93 research outputs found

    A simple microbiological tool to evaluate the effect of environmental health interventions on hand contamination.

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    The effects of interventions such as sanitation or hand hygiene on hand contamination are difficult to evaluate. We explored the ability of a simple microbiological test to: (1) detect recontamination after handwashing; (2) reflect risk factors for microbial contamination and (3) be applicable to large populations. The study was done in rural Andhra Pradesh, India, and Maputo, Mozambique. Participants placed all 10 fingertips on a chromogenic agar that stains Enterococcus spp. and E. coli spp. Outcomes were the number of colonies and the number of fingertips with colonies. In the recontamination study, participants were randomised to handwashing with soap and no handwashing, and tested at 30 min intervals afterwards. In two cross sectional studies, risk factors for hand contamination were explored. Recontamination of hands after washing with soap was fast, with baseline levels reached after 1 h. Child care was associated with higher Enterococcus spp. counts, whereas agricultural activities increased E. coli spp. counts. Food preparation was associated with higher counts for both organisms. In Maputo, counts were not strongly associated with water access, latrine type, education or diarrhoea. The method seems unsuitable for the evaluation of handwashing promotion. It may reflect immediately preceding risk practices but not household-level risk factors

    Risk Factors associated with Lack of Seroprotection against Type 3 Poliovirus.

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    The reasons for lack of seroprotection after Oral Polio Vaccination (OPV) are poorly understood. This study explored socio-demographic, nutritional, birth related, water, sanitation and operational factors to explain lack of seroprotection to type 3 poliovirus, in children 6 - 12 months. Methods The study was conducted in Vellore district in rural and urban low income neighbourhoods. This was a case-control study in 142 OPV Type 3 seropositive and 142 seronegative children who had received OPV, selected at random from an existing cohort of children as part of an earlier vaccine study. Data Collection took place between April and May 2015. A questionnaire was administered along with measuring height and weight. Vaccine status was recorded based on vaccination cards where available (83%) and verbal reports from mothers. Univariable and multivariable analysis using logistic regression was done. Results The results suggest that some of the explored biological factors, such as feeding colostrums (O.R.:11.77, 95% CI:1.21 – 114.89) and some evidence of early weaning to be associated with vaccine failure. Further, there were trends towards several socio economic factors such maternal education (O.R.:0.92, 95% C.I.: 0.86 – 0.99), HAZ score (O.R.:0.82, 95% C.I.:0.65 – 1.04) and being able to name the village health nurse (possibly a proxy for social inclusion and/or education) being associated with vaccine failure (O.R.:1.70, 95% C.I.: 1.00 – 2.88). The per dose vaccine efficacy was calculated to be 26% (7% - 41%). Conclusion We identified modifiable risk factors such as early weaning and feeding colostrum. Exclusive breastfeeding should be encouraged as the overall benefit of feeding colostrum with respect to the risk of diarrhea and pneumonia is likely to exceed the risks associated with non-seroconversion to OPV. Other risk factors identified in this study are related to more upstream socio-economic and educational factors tackling of which will require broad political and social measures

    Effectiveness of reflexology on progress of first stage of labour among primiparturients at selected hospital, Salem

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    “A Study was conducted to Evaluate the Effectiveness of Reflexology on Progress of First Stage of Labour among Primiparturients at Selected Hospital, Salem”. Quasi experimental time series design was adopted. Non probability convenience sampling technique was used to select 60 primiparturients among which 30 were assigned to experimental group and 30 were assigned to control group. The data was collected using structured interview schedule, Numerical Pain Intensity Scale and observational checklist. Pre test was done for both experimental and control group. Reflexology was given for the experimental group for 15 minutes in every 45 minutes and withheld for control group. Post test was done for both experimental and control group after the intervention. The findings showed that in experimental group 13(43.33%) belong to the age group of 21-25 years, 12(40%) were illiterate, 20(66.66%) were unemployed, 18(60%) were residing in rural area, 21(70%) have the monthly family income ranging from Rs.2000-5000, 17(56.66%) were in joint family, 11(46.66%) had 1-3 antenatal visits and 9(30%) were in 37 weeks of gestation. In control group 14(46.66%) belong to the age group of 21-25 years, 10(33.33%) were illiterate, 23(76.66%) were unemployed, 21(70%) were residing in rural area, 19(63.33%) have the monthly family income of Rs.2000 – 5000, 16(53.33%) were in joint family, 11(36.66%) had no antenatal visits, 11(36.66%) had 1 – 3 antenatal visits and 11(36.66%) were in 39 weeks of gestation. Mean difference on level of pain were, in experimental group 1.43, 2.04, 1.70, 1.90 and in control group 0.70, 0.80, 0.74, 0.80. Mean difference on duration of first stage of labour was 129.50. ‘t’ value on level of pain in experimental group before and after reflexology were 13.20, 15.50, 17.40, 19.00 at P<0.05 level. Hence H1 was retained. The post test ‘t’ value on progress of first stage of labour were 8.073, 12.349 at P<0.05 level. Hence H2 was retained. The chi-square value revealed that significant association was found between the progress of first stage of labour with their selected demographic variables. Hence H3 is retained for age in years (χ2 = 9.76), educational status (χ2=9.77), monthly family income (χ2 = 10.19), type of family (χ2 = 4.98) and number of antenatal visits (χ2=7.70) in experimental group, educational status (χ2 = 10.39), occupation (χ2=6.67), monthly family income (χ2 = 8.91) and type of family (χ2 = 4.69) in control group at P<0.05 level. The complementary therapy is the best ancient form of healing therapy. Reflexology is one of the complementary therapy which the researcher has used to promote the progress of first stage of labour

    Risk Factors for Scrub Typhus, Murine Typhus, and Spotted Fever Seropositivity in Urban Areas, Rural Plains, and Peri-Forest Hill Villages in South India: A Cross-Sectional Study.

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    Scrub typhus and spotted fever group rickettsioses are thought to be common causes of febrile illness in India, whereas they rarely test for murine typhus. This cross-sectional study explored the risk factors associated with scrub typhus, tick-borne spotted fever, and murine typhus seropositivity in three different geographical settings, urban, rural, and hill villages in Tamil Nadu, South India. We enrolled 1,353 participants living in 48 clusters. The study included a questionnaire survey and blood sampling. Blood was tested for Orientia tsutsugamushi (scrub typhus), Rickettsia typhi (murine typhus), and spotted fever group Rickettsia IgG using ELISA. The seroprevalence of scrub typhus, spotted fever, and murine typhus were 20.4%, 10.4%, and 5.4%, respectively. Scrub typhus had the highest prevalence in rural areas (28.1%), and spotted fever was most common in peri-forested areas (14.9%). Murine typhus was more common in rural (8.7%) than urban areas (5.4%) and absent in peri-forested hill areas. Agricultural workers had a higher relative risk for scrub typhus, especially in urban areas. For murine typhus, proximity to a waterbody and owning a dog were found to be major risk factors. The main risk factors for spotted fever were agricultural work and living in proximity to a forest. Urban, rural plains, and hill settings display distinct epidemiological pattern of Orientia and rickettsial infections. Although scrub typhus and spotted fever were associated with known risk factors in this study, the findings suggest a different ecology of murine typhus transmission compared with other studies conducted in Asia

    Hospitalisations and outpatient visits for undifferentiated fever attributable to scrub typhus in rural South India: Retrospective cohort and nested case-control study.

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    BACKGROUND: The burden of scrub typhus in endemic areas is poorly understood. This study aimed at estimating the proportion of hospitalisations and outpatient visits for undifferentiated fever in the community that may be attributable to scrub typhus. METHODOLOGY AND PRINCIPAL FINDINGS: The study was a retrospective cohort with a nested case-control study conducted in the South Indian state of Tamil Nadu. We conducted house-to-house screening in 48 villages (42965 people, 11964 households) to identify hospitalised or outpatient cases due to undifferentiated fever during the preceding scrub typhus season. We used scrub typhus IgG to determine past infection. We calculated adjusted odds ratios for the association between IgG positivity and case status. Odds ratios were used to estimate population attributable fractions (PAF) indicating the proportion of hospitalised and outpatient fever cases attributable to scrub typhus. We identified 58 cases of hospitalisation and 236 outpatient treatments. 562 people were enrolled as control group to estimate the background IgG sero-prevalence. IgG prevalence was 20.3% in controls, 26.3% in outpatient cases and 43.1% in hospitalised cases. The PAFs suggested that 29.5% of hospitalisations and 6.1% of outpatient cases may have been due to scrub typhus. In villages with a high IgG prevalence (defined as ≥15% among controls), the corresponding PAFs were 43.4% for hospitalisations and 5.6% for outpatients. The estimated annual incidence of scrub typhus was 0.8/1000 people (0.3/1000 in low, and 1.3/1000 in high prevalence villages). Evidence for recall error suggested that the true incidences may be about twice as high as these figures. CONCLUSIONS: The study suggests scrub typhus as an important cause for febrile hospitalisations in the community. The results confirm the adequacy of empirical treatment for scrub typhus in hospitalised cases with undifferentiated fever. Since scrub typhus may be rare among stable outpatients, the use of empirical treatment remains doubtful in these

    Incidence of scrub typhus in rural south India

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    Background Hospital studies suggest that scrub typhus is a leading cause of severe undifferentiated fever in regions across Asia where the disease is endemic, but the population-based incidence of infection and illness has been little studied. Methods We conducted a population-based cohort study to assess epidemiologic and clinical characteristics of scrub typhus in 37 villages in Tamil Nadu, India, where the disease is highly endemic. Study participants were visited every 6 to 8 weeks over a period of 2 years; a venous blood sample was obtained from those who had had fever since the last visit. A subcohort of participants underwent blood sampling to estimate the incidence of serologically confirmed Orientia tsutsugamushi infection. Results We systematically assessed 32,279 participants from 7619 households for acute febrile illness. During 54,588 person-years of follow-up, we observed 6175 episodes of fever. A blood sample was obtained in 4474 episodes (72.5%), of which 328 (7.3%) met the clinical case definition of scrub typhus (detection of IgM against O. tsutsugamushi on enzyme-linked immunosorbent assay [ELISA] or detection of O. tsutsugamushi on polymerase-chain-reaction assay). The incidence of clinical infection was 6.0 cases per 1000 person-years (95% confidence interval [CI], 4.8 to 7.5). A total of 71 clinical cases (21.6%) resulted in hospitalization (incidence, 1.3 events per 1000 person-years; 95% CI, 1.0 to 1.7). A total of 29 clinical cases (8.8%) were severe, as indicated by the presence of organ dysfunction or adverse pregnancy outcomes (incidence, 0.5 cases per 1000 person-years; 95% CI, 0.4 to 0.8). Among 2128 participants in the subcohort who provided samples at the beginning and end of a study year, the incidence of seroconversion independent of any symptoms was 81.2 events per 1000 person-years (95% CI, 70.8 to 91.6). The incidence of clinical infection was higher in older age groups than in younger age groups and higher among female participants than among male participants. By contrast, the age-adjusted rate of severe infection was similar among male and female participants. Among 5602 participants assessed at the start of the first year of the study, the seroprevalence of IgG as assessed with ELISA was 42.8% (95% CI, 35.8 to 50.2). IgG seropositivity at the beginning of years 1 or 2 did not protect against clinical illness during the subsequent year but was associated with less severe disease than IgG seronegativity. Conclusions We describe the burden of scrub typhus, including the incidence of asymptomatic infection, in a region of Asia where the disease is endemic. (Funded by the U.K. Medical Research Council; ClinicalTrials.gov number, NCT04506944.

    Antibody response following scrub typhus infection: clinical cohort study.

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    OBJECTIVE: Scrub typhus is a common cause of fever in Asia. The antibody response to infection and its effect on subsequent infection are unclear. We studied the IgM and IgG antibody response after infection, accounting for clinical severity. METHOD: We studied 197 scrub typhus patients for up to 2 years post-infection. Overall, 501 blood samples were analysed for scrub typhus antibodies using ELISA. IgM and IgG ELISA optical densities (OD) were analysed using quantile regression. OD values of 1.0 (IgM) and 1.5 (IgG) were used to define seropositivity. RESULTS: IgM OD values fell rapidly from an initial peak after infection. 50% of cases were IgM seronegative after 82 days. About 2 years after fever onset, 50% of cases had fitted IgG OD values of <1.5. Patients with high initial IgG OD values (≥2.5, used as a proxy for probable previous scrub typhus infection) had a more sustained IgG response than those with a low initial IgG OD, and more often presented with complications (18/36 = 50% vs. 28/91 = 30.8%, risk ratio = 1.63, 95% CI 1.04, 2.55, P = 0.035). This association was robust to adjusting for age (risk ratio 1.50, 95% CI 0.96, 2.33, P = 0.072). CONCLUSION: Cross-sectional IgG seroprevalence data substantially underestimate the proportion in a population ever infected with scrub typhus. A high initial IgG as a potential marker for previous scrub typhus infection may be associated with long-term IgG persistence and a higher risk of complicated scrub typhus

    Distinct structural mechanisms determine substrate affinity and kinase activity of protein kinase Cα

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    Protein kinase Cα (PKCα) belongs to the family of AGC kinases that phosphorylate multiple peptide substrates. Although the consensus sequence motif has been identified and used to explain substrate specificity for PKCα, it does not inform the structural basis of substrate-binding and kinase activity for diverse substrates phosphorylated by this kinase. The transient, dynamic, and unstructured nature of this protein–protein interaction has limited structural mapping of kinase–substrate interfaces. Here, using multiscale MD simulation-based predictions and FRET sensor-based experiments, we investigated the conformational dynamics of the kinase–substrate interface. We found that the binding strength of the kinase–substrate interaction is primarily determined by long-range columbic interactions between basic (Arg/Lys) residues located N-terminally to the phosphorylated Ser/Thr residues in the substrate and by an acidic patch in the kinase catalytic domain. Kinase activity stemmed from conformational flexibility in the region C-terminal to the phosphorylated Ser/Thr residues. Flexibility of the substrate–kinase interaction enabled an Arg/Lys two to three amino acids C-terminal to the phosphorylated Ser/Thr to prime a catalytically active conformation, facilitating phosphoryl transfer to the substrate. The structural mechanisms determining substrate binding and catalytic activity formed the basis of diverse binding affinities and kinase activities of PKCα for 14 substrates with varying degrees of sequence conservation. Our findings provide insight into the dynamic properties of the kinase–substrate interaction that govern substrate binding and turnover. Moreover, this study establishes a modeling and experimental method to elucidate the structural dynamics underlying substrate selectivity among eukaryotic kinases

    Distinct structural mechanisms determine substrate affinity and kinase activity of protein kinase Cα

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    Protein kinase Cα (PKCα) belongs to the family of AGC kinases that phosphorylate multiple peptide substrates. Although the consensus sequence motif has been identified and used to explain substrate specificity for PKCα, it does not inform the structural basis of substrate-binding and kinase activity for diverse substrates phosphorylated by this kinase. The transient, dynamic, and unstructured nature of this protein–protein interaction has limited structural mapping of kinase–substrate interfaces. Here, using multiscale MD simulation-based predictions and FRET sensor-based experiments, we investigated the conformational dynamics of the kinase–substrate interface. We found that the binding strength of the kinase–substrate interaction is primarily determined by long-range columbic interactions between basic (Arg/Lys) residues located N-terminally to the phosphorylated Ser/Thr residues in the substrate and by an acidic patch in the kinase catalytic domain. Kinase activity stemmed from conformational flexibility in the region C-terminal to the phosphorylated Ser/Thr residues. Flexibility of the substrate–kinase interaction enabled an Arg/Lys two to three amino acids C-terminal to the phosphorylated Ser/Thr to prime a catalytically active conformation, facilitating phosphoryl transfer to the substrate. The structural mechanisms determining substrate binding and catalytic activity formed the basis of diverse binding affinities and kinase activities of PKCα for 14 substrates with varying degrees of sequence conservation. Our findings provide insight into the dynamic properties of the kinase–substrate interaction that govern substrate binding and turnover. Moreover, this study establishes a modeling and experimental method to elucidate the structural dynamics underlying substrate selectivity among eukaryotic kinases

    High initial IgG antibody levels against Orientia tsutsugamushi are associated with an increased risk of severe scrub typhus infection.

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    BACKGROUND: Scrub typhus is a dominant cause of febrile illness in many parts of Asia. Immunity is limited by the great strain diversity of Orientia tsutsugamushi. It is unclear whether previous infection protects from severe infection or enhances the risk. METHODS/PRINCIPAL FINDINGS: We studied IgG antibody levels against O. tsutsugamushi at presentation in 636 scrub typhus patients using enzyme-linked immunosorbent assays (ELISA). The association between ELISA optical density (OD) and risk of severe infection was modelled using Poisson regression. OD was categorised as low (<1.0), intermediate (1.0 to 2.9), and high (≥3.0). OD was also modelled as a continuous variable (cubic spline). Median age of cases was 41 years (range 0-85), with 37% having severe infection. Compared to the low category, the age-adjusted risk of severe infection was 1.5 times higher in the intermediate category (95%CI 1.2, 1.9), and 1.3 times higher in the high category (95%CI 1.0, 1.7). The effect was stronger in cases <40 years, doubling the risk in the intermediate and high categories compared to the low category. The effect was more pronounced in cases tested within 7 days of fever onset when IgG ODs are more likely to reflect pre-infection levels. CONCLUSIONS/SIGNIFICANCE: Intermediate and high IgG antibody levels at the time of diagnosis are associated with a higher risk of severe scrub typhus infection. The findings may be explained by severe infection eliciting an accelerated IgG response or by previous scrub typhus infection enhancing the severity of subsequent episodes
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