Natural contamination of human hands with enteric parasites in Indian Subcontinent

AIM: To investigate the prevalence of enteric parasite contamination on hands and the potential role naturally contaminated hands may have in their transmission. METHODS: Prior to initiating the survey, the protocol was reviewed and approved by respective Institutional Review Boards of each survey site(Dhaka, Bangladesh and Kolkata, India). Both stool and corresponding hand wash samples collected, were analyzed for the presence of enteric parasitic ova/(oo)cysts employing conventional microscopy coupled with permanent staining techniques. Additionally molecular approachessuch as polymerase chain reaction(PCR) of enteric parasites recovered from both stool and corresponding hand wash samples, were also used to further confirm their identity. RESULTS: A total of 972 stool samples were collected from both sites surveyed(300 volunteers from Kolkata, India and 672 from Dhaka, Bangladesh). Parasitic analysis revealed, 113(38%) from Kolkata, India and 267(40%) of stool samples from Dhaka, Bangladesh were positive for parasitic ova/(oo)cysts. When the corresponding hand wash samples were analyzed, 43(14%) stool-positive volunteers in Kolkata, India and 47(7%) in Dhaka, Bangladesh were positive for enteric parasitic ova/(oo)cysts. Ascaris lumbricoides(A. lumbricoides) ova and Giardia lamblia(G. lamblia) cysts predominated in hands wash samples from both sites surveyed(from India, A. lumbricoides ova, 53%; G. lamblia cysts 31% and from Bangladesh, A. lumbricoides ova, 47%; G. lamblia cysts 19%). Genotypic analysis of enteric parasitic ova/(oo)cysts obtained from both stool and corresponding hand wash samples taken from the same person were found to be identical. CONCLUSION: These results suggest a possible role of hands contaminated with enteric parasites' ova/(oo)cysts in the transmission of these parasites highlighting another role of hand hygiene/proper hand washing in reducing the disease burden in low socioeconomic communities.

Significant increase in HBV, HCV, HIV and syphilis infections among blood donors in West Bengal, Eastern India 2004-2005: Exploratory screening reveals high frequency of occult HBV infection

AIM: To evaluate the prevalence of markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) and human immunodeficiency virus (HIV) among blood donors in Kolkata, Eastern India for two consecutive years and to conduct a pilot study to explore the presence of HBV DNA among hepatitis B surface antigen (HBsAg) negative but anti-HBc positive blood donors. METHODS: Seroprevalence of HBsAg, anti-HCV and anti-HIV was studied among 113 051 and 106 695 voluntary blood donors screened in 2004 and 2005, respectively. Moreover, a pilot study on 1027 HBsAg negative donors was carried out for evaluating the presence of HBV DNA by PCR on HBsAg negative/anti- HBc positive donors. RESULTS: A statistically significant increase in the prevalence of HBV (1448 vs 1768, P < 0.001), HIV (262 vs 374, P < 0.001), HCV (314 vs 372, P = 0.003) and syphilis (772 vs 853, P = 0.001) infections was noted among blood donors of Kolkata West Bengal in 2005 as compared to 2004. Moreover, the exploratory study on 1027 HBsAg negative donors revealed that 188 (18.3%)of them were anti-HBc positive out of which 21% were positive for HBV DNA. CONCLUSION: The findings of this study underscore the significantly increasing endemicity of hepatitis viruses, syphilis and HIV among the voluntary blood donors of our community. The pilot study indicates a high rate of prevalence of HBV DNA among HBsAg negative/anti-HBc positive donors and thus emphasizes the need for a more sensitive and stringent screening algorithm for blood donations.

Curcumin as a potential therapeutic candidate for Helicobacter pylori associated diseases

Curcumin, a yellow pigment and principal polyphenolic Curcuminoid obtained from the turmeric rhizome Curcuma longa, is commonly used as a food-coloring agent. Studies suggest that curcumin has a wide range of beneficial properties e.g., anti-inflammatory, antioxidant, anti-cancer, anti-proliferative, anti-fungal and anti-microbial. These pleiotropic activities prompted several research groups to elucidate the role of curcumin in Helicobacter pylori(H. pylori) infection. This is the first review with this heading where we discussed regarding the role of curcumin as an anti-H. pylori agent along with its potential in other gastrointestinal diseases. Based on several in vitro, early cell culture, animal research and few pre-clinical trials, curcumin projected as a potential therapeutic candidate against H. pylori mediated gastric pathogenesis. This review sheds light on the anti-H. pylori effects of curcumin in different models with meticulous emphasis on its anti-oxidant, anti-inflammatory and anti-carcinogenic effects as well as some critical signaling and effecter molecules. Remarkably, non-toxic molecule curcumin fulfills the characteristics for an ideal chemopreventive agent against H. pylori mediated gastric carcinogenesis but the foremost challenge is to obtain the optimum therapeutic levels of curcumin, due to its low solubility and poor bioavailability. Further, we have discussed about the possibilities for improving its efficacy and bioavailability. Lastly, we concluded with the anticipation that in near future curcumin may be used to develop a therapeutic drug against H. pylori mediated gastric ailments through improved formulation or delivery systems, facilitating its enhanced absorption and cellular uptake.

Detection of hepatitis B virus infection: A systematic review

AIM: To review published methods for detection of hepatitis B virus(HBV) infection.METHODS: A thorough search on Medline database was conducted to find original articles describing different methods or techniques of detection of HBV, which are published in English in last 10 years. Articles outlining methods of detection of mutants or drug resistance were excluded. Full texts and abstracts(if full text not available) were reviewed thoroughly. Manual search of references of retrieved articles were also done. We extracted data on different samples and techniques of detection of HBV, their sensitivity(Sn), specificity(Sp) and applicability.RESULTS: A total of 72 studies were reviewed. HBV was detected from dried blood/plasma spots, hepatocytes, ovarian tissue, cerumen, saliva, parotid tissue, renal tissue, oocytes and embryos, cholangiocarcinoma tissue, etc. Sensitivity of dried blood spot for detecting HBV was > 90% in all the studies. In case of seronegative patients, HBV DNA or serological markers have been detected from hepatocytes or renal tissue in many instances. Enzyme linked immunosorbent assay and Chemiluminescent immunoassay(CLIA) are most commonly used serological tests for detection. CLIA systems are also used for quantitation. Molecular techniques are used qualitatively as well as for quantitative detection. Among the molecular techniques version 2.0 of the Cobas Ampliprep/Cobas Taq Man assay and Abbott's real time polymerase chain reaction kit were found to be most sensitive with a lower detection limit of only 6.25 IU/m L and 1.48 IU/m L respectively. CONCLUSION: Serological and molecular assays are predominant and reliable methods for HBV detection. Automated systems are highly sensitive and quantify HBV DNA and serological markers for monitoring.

Indistinguishable cellular changes in gastric mucosa between Helicobacter pylori infected asymptomatic tribal and duodenal ulcer patients

AIM:To investigate the changing pattern of different histological parameters occurring in the stomach tissue of Helicobacter pylori (H pylori) infected tribal populations and duodenal ulcer patients among ethnic Bengalis and correlation of the genotypes of H pylori with different histological parameters.were enrolled into this study between 2002 and 2004. Among them,72 had clinical features of duodenal ulcer (DU) from ethnic Bengali population and 40 were asymptomatic ethnic tribals. Endoscopic gastric biopsy samples were processed for histology,genotyping and rapid urease test. Histologically,haematoxylin and eosin staining was applied to assess the pathomorphological changes and a modified Giemsa staining was used for better detection of H pylori. For intestinal metaplasia,special stainings,i.e. Alcian blue periodic acid-Schiff and high iron diamine-Alcian blue staining,were performed. PCR was performed on bacterial DNA to characterize the presence or absence of virulence-associated genes,like cagA,and distribution of different alleles of vacA and iceA. RESULTS:Intraglandular neutrophil infiltration,a hallmark of activity of gastritis,was present in 34 (94%) of tribals (TRs) and 42 (84%) of DU individuals infected with H pylori. Lymphoid follicles and aggregates,which are important landmarks in H pylori infection,were positive amongst 15 (41%) of TRs and 20 (40%) of DU subjects. Atrophic changes were observed in 60% and 27.7%,respectively,among DU cases and tribals (P > 0.003). Metaplastic changes were detected in low numbers in both groups. Moderate to severe density distribution of H pylori in the gastric mucosa was 63% among TRs,whereas it was 62% in DU subjects. There were no significant differences in the distribution of virulence-associated genes like cagA,vacA and iceA of H pylori strains carried by these two populations. CONCLUSION:Our study showed almost similar distribution of inflammatory cells among asymptomatic tribals and DU Bengali patients. Interestingly,the tribal population are free from any clinical symptoms despite evidence of active histologic gastritis and infection with H pylori strains carrying similar virulence markers as of strains isolated from patients with DU. There was an increased cellular response,especially in terms of neutrophil infiltration,but much lower risk of developing atrophy and metaplastic changes among the tribal population.

Sero diagnosis of dengue activity in an unknown febrile outbreak at the Siliguri Town,District Darjeeling,West Bengal

Objective:To investigate the outbreak of unknown fever at Siliguri town,Darjeeling District on request from the State Health Department,Government of West Bengal.Methods: Investigations were made to the affected wards,Sub Divisional Hospital and the nursing homes of Siliguri Town.Duration of illness was 3-5 days.Interesting observations were made in some cases which had gastrointestinal disorders with high serum glutamate pyruvate transaminase(SGPT) and serum glutamic oxaloacetic transaminase(SCOT) levels.A total of 69 blood samples and 7 throat swabs(in Minimum Essential Media) were collected and brought to the ICMR Virus Unit, Kolkata for analysis.Mosquitoes from different affected areas were collected for the identification of the definite vector.Results:Amongst the 69 blood samples,42(60.86%) were positive to IgM antibody against dengue virus by Mac enzyme-linked immunosorbent assay(ELISA) test.No IgM antibody to Japanese encephalitis virus was detected among the collected blood samples.Based on the clinical symptoms,presence of IgM antibody to dengue virus and identification of Aedes mosquito,it amply proves that,the illness of those cases were due to dengue virus infection. Conclusions:Based on clinical-epidemiological observations of the investigations the possibility of a communicable disease of viral origin,the detection of IgM antibody and the identification of Aedes egypti,and the potential circulation of denge virus in Siliguri town for the first time were all suggested.

Changing HIV Epidemic in North-Eastern India and Its Relationship with Development and Programmatic Indicators

Background: Although there has been significant reduction in HIV prevalence and new HIV infections in India, some of the low/moderate prevalence states have been showing long term increase in HIV prevalence and new HIV infections. Assam, a state in northeast India is one such low HIV prevalence state where HIV prevalence and new HIV infections have almost doubled in the last few years. This study examined the trend of HIV prevalence across districts/regions of Assam and its association with developmental and program indicators. Materials and Methods: A retrospective descriptive analysis of secondary data from the National AIDS Control Program, Census of India-2011, and District Level Household and Facility Survey-3 was conducted. The time period covered under the secondary data analysis was 2007 to 2012. Correlation and Chi-square for trend tests were also used in this paper. Results: During 2007 and 2012, HIV positivity (%) increased relatively in North Assam (46.9%) followed by South Assam (11.5%) while there has been a relative decline in West Assam (﹣51.5%). Correlation analysis showed statistically significant association between HIV prevalence and female literacy, population using mobile phone, population using internet, women (15 - 49 years) seeking treatment for any STI/RTI, proportion of brothel based FSWs, FSWs having <5 clients per week and proportion of condom utilized annually. Conclusion: Program efforts in the state should be focus on the districts with increasing HIV prevalence. Emphasis should be given in planning strategies to address the program gaps among the high risk and vulnerable populations in the state.

Oligomerization of Vibrio cholerae Hemolysin Induces CXCR3 Upregulation and Activation of B-1a Cell

The hemolysin oligomer promotes the proliferation of B-1a cells and the expression of CD25, which is indicative of cell activation, on B-1a cells. The upregulation of CD86 induced by the oligomer showed its selective bias for the B7-2 member of B7 family while the monomer failed to induce these effects. The oligomer induced the expression of CXCR3, associated with B cell activation, while the monomer induced the expression of CXCL4, a powerful angiostatic chemokine. In conclusion, we found that B-1a cells responded to the apoptogenic monomer by expressing CXCL4, whereas oligomerization of the immunogen induced CXCR3 to shift the response towards activation.

Environmental Arsenic and Selenium Contamination and Approaches Towards Its Bioremediation Through the Exploration of Microbial Adaptations:A Review

Bioaccumulation of selenium and arsenic resulting from geogenic activities and aggravated by anthropogenic actions has now become a serious environmental issue. Different parts of the world are experiencing issues of selenium and arsenic contamination, especially in soil and ground water. The present selenium and arsenic contamination scenario has been well represented in contemporary literature, and there are an array of remediation techniques targeting the decontamination of environmental contamination. The use of microbe-mediated remediation of selenium and arsenic contamination is gaining scientific attention for sustainable environmental bioremediation. The present review elucidates the different aspects of selenium and arsenic contamination, bioaccumulation, and bioremediation with implications for successful decontamination of these heavy metals.

Therapeutic methods for diarrhea in children

DEFINITIONAcute diarrhoea is defined as passage of loose or waterystools at least three times in a 24 h period.When loosestools contain blood,it is called bloody diarrhoea(dysentery).It is the consistency of the stools which ismost important rather than the frequency.Breast-fed babiesoften pass'pasty'stools frequently which is not diarrhoea.The raother can often tell accurately whether child hasdiarrhoea or not.

印度Kolkata贫民区内霍乱所造成的经济负担:一项前瞻性社区研究情况

Aims: To conduct a prospective, community based study in an impoverished urban site in Kolkata (formerly Calcutta) in order to measure the burden of cholera, describe its epidemiology, and search for potential risk factors that could be addressed by public health strategies. Methods: The study population was enumerated at the beginning and end of the study period. Surveillance through five field outposts and two referral hospitals for acute, watery, non bloody diarrhoea was conducted from 1 May 2003 to 30 April 2004. Data and a stool sample for culture of Vibrio cholerae were collected from each patient. Treatment was provided in accordance with national guidelines. Results: From 62 329 individuals under surveillance, 3284 diarrhoea episodes were detected, of which 3276 (99% ) had a stool sample collected and 126 (4% ) were culture confirmed cholera. Nineteen (15% ) were children less than 2 years of age, 29 (23% ) had severe dehydration, and 48 (38% ) were hospitalised. Risk factors for cholera included a household member with cholera during the period of surveillance, young age, and lower educational level. Conclusions: There was a substantial burden of cholera in Kolkata with risk factors not easily amenable to intervention. Young children bear the brunt not only of diarrhoeal diseases in general, but of cholera as well. Mass vaccination could be a potentially useful tool to prevent and control seasonal cholera in this community.

Metagenomic Surveys of Gut Microbiota

Gut microbiota of higher vertebrates is host-specific. The number and diversity of the organisms residing within the gut ecosystem are defined by physiological and environmental factors, such as host genotype, habitat, and diet. Recently, culture-independent sequencing techniques have added a new dimension to the study of gut microbiota and the challenge to analyze the large volume of sequencing data is increasingly addressed by the development of novel computational tools and methods. Interestingly, gut microbiota maintains a constant relative abundance at operational tax- onomic unit （OTU） levels and altered bacterial abundance has been associated with complex diseases such as symptomatic atherosclerosis, type 2 diabetes, obesity, and colorectal cancer. Therefore, the study of gut microbial population has emerged as an important field of research in order to ulti- mately achieve better health. In addition, there is a spontaneous, non-linear, and dynamic interac- tion among different bacterial species residing in the gut. Thus, predicting the influence of perturbed microbe-microbe interaction network on health can aid in developing novel therapeutics. Here, we summarize the population abundance of gut microbiota and its variation in different clinical states, computational tools available to analyze the pyrosequencing data, and gut microbe-microbe inter- action networks.

IL-15 temporally reorients IL-10 biased B-la cells toward I L- 12 expression

Interleukin （IL）-15 is known to strongly modulate T-cell function; however, its role in controlling mucosal immunity, including its ability to modulate B-la cell activity, remains to be elucidated. Here, we show that IL-15 upregulates activation molecules and the costimulatory molecule CD80 on viable B-la cells. Cell activation was accompanied by the depletion of sialic acid-binding immunoglobulin-like lectin （Siglec）-G, an inhibitor of cell activation that is present on B-la cells. The IL-15 receptor CD122 was stimulated on B-la cells by the cytokine showing its direct involvement in IL-15-mediated responses. IL-IO is responsible for the long term survival of B-la cells in culture, which is initially promoted by IL-15. The upregulation of IL-IO was followed by the appearance of suppressor of cytokine signaling （SOCS）I in the presence of IL-15 and the loss of IL-IO. This resulted in the cells switching to IL-12 expression. This anti-inflammatory to pro-inflammatory shift in the B-la cell character was independent of the cell-specific marker CD5, which remained highly expressed throughout the in vitro life of the cells. The presence of the immunosuppressive receptor programmed cell death （PD）-I and its ligand PD-L2 were features of a predominantly IL-IO response. PD-1 and PD-L2 can mediate juxtacrine signaling. However, the abrogation of PD-1 and its ligand was observed when the cells expressed IL-12. This demonstrates an inverse relationship between the receptor and ligand and the pro-inflammatory cytokine. The induction of IgM and IgA, which can play pivotal roles in mucosal immunity, was promoted in the presence of IL-15. Collectively, the data implicate IL-15 as the master cytokine that induces B-la cells to mount a mucosal immune response.