Evaluation of the use of GeneXpert MTB/RIF in a zone with high burden of tuberculosis in Thailand.

GeneXpert MTB/RIF is a reliable molecular diagnostic tool capable of detecting Mycobacterium tuberculosis (MTB) and identifying genetic determinants of rifampicin (RIF) resistance. This study aimed to assess physicians' diagnostic decision-making processes for TB based on GeneXpert MTB/RIF results and how this affected the initiation of multidrug resistance (MDR) treatment. This study employed a mixed method: data were collected retrospectively from the medical records of TB patients and in-depth interviews were conducted with healthcare workers in areas with a high TB burden in Thailand. A total of 2,030 complete TB records from 2 patient groups were reviewed, including 1443 suspected cases with negative smear results and 587 with high risk of MDR-TB. GeneXpert MTB/RIF was routinely used to assist the physicians in their decision-making for the diagnosis of pulmonary tuberculosis (PTB) and the initiation of MDR-TB treatment. The physicians used it as a "rule-in test" for all patients with negative chest X-rays (CXR) and smear results, to ensure timely treatment. Approximately one-fourth of the patients with negative CXR/smear and GeneXpert MTB/RIF results were diagnosed with PTB by the physicians, who based their decisions on other evidence, such as clinical symptoms, and did not use GeneXpert MTB/RIF as a "rule-out test." GeneXpert MTB/RIF proved effective in early detection within a day, thereby radically shortening the time required to initiate second-line drug treatment. Despite its high sensitivity for detecting PTB and MDR-TB, GeneXpert MTB/RIF had contradictory results (false positive and/or false negative) for 21.8% of cases among patients with negative smear results and 41.1% of cases among patients with high risk of MDR-TB. Therefore, physicians still used the results of other conventional tests in their decision-making process. It is recommended that GeneXpert MTB/RIF should be established at all points of care and be used as the initial test for PTB and MDR-TB diagnosis.

Late boosting of the RV144 regimen with AIDSVAX B/E and ALVAC-HIV in HIV-uninfected Thai volunteers: a double-blind, randomised controlled trial.

BACKGROUND: The RV144 phase 3 vaccine trial in Thailand demonstrated that ALVAC-HIV (vCP1521) and AIDSVAX B/E administration over 6 months resulted in a 31% efficacy in preventing HIV acquisition. In this trial, we assessed the immunological effect of an additional vaccine boost to the RV144 regimen at varying intervals between the priming vaccine series and the boost. METHODS: RV306 is a double-blind, placebo-controlled, randomised clinical trial done at three clinical sites in Thailand. Eligible volunteers were HIV-uninfected individuals aged 20-40 years who were at low risk for HIV infection and in good health. A randomisation schedule was centrally generated with fixed sized strata for Research Institute for Health Sciences Chiang Mai and combined Bangkok clinics. Participants were randomly assigned to one of five groups and then further randomly assigned to either vaccine or placebo. All participants received the primary RV144 vaccine series at months 0, 1, 3, and 6. Group 1 received no additional boost, group 2 received additional AIDSVAX B/E and ALVAC-HIV (vCP1521) or placebo at month 12, group 3 received AIDSVAX B/E alone or placebo at month 12, group 4a received AIDSVAX B/E and ALVAC-HIV or placebo at month 15, and group 4b received AIDSVAX B/E and ALVAC-HIV or placebo at month 18. Primary outcomes were safety and tolerability of these vaccination regimens and cellular and humoral immune responses compared between the RV144 series alone and regimens with late boosts at different timepoints. Safety and tolerability outcomes were assessed by evaluating local and systemic reactogenicity and adverse events in all participants. This trial is registered at ClinicalTrials.gov (NCT01931358); clinical follow-up is now complete. FINDINGS: Between Oct 28, 2013, and April 29, 2014, 367 participants were enrolled, of whom 27 were assigned active vaccination in group 1, 102 in group 2, 101 in group 3, 52 in group 4a, 51 in group 4b, and 34 combined placebo across all the groups. No vaccine-related serious adverse events were recorded. Occurrence and severity of local and systemic reactogenicity were similar across active groups. Groups with late boosts (groups 2, 3, 4a, and 4b) had increased peak plasma IgG-binding antibody levels against gp70 V1V2 relative to group 1 vaccine recipients with no late boost (gp70 V1V2 92TH023 adjusted p<0·02 for each; gp70 V1V2 CaseA2 adjusted p<0·0001 for each). Boosting at month 12 (groups 2 and 3) did not increase gp120 responses compared with the peak responses after the RV144 priming regimen at month 6; however, boosting at month 15 (group 4a) improved responses to gp120 A244gD- D11 (p=0·0003), and boosting at month 18 (group 4b) improved responses to both gp120 A244gD- D11 (p<0·0001) and gp120 MNgD- D11 (p=0·0016). Plasma IgG responses were significantly lower among vaccine recipients boosted at month 12 (pooled groups 2 + 3) than at month 15 (group 4a; adjusted p<0·0001 for each, except for gp70 V1V2 CaseA2, p=0·0142) and at month 18 (group 4b; all adjusted p<0·001). Boosting at month 18 versus month 15 resulted in a significantly higher plasma IgG response to gp120 antigens (all adjusted p<0·01) but not gp70 V1V2 antigens. CD4 functionality and polyfunctionality scores after stimulation with HIV-1 Env peptides (92TH023) increased with delayed boosting. Groups with late boosts had increased functionality and polyfunctionality scores relative to vaccine recipients with no late boost (all adjusted p<0·05, except for the polyfunctionality score in group 1 vs group 4b, p<0·01). INTERPRETATION: Taken together, these results suggest that additional boosting of the RV144 regimen with longer intervals between the primary vaccination series and late boost improved immune responses and might improve the efficacy of preventing HIV acquisition. FUNDING: US National Institute of Allergy and Infectious Diseases and US Department of the Army.

Low folate status, and MTHFR 677C > T and MTR 2756A > G polymorphisms associated with colorectal cancer risk in Thais: a case-control study.

Folate plays essential roles in DNA synthesis, repair, and methylation; thus, folate status may affect carcinogenesis. Genetics polymorphisms involved in folate metabolisms have been linked with colorectal cancer (CRC) development. Therefore, we hypothesized that low folate status and related genetic polymorphisms are associated with higher risk of CRC. This case-control study enrolled 105 new cases of CRC, 101 of colorectal adenoma (CRA), and 182 controls from hospitals in Bangkok, Thailand, to examine the association between folate status and methylenetetrahydrofolate reductase (MTHFR) 677C > T, methionine synthase (MTR) 2756A > G, and methionine synthase reductase (MTRR) 66A > G with the risk of CRC and CRA. Regarding CRC risk, the lowest quartile group of serum folate and folate intake had higher risk of CRC than the highest quartile group (odds ratio [OR] = 11.45, 95% confidence interval [CI] = 4.43-29.59) and (OR = 10.29, 95% CI = 4.17-25.41). The lowest quartile group of folate intake also had a higher risk of CRA (OR = 5.22, 95% CI = 2.19-6.09). Low red blood cell folate combined with MTHFR 677C > T polymorphism statistically increased CRC risk (OR = 10.00, 95% CI = 1.36-73.42). Low folate status combined with MTR 2756A > G significantly increased CRA risk (OR = 6.43, 95% CI = 1.38-29.94). Moreover, the risk of CRC was elevated with alcohol consumption and low exercise activity when combined with low folate status (P < .05). This study supported the hypothesis that, in Thais, low folate status is associated with a higher risk of CRC, particularly among those with polymorphisms of the MTHFR 677C > T and MTR 2756 A > G genes.

Monoclonal Antibodies, Derived from Humans Vaccinated with the RV144 HIV Vaccine Containing the HVEM Binding Domain of Herpes Simplex Virus (HSV) Glycoprotein D, Neutralize HSV Infection, Mediate Antibody-Dependent Cellular Cytotoxicity, and Protect Mice from Ocular Challenge with HSV-1.

The RV144 HIV vaccine trial included a recombinant HIV glycoprotein 120 (gp120) construct fused to a small portion of herpes simplex virus 1 (HSV-1) glycoprotein D (gD) so that the first 40 amino acids of gp120 were replaced by the signal sequence and the first 27 amino acids of the mature form of gD. This region of gD contains most of the binding site for HVEM, an HSV receptor important for virus infection of epithelial cells and lymphocytes. RV144 induced antibodies to HIV that were partially protective against infection, as well as antibodies to HSV. We derived monoclonal antibodies (MAbs) from peripheral blood B cells of recipients of the RV144 HIV vaccine and showed that these antibodies neutralized HSV-1 infection in cells expressing HVEM, but not the other major virus receptor, nectin-1. The MAbs mediated antibody-dependent cellular cytotoxicity (ADCC), and mice that received the MAbs and were then challenged by corneal inoculation with HSV-1 had reduced eye disease, shedding, and latent infection. To our knowledge, this is the first description of MAbs derived from human recipients of a vaccine that specifically target the HVEM binding site of gD. In summary, we found that monoclonal antibodies derived from humans vaccinated with the HVEM binding domain of HSV-1 gD (i) neutralized HSV-1 infection in a cell receptor-specific manner, (ii) mediated ADCC, and (iii) reduced ocular disease in virus-infected mice.IMPORTANCE Herpes simplex virus 1 (HSV-1) causes cold sores and neonatal herpes and is a leading cause of blindness. Despite many trials, no HSV vaccine has been approved. Nectin-1 and HVEM are the two major cellular receptors for HSV. These receptors are expressed at different levels in various tissues, and the role of each receptor in HSV pathogenesis is not well understood. We derived human monoclonal antibodies from persons who received the HIV RV144 vaccine that contained the HVEM binding domain of HSV-1 gD fused to HIV gp120. These antibodies were able to specifically neutralize HSV-1 infection in vitro via HVEM. Furthermore, we showed for the first time that HVEM-specific HSV-1 neutralizing antibodies protect mice from HSV-1 eye disease, indicating the critical role of HVEM in HSV-1 ocular infection.

Antibody to HSV gD peptide induced by vaccination does not protect against HSV-2 infection in HSV-2 seronegative women.

BACKGROUND: In the HIV-1 vaccine trial RV144, ALVAC-HIV prime with an AIDSVAX® B/E boost reduced HIV-1 acquisition by 31% at 42 months post first vaccination. The bivalent AIDSVAX® B/E vaccine contains two gp120 envelope glycoproteins, one from the subtype B HIV-1 MN isolate and one from the subtype CRF01_AE A244 isolate. Each envelope glycoprotein harbors a highly conserved 27-amino acid HSV-1 glycoprotein D (gD) tag sequence that shares 93% sequence identity with the HSV-2 gD sequence. We assessed whether vaccine-induced anti-gD antibodies protected females against HSV-2 acquisition in RV144. METHODS: Of the women enrolled in RV144, 777 vaccine and 807 placebo recipients were eligible and randomly selected according to their pre-vaccination HSV-1 and HSV-2 serostatus for analysis. Immunoglobulin G (IgG) and IgA responses to gD were determined by a binding antibody multiplex assay and HSV-2 serostatus was determined by Western blot analysis. Ninety-three percent and 75% of the vaccine recipients had anti-gD IgG and IgA responses two weeks post last vaccination, respectively. There was no evidence of reduction in HSV-2 infection by vaccination compared to placebo recipients over 78 weeks of follow-up. The annual incidence of HSV-2 infection in individuals who were HSV-2 negative at baseline or HSV-1 positive and HSV-2 indeterminate at baseline were 4.38/100 person-years (py) and 3.28/100 py in the vaccine and placebo groups, respectively. Baseline HSV-1 status did not affect subsequent HSV-2 acquisition. Specifically, the estimated odds ratio of HSV-2 infection by Week 78 for female placebo recipients who were baseline HSV-1 positive (n = 422) vs. negative (n = 1120) was 1.14 [95% confidence interval 0.66 to 1.94, p = 0.64)]. No evidence of reduction in the incidence of HSV-2 infection by vaccination was detected. CONCLUSIONS: AIDSVAX® B/E containing gD did not confer protection from HSV-2 acquisition in HSV-2 seronegative women, despite eliciting anti-gD serum antibodies.

Asymptomatic and sub-microscopic malaria infection in Kayah State, eastern Myanmar.

BACKGROUND: Myanmar has the heaviest burden of malaria in the Greater Mekong Sub-region. Asymptomatic Plasmodium spp. infections are common in this region and may represent an important reservoir of transmission that must be targeted for malaria elimination. METHODS: A mass blood survey was conducted among 485 individuals from six villages in Kayah State, an area of endemic but low transmission malaria in eastern Myanmar. Malaria infection was screened by rapid diagnostic test (RDT), light microscopy and real-time polymerase chain reaction (PCR), and its association with demographic factors was explored. RESULTS: The prevalence of asymptomatic Plasmodium spp. infection was 2.3% (11/485) by real-time PCR. Plasmodium vivax accounted for 72.7% (8/11) and Plasmodium falciparum for 27.3% (3/11) of infections. Men were at greater risk of infection by Plasmodium spp. than women. Individuals who worked as farmers or wood and bamboo cutters had an increased risk of infection. CONCLUSION: A combination of RDT, light microscopy and PCR diagnostics were used to identify asymptomatic malaria infection, providing additional information on asymptomatic cases in addition to the routine statistics on symptomatic cases, so as to determine the true burden of disease in the area. Such information and risk factors can improve malaria risk stratification and guide decision-makers towards better design and delivery of targeted interventions in small villages, representative of Kayah State.

Human Non-neutralizing HIV-1 Envelope Monoclonal Antibodies Limit the Number of Founder Viruses during SHIV Mucosal Infection in Rhesus Macaques.

HIV-1 mucosal transmission begins with virus or virus-infected cells moving through mucus across mucosal epithelium to infect CD4+ T cells. Although broadly neutralizing antibodies (bnAbs) are the type of HIV-1 antibodies that are most likely protective, they are not induced with current vaccine candidates. In contrast, antibodies that do not neutralize primary HIV-1 strains in the TZM-bl infection assay are readily induced by current vaccine candidates and have also been implicated as secondary correlates of decreased HIV-1 risk in the RV144 vaccine efficacy trial. Here, we have studied the capacity of anti-Env monoclonal antibodies (mAbs) against either the immunodominant region of gp41 (7B2 IgG1), the first constant region of gp120 (A32 IgG1), or the third variable loop (V3) of gp120 (CH22 IgG1) to modulate in vivo rectal mucosal transmission of a high-dose simian-human immunodeficiency virus (SHIV-BaL) in rhesus macaques. 7B2 IgG1 or A32 IgG1, each containing mutations to enhance Fc function, was administered passively to rhesus macaques but afforded no protection against productive clinical infection while the positive control antibody CH22 IgG1 prevented infection in 4 of 6 animals. Enumeration of transmitted/founder (T/F) viruses revealed that passive infusion of each of the three antibodies significantly reduced the number of T/F genomes. Thus, some antibodies that bind HIV-1 Env but fail to neutralize virus in traditional neutralization assays may limit the number of T/F viruses involved in transmission without leading to enhancement of viral infection. For one of these mAbs, gp41 mAb 7B2, we provide the first co-crystal structure in complex with a common cyclical loop motif demonstrated to be critical for infection by other retroviruses.

Structural analysis of the unmutated ancestor of the HIV-1 envelope V2 region antibody CH58 isolated from an RV144 vaccine efficacy trial vaccinee.

Human monoclonal antibody CH58 isolated from an RV144 vaccinee binds at Lys169 of the HIV-1 Env gp120 V2 region, a site of vaccine-induced immune pressure. CH58 neutralizes HIV-1 CRF_01 AE strain 92TH023 and mediates ADCC against CD4 + T cell targets infected with CRF_01 AE tier 2 virus. CH58 and other antibodies that bind to a gp120 V2 epitope have a second light chain complementarity determining region (LCDR2) bearing a glutamic acid, aspartic acid (ED) motif involved in forming salt bridges with polar, basic side amino acid side chains in V2. In an effort to learn how V2 responses develop, we determined the crystal structures of the CH58-UA antibody unliganded and bound to V2 peptide. The structures showed an LCDR2 structurally pre-conformed from germline to interact with V2 residue Lys169. LCDR3 was subject to conformational selection through the affinity maturation process. Kinetic analyses demonstrate that only a few contacts were responsible for a 2000-fold increase in KD through maturation, and this effect was predominantly due to an improvement in off-rate. This study shows that preconformation and preconfiguration can work in concert to produce antibodies with desired immunogenic properties.

COMPASS identifies T-cell subsets correlated with clinical outcomes.

Advances in flow cytometry and other single-cell technologies have enabled high-dimensional, high-throughput measurements of individual cells as well as the interrogation of cell population heterogeneity. However, in many instances, computational tools to analyze the wealth of data generated by these technologies are lacking. Here, we present a computational framework for unbiased combinatorial polyfunctionality analysis of antigen-specific T-cell subsets (COMPASS). COMPASS uses a Bayesian hierarchical framework to model all observed cell subsets and select those most likely to have antigen-specific responses. Cell-subset responses are quantified by posterior probabilities, and human subject-level responses are quantified by two summary statistics that describe the quality of an individual's polyfunctional response and can be correlated directly with clinical outcome. Using three clinical data sets of cytokine production, we demonstrate how COMPASS improves characterization of antigen-specific T cells and reveals cellular 'correlates of protection/immunity' in the RV144 HIV vaccine efficacy trial that are missed by other methods. COMPASS is available as open-source software.

Polyfunctional Fc-effector profiles mediated by IgG subclass selection distinguish RV144 and VAX003 vaccines.

The human phase 2B RV144 ALVAC-HIV vCP1521/AIDSVAX B/E vaccine trial, held in Thailand, resulted in an estimated 31.2% efficacy against HIV infection. By contrast, vaccination with VAX003 (consisting of only AIDSVAX B/E) was not protective. Because protection within RV144 was observed in the absence of neutralizing antibody activity or cytotoxic T cell responses, we speculated that the specificity or qualitative differences in Fc-effector profiles of nonneutralizing antibodies may have accounted for the efficacy differences observed between the two trials. We show that the RV144 regimen elicited nonneutralizing antibodies with highly coordinated Fc-mediated effector responses through the selective induction of highly functional immunoglobulin G3 (IgG3). By contrast, VAX003 elicited monofunctional antibody responses influenced by IgG4 selection, which was promoted by repeated AIDSVAX B/E protein boosts. Moreover, only RV144 induced IgG1 and IgG3 antibodies targeting the crown of the HIV envelope V2 loop, albeit with limited coverage of breakthrough viral sequences. These data suggest that subclass selection differences associated with coordinated humoral functional responses targeting strain-specific protective V2 loop epitopes may underlie differences in vaccine efficacy observed between these two vaccine trials.

Vaccine induction of antibodies against a structurally heterogeneous site of immune pressure within HIV-1 envelope protein variable regions 1 and 2.

The RV144 HIV-1 trial of the canary pox vector (ALVAC-HIV) plus the gp120 AIDSVAX B/E vaccine demonstrated an estimated efficacy of 31%, which correlated directly with antibodies to HIV-1 envelope variable regions 1 and 2 (V1-V2). Genetic analysis of trial viruses revealed increased vaccine efficacy against viruses matching the vaccine strain at V2 residue 169. Here, we isolated four V2 monoclonal antibodies from RV144 vaccinees that recognize residue 169, neutralize laboratory-adapted HIV-1, and mediate killing of field-isolate HIV-1-infected CD4(+) T cells. Crystal structures of two of the V2 antibodies demonstrated that residue 169 can exist within divergent helical and loop conformations, which contrasted dramatically with the ß strand conformation previously observed with a broadly neutralizing antibody PG9. Thus, RV144 vaccine-induced immune pressure appears to target a region that may be both sequence variable and structurally polymorphic. Variation may signal sites of HIV-1 envelope vulnerability, providing vaccine designers with new options.

Knowledge, attitudes, and acceptability of a human papilloma virus vaccine among students, parents and teachers in Thailand.

The purpose of this study was to assess the knowledge and attitudes about human papilloma virus (HPV) and cervical cancer, and the acceptability of HPV vaccine among students, parents and teachers in secondary schools in Bangkok, Thailand. We conducted a school-based cross-sectional study at four public secondary schools in Bangkok. A total of 644 students aged 12-15 years, 664 parents and 304 teachers were recruited into the study. Data were collected by self-administered questionnaires. The percentages of students, parents and teachers who were willing to be vaccinated were 26, 49 and 43%, respectively. Forty-one percent of parents wanted their children to be vaccinated. Students, parents and teachers had a moderate knowledge of HPV, cervical cancer and the HPV vaccine with mean scores of 6.91 (SD = 1.75), 6.82 (SD = 1.88), and 6.70 (SD = 1.89), respectively. The attitudes of students, parents, and teachers were fair with scores of 3.46 (SD = 0.41), 3.52 (SD = 0.43), and 3.46 (SD = 0.47) out of 5, respectively. Twenty-nine percent of students and 36% of parents were willing to pay USD 14.3-28.5 per dose for the quadrivalent vaccine; 33% of teachers were willing to pay < USD 14.3 per dose for the quadrivalent vaccine. This study is the first study to report the knowledge, and attitudes and acceptability of HPV vaccination in Thailand. The findings suggest the willingness to pay was relatively low and related to the price, while knowledge and attitudes regarding the importance of the HPV vaccine were fair particularly among parents and teachers. Greater effort may be needed to educate people regarding the cost and benefits of HPV vaccination before it would be more acceptable to parents, teachers and students in Thailand.

Knowledge, attitudes, and acceptability of a human papillomavirus vaccine among healthcare providers.

A cross-sectional survey was conducted to evaluate acceptability, knowledge, and attitude regarding HPV, cervical cancer, and HPV vaccine among healthcare providers working in hospitals located in Bangkok, Thailand. Two hundred nurses and 100 doctors from three government hospitals and one private hospital were recruited. Data collection was done using a self-administered questionnaire. Nurses and doctors knowledge on HPV, cervical cancer, and HPV vaccine was at a medium level. Both nurses and doctors had positive attitude toward HPV, cervical cancer, and HPV vaccine. Approximately 80% of nurses and 63% of doctors agreed on the use of a HPV vaccination. Almost all the nurses and doctors suggested that adolescent aged < or = 18-years-old should be the target group for HPV vaccination. Furthermore, 73% of nurses and 76% of doctors would recommend clients to receive HPV vaccine.

Survival time of HIV-infected patients with cryptococcal meningitis.

OBJECTIVE: To study survival time and risk factors of mortality among HIV-infected patients who had cryptococcal meningitis. DESIGN: Retrospective cohort study. MATERIAL AND METHOD: Patients' medical records of those who had HIV-infection with newly diagnosed cryptoccocal meningitis between January 2002 and December 2004 were reviewed. Each patient was classified into one of two groups, according to their anti-retroviral status (ART). RESULTS: Five hundred and forty nine patients enrolled in the present study: 281 (51.2%) in the ART+ group and 268 (48.8%) in the ART-group. The mean age was 33.4 +/- 6.9 years old in the ART + group and 33.6 +/- 7.0 years old in the ART-group. There were more male in both groups: 207 males and 74 females in the ART+ group, and 195 males and 73 females in the ART-group. Baseline CD4 cell count of both groups was 20 (6-74) cells/mL and 24 (9-72) cells/ml. About 30% of both groups of patients experienced major opportunistic infection before cryptococcal meningitis. All patients were treated by standard amphotericin B for a 2-week duration followed by fluconazole for an additional 8 weeks. There were no differences of baseline characteristics between the two groups (p > 0.05). The survival rates at 12, 24, and 36 months were 92.8%, 87.4%, and 85.4% in the ART+ group and 55.3%, 42.2%, and 36.8% in the ART- group, respectively (p < 0.01). The median survival time in the ART- group was 15 months. From the Cox regression model, the hazard ratio for "not received ART" was 4.87 (95%CI = 2.48-9.44, p < 0.01). CONCLUSION: The present study demonstrated the substantial increasing of survival time of HIV-infected patients with cryptococcal meningitis by initiated ART even in a resource limited setting (no flucytosine, local combined antiretroviral drugs with NVP based regimens).

Predisposing factors for nevirapine toxicity among AIDS patients with low baseline CD4 count.

The objective of the study was to determine the predisposing factors and incidence of toxicity among AIDS patients treated with a nevirapine (NVP)-based regimen in clinical practice. A retrospective cohort study of representative samples of AIDS patients treated with a NVP-based regimen was performed. A total of 206 adult HIV/AIDS cases with median age (IQR) 33 years (range, 29-38 years), 51% male, treated between January 2004-December 2005, were included. Most (92.2%) of the patients were naïve to antiretroviral drug. The incidence of NVP toxicity was 1.09/100 person-months. The median onset time was 4 weeks post NVP initiation (2.57 weeks for skin toxicity and 12.43 weeks for hepatic toxicity). History of drug allergy and NVP toxicity were significantly associated (p = 0.006), as were sulfamethoxazole allergy and toxicity (p = 0.015). Regarding concomitant medication, concurrent anti-tuberculosis drugs significantly increased the risk of NVP associated liver toxicity (p = 0.001). Therefore, it is important to monitor adverse events from NVP, including liver function tests among HIV/AIDS patients with history of drug allergy, especially against sulfamethoxazole, and those concurrently treated with antituberculosis drugs.

Seroprevalence and risk factors of hepatitis B virus infection among health care workers at the Institute of Neurology.

OBJECTIVES: To define the seroepidemiology of Hepatitis B virus (HBV) infection among health care workers (HCWs) in the Institute of Neurology, and to evaluate the risk factors of HBV markers. MATERIAL AND METHOD: Blood samples were taken from 548 HCWs for HBV profiling (HBsAg, anti-HBs and anti-HBc) by Microparticle Enzyme Immunoassay (MEIA) methods. Questionnaires of demographics, type, and duration of work, history of blood exposure, HBV vaccination, and non-occupational risks of HBV infection were interviewed. RESULTS: Twenty-nine (5.3%) HCWs were HBsAg positive, 135 (24.6%) had anti-HBc with anti-HBs suggesting immunity acquired from a previous HBV infection, 232 (42.3%) had totally negative profiles, 40 (7.3%) had anti-HBc only, 105 (19.2%) had protective levels of anti-HBs, 7 (1.3%) had low anti-HBs levels. The significant risk factors included not having received the hepatitis B vaccine, male gender, past history of jaundice, viral hepatitis, family history of hepatoma, spouse with hepatitis B, and duration of employment in a clinical environment exceeding 5 years. No significant differences were found among HCWs regarding frequency of exposure to blood products. CONCLUSION: Base on the significant risk factors of hepatitis B virus infection among HCWs, these findings will help implement effective measures aimed at preventing HBV infection.

Increased risk of preterm birth among non- smoking, non- alcohol drinking women with maternal periodontitis.

The aim of this case-control study was to examine the association between periodontitis and preterm birth among non-smoking, non-alcohol drinking women. The cases were 130 women who delivered a live singleton newborn before 37 weeks gestation. A random sample of 260 women who delivered a normal child on the same day as the cases were selected as controls. Periodontal examinations were performed during 24-hour period postpartum at bedside. Other related information was collected by structured questionnaire and medical records. Multiple logistic regression analysis was performed controlling for age, ethnicity, place of residence, education, occupation, income, pre-pregnancy body mass index (BMI), weight gain, antenatal care (ANC), parity, systematic infections, genitourinary infections, antibiotics used, and history of periodontal treatment. Periodontitis (defined as presence of at least 4 teeth having > or = 1 site with a probing depth (PD) > or = 4 mm, clinical attachment loss (CAL) > or = 3 mm and bleeding on probing (BOP) after 10 seconds at the same site) was diagnosed in 33.9% of cases and 10.4% of controls. Periodontitis was significantly associated with preterm birth (adjusted OR = 4.47, 95%Cl= 2.43, 8.20). These findings suggest that periodontitis may increase the risk of preterm delivery even among women who do not smoke or drink.

Monitoring and evaluation of a model demonstration project for the control of cervical cancer in Nakhon Phanom province, Thailand.

Cancer of the uterine cervix is the second most common cancer in females in the world with about half a million new patients per year. Since the introduction by Papanicolaou of cervical smear screening, the incidence of cervical cancer has declined in many developed countries. The decrease in the incidence of and mortality from cervical cancer is mainly due to the organized mass screening using Pap smear programmes. Uterine cervical cancer is the leading cancer among women in Thailand with age-standardized incidence rates of 24.7 per 100,000 in 1999. Most cases present at advanced stages with poor prognoses of survival and cure. In the present study, cervical cancer screening programme with cervical cytology was organized for Nakhon Phanom province, Thailand. The specific objectives were: 1) to evaluate the reduction in incidence and mortality from cervical cancer in the province by means of an organised low-intensity cervical cytology programme. 2) to demonstrate the different aspects of programme implementation as a potential model for nationwide implementation. The screening activities were integrated in the existing health care system. Organized screening for women in the target population (aged 35-54 years) at 5-year intervals was free of charge. Sample taking was done by trained nurses (midwives) and primary health care personnel in the local health care centers. Sample quality was under continuous controlled by the cytology laboratories and pathologists. Confirmation and treatment were integrated into the normal health care routines. The screening results of the programme, including histologically confirmed diagnosis, were registered at the National Cancer Institute using PapReg and CanReg 4 programmes. A population-based cancer registry in Nakhon Phanom province was also set up in 1997. In the period 1999-2002, 32,632 women aged 35-54 years were screened. Women with low-grade lesions returned for routine follow-up smears. High-grade preinvasive disease was further evaluated by repeating Pap smear, conization or biopsy and subsequent treatment through surgical removal or ablation. This organized low-intensity cervical cytology programme showed a considerable increase in early carcinoma in situ and CIN II -III cases and should reduce incidence of and mortality from cervical cancer in Nakhon Phanom province in the future. Screening with the Papanicolaou smear plus adequate follow-up diagnosis and therapy can achieve major reductions in both incidence and mortality rates.

Preparation of in vivo cow control blood samples for cadmium analysis.

Quality control is essential for any analysis in the laboratory. The objective of this study was to prepare in vivo cow control blood samples. The experiment was performed by feeding cows with a single dose of cadmium in the form of cadmium chloride, withdrawing the blood at an appropriate time to get the highest level of cadmium and detecting the level of cadmium in the blood. It was found that feeding the cow a single dose of 0.06 mg cadmium per kg body weight resulted in the highest cadmium level of 3.622 microg/l 30-60 minutes after feeding. The samples were homogeneous because feeding the cows with single dose of cadmium let the cadmium be absorbed and distributed naturally. In addition, the samples were stable during transport. Therefore, they may be used as quality control samples to detect cadmium levels without using a lyophilized process. They could be used for proficiency testing and to evaluate whole blood analysis in the laboratory.

Causal relationship between health promoting behavior and quality of life in cervical cancer patients undergoing radiotherapy.

The purpose of this cross-sectional study was to examine the causal relationships among age, education, family income, and stage of carcinoma, perceived benefits, perceived barriers, perceived self-efficacy, health promoting behavior and quality of life in patients with cervical cancer. Pender's Health Promotion Model (1996) provided a guide for the conceptual framework of this study. Purposive sampling was employed to recruit 488 cervical cancer patients who were undergoing radiotherapy at seven public hospitals in five areas of Thailand. The instruments used in this study included a Personal Data Form, Cognitive perception Form, Health promoting behavior scale, the social support questionnaire and The Functional Assessment of Cancer Therapy General (FACT-G) form. The proposed model was tested and modified by the LISREL Program. The modified model adequately fitted with the data. The results demonstrate that health promoting behavior had a significant direct positive effect on quality of life (beta = 0.71, p < 0.01). Cognitive perceptual factors had a significant direct effect on health promoting behaviors (P = 0.69, p < 0.01). Social support had a significant direct effect on the cognitive perceptual factors (P = 0.64, p < 0.01), health promoting behavior (beta = 0.70, p < 0.01), and the quality of life (beta = 0.48, p < 0.01). Age and education did not have a significant total effect on the quality of life. Family income had a significant direct effect on cognitive perceptual factors (beta = 0.10, p < 0.05). The stage of cancer had a significant direct negative effect on cognitive perceptual factors (beta = -0.11, p < 0.05) and the quality of life (beta = -0.12, p < 0.01). The direct effect of the predictors on the quality of life indicated that cervical cancer patients with higher practice of health promoting behavior tended to have a higher quality of life. The findings indicate that Pender's Health Promotion Model is a useful guide for explaining and predicting the health promoting behavior and the quality of life of Thai cervical cancer patients who were undergoing radiotherapy. The significance of cognitive perceptual factors and social support confirm health promoting behavior as a goal directed towards the level of well being. This has implications for health care systems in planning interventions to promote health promoting behavior in a health promotion setting in cervical cancer patients for a better quality of life and healthy. A longitudinal study and experimental study are recommended for further study.