ABSTRACT
In HIV-1, the ability to mount antibody responses to conserved, neutralizing epitopes is critical for protection. Here we have studied the light chain usage of human and rhesus macaque antibodies targeted to a dominant region of the HIV-1 envelope second variable (V2) region involving lysine (K) 169, the site of immune pressure in the RV144 vaccine efficacy trial. We found that humans and rhesus macaques used orthologous lambda variable gene segments encoding a glutamic acid-aspartic acid (ED) motif for K169 recognition. Structure determination of an unmutated ancestor antibody demonstrated that the V2 binding site was preconfigured for ED motif-mediated recognition prior to maturation. Thus, light chain usage for recognition of the site of immune pressure in the RV144 trial is highly conserved across species. These data indicate that the HIV-1 K169-recognizing ED motif has persisted over the diversification between rhesus macaques and humans, suggesting an evolutionary advantage of this antibody recognition mode.
Subject(s)
AIDS Vaccines , Antibodies, Viral/metabolism , B-Lymphocytes/immunology , Epitopes, B-Lymphocyte/metabolism , HIV Envelope Protein gp120/metabolism , HIV Infections/immunology , HIV-1/immunology , Immunoglobulin Light Chains/metabolism , Amino Acid Sequence , Animals , Antibody Affinity/genetics , Cells, Cultured , Clinical Trials as Topic , Conserved Sequence/genetics , Epitope Mapping , Epitopes, B-Lymphocyte/genetics , Epitopes, B-Lymphocyte/immunology , HIV Envelope Protein gp120/genetics , HIV Envelope Protein gp120/immunology , HIV Infections/prevention & control , Humans , Macaca mulatta , Molecular Sequence Data , Mutation/genetics , Phylogeny , Protein Binding/genetics , Protein EngineeringABSTRACT
BACKGROUND: Over the past decade, the incidence of malaria has steadily declined in Myanmar, with Plasmodium vivax becoming predominant. The resilience of P. vivax to malaria control is attributed to the parasite's ability to form hypnozoites in the host's liver, which can cause relapse. Primaquine is used to eliminate hypnozoites but can cause haemolysis in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. It is thus necessary to estimate the frequency and variant types of G6PD deficiency in areas where primaquine will be widely used for P. vivax elimination. METHODS: In this study, a descriptive cross-sectional survey was conducted to determine the prevalence of G6PD deficiency in a population residing in Nay Pyi Taw, Myanmar, using a standard spectrophotometric assay, a rapid diagnostic test (RDT), Biosensor, and by genotyping G6PD variants. RESULTS: G6PD enzyme activity was determined from 772 leukocyte-depleted samples, with an adjusted male median G6PD activity value of 6.3 U/g haemoglobin. Using a cut-off value of 30% enzyme activity, the overall prevalence of G6PD deficiency was 10.8%. Genotyping of G6PD variants was performed for 536 samples, of which 131 contained mutations. The Mahidol variant comprised the majority, and males with the Mahidol variant showed lower G6PD enzyme activity. The G6PD Andalus variant, which has not been reported in Myanmar before, was also identified in this study. CONCLUSION: This study provides a G6PD enzyme activity reference value for the Myanmar population and further information on the prevalence and variants of G6PD deficiency among the Myanmar population; it also evaluates the feasibility of G6PD deficiency tests.
Subject(s)
Glucosephosphate Dehydrogenase Deficiency , Malaria, Vivax , Malaria , Male , Humans , Glucosephosphate Dehydrogenase Deficiency/epidemiology , Glucosephosphate Dehydrogenase/genetics , Primaquine , Prevalence , Cross-Sectional Studies , Myanmar , Genotype , Malaria/epidemiology , Malaria, Vivax/genetics , Risk Factors , Point-of-Care TestingABSTRACT
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.
Subject(s)
AIDS Vaccines/immunology , HIV Antibodies/immunology , HIV Envelope Protein gp120/immunology , Amino Acid Sequence , Amino Acid Substitution/immunology , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/metabolism , HIV Antibodies/chemistry , HIV Antibodies/metabolism , HIV Envelope Protein gp120/chemistry , HIV Envelope Protein gp120/metabolism , Humans , Molecular Docking Simulation , Molecular Sequence Data , Peptides/chemistry , Peptides/immunology , Peptides/metabolism , Protein Binding/immunology , Protein ConformationABSTRACT
In this article, we aimed to understand the life experiences of Thai persons diagnosed with multi-drug-resistant tuberculosis (MDR-TB). A qualitative study using a face-to-face in-depth interview was conducted at a hospital in Thailand which has the highest prevalence of MDR-TB in the country between January and February 2019. Twenty persons living with MDR-TB in Thailand were purposively selected to represent a variety of experiences based on different gender, ages, and treatment phases. Qualitative data were transcribed and thematic analysis was applied to identify common themes and sub-themes. The results indicated that all participants faced emotional difficulties, such as fear of death, fear of stigmatization, confusion, and sadness when first knowing of their diagnosis. Family and social support were the main ways that the patients coped with difficult situations. Suicidal ideas were more prevalent among patients with poor family support. Screening for mental health problems should be routinely performed in MDR-TB patients. Proper health education should be provided to patients and families to reduce emotional difficulties and stigmatization.
Subject(s)
Adaptation, Psychological , Tuberculosis, Multidrug-Resistant , Emotions , Fear , Humans , Suicidal Ideation , Thailand , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/psychologyABSTRACT
Induction of protective antibodies is a critical goal of HIV-1 vaccine development. One strategy is to induce nonneutralizing antibodies (NNAbs) that kill virus-infected cells, as these antibody specificities have been implicated in slowing HIV-1 disease progression and in protection. HIV-1 Env constant region 1 and 2 (C1C2) monoclonal antibodies (MAbs) frequently mediate potent antibody-dependent cellular cytotoxicity (ADCC), making them an important vaccine target. Here, we explore the effect of delayed and repetitive boosting of RV144 vaccine recipients with AIDSVAX B/E on the C1C2-specific MAb repertoire. It was found that boosting increased clonal lineage-specific ADCC breadth and potency. A ligand crystal structure of a vaccine-induced broad and potent ADCC-mediating C1C2-specific MAb showed that it bound a highly conserved Env gp120 epitope. Thus, boosting to affinity mature these types of IgG C1C2-specific antibody responses may be one method by which to make an improved HIV vaccine with higher efficacy than that seen in the RV144 trial.IMPORTANCE Over one million people become infected with HIV-1 each year, making the development of an efficacious HIV-1 vaccine an important unmet medical need. The RV144 human HIV-1 vaccine regimen is the only HIV-1 clinical trial to date to demonstrate vaccine efficacy. An area of focus has been on identifying ways by which to improve upon RV144 vaccine efficacy. The RV305 HIV-1 vaccine regimen was a follow-up boost of RV144 vaccine recipients that occurred 6 to 8 years after the conclusion of RV144. Our study focused on the effect of delayed boosting in humans on the vaccine-induced Env constant region 1 and 2 (C1C2)-specific antibody repertoire. It was found that boosting with an HIV-1 Env vaccine increased C1C2-specific antibody-dependent cellular cytotoxicity potency and breadth.
Subject(s)
AIDS Vaccines/immunology , HIV Envelope Protein gp120/immunology , Antibodies, Monoclonal/immunology , Antibody Formation/immunology , Antibody Specificity/immunology , Antibody-Dependent Cell Cytotoxicity/immunology , Epitopes/immunology , HIV Antibodies/immunology , HIV Antibodies/ultrastructure , HIV Envelope Protein gp120/ultrastructure , HIV Infections/immunology , HIV-1/immunology , Humans , Immunization, Secondary/methods , Immunoglobulin G/immunologyABSTRACT
PURPOSE: To compare the effect of solid (SAFO) and hinged (HAFO) ankle-foot orthoses in children with cerebral palsy spastic diplegia and true equinus and jump gait. METHODS: Participants were 26 children (13 wore SAFO and 13 wore HAFO) aged 4 to 14 years classified as Gross Motor Function Classification System levels I to III. Children were tested on standardized measures of body structure and function, activity, and participation. RESULTS: Children wearing HAFO reached further in standing than those wearing SAFO. Among children who walked without an assistive device, children wearing HAFO had greater stride length and faster velocity. Mean Gross Motor Function Measure and Pediatric Evaluation of Disability Inventory mobility scores did not differ between groups. The cost-to-benefit ratios showed parents preferred HAFO. CONCLUSIONS: Among children with true equinus and jump gait, the effects of HAFO were greater in children who walked without an assistive mobility device.
Subject(s)
Cerebral Palsy , Foot Orthoses , Ankle , Child , Equipment Design , Gait , Humans , Orthotic DevicesABSTRACT
BACKGROUND: Early diagnosis of neonatal sepsis is essential to prevent severe complications and avoid unnecessary use of antibiotics. The mortality of neonatal sepsis is over 18%in many countries. This study aimed to develop a predictive model for the diagnosis of bacterial late-onset neonatal sepsis. METHODS: A case-control study was conducted at Queen Sirikit National Institute of Child Health, Bangkok, Thailand. Data were derived from the medical records of 52 sepsis cases and 156 non-sepsis controls. Only proven bacterial neonatal sepsis cases were included in the sepsis group. The non-sepsis group consisted of neonates without any infection. Potential predictors consisted of risk factors, clinical conditions, laboratory data, and treatment modalities. The model was developed based on multiple logistic regression analysis. RESULTS: The incidence of late proven neonatal sepsis was 1.46%. The model had 6 significant variables: poor feeding, abnormal heart rate (outside the range 100-180 x/min), abnormal temperature (outside the range 36o-37.9 °C), abnormal oxygen saturation, abnormal leucocytes (according to Manroe's criteria by age), and abnormal pH (outside the range 7.27-7.45). The area below the Receiver Operating Characteristics (ROC) curve was 95.5%. The score had a sensitivity of 88.5% and specificity of 90.4%. CONCLUSION: A predictive model and a scoring system were developed for proven bacterial late-onset neonatal sepsis. This simpler tool is expected to somewhat replace microbiological culture, especially in resource-limited settings.
Subject(s)
Neonatal Sepsis/diagnosis , Anti-Bacterial Agents/therapeutic use , Case-Control Studies , Female , Heart Rate , Humans , Incidence , Infant, Newborn , Male , Models, Biological , Neonatal Sepsis/drug therapy , Neonatal Sepsis/epidemiology , Neonatal Sepsis/microbiology , ROC Curve , Risk Factors , Sensitivity and Specificity , Tertiary Care Centers/statistics & numerical data , Thailand/epidemiologyABSTRACT
The heterogeneity and complexity of malaria involves political and natural environments, socioeconomic development, cross-border movement, and vector biology; factors that cannot be changed in a short time. This study aimed to assess the impact of economic growth and cross-border movement, toward elimination of malaria in Yunnan Province during its pre-elimination phase. Malaria data during 2011-2016 were extracted from 18 counties of Yunnan and from 7 villages, 11 displaced person camps of the Kachin Special Region II of Myanmar. Data of per-capita gross domestic product (GDP) were obtained from Yunnan Bureau of Statistics. Data were analyzed and mapped to determine spatiotemporal heterogeneity at county and village levels. There were a total 2,117 malaria cases with 85.2% imported cases; most imported cases came from Myanmar (78.5%). Along the demarcation line, malaria incidence rates in villages/camps in Myanmar were significantly higher than those of the neighboring villages in China. The spatial and temporal trends suggested that increasing per-capita GDP may have an indirect effect on the reduction of malaria cases when observed at macro level; however, malaria persists owing to complex, multi-faceted factors including poverty at individual level and cross-border movement of the workforce. In moving toward malaria elimination, despite economic growth, cooperative efforts with neighboring countries are critical to interrupt local transmission and prevent reintroduction of malaria via imported cases. Cross-border workers should be educated in preventive measures through effective behavior change communication, and investment is needed in active surveillance systems and novel diagnostic and treatment services during the elimination phase.
Subject(s)
Economics , Malaria/epidemiology , Transients and Migrants , China/epidemiology , Female , Guanosine Diphosphate , Health Education , Humans , Malaria/prevention & control , Male , Myanmar/epidemiology , Socioeconomic FactorsABSTRACT
Vaccine-elicited humoral immune responses comprise an array of antibody forms and specificities, with only a fraction contributing to protective host immunity. Elucidation of antibody effector functions responsible for protective immunity against human immunodeficiency virus type 1 (HIV-1) acquisition is a major goal for the HIV-1 vaccine field. Immunoglobulin A (IgA) is an important part of the host defense against pathogens; however, little is known about the role of vaccine-elicited IgA and its capacity to mediate antiviral functions. To identify the antiviral functions of HIV-1-specific IgA elicited by vaccination, we cloned HIV-1 envelope-specific IgA monoclonal antibodies (MAbs) by memory B cell cultures from peripheral blood mononuclear cells from an RV144 vaccinee and produced two IgA clonal cell lines (HG129 and HG130) producing native, nonrecombinant IgA MAbs. The HG129 and HG130 MAbs mediated phagocytosis by monocytes, and HG129 blocked HIV-1 Env glycoprotein binding to galactosylceramide, an alternative HIV-1 receptor. These findings elucidate potential antiviral functions of vaccine-elicited HIV-1 envelope-specific IgA that may act to block HIV-1 acquisition at the portal of entry by preventing HIV-1 binding to galactosylceramide and mediating antibody Fc receptor-mediated virion phagocytosis. Furthermore, these findings highlight the complex and diverse interactions of vaccine-elicited IgA with pathogens that depend on IgA fine specificity and form (e.g., multimeric or monomeric) in the systemic circulation and mucosal compartments.IMPORTANCE Host-pathogen interactions in vivo involve numerous immune mechanisms that can lead to pathogen clearance. Understanding the nature of antiviral immune mechanisms can inform the design of efficacious HIV-1 vaccine strategies. Evidence suggests that both neutralizing and nonneutralizing antibodies can mediate some protection against HIV in animal models. Although numerous studies have characterized the functional properties of HIV-1-specific IgG, more studies are needed on the functional attributes of HIV-1-specific IgA, specifically for vaccine-elicited IgA. Characterization of the functional properties of HIV-1 Env-specific IgA monoclonal antibodies from human vaccine clinical trials are critical toward understanding the capacity of the host immune response to block HIV-1 acquisition.
Subject(s)
AIDS Vaccines/immunology , Antibodies, Blocking/immunology , Antibodies, Monoclonal/immunology , Galactosylceramides/immunology , HIV Antibodies/immunology , HIV-1/immunology , Immunoglobulin A/immunology , Phagocytosis/immunology , Antibodies, Blocking/pharmacology , Antibodies, Monoclonal/pharmacology , Cell Line , HIV Antibodies/pharmacology , Humans , Immunoglobulin A/pharmacology , Phagocytosis/drug effectsABSTRACT
The canary pox vector and gp120 vaccine (ALVAC-HIV and AIDSVAX B/E gp120) in the RV144 HIV-1 vaccine trial conferred an estimated 31% vaccine efficacy. Although the vaccine Env AE.A244 gp120 is antigenic for the unmutated common ancestor of V1V2 broadly neutralizing antibody (bnAbs), no plasma bnAb activity was induced. The RV305 (NCT01435135) HIV-1 clinical trial was a placebo-controlled randomized double-blinded study that assessed the safety and efficacy of vaccine boosting on B cell repertoires. HIV-1-uninfected RV144 vaccine recipients were reimmunized 6-8 years later with AIDSVAX B/E gp120 alone, ALVAC-HIV alone, or a combination of ALVAC-HIV and AIDSVAX B/E gp120 in the RV305 trial. Env-specific post-RV144 and RV305 boost memory B cell VH mutation frequencies increased from 2.9% post-RV144 to 6.7% post-RV305. The vaccine was well tolerated with no adverse events reports. While post-boost plasma did not have bnAb activity, the vaccine boosts expanded a pool of envelope CD4 binding site (bs)-reactive memory B cells with long third heavy chain complementarity determining regions (HCDR3) whose germline precursors and affinity matured B cell clonal lineage members neutralized the HIV-1 CRF01 AE tier 2 (difficult to neutralize) primary isolate, CNE8. Electron microscopy of two of these antibodies bound with near-native gp140 trimers showed that they recognized an open conformation of the Env trimer. Although late boosting of RV144 vaccinees expanded a novel pool of neutralizing B cell clonal lineages, we hypothesize that boosts with stably closed trimers would be necessary to elicit antibodies with greater breadth of tier 2 HIV-1 strains. TRIAL REGISTRATION: ClinicalTrials.gov NCT01435135.
Subject(s)
AIDS Vaccines/administration & dosage , CD4 Antigens/immunology , HIV Antibodies/immunology , HIV Infections/prevention & control , Immunization, Secondary/methods , AIDS Vaccines/immunology , Cell Separation , Complementarity Determining Regions/immunology , Crystallography, X-Ray , Double-Blind Method , HIV Envelope Protein gp120/immunology , HIV Infections/immunology , HIV-1/immunology , Humans , Image Processing, Computer-Assisted , Microscopy, Electron , Neutralization Tests , Polymerase Chain Reaction , Surface Plasmon ResonanceABSTRACT
BACKGROUND: In low malaria transmission areas, many people acquire multiple malaria infections within a single season. This study aimed to describe the pattern and epidemiological profile of malaria recurrence in a hypoendemic area of western Thailand and identify factors associated with having multiple malaria episodes. METHODS: An open cohort of 7000 residents in seven clusters along the Thai-Myanmar border was followed during a 6.5-year period (2011-mid 2017). Symptomatic and asymptomatic malaria infections were detected by passive case detection (PCD), weekly household visit, and mass blood surveys every 4-6 months. Malaria recurrence was defined as subsequent parasitaemic episodes occurred later than 7 days after receiving anti-malarial treatment. This study focused on analysis of recurrent episodes that occurred within 1 year after treatment. Numbers of malaria cases with single and multiple episodes were compared between clusters. Kaplan-Meier curve was performed to determine the intervals of recurrent episodes by Plasmodium species and age groups. The ordinal logistic model was used to determine factors associated with multiple malaria episodes, and to compare with single episodes, and those with no malaria infection. RESULTS: The cumulative incidence of malaria in the study area was 5.2% over the 6.5 years. Overall, 410 malaria patients were detected. Of these patients, 20% and 16% had multiple malaria episodes during the entire period and within 1 year after initial treatment, respectively. About 80% of repeated malaria episodes were caused by the same Plasmodium species as the primary infections. The median interval and interquartile range (IQR) between the first and second episode was 88 (43-175) days for all parasites, 56 (35-133) days for two Plasmodium falciparum episodes, and 90 (59-204) days for two Plasmodium vivax episodes. The interval between the episodes was increased with age. Factors significantly associated with multiple episodes of malaria infection included male sex, young age, Karen ethnicity, forest-related occupation, and having other malaria infected persons in the same house in the same period. CONCLUSIONS: People who have multiple malaria episodes may play an important role in maintaining malaria transmission in the area. Understanding epidemiological profiles of this group is important for planning strategies to achieve the elimination goal.
Subject(s)
Malaria, Falciparum/epidemiology , Malaria, Vivax/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Asymptomatic Infections/epidemiology , Child , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Myanmar/ethnology , Prospective Studies , Recurrence , Risk Factors , Thailand/epidemiology , Young AdultABSTRACT
BACKGROUND: Tak Province, at the Thai-Myanmar border, is one of three high malaria incidence areas in Thailand. This study aimed to describe and identify possible factors driving the spatiotemporal trends of disease incidence from 2012 to 2015. METHODS: Climate variables and forest cover were correlated with malaria incidence using Pearson's r. Statistically significant clusters of high (hot spots) and low (cold spots) annual parasite incidence per 1000 population (API) were identified using Getis-Ord Gi* statistic. RESULTS: The total number of confirmed cases declined by 76% from 2012 to 2015 (Plasmodium falciparum by 81%, Plasmodium vivax by 73%). Incidence was highly seasonal with two main annual peaks. Most cases were male (62.75%), ≥ 15 years (56.07%), and of Myanmar (56.64%) or Thai (39.25%) nationality. Median temperature (1- and 2-month lags), average temperature (1- and 2-month lags) and average relative humidity (2- and 3-month lags) correlated positively with monthly total, P. falciparum and P. vivax API. Total rainfall in the same month correlated with API for total cases and P. vivax but not P. falciparum. At sub-district level, percentage forest cover had a low positive correlation with P. falciparum, P. vivax, and total API in most years. There was a decrease in API in most sub-districts for both P. falciparum and P. vivax. Sub-districts with the highest API were in the Tha Song Yang and Umphang Districts along the Thai-Myanmar border. Annual hot spots were mostly in the extreme north and south of the province. CONCLUSIONS: There has been a large decline in reported clinical malaria from 2012 to 2015 in Tak Province. API was correlated with monthly climate and annual forest cover but these did not account for the trends over time. Ongoing elimination interventions on one or both sides of the border are more likely to have been the cause but it was not possible to assess this due to a lack of suitable data. Two main hot spot areas were identified that could be targeted for intensified elimination activities.
Subject(s)
Malaria, Falciparum/epidemiology , Malaria, Vivax/epidemiology , Plasmodium falciparum/physiology , Plasmodium vivax/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Environment , Female , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Myanmar/ethnology , Seasons , Thailand/epidemiology , Thailand/ethnology , Young AdultABSTRACT
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.
Subject(s)
AIDS Vaccines/immunology , Antibodies, Monoclonal/immunology , Eye Diseases/prevention & control , HIV Envelope Protein gp120/immunology , Herpes Simplex/prevention & control , Receptors, Tumor Necrosis Factor, Member 14/immunology , Simplexvirus/immunology , Viral Envelope Proteins/immunology , Animals , Antibodies, Monoclonal/administration & dosage , Antibody-Dependent Cell Cytotoxicity/immunology , Cell Line , Eye Diseases/virology , Female , HIV Envelope Protein gp120/genetics , Herpes Simplex/immunology , Herpes Simplex/virology , Humans , Killer Cells, Natural/immunology , Leukocytes, Mononuclear/immunology , Lymphocyte Activation/immunology , Mice , Mice, Inbred BALB C , Simplexvirus/genetics , Viral Envelope Proteins/geneticsABSTRACT
BACKGROUND: One challenge in moving towards malaria elimination is cross-border malaria infection. The implemented measures to prevent and control malaria re-introduction across the demarcation line between two countries require intensive analyses and interpretation of data from both sides, particularly in border areas, to make correct and timely decisions. Reliable maps of projected malaria distribution can help to direct intervention strategies. In this study, a Bayesian spatiotemporal analytic model was proposed for analysing and generating aggregated malaria risk maps based on the exceedance probability of malaria infection in the township-district adjacent to the border between Myanmar and Thailand. Data of individual malaria cases in Hlaingbwe Township and Tha-Song-Yang District during 2016 were extracted from routine malaria surveillance databases. Bayesian zero-inflated Poisson model was developed to identify spatial and temporal distributions and associations between malaria infections and risk factors. Maps of the descriptive statistics and posterior distribution of predicted malaria infections were also developed. RESULTS: A similar seasonal pattern of malaria was observed in both Hlaingbwe Township and Tha-Song-Yang District during the rainy season. The analytic model indicated more cases of malaria among males and individuals aged ≥ 15 years. Mapping of aggregated risk revealed consistently high or low probabilities of malaria infection in certain village tracts or villages in interior parts of each country, with higher probability in village tracts/villages adjacent to the border in places where it could easily be crossed; some border locations with high mountains or dense forests appeared to have fewer malaria cases. The probability of becoming a hotspot cluster varied among village tracts/villages over the year, and some had close to no cases all year. CONCLUSIONS: The analytic model developed in this study could be used for assessing the probability of hotspot cluster, which would be beneficial for setting priorities and timely preventive actions in such hotspot cluster areas. This approach might help to accelerate reaching the common goal of malaria elimination in the two countries.
Subject(s)
Malaria/epidemiology , Topography, Medical , Adolescent , Adult , Aged , Aged, 80 and over , Bayes Theorem , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Myanmar/epidemiology , Risk Assessment , Risk Factors , Spatio-Temporal Analysis , Thailand/epidemiology , Young AdultABSTRACT
BACKGROUND: Dengue prevention is important for controlling the spread of dengue infection. Transmission of dengue can be prevented by controlling mosquito breeding sites. Indonesia has dengue a prevention program to minimize mosquito breeding sites known as 3 M Plus. This study aimed to investigate factors associated with dengue prevention behaviour among respondents in the Lowokwaru subdistrict, an urban area in Malang, Indonesia. METHODS: This cross-sectional study used a semi-structured questionnaire that was conducted by face-to-face interview. RESULTS: Older respondents (> 60 years and 41-60 years) showed better dengue prevention behaviour than younger respondents (21-40 years and < 21 years) (p value = 0.01). Proportionally more male respondents showed poor dengue prevention behaviour compared with female respondents (p value = 0.007). Respondents who lived in Malang for long durations showed better dengue prevention behaviour compared with those who lived there for a shorter period (p value = 0.016). Those with more family members in their households practiced better dengue prevention behaviour compared with those with fewer family members (p value = 0.004). Perception was associated with dengue prevention behaviour. Respondents who had higher perceived susceptibility showed better dengue prevention behaviour compared with those who had moderate perceptions (p value = 0.000). CONCLUSIONS: Age, gender, duration of stay in Malang, number of family members, and perception of dengue susceptibility were associated with dengue prevention behaviour.
Subject(s)
Dengue/prevention & control , Urban Population , Adolescent , Adult , Cross-Sectional Studies , Family Characteristics , Female , Health Knowledge, Attitudes, Practice , Humans , Indonesia , Male , Middle Aged , Socioeconomic Factors , Surveys and Questionnaires , Urban Population/statistics & numerical data , Young AdultABSTRACT
BACKGROUND: Delays in diagnosis and treatment initiation may allow the emergence of new cases by transmission to the community, and is one of the challenges facing programme management of drug resistance in Myanmar. This study aimed to explore delays in diagnosis and treatment initiation, and associated factors among patients with multidrug-resistant tuberculosis. METHODS: A cross-sectional study was conducted at Yangon Regional Tuberculosis Centre, Myanmar. Data were collected by face-to-face interviews and treatment-card reviews of all adult patients who had registered and started treatment with the standard regimen from May to November, 2017. Delay time was categorized by using median cut-off and analyzed using SPSS version 23.0. Logistic regression analysis was performed to assess the relative impact of predictor variables on diagnosis and treatment delays. RESULTS: A total of 210 patients participated in this study. The median diagnosis delay was 9 days, IQR 3 (8-11) and 58.6% of the patients experienced a long diagnosis delay. Below middle school education (adjusted odds ratio [AOR] = 2.75, 95% CI = 1.22-6.21), non-permanent salaried employment (AOR = 3.03, 95% CI = 1.32-6.95), co-existing diabetes mellitus (AOR = 5.06, 95% CI = 1.97-13.01) and poor awareness (AOR = 2.99, 95% CI = 1.29-6.92) were independent predictors of long diagnosis delay. The median treatment delay was 13 days, IQR 9 (8-17) and 51% of the patients experienced long treatment delay. Age 31-50 years (AOR = 4.50, 95% CI = 1.47-13.97) and age > 50 years (AOR = 9.40, 95% CI = 2.55-34.83), history with MDR-TB patient (AOR = 3.16, 95% CI = 1.29-7.69), > 20 km away from a Regional TB Centre (AOR = 14.33, 95% CI = 1.91-107.64) and poor awareness (AOR = 4.62, 95% CI = 1.56-13.67) were independent predictors of long treatment delay. CONCLUSIONS: Strengthening comprehensive health education, enhancing treatment adherence counseling, providing more Xpert MTB/RIF machines, expanding decentralized MDR-TB treatment centers, ensuring timely sputum transportation, provision of a patient support package immediately after confirmation, and strengthening contact-tracing for all household contacts with MDR-TB patients and active tuberculosis screening were the most effective ways to shorten delays in MDR-TB diagnosis and treatment initiation.
Subject(s)
Delayed Diagnosis , Tuberculosis, Multidrug-Resistant/diagnosis , Tuberculosis, Pulmonary/diagnosis , Adolescent , Adult , Cross-Sectional Studies , Delivery of Health Care/standards , Diabetes Complications/complications , Female , Humans , Male , Middle Aged , Myanmar , Odds Ratio , Time-to-Treatment , Tuberculosis, Multidrug-Resistant/complications , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Pulmonary/complications , Tuberculosis, Pulmonary/drug therapyABSTRACT
Background: The RV144 ALVAC-HIV prime, AIDSVAX B/E boost afforded 60% efficacy against human immunodeficiency virus (HIV) acquisition at 1 year, waning to 31.2% after 3.5 years. We hypothesized that additional vaccinations might augment immune correlates of protection. Methods: In a randomized placebo-controlled double-blind study of 162 HIV-negative RV144 vaccine recipients, we evaluated 2 additional boosts, given 6-8 years since RV144 vaccination, for safety and immunogenicity, at weeks 0 and 24. Study groups 1-3 received ALVAC-HIV+AIDSVAX B/E, AIDSVAX B/E, and ALVAC-HIV, respectively, or placebo. Results: Vaccines were well tolerated. For groups 1 and 2, plasma immunoglobulin (Ig) G, IgA, and neutralizing antibody responses at week 2 were all significantly higher than 2 weeks after the last RV144 vaccination. IgG titers against glycoprotein (gp) 70V1V2 92TH023 increased 14-fold compared with 2 weeks after the last RV144 vaccination (14069 vs 999; P < .001). Groups 1 and 2 did not differ significantly from each other, whereas group 3 was similar to placebo recipients. Responses in groups 1 and 2 declined by week 24 but were boosted by the second vaccination, albeit at lower magnitude than for week 2. Conclusions: In RV144 vaccinees, AIDSVAX B/E with or without ALVAC-HIV 6-8 years after initial vaccination generated higher humoral responses than after RV144, but these responses were short-lived, and their magnitude did not increase with subsequent boost. Clinical Trials Registration: NCT01435135.
Subject(s)
AIDS Vaccines/administration & dosage , HIV Envelope Protein gp120/immunology , HIV Infections/prevention & control , Immunity, Humoral , Immunization, Secondary , Adult , Antibodies, Neutralizing/blood , Cytokines/immunology , Double-Blind Method , Female , HIV Antibodies/blood , HIV-1 , Healthy Volunteers , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Male , ThailandABSTRACT
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.
Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Viral/immunology , Simian Acquired Immunodeficiency Syndrome/prevention & control , Simian Immunodeficiency Virus/immunology , Viral Envelope Proteins/immunology , Animals , CD4-Positive T-Lymphocytes/immunology , Fluorescent Antibody Technique , HIV-1/immunology , Humans , Intestinal Mucosa/virology , Macaca mulatta , Protein Conformation , Rectum , Reverse Transcriptase Polymerase Chain Reaction , Surface Plasmon Resonance , Viral Envelope Proteins/chemistryABSTRACT
BACKGROUND: Migration flows and the emerging resistance to artemisinin-based combination therapy in the Greater Mekong Sub-region (GMS) create programmatic challenges to meeting the AD 2030 malaria elimination target in Myanmar. The National Malaria Control Programme (NMCP) targeted migrant workers based mainly on the stability of their worksites (categories 1: permanent work-setting; categories 2 and 3: less stable work-settings). This study aims to assess the migration patterns, malaria treatment-seeking preferences, and challenges encountered by mobile/migrant workers at remote sites in a malaria-elimination setting. METHODS: A mixed-methods explanatory sequential study retrospectively analysed the secondary data acquired through migrant mapping surveys (2013-2015) in six endemic regions (n = 9603). A multivariate logistic regression model was used to ascertain the contributing factors. A qualitative strand (2016-2017) was added by conducting five focus-group discussions (n = 50) and five in-depth interviews with migrant workers from less stable worksites in Shwegyin Township, Bago Region. The contiguous approach was used to integrate quantitative and qualitative findings. RESULTS: Among others, migrant workers from Bago Region were significantly more likely to report the duration of stay ≥ 12 months (63% vs. 49%) and high seasonal mobility (40% vs. 35%). Particularly in less stable settings, a very low proportion of migrant workers (17%) preferred to seek malaria treatment from the public sector and was significantly influenced by the worksite stability (adjusted OR = 1.4 and 2.3, respectively for categories 2 and 1); longer duration of stay (adjusted OR = 3.5); and adjusted OR < 2 for received malaria messages, knowledge of malaria symptoms and awareness of means of malaria diagnosis. Qualitative data further elucidated their preference for the informal healthcare sector, due to convenience, trust and good relations, and put migrant workers at risk of substandard care. Moreover, the availability of cheap anti-malarial in unregistered small groceries encouraged self-medication. Infrequent or no contact with rural health centres and voluntary health workers worsened the situation. CONCLUSIONS: Mitigating key drivers that favour poor utilization of public-sector services among highly mobile migrant workers in less stable work-settings should be given priority in a malaria-elimination setting. These issues are challenging for the NMCP in Myanmar and might be generalized to other countries in the GMS to achieve malaria-elimination goals. Further innovative out-reach programmes designed and implemented specific to the nature of mobile/migrant workers is crucial.
Subject(s)
Health Behavior , Health Knowledge, Attitudes, Practice , Malaria/prevention & control , Transients and Migrants/psychology , Adolescent , Adult , Early Diagnosis , Female , Humans , Male , Middle Aged , Myanmar , Public Sector/statistics & numerical data , Transients and Migrants/statistics & numerical data , Young AdultABSTRACT
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.