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Biomedical subjects

T M Hooton

Publications and source records attributed to T M Hooton.

At least 37 records · Page 2Linked to original sources

Risk factors for HIV-1 shedding in semen.

Semen is the body fluid most commonly associated with sexual transmission of human immunodeficiency virus type-1 (HIV-1). Because the male genitourinary tract is distinct immunologically from blood, compartment-dependent factors may determine HIV-1 shedding in semen. To identify these factors, the authors obtained 411 semen and blood specimens from 149 men seen up to three times. Seminal plasma was assayed for HIV-1 RNA and semen was cocultured for HIV-1 and cytomegalovirus (CMV), which may up-regulate HIV-1 replication. The best multivariate model for predicting a positive semen HIV-1 coculture included two local urogenital factors, increased seminal polymorphonuclear cell count (odds ratio (OR) = 12.6 for each log10 increase/mL, 95% confidence interval (CI) 12.2, 134.5) and a positive CMV coculture (OR = 3.0, 95% CI 1.2, 7.7). The best multivariate model for predicting semen HIV-1 RNA included two systemic host factors, CD4+ cell counts <200/microliter (OR = 3.0, 95 percent CI 1.3, 6.9) and nucleoside antiretroviral therapy (monotherapy: OR = 0.5, 95% CI 0.3, 1.0; combination therapy: OR = 0.4, 95% CI 0.2, 0.9), and a positive CMV coculture (OR = 1.7, 95% CI 1.0, 3.0). Thus, both systemic and local genitourinary tract factors influence the risk of semen HIV-1 shedding. These findings suggest that measures of systemic virus burden alone may not predict semen infectivity reliably.

Adult↗

Effect of trimethoprim-sulfamethoxazole as Pneumocystis carinii pneumonia prophylaxis on bacterial illness, Pneumocystis carinii pneumonia, and death in persons with AIDS.

To measure the effect of trimethoprim-sulfamethoxazole (TMP-SMX) in preventing bacterial illness, Pneumocystis carinii pneumonia (PCP), and death in people with AIDS, we conducted a retrospective medical record review of 1078 persons who were observed for 3 years on average who attended nine outpatient facilities in Seattle, Washington between January 1990 and April 1996. We calculated relative risk estimates to measure the protective effect of TMP-SMX on the development of major bacterial illnesses, PCP, and death. Use of TMP-SMX decreased the risk of PCP (relative risk [RR] = 0.23; 95% confidence interval [CI], 0.14-0.36) and deaths not attributable to PCP (RR = 0.59; 95% CI, 0.47-0.73). Prevention of major bacterial illnesses of known etiology was of borderline significance (RR = 0.77; 95% CI, 0.57-1.05) and became statistically significant with the addition of patients with infections of unknown etiology (RR = 0.77; 95% CI 0.61-0.97). Use of TMP-SMX PCP prophylaxis significantly reduced the risks of death and of PCP and was associated with a trend toward reduced risk of major bacterial infections.

AIDS-Related Opportunistic Infections↗

Practice guidelines for urinary tract infection in the era of managed care.

Acute uncomplicated cystitis among young women is very common, relatively easy to diagnose, and easy to treat with short-course antimicrobial regimens. However, there is great variability among physicians in the approaches to diagnosis and management. Cystitis, therefore, lends itself well to management by clinical practice guidelines which de-emphasize costly office visits, pre-therapy urine cultures and long courses of therapy. As cystitis guidelines continue to be developed by medical care organizations, however, it is important that they be evidence based, include the participation of practicing physicians and provide a mechanism for evaluation to ensure that quality of care and patient satisfaction are not compromised.

Anti-Infective Agents↗

The prevalence of antimicrobial resistance among uropathogens causing acute uncomplicated cystitis in young women.

Four hundred and fifty-two urine isolates from women with acute uncomplicated cystitis and a positive urine culture presenting to a sexually transmitted disease clinic were collected during 1989-1991, and 213 specimens were collected over 1995-1997. The predominant species was Escherichia coli, representing 68% of the isolates; others included Staphylococcus saprophyticus (8%), Group B streptococci (7%), Proteus spp. (6%), Klebsiella spp. (4%) and Enterococcus spp.(3%). More than 10% of the E. coli isolates were resistant to ampicillin, cephalothin, tetracycline and trimethoprim sulfamethoxazole (TMP SMX ) during both study periods, with the greatest increase in resistance to ampicillin and TMP/SMX between the two periods. Six hundred and four urinary tract infection isolates, including 83% E. coli, 7% S. saprophyticus, 3%, Klebsiella spp. 2% Proteus spp., 2% enterococci, 1% Enterobacter spp. and 2% other organisms, were collected from women with acute cystitis attending a university student health service during 1995. Among E. coli isolates, 25% were resistant to ampicillin, 24% to tetracycline and 11%, to TMP SMX. Resistance to fluoroquinolones was essentially absent among gram-negative pathogens. Continued evaluation of susceptibility patterns of pathogens causing acute uncomplicated cystitis to traditional as well as new antimicrobials in well defined populations is necessary to ascertain the optimal empiric therapy.

Acute Disease↗

Thalidomide for the treatment of esophageal aphthous ulcers in patients with human immunodeficiency virus infection. National Institute of Allergy and Infectious Disease AIDS Clinical Trials Group.

A multicenter, double-blind, randomized, placebo-controlled clinical trial was conducted to determine the safety and efficacy of thalidomide for treating esophageal aphthous ulceration in persons infected with human immunodeficiency virus (HIV). Twenty-four HIV-infected patients with biopsy-confirmed aphthous ulceration of the esophagus were randomly assigned to receive either oral thalidomide, 200 mg/day, or oral placebo daily for 4 weeks. Eight (73%) of 11 patients randomized to receive thalidomide had complete healing of aphthous ulcers at the 4-week endoscopic evaluation, compared with 3 (23%) of 13 placebo-randomized patients (odds ratio, 13.82; 95% confidence interval, 1.16-823.75; P=.033). Odynophagia and impaired eating ability caused by esophageal aphthae were improved markedly by thalidomide treatment. Adverse events among patients receiving thalidomide included somnolence (4 patients), rash (2 patients), and peripheral sensory neuropathy (3 patients). Thalidomide is effective in healing aphthous ulceration of the esophagus in patients infected with HIV.

Acquired Immunodeficiency Syndrome↗

Atovaquone compared with dapsone for the prevention of Pneumocystis carinii pneumonia in patients with HIV infection who cannot tolerate trimethoprim, sulfonamides, or both. Community Program for Clinical Research on AIDS and the AIDS Clinical Trials Group.

BACKGROUND: Although trimethoprim-sulfamethoxazole is the drug of choice for the prevention of Pneumocystis carinii pneumonia, many patients cannot tolerate it and must switch to an alternative agent. METHODS: We conducted a multicenter, open-label, randomized trial comparing daily atovaquone (1500-mg suspension) with daily dapsone (100 mg) for the prevention of P. carinii pneumonia among patients infected with the human immunodeficiency virus who could not tolerate trimethoprim-sulfamethoxazole. The median follow-up period was 27 months. RESULTS: Of 1057 patients enrolled, 298 had a history of P. carinii pneumonia. P. carinii pneumonia developed in 122 of 536 patients assigned to atovaquone (15.7 cases per 100 person-years), as compared with 135 of 521 in the dapsone group (18.4 cases per 100 person-years; relative risk for atovaquone vs. dapsone, 0.85; 95 percent confidence interval, 0.67 to 1.09; P=0.20). The relative risk of death was 1.07 (95 percent confidence interval, 0.89 to 1.30; P=0.45), and the relative risk of discontinuation of the assigned medication because of adverse events was 0.94 (95 percent confidence interval, 0.74 to 1.19; P=0.59). Among the 546 patients who were receiving dapsone at base line, the relative risk of discontinuation because of adverse events was 3.78 for atovaquone as compared with dapsone (95 percent confidence interval, 2.37 to 6.01; P<0.001); among those not receiving dapsone at base line, it was 0.42 (95 percent confidence interval, 0.30 to 0.58; P<0.001). CONCLUSIONS: Among patients who cannot tolerate trimethoprim-sulfamethoxazole, atovaquone and dapsone are similarly effective for the prevention of P. carinii pneumonia. Our results support the continuation of dapsone prophylaxis among patients who are already receiving it. However, among those not receiving dapsone, atovaquone is better tolerated and may be the preferred choice for prophylaxis against P. carinii pneumonia.

AIDS-Related Opportunistic Infections↗

A phase II/III trial of antimicrobial therapy with or without amikacin in the treatment of disseminated Mycobacterium avium infection in HIV-infected individuals. AIDS Clinical Trials Group Protocol 135 Study Team.

OBJECTIVE: To determine the clinical and microbiologic benefit of adding amikacin to a four-drug oral regimen for treatment of disseminated Mycobacterium avium infection in HIV-infected patients. DESIGN: A randomized, open-labeled, comparative trial. SETTING: Outpatient clinics. PATIENTS: Seventy-four patients with HIV and symptomatic bacteremic M. avium infection. INTERVENTIONS: Rifampin 10 mg/kg daily, ciprofloxacin 500 mg twice daily, clofazimine 100 mg every day, and ethambutol 15 mg/kg orally daily for 24 weeks, with or without amikacin 10 mg/kg intravenously or intramuscularly 5 days weekly for the first 4 weeks. MAIN OUTCOME MEASURE: Clinical and microbiologic response at 4 weeks; quantitative level of bacteremia with M. avium. RESULTS: No difference in clinical response was noted with the addition of amikacin to the four-drug oral regimen, and only 25% in either group had a complete or partial response at 4 weeks. A comparable quantitative decrease in bacteremia was noted in both treatment groups, with 16% of patients being culture-negative at 4 weeks and 38% at 12 weeks. Toxicities were mainly gastrointestinal. Amikacin was well tolerated. Median survival was 30 weeks in both groups. CONCLUSIONS: The addition of amikacin to a four-drug oral regimen of rifampin, ciprofloxacin, clofazimine, and ethambutol did not provide clinical or microbiologic benefit.

AIDS-Related Opportunistic Infections↗

Etiology of nongonococcal nonchlamydial urethritis.

The majority of cases of acute nongonococcal urethritis (NGU) are due to causes other than infection with Chlamydia trachomatis. Pathogens implicated as causes of nonchlamydial nongonococcal urethritis (NCNGU) include Mycoplasma genitalium, Ureaplasma urealyticum, Trichomonas vaginalis, and primary infection with herpes simplex virus. In a majority of cases of acute NCNGU, no pathogen can be isolated. The etiology of chronic NCNGU is unknown.

Acute Disease↗

Association between culturable human immunodeficiency virus type 1 (HIV-1) in semen and HIV-1 RNA levels in semen and blood: evidence for compartmentalization of HIV-1 between semen and blood.

Both qualitative and quantitative virologic measurements were compared between blood and genital compartments for 128 men infected with human immunodeficiency virus type 1 (HIV-1) to address several controversial issues concerning HIV-1 shedding in semen and to obtain further information about the distribution of virus between these two compartments. Evidence for viral compartmentalization was suggested by earlier studies that noted the poor correlation between blood and seminal virus load, phenotype, and genotype. Further support for this viral compartmentalization was based on the following observations between semen and blood: lack of association between culturability of virus in semen and viral RNA level in blood, discordant distribution of viral phenotypes, discordant viral RNA levels, a weak correlation between viral RNA level in semen and CD4 cell count in blood, differences in the biologic variability of viral RNA levels, and differences in the virus load response to antiretroviral therapy.

Adult↗

Inverse association of H2O2-producing lactobacilli and vaginal Escherichia coli colonization in women with recurrent urinary tract infections.

Women with recurrent urinary tract infection (UTI) often demonstrate persistent vaginal colonization with Escherichia coli. Since strains of lactobacilli that produce hydrogen peroxide inhibit the growth of E. coli, the absence of these strains may predispose to E. coli colonization and to UTI. To test this hypothesis, vaginal introital cultures were obtained from 140 women, 65 with recurrent UTI (case-patients) and 75 without (controls). Vaginal E. coli colonization was significantly more frequent in case-patients than controls (35% vs. 11%; P < .001) and in women without H2O2-positive lactobacilli than in women with (odds ratio [OR], 4.0; P = .01). Spermicide use was associated with greater risk of vaginal E. coli colonization (OR, 12.5; P < .001) and with absence of H2O2-positive lactobacilli (OR, 2.9; P = .04). The inverse association between H2O2-positive lactobacilli and vaginal E. coli colonization remained in case-patients after controlling for spermicide use (OR, 6.5; P = .02). Thus, absence of H2O2-positive lactobacilli may be important in the pathogenesis of recurrent UTI by facilitating E. coli introital colonization.

Adult↗

Diagnosis and treatment of uncomplicated urinary tract infection.

Acute uncomplicated urinary tract infection is one of the most common problems for which young women seek medical attention and accounts for considerable morbidity and health care costs. Acute cystitis or pyelonephritis in the adult patient should be considered uncomplicated if the patient is not pregnant or elderly, if there has been no recent instrumentation or antimicrobial treatment, and if there are no known functional or anatomic abnormalities of the genitourinary tract. Most of these infections are caused by E. coli, which are susceptible to many oral antimicrobials, although resistance is increasing to some of the commonly used agents. Review of the published data suggests that a 3-day regimen is more effective than a single-dose regimen for all antimicrobials tested. Regimens with trimethoprim-sulfamethoxazole seem to be more effective than those with beta lactams, regardless of the duration. Because of increasing resistance to trimethoprim-sulfamethoxazole, an alternative regimen such as nitrofurantoin (in a 7-day regimen), a fluoroquinolone, or an oral third-generation cephalosporin may be a better empiric choice in some areas. Acute pyelonephritis caused by highly virulent uropathogens in an otherwise healthy woman may be considered an uncomplicated infection. The optimal treatment duration for acute uncomplicated pyelonephritis has not been established, but 10- to 14-day regimens are recommended. We prefer to use antimicrobials that attain high renal tissue levels, such as a fluoroquinolone, trimethoprim-sulfamethoxazole, or an aminoglycoside, for pyelonephritis. Acute uncomplicated cystitis or pyelonephritis in healthy adult men is uncommon but is generally caused by the same spectrum of uropathogens with the same antimicrobial susceptibility profile as that seen in women.

Adult↗

Antecedent antimicrobial use increases the risk of uncomplicated cystitis in young women.

To examine whether antecedent antimicrobial use influenced subsequent relative risk of urinary tract infection (UTI) in premenopausal women, data were analyzed from two cohorts of women observed prospectively for 6 months to determine risk factors for UTI. Using a Cox proportional hazards model to adjust for covariates, we found that 326 women in a University cohort and 425 women in a health-maintenance organization cohort were at increased risks for UTI (2.57 [95% confidence interval (CI), 1.24-5.32] and 5.83 [95% CI, 3.17-10.70], respectively) if antimicrobials had been taken during the previous 15-28 days but not during the previous 3, 7, or 14 days. The increased risks were noted both for women whose antimicrobial use was for treatment of a previous UTI and for women who received antimicrobials for other illnesses. These results suggest that recent antimicrobial use increases a woman's risk of UTI, perhaps by altering the indigenous urogenital flora and predisposing to vaginal colonization with uropathogens.

Adolescent↗

Bacterial infections in adult patients hospitalized with AIDS: case-control study of prophylactic efficacy of trimethoprim-sulfamethoxazole versus aerosolized pentamidine.

To determine the association between trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis for Pneumocystis carinii pneumonia and risk of bacterial infections in persons with AIDS, we abstracted hospital records from 6496 adult admissions to 42 hospitals in western Washington state. Of these admissions, 570 involved 637 bacterial infections diagnosed among patients who had been prescribed prophylactic TMP-SMX or aerosolized pentamidine. Cases [admissions with bacteraemia, bacterial pneumonia, acute or chronic sinusitis, or urinary tract infection (UTI)] were compared to controls (admissions not associated with any of the 5 bacterial infections). After adjusting for CD4 lymphocyte count and presence of P. carinii pneumonia, TMP-SMX prophylaxis, relative to aerosolized pentamidine prophylaxis, was associated with a reduced risk of bacteraemia (adjusted OR = 0.5; 95% CI, 0.2-1.0; P = 0.04), bacterial pneumonia (adjusted OR = 0.5; 95% CI, 0.3-0.8; P = 0.01), acute sinusitis (adjusted OR = 0.5; 95% CI, 0.2-1.3; P = 0.2), chronic sinusitis (adjusted OR = 0.3; 95% CI, 0.1-0.7; P = 0.01), and UTI (adjusted OR = 0.5; 95% CI, 0.2-1.2; P = 0.1), and all 5 bacterial infections combined (adjusted OR = 0.6; 95% CI, 0.5-0.8; P < 0.001).

AIDS-Related Opportunistic Infections↗

A prospective study of risk factors for symptomatic urinary tract infection in young women.

BACKGROUND: Although acute urinary tract infections are common in young women, the associated risk factors have not been defined prospectively. METHODS: We recruited sexually active young women who were starting a new method of contraception at a university health center or a health maintenance organization (HMO) and monitored them for six months for symptomatic urinary tract infections. Daily diaries and serial interviews were used to collect data on potential risk factors. RESULTS: Among 796 women, the incidence of urinary tract infections per person-year was 0.7 in the university cohort (mean age, 23 years; n = 348) and 0.5 in the HMO cohort (mean age, 29; n = 448). In both cohorts, there were strong dose-response relations between the risk of infection and both recent use of a diaphragm with spermicide (respective relative risks for one, three, and five days of use in the past week, 1.42, 2.83, and 5.68 in the university cohort, P<0.001; and 1.29, 2.14, and 3.54 in the HMO cohort, P=0.04) and recent sexual intercourse (respective relative risks for one, three, and five days with intercourse in the past week, 1.37, 2.56, and 4.81 in the university cohort, P<0.001; and 1.24, 1.91, and 2.96 in the HMO cohort, P=0.002). The risk of acute infection was also associated with a history of recurrent infection (relative risk, 5.58 in the university group and 2.10 in the HMO group) but not with cervical-cap use, ABO-blood-group nonsecretor phenotype, or delayed postcoital voiding. CONCLUSIONS: Among sexually active young women the incidence of symptomatic urinary tract infection is high, and the risk is strongly and independently associated with recent sexual intercourse, recent use of a diaphragm with spermicide, and a history of recurrent urinary tract infections.

Acute Disease↗

Frequency of thyroid disease among Southeast Asian primary care patients.

We prospectively assessed 99 Southeast Asians for the presence of thyroid disease who were attending a primary care clinic devoted to the care of refugees. Subjects were undergoing evaluation as new patients and had no previously diagnosed thyroid abnormality. Each patient had a physical examination performed by his or her primary-care provider, was given a standardized questionnaire that focused on symptoms of thyroid disease and underwent a venipuncture for total thyroxine, triiodothyronine resin uptake and thyrotropin (TSH) concentration. Those who had an abnormal examination, calculated free thyroxine index (FT4I) or TSH level were re-examined by an endocrinologist and had repeat thyroid studies performed. Although 81% of patients reported > or = 1 symptom compatible with thyroid dysfunction, only 17% were found to have laboratory abnormalities. An abnormal FT4I and TSH level was found in 5% and 13% of subjects, respectively, but only one case of clinically significant hyperthyroidism and no cases of hypothyroidism were confirmed. TSH suppression, noted in 12% of subjects, persisted over a median follow-up of 6 months. Among seven patients with an anatomic abnormality of the thyroid, four had an abnormal FT4I or TSH. We conclude that the clinical prevalence of symptomatic thyroid dysfunction among Southeast Asians is comparable to that reported for non-Asian populations, but that the frequency of subclinical hyperthyroidism may be higher. Although symptoms suggestive of thyroid disease are common, routine screening for thyroid disease is not indicated in this study.

Adult↗

Evaluation of an extended blood culture protocol to isolate fastidious organisms from patients with AIDS.

Recent reports of fastidious pathogens suggest the need for special blood cultures for immunocompromised patients. Blood cultures from 45 human immunodeficiency virus (HIV)-infected patients with unexplained fever (> or = 38.0 degrees C) and CD4 counts of < 125 cells per mm3 were collected into a vacuum tube with sodium polyanetholsulfonate, an Isolator tube, and BACTEC aerobic and anaerobic bottles. Blood from the sodium polyanethosulfonate tube was inoculated into BACTEC 13A bottles, which were read weekly for 16 weeks. Isolator sediment was divided among eight agar media, including four sheep blood agar media: chocolate agar, brain heart infusion blood agar, heart infusion blood agar, and brucella blood agar. Other agar plates included Sabouraud's, buffered charcoal-yeast extract, Middlebrook 7H11 (M7H11) with hemoglobin, and M7H11 with mycobactin J. Incubation conditions included air and CO2-enriched aerobic, microaerophilic, and anaerobic atmospheres. Aerobic BACTEC broths received an acridine orange stain on day 8 and were subcultured at 2, 4, and 8 weeks. Anaerobic BACTEC bottles were subcultured at 4 weeks. All solid media, including subcultures, were incubated for 8 weeks, providing a total of 16 weeks of incubation for each specimen. Clinically significant isolates included eight Mycobacterium avium complex isolates and one each of Bartonella henselae, Bartonella quintana, Shigella flexneri, Klebsiella oxytoca, and Cryptococcus neoformans. All isolates were detected with commercially available media and, with the exception of Bartonella spp., were recovered within incubation times routinely used in most clinical laboratories.

Acquired Immunodeficiency Syndrome↗