's method and ESBL production by double disk diffusion method (ceftazidime and clavulanic acid). The clinical and demographic profile of the patients was noted. RESULTS: Sixty two of the 233 isolates tested (26.6%) were ESBL producers. Approximately 38.5 per cent of Klebsiellae, 24.7 per cent of Escherichia coli, 24 per cent of Enterobacter aerogenes, 33.3 per cent of Proteus sp. and the only Citrobacter strain produced ESBL. Recent surgery was found to be a significant (P < 0.01) risk factor for acquisition of ESBLs. Approximately 30 per cent of the ESBL producers appeared falsely sensitive or moderately sensitive to cefotaxime/ceftazidime in routine susceptibility testing. There was no difference between the ESBL producers and non-producers in the susceptibility to non-beta lactam agents except for gentamicin. INTERPRETATION & CONCLUSION: A high percentage of urinary tract isolates produced ESBL. Since they are likely to be missed in routine disk diffusion susceptibility tests, all microbiology laboratories should look for ESBL production routinely to avoid treatment failures.