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Objective HIV prevention has been ongoing in Lusaka for many years. Recent reports suggest a possible decline in HIV seroincidence in Zambia and some neighbouring countries. This study aimed to examine trends in HIV seroprevalence among pregnant and parturient women between 2002 and 2006. Methods We analysed HIV seroprevalence trends from two Lusaka sources: (i) antenatal data from a city-wide programme to prevent mother-to-child HIV transmission, and (ii) delivery data from two anonymous unlinked cord-blood surveillances performed in 2003 and again in 2005-2006, where specimens from > 97% of public-sector births in each period were obtained and analysed. Findings Between July 2002 and December 2006, the Lusaka district tested 243 302 antenatal women for HIV; 54 853 (22.5%) were HIV infected. Over this period, the HIV seroprevalence among antenatal attendees who were tested declined steadily from 24.5% in the third quarter of 2002 to 21.4% in the last quarter of 2006 (P < 0.001). The cord-blood surveillances were conducted between June and August 2003 and again between October 2005 and January 2006. Overall HIV seroprevalence declined from 25.7% in 2003 to 21.8% in 2005-2006 (P = 0.001). Among women 17 years of age, seroprevalence declined from 12.1% to 7.7% (P = 0.015). Conclusion HIV seroprevalence appears to be declining among antenatal and parturient women in Lusaka. The decline is most dramatic among women <= 17 years of age, suggesting a reduction in sero-incidence in this important age group. Copyright © 2008 World Health Organization [ABSTRACT FROM AUTHOR]

Introduction: Microvascular and macrovascular complications in type 1 diabetes (T1D) may be linked to endothelial stress due to glycaemic variability. Continuous glucose monitoring systems (CGMs) provide new opportunities to quantify this variability, utilising the amplitude of glucose change summated over time. The aim of this study was to examine whether this determination of glucose variability (GV) is associated with microvascular clinical sequelae., Methods: Continuous glucose monitoring values were downloaded for 89 type 1 diabetes mellitus (T1D) individuals for up to 18 months from 2021 to 2023. Data for patient demographics was also taken from the patient record which included Sex, Date of Birth, and Date of Diagnosis. The recorded laboratory glycated haemoglobin (HbA1c) test results were also recorded. The glucose management index (GMI) was calculated from average glucose readings for 18 months using the formula GMI (%) = (0.82-(Average glucose/100)). This was then adjusted to give GMI (mmol/mol) = 10.929 * (GMI (%) - 2.15). Average Glucose Fluctuation (AGF) was calculated by adding up the total absolute change value between all recorded results over 18 months and dividing by the number of results minus one. The % Above Critical Threshold (ACT) was calculated by summing the total number of occurrences for each result value. A cumulative 95% limit was then applied to identify the glucose value that only 5% of results exceeded in the overall population. Using this value, we estimated the percentage of total tests that were above the Critical Threshold (ACT)., Results: Results for the 89 individuals (44 men and 45 women) were analysed over 18 months. The mean age of participants was 43 years and the mean duration of diabetes was 18 years. A total of 3.22 million readings were analysed, giving an average of 10.3 mmol/L blood glucose. Those with the largest change in glucose from reading to reading, summated over time, showed the greatest change in eGFR of 3.12 ml/min/1.73 m 2 (p = 0.007). People with a higher proportion of glucose readings > 18 mmol/L showed a fall in eGFR of 2.8 ml/min/1.73 m 2 (p = 0.009) and experienced higher rates of sight-threatening retinopathy (44% of these individuals) (p = 0.01) as did 39% of individuals in the highest tertile of glucose levels (p = 0.008)., Conclusion: Those individuals with T1D in the highest tertile of reading-to-reading glucose change showed the greatest change in eGFR. Those with a higher proportion of glucose readings > 18 mmol/L also showed a fall in eGFR and experienced higher rates of sight-threatening retinopathy, as did people with higher mean glucose. Discussions with T1D individuals could reflect on how the percentage recorded glucose above a critical level and degree of change in glucose are important in avoiding future tissue complications., Competing Interests: Declarations Conflict of interest Adrian H Heald, Mike Stedman, John Warner Levy, Lleyton Belston, Angela Paisley, Reena Patel, Alison White, Edward Jude, J Martin Gibson, Hellena Habte-Asres, Martin Whyte and Angus Forbes have nothing to declare. Ethical Approval All participants were attending the clinic of one of the authors (Adrian H Heald). The FreeStyle Libre data are available in its entirety as part of their usual care for analysis by the clinical team. All patients were given the option to opt out of their data being analysed. Such data analysis in relation to clinical care is acceptable under UK research ethics guidance. Patients whose data were analysed were kept fully informed, in accordance with the UK guidance at https://digital.nhs.uk/services/national-data-opt-out/understanding-the-national-data-opt-out/protecting-patient-data. All data were full anonymised prior to analysis., (© 2024. The Author(s).)

Background: The psychosocial consequences of tuberculosis (TB) are key barriers to ending TB globally. We evaluated and compared stigma, depression, and quality of life (QoL) among people with TB diagnosed through active (ACF) and passive (PCF) case-finding in Nepal., Methods: We prospectively recruited adults with TB diagnosed through ACF and PCF in four districts of Nepal between August 2018 and April 2019. Participants were interviewed at 8-12 weeks (baseline) and 22-26 weeks (follow-up) following treatment initiation. TB stigma was measured using an adapted Van Rie Stigma Scale (0 = no stigma to 30 = highest stigma). Depression was measured using a locally-validated Patient Health Questionnaire (PHQ-9). Mild and major depression were indicated by  PHQ-9 scores 5-9 and ≥ 10, respectively. QoL was measured using the EuroQoL 5-Dimension 5-level (EQ-5D-5L) from 0 to 1 (optimal QoL); and self-rated health from 0 to 100 (optimal self-rated health)., Results: We recruited 221 participants (111 ACF; 110 PCF) with a mean age of 48 years (standard deviation [SD] =  ± 16), of whom 147/221 (67%) were men. The mean TB stigma score was 12 (SD = 7.3) at baseline and 12 (SD = 6.7) at follow-up. The most commonly perceived elements of TB stigma at baseline were that people with TB experienced guilt (110/221, 50%) and feared disclosure outside their household (114/221, 52%). Self-rated health and EQ-5D-5L scores increased from baseline to follow-up (69.3 to 80.3, p < 0.001; 0.92 to 0.9, p = 0.009). Nearly one-third of participants (68/221, 31%) had mild or major depression at baseline. The proportion of participants with major depression decreased from baseline to follow-up (11.5% vs. 5%, p = 0.012). There was a moderate, significant positive correlation between depression and stigma scores (r = 0.41, p < 0.001). There were no differences found in TB stigma, self-rated health, QoL, or prevalence of mild/major depression between ACF and PCF participants., Conclusions: We found a substantial, persistent, and clustered psychosocial impact among adults with TB diagnosed through both ACF and PCF strategies in Nepal. These findings suggest an urgent need to develop effective, evidence-based psychosocial support interventions with the potential to be integrated with existing ACF strategies and routine TB service activities., Competing Interests: Declarations. Ethics approval and consent to participate: The study conformed to the principles outlined in the Declaration of Helsinki. The study received ethical approval from the University of Liverpool, UK (approval number 2436) and Nepal Health Research Council (approval number 320/2018). Participants were provided with a leaflet that detailed the objective, duration, risks and benefits of participating in the study [99]. Written informed consent was obtained from all the participants. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Conotruncal heart defects (CTDs) are heart malformations that affect the cardiac outflow tract and typically cause significant morbidity and mortality. Evidence from epidemiological studies suggests that maternal folate intake is associated with a reduced risk of heart defects, including CTD. However, it is unclear if folate-related gene variants and maternal folate intake have an interactive effect on the risk of CTDs. In this study, we performed targeted sequencing of folate-related genes on DNA from 436 case families with CTDs who are enrolled in the National Birth Defects Prevention Study and then tested for common and rare variants associated with CTD. We identified risk alleles in maternal MTHFS (OR meta = 1.34; 95% CI 1.07 to 1.67), maternal NOS2 (OR meta = 1.34; 95% CI 1.05 to 1.72), fetal MTHFS (OR meta = 1.35; 95% CI 1.09 to 1.66), and fetal TCN2 (OR meta = 1.38; 95% CI 1.12 to 1.70) that are associated with an increased risk of CTD among cases without folic acid supplementation. We detected putative de novo mutations in genes from the folate, homocysteine, and transsulfuration pathways and identified a significant association between rare variants in MGST1 and CTD risk. Results suggest that periconceptional folic acid supplementation is associated with decreased risk of CTD among individuals with susceptible genotypes.

The aim of this study was to compare costs and socio-economic impact of tuberculosis (TB) for patients diagnosed through active (ACF) and passive case finding (PCF) in Nepal. A longitudinal costing survey was conducted in four districts of Nepal from April 2018 to October 2019. Costs were collected using the WHO TB Patient Costs Survey at three time points: intensive phase of treatment, continuation phase of treatment and at treatment completion. Direct and indirect costs and socio-economic impact (poverty headcount, employment status and coping strategies) were evaluated throughout the treatment. Prevalence of catastrophic costs was estimated using the WHO threshold. Logistic regression and generalized estimating equation were used to evaluate risk of incurring high costs, catastrophic costs and socio-economic impact of TB over time. A total of 111 ACF and 110 PCF patients were included. ACF patients were more likely to have no education (75% vs 57%, P = 0.006) and informal employment (42% vs 24%, P = 0.005) Compared with the PCF group, ACF patients incurred lower costs during the pretreatment period (mean total cost: US$55 vs US$87, P < 0.001) and during the pretreatment plus treatment periods (mean total direct costs: US$72 vs US$101, P < 0.001). Socio-economic impact was severe for both groups throughout the whole treatment, with 32% of households incurring catastrophic costs. Catastrophic costs were associated with 'no education' status [odds ratio = 2.53(95% confidence interval = 1.16-5.50)]. There is a severe and sustained socio-economic impact of TB on affected households in Nepal. The community-based ACF approach mitigated costs and reached the most vulnerable patients. Alongside ACF, social protection policies must be extended to achieve the zero catastrophic costs milestone of the End TB strategy., (© The Author(s) 2020. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine.)

This study compared the yield of tuberculosis (TB) active case finding (ACF) interventions applied under TB REACH funding. Between June 2017 to November 2018, Birat Nepal Medical Trust identified presumptive cases using simple verbal screening from three interventions: door-to-door screening of social contacts of known index cases, TB camps in remote areas, and screening for hospital out-patient department (OPD) attendees. Symptomatic individuals were then tested using smear microscopy or GeneXpert MTB/RIF as first diagnostic test. Yield rates were compared for each intervention and diagnostic method. We evaluated additional cases notified from ACF interventions by comparing case notifications of the intervention and control districts using standard TB REACH methodology. The project identified 1092 TB cases. The highest yield was obtained from OPD screening at hospitals (n = 566/1092; 52%). The proportion of positive tests using GeneXpert (5.5%, n = 859/15,637) was significantly higher than from microscopy testing 2% (n = 120/6309). (OR = 1.4; 95%CI = 1.12-1.72; p = 0.0026). The project achieved 29% additionality in case notifications in the intervention districts demonstrating that GeneXpert achieved substantially higher case-finding yields. Therefore, to increase national case notification for TB, Nepal should integrate OPD screening using GeneXpert testing in every district hospital and scale up of community-based ACF of TB patient contacts nationally.

Background:  WHO's 2015 End TB Strategy advocates social and economic (socioeconomic) support for TB-affected households to improve TB control. However, evidence concerning socioeconomic support for TB-affected households remains limited, especially in low-income countries. Protocol:  This mixed-methods study in Nepal will: evaluate the socioeconomic impact of accessing TB diagnosis and care (Project 1); and create a shortlist of feasible, locally-appropriate interventions to mitigate this impact (Project 2). The study will be conducted in the Chitwan, Mahottari, Makawanpur, and Dhanusha districts of Nepal, which have frequent TB and poverty. The study population will include: approximately 200 people with TB (Cases) starting TB treatment with Nepal's National TB Program and 100 randomly-selected people without TB (Controls) in the same sites (Project 1); and approximately 40 key in-country stakeholders from Nepal including people with TB, community leaders, and TB healthcare professionals (Project 2). During Project 1, visits will be made to people with TB's households during months 3 and 6 of TB treatment, and a single visit made to Control households. During visits, participants will be asked about: TB-related costs (if receiving treatment), food insecurity, stigma; TB-related knowledge; household poverty level; social capital; and quality of life. During Project 2, stakeholders will be invited to participate in: a survey and focus group discussion (FGD) to characterise socioeconomic impact, barriers and facilitators to accessing and engaging with TB care in Nepal; and a one-day workshop to review FGD findings and suggest interventions to mitigate the barriers identified. Ethics and dissemination:  The study has received ethical approval. Results will be disseminated through scientific meetings, open access publications, and a national workshop in Nepal.  Conclusions:  This research will strengthen understanding of the socioeconomic impact of TB in Nepal and generate a shortlist of feasible and locally-appropriate socioeconomic interventions for TB-affected households for trial evaluation., Competing Interests: No competing interests were disclosed., (Copyright: © 2020 Dixit K et al.)

Background: The World Health Organization (WHO) End TB Strategy has established a milestone to reduce the number of tuberculosis (TB)- affected households facing catastrophic costs to zero by 2020. The role of active case finding (ACF) in reducing patient costs has not been determined globally. This study therefore aimed to compare costs incurred by TB patients diagnosed through ACF and passive case finding (PCF), and to determine the prevalence and intensity of patient-incurred catastrophic costs in Nepal., Methods: The study was conducted in two districts of Nepal: Bardiya and Pyuthan (Province No. 5) between June and August 2018. One hundred patients were included in this study in a 1:1 ratio (PCF: ACF, 25 consecutive ACF and 25 consecutive PCF patients in each district). The WHO TB patient costing tool was applied to collect information from patients or a member of their family regarding indirect and direct medical and non-medical costs. Catastrophic costs were calculated based on the proportion of patients with total costs exceeding 20% of their annual household income. The intensity of catastrophic costs was calculated using the positive overshoot method. The chi-square and Wilcoxon-Mann-Whitney tests were used to compare proportions and costs. Meanwhile, the Mantel Haenszel test was performed to assess the association between catastrophic costs and type of diagnosis., Results: Ninety-nine patients were interviewed (50 ACF and 49 PCF). Patients diagnosed through ACF incurred lower costs during the pre-treatment period (direct medical: USD 14 vs USD 32, P = 0.001; direct non-medical: USD 3 vs USD 10, P = 0.004; indirect, time loss: USD 4 vs USD 13, P <  0.001). The cost of the pre-treatment and intensive phases combined was also lower for direct medical (USD 15 vs USD 34, P = 0.002) and non-medical (USD 30 vs USD 54, P = 0.022) costs among ACF patients. The prevalence of catastrophic direct costs was lower for ACF patients for all thresholds. A lower intensity of catastrophic costs was also documented for ACF patients, although the difference was not statistically significant., Conclusions: ACF can reduce patient-incurred costs substantially, contributing to the End TB Strategy target. Other synergistic policies, such as social protection, will also need to be implemented to reduce catastrophic costs to zero among TB-affected households.

The prevalence of the overweight and obesity is on the rise worldwide. Obesity can increase the risk of certain cancers and liver steatosis development. Previously, we reported that obesity increased liver steatosis in a mammary tumor model, but little is known about the effects of obesity in the liver in regard to global DNA methylation, DNA damage, and oxidative/nitrosative stress. Using a mammary tumor model, we investigated the effects of obesity on oxidative stress and DNA reaction. Five-week-old lean and obese female rats were used. At 50 days of age, all rats received 7,12-dimethylbenz( α )anthracene (DMBA) and were sacrificed 155 days later. HPLC with electrochemical and ultraviolet detection and LC-MS were used. Obesity caused higher ( p < 0.0004) methionine levels, had no effect ( p < 0.055) on SAM levels, caused lower ( p < 0.0005) SAH levels, caused higher ( p < 0.0005) SAM/SAH ratios, and increased ( p < 0.02) global DNA methylation. Levels of free reduced GSH were not significantly lower ( p < 0.08), but free oxidized GSSG was higher ( p < 0.002) in obese rats. The GSH/GSSG ratio was lower ( p < 0.0001), and oxidized guanosine was higher ( p < 0.002) in DNA of obese rats compared to lean rats. Obesity caused significant oxidative/nitrosative stress, oxidative DNA damage, and change of DNA methylation pattern in the liver, and these changes may contribute to the development of liver steatosis in breast cancer models., Competing Interests: The authors declare no conflict of interest.

Proper understanding of the long-term epidemiology of chikungunya has been hampered by poor surveillance. Outbreak years are unpredictable and cases often misdiagnosed. Here we analyzed age-specific data from 2 serological studies (from 1973 and 2012) in Cebu, Philippines, to reconstruct both the annual probability of infection and population-level immunity over a 60-year period (1952-2012). We also explored whether seroconversions during 2012-2013 were spatially clustered. Our models identified 4 discrete outbreaks separated by an average delay of 17 years. On average, 23% (95% confidence interval [CI], 16%-37%) of the susceptible population was infected per outbreak, with >50% of the entire population remaining susceptible at any point. Participants who seroconverted during 2012-2013 were clustered at distances of <230 m, suggesting focal transmission. Large-scale outbreaks of chikungunya did not result in sustained multiyear transmission. Nevertheless, we estimate that >350 000 infections were missed by surveillance systems. Serological studies could supplement surveillance to provide important insights on pathogen circulation., (© The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America.)

Background: The mean age of dengue has been increasing in some but not all countries. We sought to determine the incidence of dengue virus (DENV) infection in adults and children in a prospective cohort study in the Philippines where dengue is hyperendemic., Methodology/principal Findings: A prospective cohort of subjects ≥6 months old in Cebu City, Philippines, underwent active community-based surveillance for acute febrile illnesses by weekly contact. Fever history within the prior seven days was evaluated with an acute illness visit followed by 2, 5, and 8-day, and 3-week convalescent visits. Blood was collected at the acute and 3-week visits. Scheduled visits took place at enrolment and 12 months that included blood collections. Acute samples were tested by DENV PCR and acute/convalescent samples by DENV IgM/IgG ELISA to identify symptomatic infections. Enrolment and 12-month samples were tested by DENV hemagglutination inhibition (HAI) assay to identify subclinical infections. Of 1,008 enrolled subjects, 854 completed all study activities at 12 months per-protocol undergoing 868 person-years of surveillance. The incidence of symptomatic and subclinical infections was 1.62 and 7.03 per 100 person-years, respectively. However, in subjects >15 years old, only one symptomatic infection occurred whereas 27 subclinical infections were identified. DENV HAI seroprevalence increased sharply with age with baseline multitypic HAIs associated with fewer symptomatic infections. Using a catalytic model, the historical infection rate among dengue naïve individuals was estimated to be high at 11-22%/year., Conclusions/significance: In this hyperendemic area with high seroprevalence of multitypic DENV HAIs in adults, symptomatic dengue rarely occurred in individuals older than 15 years. Our findings demonstrate that dengue is primarily a pediatric disease in areas with high force of infection. However, the average age of dengue could increase if force of infection decreases over time, as is occurring in some hyperendemic countries such as Thailand.

Background: New recruits within military barracks present conditions favorable for the spread of respiratory pathogens. However, respiratory pathogen transmission in such confined settings in the tropics has not been well studied., Methods: Recruits in four successive Royal Thai Army basic training classes living in military barracks were monitored for the symptoms of influenza-like illness (ILI) or upper respiratory illness (URI). Classes 1 and 2 were also monitored after basic training. Nasal/throat swabs from acute illnesses were collected and tested by influenza RT-PCR (all four classes). In addition, class 1 had multiplex PCR performed along with the analysis of bed locations within the barracks., Results: Influenza-like illness/upper respiratory illness rates ranged from 4·7 to 6·9 per 100 recruit-weeks in the four classes and generally decreased during the course of basic training (P < 0·05 in three of four classes). Rates during basic training were 1·7 (95% CI: 1·29, 2·29) and 2·5 (95% CI: 1·5, 4·1) times higher than after basic training (classes 1 and 2, respectively). In class 1, coronavirus, parainfluenza virus, and rhinovirus were the most commonly identified respiratory pathogens; only one influenza PCR-positive infection was detected in all four classes. Bed locations of URI/ILI cases in class 1 tended to be in closer proximity to each other., Conclusion: Basic training recruits in military barracks in the tropics had high rates of acute respiratory illnesses with illness patterns consistent with external seeding followed by substantial internal transmission. Our findings may contribute to control measures in similar confined settings both within and outside the military., (© 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.)

Influenza in the tropics occurs year round with peaks that correspond variably to temperate regions. However, data on influenza vaccine effectiveness (VE) in the tropics is sparse. We report on the effectiveness of influenza vaccine to prevent medically attended laboratory confirmed influenza from sentinel surveillance conducted at a Thai military medical facility in Bangkok, Thailand from August 2009 to January 2013. Patients ≥6 months old presenting with influenza-like illness underwent combined nasal/throat swabs which were tested by influenza RT-PCR. A case test-negative study design was used to evaluate VE. Of 2999 samples available for analysis,1059 (35.3%) were PCR-positive (cases) and 1940 (64.6%) were PCR-negative (test-negative controls). Five hundred and seven (16.9%) of these patients reported being vaccinated within the previous 12 months. Periods of high and low influenza activity were defined based on publicly available Thai Ministry of Public Health data. Overall VE adjusted for age and epiweek was found to be 50.1% (95%CI: 35.0, 61.9%). The May to April adjusted VE for year 2010, 2011 and 2012 was 57.7% (95%CI: 33.7, 73.8%), 57.1% (95% CI: 35.2, 68.3%) and 37.6% (95% CI: 3.5, 62.9%).During high influenza activity in years with the same vaccine formulation, the adjusted VE was 54.9% (95%CI: 38.9, 66.9%). VE appeared to be much higher during high versus low influenza activity periods. The adjusted point estimate for VE was highest in the 18-49 year age group (76.6%) followed by 6-23 months (58.1%) and 2-17 years (52.5%). Adjusted estimates were not done for those ≥50 years of age due to small numbers. VE in patients with underlying disease was 75.5% compared to 48.0% in those without. Our findings demonstrate moderate protection by influenza vaccination and support the utility of influenza vaccination in the tropics including in very young children and those with underlying disease.

Background: Chikungunya virus (CHIKV) is a globally re-emerging arbovirus for which previous studies have indicated the majority of infections result in symptomatic febrile illness. We sought to characterize the proportion of subclinical and symptomatic CHIKV infections in a prospective cohort study in a country with known CHIKV circulation., Methods/findings: A prospective longitudinal cohort of subjects ≥6 months old underwent community-based active surveillance for acute febrile illness in Cebu City, Philippines from 2012-13. Subjects with fever history were clinically evaluated at acute, 2, 5, and 8 day visits, and at a 3-week convalescent visit. Blood was collected at the acute and 3-week convalescent visits. Symptomatic CHIKV infections were identified by positive CHIKV PCR in acute blood samples and/or CHIKV IgM/IgG ELISA seroconversion in paired acute/convalescent samples. Enrollment and 12-month blood samples underwent plaque reduction neutralization test (PRNT) using CHIKV attenuated strain 181/clone25. Subclinical CHIKV infections were identified by ≥8-fold rise from a baseline enrollment PRNT titer <10 without symptomatic infection detected during the intervening surveillance period. Selected CHIKV PCR-positive samples underwent viral isolation and envelope protein-1 gene sequencing. Of 853 subjects who completed all study procedures at 12 months, 19 symptomatic infections (2.19 per 100 person-years) and 87 subclinical infections (10.03 per 100 person-years) occurred. The ratio of subclinical-to-symptomatic infections was 4.6:1 varying with age from 2:1 in 6 month-5 year olds to 12:1 in those >50 years old. Baseline CHIKV PRNT titer ≥10 was associated with 100% (95%CI: 46.1, 100.0) protection from symptomatic CHIKV infection. Phylogenetic analysis demonstrated Asian genotype closely related to strains from Asia and the Caribbean., Conclusions: Subclinical infections accounted for a majority of total CHIKV infections. A positive baseline CHIKV PRNT titer was associated with protection from symptomatic CHIKV infection. These findings have implications for assessing disease burden, understanding virus transmission, and supporting vaccine development.

CYP2E1 metabolizes a wide array of small, hydrophobic molecules, resulting in their detoxification or activation into carcinogens through Michaelis-Menten as well as cooperative mechanisms. Nevertheless, the molecular determinants for CYP2E1 specificity and metabolic efficiency toward these compounds are still unknown. Herein, we employed computational docking studies coupled to molecular dynamics simulations to provide a critical perspective for understanding a structural basis for cooperativity observed for an array of azoles from our previous binding and catalytic studies (Hartman et al., 2014). The resulting 28 CYP2E1 complexes in this study revealed a common passageway for azoles that included a hydrophobic steric barrier causing a pause in movement toward the active site. The entrance to the active site acted like a second sieve to restrict access to the inner chamber. Collectively, these interactions impacted the final orientation of azoles reaching the active site and hence could explain differences in their biochemical properties observed in our previous studies, such as the consequences of methylation at position 5 of the azole ring. The association of a second azole demonstrated significant differences in interactions stabilizing the bound complex than observed for the first binding event. Intermolecular interactions occurred between the two azoles as well as CYP2E1 residue side chains and backbone and involved both hydrophobic contacts and hydrogen bonds. The relative importance of these interactions depended on the structure of the respective azoles indicating the absence of specific defining criteria for binding unlike the well-characterized dominant role of hydrophobicity in active site binding. Consequently, the structure activity relationships described here and elsewhere are necessary to more accurately identify factors impacting the observation and significance of cooperativity in CYP2E1 binding and catalysis toward drugs, dietary compounds, and pollutants., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Within a hand-washing clinical trial, we evaluated factors associated with fomite contamination in households with an influenza-infected child. Influenza virus RNA contamination was higher in households with low absolute humidity and in control households, suggesting that hand washing reduces surface contamination., (© 2013 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.)

The serial interval (SI) of human influenza virus infections is often described by a single distribution. Understanding sources of variation in the SI could provide valuable information for understanding influenza transmission dynamics. Using data from a randomized household study of nonpharmaceutical interventions to prevent influenza transmission in Bangkok, Thailand, over 34 months between 2008 and 2011, we estimated the influence of influenza virus type/subtype and other characteristics of 251 pediatric index cases and their 315 infected household contacts on estimates of household SI. The mean SI for all households was 3.3 days. Relative to influenza A(H1N1)pdm09 (3.1 days), the SI for influenza B (3.7 days) was 22% longer (95% confidence interval: 4, 43), or about half a day. The SIs for influenza viruses A(H1N1) and A(H3N2) were similar to that for A(H1N1)pdm09. SIs were shortest for older index cases (age 11-14 years) and for younger infected household contacts (age ≤15 years). Greater time spent in proximity to the index child was associated with shorter SIs. Differences in the SI might reflect differences in incubation period, viral shedding, contact, or susceptibility. These findings could improve parameterization of mathematical models to better predict the impact of epidemic or pandemic influenza mitigation strategies.

Background: Although generic anti-retroviral drugs are in common use throughout the developing world, studies comparing their clinical effectiveness with that of proprietary formulations are lacking., Methods: We analysed observational data from a large cohort of adults on anti-retroviral therapy (ART) to assess potential differences between generic and proprietary zidovudine (ZDV) formulations in post-90-day mortality, 'programme failure' (a composite of death, follow-up losses and withdrawals) and other clinical outcomes. We accounted for drug exposure in three ways: an 'initial dispensation' approach that categorized patients according to the first prescription; 'time-varying' approach that attributed an outcome to the formulation taken at the time of event; and 'predominant exposure' approach that considered only those with >75% exposure to either brand or generic ZDV. Proprietary formulations were used as the reference group in all adjusted Cox proportional hazard regressions., Results: Among 14 736 patients eligible for analysis, 7277 (49%) initiated a generic formulation of ZDV and 7459 (51%) initiated a proprietary formulation. When categorized according to initial dispensation, no difference in post-90-day mortality was observed between the two groups [adjusted hazard ratio (AHR): 0.93, 95% confidence interval (CI): 0.77-1.12]. Similar findings were noted when drug formulation was treated as a time-varying exposure (AHR: 1.15, 95% CI: 0.89-1.48) when analysis was limited to those with a predominant exposure to one formulation or the other (AHR: 0.59, 95% CI: 0.24-1.49). Results were consistent across all approaches when programme failure was considered as an outcome. No longitudinal differences were detected between formulations for CD4 response, weight change and haemoglobin concentration. Generic ZDV formulations were associated with slight decreases in single-drug substitution., Conclusions: In this large programmatic cohort of adults starting ZDV-based first-line therapy, clinical outcomes appeared similar among patients on generic or proprietary formulations. These findings support continued use of generic anti-retroviral drug formulations in resource-constrained settings.

Although the individual-level impact of antiretroviral therapy (ART) is well documented, there are few available data describing the public health impact of services for persons infected with human immunodeficiency virus in resource-constrained settings. We describe the methods and baseline results of a household survey that assessed the population-level impact of the national program for HIV care in Zambia and treatment in the city of Lusaka. The survey was timed with the staggered expansion of services and repeated cross-sectional surveys planned for pre-implementation and post-implementation comparisons made by community. In the initial survey round, which was performed during the early phases of the program (November-December 2004), 18,110 persons were enumerated from 3,600 households surveyed. Respondents were asked questions designed to evaluate community-level mortality and respondent knowledge and attitudes towards HIV. These findings will serve as a reliable reference in the future analysis of the population-level impact of this HIV treatment and care program in Zambia.

Background: High-level adherence to antiretroviral therapy (ART) is associated with favourable patient outcomes. In resource-constrained settings, however, there are few validated measures. We examined the correlation between clinical outcomes and the medication possession ratio (MPR), a pharmacy-based measure of adherence., Methods: We analysed data from a large programmatic cohort across 18 primary care centres providing ART in Lusaka, Zambia. Patients were stratified into three categories based on MPR-calculated adherence over the first 12 months: optimal (> or =95%), suboptimal (80-94%) and poor (<80%)., Results: Overall, 27 115 treatment-naïve adults initiated and continued ART for > or =12 months: 17 060 (62.9%) demonstrated optimal adherence, 7682 (28.3%) had suboptimal adherence and 2373 (8.8%) had poor adherence. When compared with those with optimal adherence, post-12-month mortality risk was similar among patients with sub-optimal adherence [adjusted hazard ratio (AHR) = 1.0; 95% CI: 0.9-1.2] but higher in patients with poor adherence (AHR = 1.7; 95% CI: 1.4-2.2). Those <80% MPR also appeared to have an attenuated CD4 response at 18 months (185 cells/microl vs 217 cells/microl; P < 0.001), 24 months (213 cells/microl vs 246 cells/microl; P < 0.001), 30 months (226 cells/microl vs 261 cells/microl; P < 0.001) and 36 months (245 cells/microl vs 275 cells/microl; P < 0.01) when compared with those above this threshold., Conclusions: MPR was predictive of clinical outcomes and immunologic response in this large public sector antiretroviral treatment program. This marker may have a role in guiding programmatic monitoring and clinical care in resource-constrained settings.

We evaluated the association between two antiretroviral therapy (ART) adherence measurements--the medication possession ratio (MPR) and patient self-report--and detectable HIV viremia in the setting of rapid service scale-up in Lusaka, Zambia. Drug adherence and outcomes were assessed in a subset of patients suspected of treatment failure based on discordant clinical and immunologic responses to ART. A total of 913 patients were included in this analysis, with a median time of 744 days (Q1, Q3: 511, 919 days) from ART initiation to viral load (VL) measurement. On aggregate over the period of follow-up, 531 (58%) had optimal adherence (MPR > or =95%), 306 (34%) had suboptimal adherence (MPR 80-94%), and 76 (8%) had poor adherence (MPR <80%). Of the 913 patients, 238 (26%) had VL > or =400 copies/ml when tested. When compared to individuals with optimal adherence, there was increasing risk for virologic failure in those with suboptimal adherence [adjusted relative risk (ARR): 1.3; 95% confidence interval (CI): 1.0, 1.6] and those with poor adherence (ARR: 1.7; 95% CI: 1.3, 2.4) based on MPR. During the antiretroviral treatment course, 676 patients (74%) reported no missed doses. The proportion of patients with virologic failure did not differ significantly among those reporting any missed dose from those reporting perfect adherence (26% vs. 26%, p = 0.97). Among patients with suspected treatment failure, a lower MPR was associated with higher rates of detectable viremia. However, the suboptimal sensitivity and specificity of MPR limit its utility as a sole predictor of virologic failure.

Background: Zambia faces overlapping tuberculosis (TB) and human immunodeficiency virus (HIV) epidemics; however, care for co-infected patients often occurs through separate, vertical programs., Objective: To establish a program to integrate TB and HIV services in Lusaka primary care centers., Methods: In collaboration with the Zambian Ministry of Health, TB-HIV integration activities began in December 2005 and were expanded to seven health centers by March 2007. Principal activities included developing staff capacity to manage co-infected patients, implementing HIV testing within TB departments and establishing referral systems between departments., Results: Using a provider-initiated approach, 2053 TB patients were offered HIV testing. Seventy-seven per cent agreed to be tested; 69% of those tested were HIV-infected. Of these, 59% were enrolled in HIV care. The proportion of antiretroviral treatment (ART) program enrollees who were TB-HIV co-infected increased by 38% after program implementation. The median CD4 count among co-infected patients was 161 cells/microl, with 88% eligible for ART., Conclusion: Integration of HIV testing and referral services into urban primary care centers identified many co-infected patients and significantly increased the proportion of TB patients among people accessing HIV care. Ongoing challenges include maximizing the number of patients accepting HIV testing and overcoming barriers to enrollment into HIV care.

Despite the availability of antiretroviral prophylaxis, roughly one-fifth of public-sector antenatal patients decline HIV testing in Lusaka, Zambia. We administered a survey to determine individual-level predictors of HIV testing. Of 1064 antenatal attendees approached after pretest counseling, 1060 (>99%) participated. Of these, 686 (65%) agreed to HIV testing. On bivariate analysis controlling for clinic of attendance, women younger than 20 years old (adjusted RR [ARR] = 1.14), unmarried (ARR = 1.14), pregnant for the first time (ARR = 1.14), with lower educational attainment (ARR = 1.15), and with lower income (ARR = 1.14) were all more likely to undergo testing. When HIV risk was considered, women with low self-perceived risk were most likely to undergo HIV testing. As risk perception increased, likelihood for testing decreased (P for trend < 0.001). Although not statistically predictive, we identified prevalent community beliefs that may act as barriers to testing. Because individual-level characteristics were only weakly predictive of HIV testing, future work should concentrate on community-level factors.