Sub-City Scale Hourly Air Quality Forecasting by Combining Models, Satellite Observations, and Ground Measurements.

While multiple information sources exist concerning surface-level air pollution, no individual source simultaneously provides large-scale spatial coverage, fine spatial and temporal resolution, and high accuracy. It is, therefore, necessary to integrate multiple data sources, using the strengths of each source to compensate for the weaknesses of others. In this study, we propose a method incorporating outputs of NASA's GEOS Composition Forecasting model system with satellite information from the TROPOMI instrument and ground measurement data on surface concentrations. Although we use ground monitoring data from the Environmental Protection Agency network in the continental United States, the model and satellite data sources used have the potential to allow for global application. This method is demonstrated using surface measurements of nitrogen dioxide as a test case in regions surrounding five major US cities. The proposed method is assessed through cross-validation against withheld ground monitoring sites. In these assessments, the proposed method demonstrates major improvements over two baseline approaches which use ground-based measurements only. Results also indicate the potential for near-term updating of forecasts based on recent ground measurements.

Risk of cardiovascular disease in HIV, hepatitis C, or HIV/hepatitis C patients compared to the general population.

BACKGROUND: As a result of effective antiretroviral therapy HIV patients are living longer, and their risk of cardiovascular disease (CVD) is a growing concern. It remains unknown whether coinfection with hepatitis C (HCV) changes an HIV person's CVD risk, and how the risks compare to the general population. The objective of this study was to compare the Framingham Risk Score (FRS) and vascular age differences in persons with HIV, HCV or HIV/HCV disease to the general population. METHODS: HIV, HCV, and HIV/HCV patients with clinic visits between 2004 and 2009 were sampled from medical clinics in Rochester, NY. Uninfected persons were randomly selected from the National Health and Nutrition Examination Survey (NHANES), and individually matched on gender, race, and age. We stratified by infection group and conducted separate multivariable linear regression analyses between each infection group and the gender, race, and age matched participants from NHANES. RESULTS: Rochester patients (HIV = 239, HCV = 167, HIV/HCV = 182) were compared 3 : 1 with the NHANES participants. After controlling for weight, marital status, current pharmacotherapies and the matching variables of gender, race, and age, HIV/HCV patients had a 2% higher general FRS compared with the general population (p = 0.03), and vascular age differences that were 4.1 years greater (p = .01). HCV patients had a 2.4% higher general FRS than the general population (p < .001), and vascular age differences that were 4.4 years greater (p < .001). CVD risk was elevated but not significantly different between HIV patients and the general population. CONCLUSION: Cardiovascular disease risk is elevated among HIV/HCV and HCV infected persons compared with the general population.

Upper gastrointestinal bleeding in haemophiliacs: incidence and relation to use of non-steroidal anti-inflammatory drugs.

This multicentre study sought to estimate the incidence of upper gastrointestinal (UGI) bleeding in haemophiliacs and its relationship to use of non-steroidal anti-inflammatory drugs (NSAIDs). Cox models were used to estimate relative hazards (RH) with 95% confidence intervals (CI) for postulated risk factors. Conditional logistic regression and stored sera were used to assess UGI bleeding risk with Heliobacter pylori seropositivity in cases compared with closely matched controls. During a mean of 17.4 months (range 2-34), 2285 participants, ages 13-89 (mean 36.5) were followed for 3309 person-years (py). Forty-two experienced a UGI bleeding event (incidence 1.3 per 100 py), most from ulcer (11), gastritis (four), varices (five) and Mallory Weiss tears (eight). RH was significantly increased with traditional NSAID use for <1 month (OR: 3.66; 95% CI: 1.1-11.9), but not with coxibs use. RH was significantly and independently increased with age >46 years (3.5; 95% CI: 1.1-10.6) and hepatic decompensation (4.4; 95% CI: 1.7-11.6). Likelihood of bleeding was substantially but not significantly increased (OR: 4.6; 95% CI: 0.3-83.9) with H. pylori seropositivity. These findings suggest that coxibs are a safer alternative than traditional NSAIDs in the treatment of haemophilic arthropathy.

Depo-medroxyprogesterone in women on antiretroviral therapy: effective contraception and lack of clinically significant interactions.

We conducted an open-label, steady-state pharmacokinetic (PK) study of drug interactions among HIV-infected women treated with depo-medroxyprogesterone acetate (DMPA) while on nucleoside analogues plus nelfinavir (N=21), efavirenz (N=17), or nevirapine (N=16); or nucleosides only or no antiretroviral therapy as a control group (N=16). PK parameters were estimated using non-compartmental analysis, with between-group comparisons of medroxyprogesterone acetate (MPA) PKs and within-subject comparisons of ARV PKs before and 4 weeks after DMPA dosing. Plasma progesterone levels were measured at baseline and at 2, 4, 6, 8, 10, and 12 weeks after DMPA dosing. There were no significant changes in MPA area under the concentration curve, peak or trough concentrations, or apparent clearance in the nelfinavir, efavirenz, or nevirapine groups compared to the control group. Minor changes in nelfinavir and nevirapine drug exposure were seen after DMPA, but were not considered clinically significant. Suppression of ovulation was maintained.

Lupus-like nephritis in an HIV-positive patient: report of a case and review of the literature.

The most common manifestation of HIV/AIDS in the kidney is the collapsing variant of focal segmental glomerular sclerosis, HIV-associated nephropathy (HIVAN). Other forms of renal disease in HIV-infected patients include mesangial proliferative glomerulonephritis (GN), membranoproliferative GN, IgA nephropathy, minimal change disease and proliferative immune-complex GN. We present the case of a 42-year-old Caucasian male with HIV infection, treatment associated peripheral neuropathy, nephrotic syndrome and progressive renal failure. The initial and subsequent kidney biopsies showed diffuse proliferative glomerulonephritis resembling diffuse proliferative (WHO class IV) lupus nephritis. There was no clinical or serological evidence of systemic lupus erythematosus (SLE). Proteinuria improved with ACE-inhibitors, and renal function remained relatively stable while receiving highly active antiretroviral therapy (HAART). A precipitous decline in renal function to end-stage renal disease followed a brief period of withdrawal from potent antiretroviral therapy during which the viral load rebounded. Considering previously reported cases, it appears that lupus-like nephritis is a rare but well-defined pattern of immune-complex-induced renal injury seen in HIV-infected patients. It appears to be markedly responsive to HAART.

Development and validation of a self-completed HIV symptom index.

Traditional, open-ended provider questions regarding patient symptoms are insensitive. Better methods are needed to measure symptoms for clinical management, patient-oriented research, and adverse drug-event reporting. Our objective was to develop and initially validate a brief, self-reported HIV symptom index tailored to patients exposed to multidrug antiretroviral therapies and protease inhibitors, and to compare the new index to existing symptom measures. The research design was a multistage design including quantitative review of existing literature, qualitative and quantitative analyses of pilot data, and quantitative analyses of a prospective sample. Statistical analyses include frequencies, chi-square tests for significance, linear and logistic regression. The subjects were from a multisite convenience sample (n = 73) within the AIDS Clinical Trials Group and a prospective sample from the Cleveland Veterans Affairs Medical Center (n = 115). Measures were patient-reported symptoms and health-related quality of life, physician-assessed disease severity, CD4 cell count, and HIV-1 RNA viral quantification. A 20-item, self-completed HIV symptom index was developed based upon prior reports of symptom frequency and bother and expert opinion. When compared with prior measures the index included more frequent and bothersome symptoms, yet was easier to use (self-report rather than provider interview). The index required less than 5 minutes to complete, achieved excellent completion rates, and was thought comprehensive and comprehensible in a convenience sample. It was further tested in a prospective sample of patients and demonstrated strong associations with physical and mental health summary scores and with disease severity. These associations were independent of CD4 cell count and HIV-1 RNA viral quantification. This 20-item HIV symptom index has demonstrated construct validity, and offers a simple and rational approach to measuring HIV symptoms for clinical management, patient-oriented research, and adverse drug reporting.

The care of HIV-infected adults in rural areas of the United States.

OBJECTIVE: This study describes the population of HIV-infected adults receiving care in rural areas of the United States and compares HIV care received in rural and urban areas. METHODS: Interviews were conducted with a nationally representative sample of 367 HIV-infected adults receiving health care in rural areas and 2806 HIV-infected adults receiving health care in urban areas of the contiguous United States. RESULTS: We estimate that 4800 HIV-infected persons received medical care in rural areas during the first half of 1996. Patients in rural HIV care were more likely than patients in urban HIV care to receive care from providers seeing few (<10) HIV-infected patients (38% vs. 3%; p <.001). Rural care patients were less likely than urban care patients to have taken highly active antiretroviral agents (57% vs. 73%; p <.001) or Pneumocystis carinii pneumonia prophylactic medication when indicated (60% vs. 75%; p =.006). CONCLUSIONS: Few American adults received HIV care in rural areas of the United States. Our findings suggest ongoing disparities between urban and rural areas in access to high-quality HIV care.

Skin test reactivity and cellular immune responses to Mycobacterium avium sensitin in AIDS patients at risk for disseminated M. avium infection.

Skin tests and lymphocyte proliferation assays (LPA) were performed with Mycobacterium avium sensitin on patients with AIDS. Among 139 subjects, 13% had positive skin test results and 32% had positive LPA results. The LPA may be a more sensitive indicator of prior M. avium infection in this population.

Discontinuation of Mycobacterium avium complex prophylaxis in patients with antiretroviral therapy-induced increases in CD4+ cell count. A randomized, double-blind, placebo-controlled trial. AIDS Clinical Trials Group 362 Study Team.

BACKGROUND: Patients infected with HIV who experience increases in CD4(+) cell counts are at reduced risk for opportunistic infections. However, the safety of discontinuing prophylaxis against Mycobacterium avium complex has been uncertain. OBJECTIVE: To compare the rate of M. avium complex infection in patients with increased CD4(+) cell counts who receive azithromycin and those receiving placebo. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: 29 university-based clinical centers in the United States. PARTICIPANTS: 643 HIV-1-infected patients with a previous CD4(+) cell count less than 0.05 x 10(9) cells/L and a sustained increase to greater than 0.10 x 10(9) cells/L during antiretroviral therapy. INTERVENTION: Azithromycin, 1200 mg once weekly (n = 321), or matching placebo (n = 322). MEASUREMENTS: Mycobacterium avium complex cultures, CD4(+) cell counts, and clinical evaluations for AIDS-defining illnesses and bacterial infections were done every 8 weeks. Plasma HIV-1 RNA levels were measured at 16-week intervals. RESULTS: During follow-up (median, 16 months), 2 cases of M. avium complex infection were reported among the 321 patients assigned to placebo (incidence rate, 0.5 event per 100 person-years [95% CI, 0.06 to 1.83 events per 100 person-years]) compared with no cases among the 322 patients assigned to azithromycin (CI, 0 to 0.92 events per 100 person-years), resulting in a treatment difference of 0.5 event per 100 person-years (CI, -0.20 to 1.21 events per 100 person-years) for placebo versus azithromycin. Both cases were atypical in that M. avium complex was localized to the vertebral spine. Patients receiving azithromycin were more likely than those receiving placebo to discontinue treatment with the study drug permanently because of adverse events (8% vs. 2%; hazard ratio, 0.24 [CI, 0.10 to 0.57]). CONCLUSIONS: Prophylaxis against Mycobacterium avium complex can safely be withdrawn or withheld in adults with HIV infection who experience increases in CD4(+) cell count while receiving antiretroviral therapy.

Refractory mucosal candidiasis in advanced human immunodeficiency virus infection.

We conducted a multicenter, prospective study of the risk factors, natural history, and outcome of fluconazole-refractory mucosal candidiasis (FRMC) in 832 persons with advanced human immunodeficiency virus (HIV) infection (median CD4 cell count, 14/mm3) during 1994-1996. FRMC was defined as mucosal candidiasis that failed to resolve despite 14 days of therapy with daily doses (> or =200 mg) of fluconazole. Thirty-six persons (4.3%) had FRMC (35, oral; 1, esophageal), for an incidence of 4.2 per 100 person-years (859.7 total years of follow-up). In a multivariate model, the use of trimethoprim-sulfamethoxazole within 6 months of enrollment (relative risk [RR], 2.39; P=.04) and the use of fluconazole daily or every other day (RR, 5.64; P=.004) were significantly associated with the development of FRMC. The median survival after the development of FRMC was 32.6 weeks. In conclusion, the annual incidence of FRMC was <5%. Refractory candidiasis was a poor prognostic indicator. Daily or every-other-day use of fluconazole was associated with the development of refractory infection.

National probability samples in studies of low-prevalence diseases. Part II: Designing and implementing the HIV cost and services utilization study sample.

OBJECTIVE: The design and implementation of a nationally representative probability sample of persons with a low-prevalence disease, HIV/AIDS. DATA SOURCES/STUDY SETTING: One of the most significant roadblocks to the generalizability of primary data collected about persons with a low-prevalence disease is the lack of a complete methodology for efficiently generating and enrolling probability samples. The methodology developed by the HCSUS consortium uses a flexible, provider-based approach to multistage sampling that minimizes the quantity of data necessary for implementation. STUDY DESIGN: To produce a valid national probability sample, we combined a provider-based multistage design with the M.D.-colleague recruitment model often used in non-probability site-specific studies. DATA COLLECTION: Across the contiguous United States, reported AIDS cases for metropolitan areas and rural counties. In selected areas, caseloads for known providers for HIV patients and a random sample of other providers. For selected providers, anonymous patient visit records. PRINCIPAL FINDINGS: It was possible to obtain all data necessary to implement a multistage design for sampling individual HIV-infected persons under medical care with known probabilities. Taking account of both patient and provider nonresponse, we succeeded in obtaining in-person or proxy interviews from subjects representing over 70 percent of the eligible target population. CONCLUSIONS: It is possible to design and implement a national probability sample of persons with a low-prevalence disease, even if it is stigmatized.

Gender differences in early suspicion of tuberculosis in hospitalized, high-risk patients during 4 epidemic years, 1987 to 1990.

OBJECTIVES: To assess the degree to which, from 1987 to 1990, physicians suspected tuberculosis (TB) in the first 2 hospital days in human immunodeficiency virus (HIV)-infected patients with pulmonary disease. DESIGN: Retrospective cohort study. SETTING: 96 hospitals in five US cities. PATIENTS: 2,174 adult patients with acquired immunodeficiency syndrome discharged with a diagnosis of Pneumocystis carinii pneumonia from 1987 to 1990. The diagnosis generally was not known on admission. RESULTS: Physicians suspected TB in the first 2 hospital days in 66% of these patients in 1987, a rate that increased steadily to 74% in 1990. However, the extent to which physicians considered TB among female patients decreased from 76% to 71% over the 4 years. Controlling for confounding variables by multiple logistic regression, the odds that TB would be suspected early increased 1.8-fold among men (odds ratio [OR], 1.8; 95% confidence interval [CI95], 1.4-2.4), but not in women (OR, 0.6; CI95, 0.2-1.9). Among the five cities, the odds of early suspicion of TB increased most in New York City (OR, 3.9; CI95, 2.0-7.9). CONCLUSIONS: Physicians considered TB in a timely manner in an increasing majority of male, but not female, high-risk patients during the first years of TB resurgence in the United States. Physicians must be aware of the changing epidemiology of HIV and TB, as well as their practice patterns, to prevent nosocomial transmission of this disease.

Geographic variation in the management and outcome of patients with AIDS-related Pneumocystis carinii pneumonia.

Pneumocystis carinii pneumonia (PCP) is one of the most common reasons for the hospitalization of AIDS patients; however, geographic differences in PCP management have not been evaluated previously. Therefore, we abstracted data on socioeconomic characteristics, prior HIV care, severity of illness, timeliness and intensity of in-hospital care, duration of hospitalization, and survival from 1547 randomly selected medical records of patients hospitalized with AIDS-related PCP between 1987 and 1990 at 82 hospitals in Chicago, Los Angeles, Miami, New York City, and Raleigh-Durham, North Carolina. Multivariate regression models were used to assess factors associated with longer hospital stays and increased inpatient mortality. Our results showed that in-hospital mortality ranged from 15% to 27%, bronchoscopy rates from 53% to 70%, and mean length of stay from 14 days to 23 days. Geographic variations in mortality were accounted for by differences in severity of illness at admission, insurance status, and in-hospital patient management. However, significant regional variations in hospital length of stay persisted, even after adjusting for patient demographics, severity of illness, and use of diagnostic and therapeutic care resources.

Idiopathic genital ulcers in women infected with human immunodeficiency virus.

A national survey of investigators caring for human immunodeficiency virus (HIV)-infected women was undertaken to describe the clinical presentation of idiopathic genital ulcer disease. Patients with negative syphilis and herpes simplex testing and/or negative genital ulcer biopsy were included in this study. Study participants (n = 29) were generally severely immunocompromised (median CD4 cell count was 50/mm3, and 68% had an acquired immunodeficiency syndrome [AIDS]-defining opportunistic process). Thirty-seven percent had coexistent oral ulcers and 19% had their genital ulcer progress to fistula formation (four rectovaginal and one vaginal-perineal). There was generally a favorable response to topical, systemic, and intralesional steroid treatment. This study suggests that idiopathic or probable aphthous genital ulcers in women have similar clinical characteristics to aphthous oroesophageal ulcers. Although infrequent, these genital ulcers can cause severe morbidity. Further research is warranted to better define the pathophysiology and optimal management.

Predictors of resource utilization for hospitalized patients with Pneumocystis carinii pneumonia (PCP): a summary of effects from the multi-city study of quality of PCP care.

To determine whether patient and hospital characteristics were significantly associated with variations in Pneumocystis carinii (PCP) care and outcomes, we analyzed the use of diagnostic tests, intensive care units (ICUs), anti-PCP medications for persons hospitalized with human immunodeficiency virus (HIV)-related PCP, and hospital discharge status. We conducted retrospective chart reviews of a cohort of 2,174 patients with PCP hospitalized in 1987-1990. Outcomes included process of care for PCP and in-hospital mortality rates. Persons with PCP who were more severely ill at admission were more likely to have early medical care, to receive care in an intensive care unit, and to die in hospital. After we adjusted for differences in this severity of illness, we noted that Medicaid patients, injection drug users (IDUs), and patients treated at VA or county hospitals were significantly less likely than others to have diagnostic bronchoscopies and that persons covered by Medicaid, with a previous diagnosis of acquired immunodeficiency syndrome (AIDS), who did not receive prior zidovudine (AZT) or who received care in a VA hospital had the highest chances of in-hospital death. Insurance and risk group characteristics, severity of illness, and hospital characteristics appear to be the most important determinants of the intensity and timing of medical care and outcomes among patients hospitalized with PCP.