Pre-treatment impairment of oral health-related quality of life is associated with variations in minimal clinically important differences among patients with removable partial denture treatment.

BACKGROUND: The minimal clinically important differences (MID) of the Oral Health-related Quality of Life (OHRQoL) are the benchmark to meaningfully interpret treatment outcomes. However, there is no available information regarding the factors impact the MID variations after removable partial denture (RPD) treatment. OBJECTIVE: The purpose of this study was to determine the influence of the pre-treatment OHRQoL impairment on the MID in the oral health impact profile (OHIP) after RPD treatment. METHODS: In this prospective study, OHIP and Self-reported Oral Health (SROH) questionnaires were administered to patients before and 3 months after RPD treatment. The MID in each OHIP version (OHIP-49, OHIP-20, OHIP-14 and OHIP-5) was the mean score of patients who showed a minimum SROH improvement. Multiple linear regression analysis was conducted to determine the influence of the pre-treatment OHIP summary score on the MID score. RESULTS: Among 248 participants who completed both evaluations, 85 (34%) patients had minimum SROH improvements after RPD treatment. Multiple regression analysis indicated that each 10-point increase in the pre-treatment summary OHIP score was associated with an increase in the MID score of three points for OHIP-49 and four points for OHIP-20, OHIP-14 and OHIP-5 (P < .05), after controlling for age, sex and the number of missing teeth. Therefore, the MID increased as the pre-treatment OHRQoL was impaired. CONCLUSIONS: The MID was accounted for by approximately one-third of the pre-treatment summary score, independent of the OHIP version, in the interpretation of the effects of RPD treatment on patients' OHRQoL.

On the glacial-interglacial variability of the Asian monsoon in speleothem δ18O records.

While Asian monsoon (AM) changes have been clearly captured in Chinese speleothem oxygen isotope (δ18O) records, the lack of glacial-interglacial variability in the records remains puzzling. Here, we report speleothem δ18O records from three locations along the trajectory of the Indian summer monsoon (ISM), a major branch of the AM, and characterize AM rainfall over the past 180,000 years. We have found that the records close to the monsoon moisture source show large glacial-interglacial variability, which then decreases landward. These changes likely reflect a stronger oxygen isotope fractionation associated with progressive rainout of AM moisture during glacial periods, possibly due to a larger temperature gradient and suppressed plant transpiration. We term this effect, which counteracts the forcing of glacial boundary conditions, the moisture transport pathway effect.

Minimal clinically important differences of oral health-related quality of life after removable partial denture treatments.

OBJECTIVES: This study aimed to determine the minimal clinically important difference (MID) of the oral health-related quality of life (OHRQoL) in removable partial dentures (RPDs) wearers, using the oral health impact profile (OHIP). METHODS: In this study, RPD patients were asked to complete the OHIP and self-reported oral health (SROH) questionnaires before the treatment and 3 months after the RPD treatment. The Wilcoxon signed ranked test compared the pre- and post-treatment status and the Spearman correlation analysis evaluated the relationship between the pre- and post- treatment change scores of the OHIP and SROH. The median OHIP change score in a subgroup that showed minimum SROH improvement was determined as the MID. RESULTS: Of the 277 participants, 248 (89.5 %) completed the pre-and post- treatment evaluations. SROH and OHIP scores showed significant improvements after RPD treatment (P < 0.05). The OHIP change scores showed significant moderate correlations with the SROH change scores (P < 0.05). The MIDs for the summary scores of OHIP-49, 20, 14, and 5 versions were 14, 7, 3, and 2 points, respectively. An additional 2-3 points were assigned to the four dimensions (oral function, orofacial pain, orofacial appearance, and psychological impact). CONCLUSIONS: An OHIP change of more than 14 points (OHIP-49), 7 points (OHIP-20), 3 points (OHIP-14), 2 points (OHIP-5) and 2-3 points (4 dimensions) was considered clinically meaningful in RPD treatments. CLINICAL SIGNIFICANCE: The proposed MID scores could be used as a benchmark for clinical decision making, interpretation of RPD treatment effects on OHRQoL, and sample size calculations in clinical trials.

Retracted: Risks of avian influenza (H5) in duck farms in the Ayeyarwaddy Delta region, Myanmar.

The Ayeyarwaddy delta region in the south-west of Myanmar is the main agricultural and rice-growing area. The region has a high density of duck and backyard chicken populations with low biosecurity. The objective of this study was to analyse risk factors for avian influenza (H5) in the Ayeyarwaddy delta region, Myanmar. A case­control risk factor study was conducted from April to June 2010 by individual interviews including risk factor questionnaires given to duck farmers (n = 50) in five townships in the Ayeyarwaddy delta region, Myanmar. Risk factor analyses were conducted using univariate analysis and multivariate logistic regression model with backward stepwise (wald) method. The results showed significant risk factors for AI (H5) sero-positivity in ducks were wooden egg box containers (OR = 52.7, 95% CI = 2.34-1188, P = 0.013) and water sourced from wetlands (OR = 30.7, 95% CI = 1.96-481.6, P = 0.015). Conversely, the cleaning of reusable egg containers was determined as a protective factor (OR = 0.03, 95% CI = 0.00-0.42, P = 0.01). In conclusion, this study identified risk factors for AI (H5) in duck farms and the importance of avian influenza prevention and control.

Serum prealbumin predicts survival in hemodialysis and peritoneal dialysis: 10 years of prospective observation.

Malnutrition is a major factor contributing to the high mortality rate in hemodialysis (HD) and peritoneal dialysis (PD) patients. We and others have reported previously that single enrollment levels of serum biochemical markers, such as albumin, cholesterol, creatinine, and prealbumin, are correlated directly with mortality in HD and PD patients. We have studied prospectively the relationship of enrollment prealbumin levels, demographic characteristics, and other biochemical markers to all causes of mortality in 130 HD and 128 PD patients who were monitored for 10 years. The Kaplan-Meier method was used to compute observed survival, and the Cox proportional hazards model was used to identify independent predictors of mortality risk. For HD patients, enrollment serum prealbumin remained a strong independent predictor of long-term survival after adjusting for age, race, gender, months on dialysis, diabetic status, and other nutritional markers. In PD and HD patients, observed and adjusted survivals (after adjusting for aforementioned confounding variables) of patients with prealbumin greater than 30 mg/dL were significantly higher than survivals of patients with prealbumin less than 30 mg/dL. For HD and PD patients, age and diabetes were associated inversely with prealbumin concentration, whereas levels of albumin, creatinine, and total cholesterol were associated directly with prealbumin concentration. In this study, prealbumin was the best biochemical predictor of mortality for HD patients and a useful tool to assess nutritional risk in HD and PD patients.

Survival on hemodialysis and peritoneal dialysis over 12 years with emphasis on nutritional parameters.

We analyzed the prognostic importance of nutritional markers and mortality data in 537 hemodialysis (HD) and 422 peritoneal dialysis (PD) patients followed for up to 12 years. Patients on HD had a 44% lower risk of mortality than did those treated with PD (P: < 0.0001). The difference in mortality between the modalities was even more striking among diabetics but less striking among younger patients. Over a 12-year period, survival of dialysis patients with lower enrollment levels of albumin, creatinine, and parathyroid hormone (PTH) were significantly lower. In multivariate Cox's proportional hazards models, serum prealbumin and enrollment PTH level of <65 pg/mL were independent predictors of mortality both in HD and PD patients. In conclusion, HD patients had higher cumulative survival than PD patients over a 12-year period. Nutritional markers at enrollment continue to be strong predictors of mortality for up to 12 years.

Emergence of new forms of human immunodeficiency virus type 1 intersubtype recombinants in central Myanmar.

We have previously shown that HIV-1 env subtypes B' (a Thai-B cluster within subtype B) and E (CRF01_AE) are distributed in Yangon, the capital city of Myanmar. However, HIV strains from the rest of country have not yet been genetically characterized. In the present study, we determined env (C2/V3) and gag (p17) subtypes of 25 specimens from central Myanmar (Mandalay). Phylogenetic analyses identified 5 subtype C (20%), in addition to 10 CRF01_AE (40%) and 4 subtype B' (16%). Interestingly, the remaining six specimens (24%) showed discordance between gag and env subtypes; three gag subtype B'/env subtype C, one gag subtype B'/env subtype E, one gag subtype C/env subtype B', and one gag subtype C/env subtype E. These discordant specimens were found frequently among injecting drug users (4 of 12, 33%) and female commercial sex workers (2 of 8, 25%) engaging in high-risk behaviors. The recombinant nature of these HIV-1 strains was verified in three specimens, indicating the presence of new forms of HIV-1 intersubtype C/B' and C/B'/E recombinants with different recombination breakpoints. The data suggest that multiple subtypes of B', C, and CRF01_AE are cocirculating in central Myanmar, leading to the evolution of new forms of intersubtype recombinants among the risk populations exhibiting one of the highest HIV infection rates in the region.

Relationship of breast-feeding and hand-washing with dehydration in infants with diarrhoea due to Escherichia coli.

This prospective cohort study was carried out in the neonatal unit of the Yangon Children Hospital, Myanmar, to gather more information on the types of feedings and hand-washing practices of mothers as the determinant of severe dehydration in infants with acute diarrhoea due to Escherichia coli. The study subjects included 100 infants with diarrhoea, aged less than 4 months, admitted to the hospital from June 1997 to May 1998. Data on isolation of E. coli from rectal swab samples, types of feedings, hand-washing practices, and dehydration status were collected. Of the 100 cases, E. coli was isolated from rectal swab samples of 48 infants. Of these 48 cases, 28 had some dehydration and 20 had severe dehydration. Exclusive breast-feeding was observed only in the age group < 1 and > 1-2 month(s). The association of the severity of dehydration with other types of feedings compared to exclusive breast-feeding was not statistically significant. In this study, most mothers washed their hands with water only after cleansing their children's defaecation, and before and after feeding their children. The severity of dehydration was statistically significant in hand-washing practices when compared to washing with water only and washing with soap and water. This study has shown the association between types of feedings and hand-washing practices with dehydration in infants with acute diarrhoea due to E. coli. The results of the study suggest that there is a need for appropriate intervention programmes to promote exclusive breast-feeding and hand-washing practices with soap and water after cleansing children's defaecation, and before and after feeding children.

Stability of saliva for measuring HIV in the tropics.

If HIV is to be detected among pregnant women in remote regions of the tropics, HIV antibodies need to remain stable until specimens arrive at the laboratory. Our objective was to assess the stability of HIV antibodies in saliva held for up to 1 month at ambient temperature in Yangon, Myanmar. We gathered 10 saliva specimens from each of 102 HIV-infected persons with the Omni-Sal collection device (Saliva Diagnostic Systems, Inc.), and for each subject, divided the saliva into 15 portions. During 33 days, the 102 saliva specimens, kept at ambient temperature, were tested every 2-3 days for HIV antibodies (total 1530 assays) with the GACELISA (Murex Diagnostics Ltd), a highly sensitive test designed for use with saliva. We observed no reduction in test performance over 33 days, indicating that the antimicrobial and antiproteolytic transport medium in the Omni-Sal device can preserve HIV antibodies without refrigeration for up to a month before saliva specimens reach the laboratory.

Local evaluation of a rapid HIV assay for use in developing countries.

We present a research scheme for evaluating inexpensive HIV rapid tests in a developing country setting and assess the field validity of the Sero Strip HIV 1/2 rapid test. The research design features the random allocation of 100 true HIV-positive and 100 true HIV-negative serum specimens to 4 groups, followed by blind testing for HIV status. After one short training session, laboratory technicians at 4 township hospitals (25-35 beds) located 20-50 km from Yangon, Myanmar were sent 800 sera labelled with only an identification number and divided into four groups of 200 specimens each, half being HIV-positive and half HIV-negative. Testing was done in the field with the Sero-Strip HIV 1/2. Determination of the test's validity was based on 399 true HIV positive and 401 true HIV negative sera. All true positives were correctly identified, as were all but two of the true negatives. The sensitivity (% of true positives that test positive) was 100%, and the specificity (% of true negatives that test negative) was 99.5%. The research was completed by in-country scientists who are best suited to evaluate the validity of HIV tests conducted in local environments.

HIV transmission in sexual partners of persons with HIV/AIDS attending the Infectious Diseases Hospital, Yangon.

A study was conducted in the Infectious Diseases Hospital, Yangon, for one year from August 1996 to 1997, to assess the extent and the factors related to HIV transmission among sexual partners of HIV/AIDS cases. It was a cross-sectional comparative study on 67 (61 males, 6 females) HIV positive individuals with or without AIDS, and their sexual partners. Separate interviews of index cases and partners were done, and clinical examination and laboratory tests for HIV and sexually transmitted diseases (STDs) were performed. HIV transmission was found in 41.8% of the partners. Male-to-female transmission was 39.3% (n=61) and female to male transmission was 66.7% (n=6), Seven and one half percent of the partners were suffering from AIDS. There were 4 (6.6%) pregnant mothers and 1 (25%) was HIV positive. Though 75% of the partners did not use condoms during their married life, HIV transmission was significantly reduced in the condom users (odds ratio (OR) = 0.18, 95% confidence interval (CI) 0.02-0.98 p = < 0.05). The seropositive men who were less than 30 years of age had greater HIV transmission (OR = 5.67, 95% CI 1.13-36.46). However, socio-demographic factors, number of marital partners and age of first sex partners, duration of marriage, number of sexual relationships between these couples, duration of HIV positivity and AIDS infection, immunological status of the index group and STD positivity among partners had no significant association with the transmission of HIV. This study demonstrated that the transmission of HIV was high among the sexual partners of persons with HIV infection. It also highlighted the requirement of effective counseling and preventive measures against HIV infection among the couples.

Genetic and serologic characterization of HIV type 1 prevailing in Myanmar (Burma).

To study the molecular epidemiology of HIV-1 spread in Myanmar and the interplay with the epidemic in surrounding Southeast Asian countries, we determined the HIV-1 subtypes prevailing in Myanmar. Thirty HIV-positive blood specimens were sampled in the capital city, Yangon, and an additional 459 sera were collected nationwide in 1995. Genetic subtyping based on the env C2/V3 sequence and serologic data, using a V3 peptide enzyme immunoassay (PEIA), revealed three patterns of HIV spread in different geographic regions in Myanmar: (1) in the capital city, Yangon, HIV-1 subtype B' ("Thai-B" cluster within subtype B) predominated both in IDUs and heterosexuals; (2) in the cities near the border with Thailand, including Tachelaik and Kawthaung, where heterosexual transmission is a major pathway of HIV-1 spread, HIV-1 subtype E was predominantly distributed among the commercial sex workers and heterosexuals; (3) in central and northeast Myanmar, both HIV-1 subtypes B' and E occurred in a mixed distribution, without showing any significant segregation by risk group. In addition, the PEIA data implied the occurrence of other subtype(s) in these areas. The interperson nucleotide sequence variations in env C2/V3 regions of B' and E, prevailing in Yangon, were 6.7 +/- 2.1 and 7.1 +/- 0.7%, respectively. They were similar to those levels observed in Thailand. These findings are consistent with the view that HIV spread in Myanmar might have taken place at about the same time as that in Thailand, and that multiple entries and exchanges of HIV-1 with neighboring countries are important factors contributing to the current distribution of subtypes in Myanmar.

Vibrio cholerae non-O1 as a causal pathogen in cholera patients in Yangon, Myanmar.

Vibrio cholerae non-O1 was studied in patients with rice watery diarrhoea admitted to the Infectious Diseases Hospital, Yangon. The study was conducted during 1993-1994 to determine the association of the pathogen with the disease. Altogether 771 rectal swabs were collected and examined. V. cholerae were isolated by the standard methods. The seasonal, age and sex distribution, serotyping and susceptibility of these isolates to antibiotics were investigated, V. cholerae were isolated from 233 (3O.2%) samples. Among them, V. cholerae O1 were isolated from 117 (5O%) samples and V. cholerae non-O1 from 116 (5O%) samples. The seasonal, age and sex distribution was identical in both V. cholerae O1 and V. cholerae non-O1 groups. V. cholerae O139 was isolated during February 1994. Thus V. cholerae non-O1 was also one of the causal pathogens of cholera, like V. cholerae O1 in this community.

Serotype distribution and antimicrobial susceptibility of Shigellae isolated from diarrhoeal patients in Yangon, Myanmar.

In Myanmar there is a changing pattern in the prevalence of Shigella strains with an increasing antimicrobial resistance, and, thus the serotype prevalence and antibiotic sensitivity pattern of Shigellae were studied in 1993. Dysenteric stool samples were collected from the laboratory of Infectious Diseases Hospital, Yangon during January-June 1993. The Shigella isolates were identified by the standard bacteriologic procedures. Four hundred and sixty stool samples containing blood and mucous were collected in this study, and Shigella spp. were isolated from the 108 (23.5%) samples. The increasing antimicrobial resistance of shigellosis from 1980 to 1993 in this community was also discussed.

Effectiveness of potash alum in decontaminating household water.

To evaluate the effectiveness of potash alum in purifying household water, this study was carried out in a suburban community in Yangon, Myanmar. It was designed to test whether the application of potash alum (0.05%) regularly into household water storage vessels during water replenishment was capable of decontaminating household water in homes using shallow well water. It was conducted in 100 households (50 each in intervention and control groups). After alum (0.05%) was added, the contamination level of water decreased on the 2nd and 3rd days. The alum-treated water was well tolerated by the users; only one member complained of a metallic taste. We conclude that potash alum was effective and acceptable in this community in decontaminating household water.

Vibrio spp. isolated from natural waters of the city of Yangon, Myanmar.

Virulence properties of the environmental isolate of vibrios from natural waters of Yangon, Myanmar were studied. Vibrio spp. were isolated for identification by the membrane filtration method and cultured on thio-sulphate-bile-sucrose media. No Vibrio cholerae O1 were isolated. V. cholerae non-O1 were the major vibrio species isolated from the samples. None of them were detected for cholera-toxin-like toxin, thermostable direct haemolysin, or heat-stable enterotoxin. Sixty-one isolates gave haemolytic activity; 27 V. cholerae non-O1 and 6 V. fluvialis isolates produced protease.

Bacteriologic studies of food and water consumed by children in Myanmar: 1. The nature of contamination.

To isolate major bacterial pathogens from children's food and drinking water, a 3-month study was conducted in a suburban community in Yangon, Myanmar. From the morning meals and stored drinking water of 208 randomly selected children, 775 food and 113 water samples were collected and were cultured using standard methods. Escherichia coli, Vibrio cholerae non-01, and Salmonella were isolated from 505, 28 and 6 food samples respectively, and E. coli and V. cholerae non-01 were isolated from 29 and 5 water samples respectively. Among the E. coli isolates, 8 produced heat-stable toxin (ST) and 3 were enteroinvasive. Nine V. cholerae non-01 produced cholera-like toxin. Of the 29 E. coli isolates from the samples of drinking water, 3 produced ST. All water samples were negative for Salmonella. The study underscores the importance of bacterial contamination of children's food and drinking water and stresses the need to improve environmental sanitation.