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Biomedical subjects

A R Ronald

Publications and source records attributed to A R Ronald.

At least 73 records · Page 4Linked to original sources
PubMed1988

Infection and disease after perinatal exposure to Chlamydia trachomatis in Nairobi, Kenya.

A cohort of 49 infants exposed to maternal chlamydial infection and 40 nonexposed infants was studied after birth for a mean of 3.3 +/- 1.5 and 3 +/- 1.7 mo, respectively. Eighteen (37%) exposed infants had at least one positive culture for Chlamydia trachomatis, whereas C. trachomatis was not isolated from any of the nonexposed infants. Eighteen (37%) exposed infants developed ophthalmia neonatorum (n = 12) or infant conjunctivitis (n = 7), compared with six (15%) of the nonexposed infants (P = .04). Six (12%) exposed infants developed pneumonia, compared with none of the 40 nonexposed infants (P = .05). One infant in the exposed group died during follow-up. These results suggest that appreciable infant morbidity in Kenya may be associated with the high prevalence of maternal chlamydial infection.

Chlamydia Infections↗
PubMed1988

Genital ulceration as a risk factor for human immunodeficiency virus infection.

Among 115 heterosexual men who presented with genital ulcers to a sexually transmitted disease clinic in Nairobi, Kenya, the prevalence of serum antibody to HIV was 16.5%. A past history of genital ulcers was reported by 12 (63%) of 19 men with antibody to HIV versus 30 (31%) of 96 without antibody (P = 0.008). HIV infection was also positively associated with lack of circumcision, but was not associated with the etiology of the current genital ulcer. Logistic regression analysis (adjusted for age, number of recent sex partners, recent prostitute contact, circumcision, tribal ethnic identity, past history of urethritis, and current diagnoses) confirmed only the association between prior history of genital ulcer disease and HIV infection; (P = 0.04, odds ratio 2.35, 95% confidence limits, 1.01-5.47). The incidence of genital ulcers, particularly chancroid, is much higher in parts of Africa than in Europe or North America. This may contribute to the increased risk of heterosexual transmission of HIV in Africa. Aggressive control of chancroid and syphilis may offer one very feasible approach to reducing transmission of HIV in this region.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Double-blind, randomized comparison of 24 weeks of norfloxacin and 12 weeks of norfloxacin followed by 12 weeks of placebo in the therapy of complicated urinary tract infection.

We evaluated the benefits of prolonging norfloxacin therapy from 12 to 24 weeks for complicated urinary tract infection in a double-blind, randomized, placebo-controlled study. During the second 12 weeks, norfloxacin was superior to placebo (P less than 0.05) in suppressing bacteriuria. Adverse effects were common but mostly confined to the initial 12 weeks.

Bacteriuria↗
PubMed1988

Treating chancroid with enoxacin.

Increasing resistance of Haemophilus ducreyi to antimicrobials necessitates further trials of new antimicrobial agents for treating chancroid. Enoxacin has excellent in vitro activity against H ducreyi, and a randomised clinical trial of three doses of enoxacin 400 mg at intervals of 12 hours compared with a single dose of trimethoprim/sulphametrole (TMP/SMT) 640/3200 mg was therefore conducted. Of 169 men enrolled in the study, 86 received enoxacin and 83 received TMP/SMT. Ulcers were improved or cured in 65/73 men treated with enoxacin and 57/70 men treated with TMP/SMT. This difference was not significant. At 72 hours after treatment, H ducreyi was eradicated from ulcers of 72/77 men treated with enoxacin and of 67/74 of those treated with TMP/SMT. Patients with buboes responded equally well to both treatments. Of 100 H ducreyi strains tested, all were susceptible to both 0.25 mg/l enoxacin and the combination of 0.25 mg/l TMP and 5 mg/l SMT. Although most men treated with either regimen were cured, neither regimen appeared to be the optimum treatment for chancroid. This study shows the efficacy of enoxacin for a soft tissue infection caused by Gram negative organisms.

Adolescent↗
PubMed1988

Single-dose versus traditional therapy for uncomplicated urinary tract infections.

In the treatment of uncomplicated urinary tract infection, single-dose therapy has appeared to be as efficacious as traditional 7-14 day therapy in women with cystitis without renal involvement. Current localizing techniques to differentiate between lower- and upper-tract disease are inadequate for routine clinical practice. As a result we have proposed that failure of cure with single-dose treatment may be the most specific test available to diagnose renal infection. Most of the published data on single-dose therapy involves treatment with either amoxicillin or trimethoprim-sulfamethoxazole. Single-dose therapy offers advantages over traditional therapy, including improved compliance, reduced adverse effects, and decreased cost. Appropriate patient selection is critical if the outcome of single-dose therapy is to be effective.

Amoxicillin↗
PubMed1988

Seroprevalence and demographic information of patients at risk for human immunodeficiency virus (HIV) infection in Manitoba, Canada.

Two hundred fifty individuals from high risk categories were enrolled in a seroprevalence survey for human immunodeficiency virus (HIV) infections in Winnipeg. The overall seroprevalence in the Manitoba AIDS Virus Epidemiology Study (MAVES) was 5.2%. Of 2651 diagnostic and screening specimens in the province of Manitoba submitted over a similar period, 103 were positive (3.9%). HIV seropositivity in Manitoba was noted mainly in homosexual/bisexual males (especially those who were also intravenous drug abusers), hemophiliacs, and individuals from endemic regions of the world. Individuals whose only risk factor was intravenous drug abuse, those with sexually transmitted diseases, or those with high risk sex contacts have not demonstrated HIV seropositivity in Manitoba to date. Manitoba is currently a low seroprevalence region for HIV infection. Our study demonstrated that the awareness level of people at risk for HIV infections was low. In our study population, one-on-one counseling was demonstrated to be an effective way to improve short-term knowledge about HIV infections. Appropriate education approaches must be considered for Native/Metis peoples (26.4% of our MAVES study population), who were younger and had a lower educational and employment level compared to Caucasian/other racial groups.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Norfloxacin: its potential in clinical practice.

The in vitro spectrum and potency of norfloxacin against both aerobic gram-negative and gram-positive bacteria, its limited activity against anaerobes, and the apparent difficulty organisms have in acquiring resistance to it, have provided a rationale for the clinical development of this oral fluoroquinolone antimicrobial agent. The clinical experience with norfloxacin as treatment for a variety of urinary tract infection syndromes, uncomplicated gonococcal infection, and diarrheal disease, and as prophylaxis of infection in neutropenic patients with cancer, is reviewed. Norfloxacin appears at least equivalent to standard regimens for the treatment of acute urinary tract infections; however, long-term studies are needed to define its role in the treatment of recurrent urinary infections. Initial studies of norfloxacin treatment of uncomplicated gonococcal infection and bacterial gastroenteritis are also promising, and in neutropenic patients, continuous norfloxacin prophylaxis has been shown to reduce the incidence of gram-negative infections. Further prospective evaluation is required to confirm these findings.

Bacterial Infections↗
PubMed1987

Treatment of chancroid with ciprofloxacin. A prospective, randomized clinical trial.

Chancroid is a major sexually transmitted disease in many developing countries. Although single-dose and short-course treatment of chancroid have been described, the increasing resistance of Hemophilus ducreyi to antimicrobial agents requires continuing evaluation of new therapies. Ciprofloxacin is a new quinolone antimicrobial agent with excellent in vitro efficacy against H. ducreyi. A double-blind, randomized clinical trial was conducted comparing a single-dose ciprofloxacin regimen (500 mg) and a three-day regimen of ciprofloxacin (500 mg twice daily) with a three-day regimen of trimethoprim-sulfamethoxazole (160 and 800 mg, respectively, twice daily) for the treatment of chancroid. The three-day ciprofloxacin regimen successfully eradicated H. ducreyi, and resulted in rapid clinical improvement in all 40 patients followed, with no failures. The other two regimens were also effective, but bacteriologic and clinical failure occurred in two and three patients following treatment with single-dose ciprofloxacin and three days of trimethoprim-sulfamethoxazole, respectively. All patients with buboes had resolution of lesions. There were no significant adverse effects associated with ciprofloxacin or trimethoprim-sulfamethoxazole. All three regimens are effective therapy for chancroid and H. ducreyi infections. If resistance to trimethoprim-sulfamethoxazole becomes widespread, ciprofloxacin may become a first-line therapy for chancroid. This study also demonstrates the efficacy of ciprofloxacin in soft tissue infection.

Adolescent↗
PubMed1987

Postpartum upper genital tract infections in Nairobi, Kenya: epidemiology, etiology, and risk factors.

We investigated the frequency of clinically defined upper genital tract infection (UGTI) and its relation to sexually transmitted diseases and other risk factors among 1,013 women initially studied while in labor at a Nairobi, Kenya maternity hospital. Women were enrolled during labor and followed up at seven days and one month postpartum. Cultures for Neisseria gonorrhoeae and Chlamydia trachomatis were done at enrollment and at day 7. The prevalence of gonococcal and chlamydial infections was 6.7% and 20.8%, respectively. The overall prevalence of UGTI was 20.3%. The development of UGTI was significantly correlated with gonococcal infection (odds ratio, 4.4; P less than .0001), chlamydial infection (odds ratio, 1.7; P less than .02), presence of ophthalmia neonatorum (odds ratio, 2.6; P less than .0001), labor greater than 12 hr (odds ratio, 1.8; P less than .01), and area of residence (odds ratio, 1.5; P less than .05). Postpartum UGTI, an enormous public health problem in Nairobi, would be partially susceptible to antenatal intervention programs focusing on sexually transmitted diseases.

Chlamydia Infections↗
PubMed1987

A prospective randomized trial of ceftazidime versus cefazolin/tobramycin in the treatment of hospitalized patients with pneumonia.

Ceftazidime and cefazolin/tobramycin were compared in the treatment of hospitalized patients with pneumonia. Iv doses 8-hourly were: ceftazidime--2 g, cefazolin--1.5 g, tobramycin--1.7 mg/kg. For patients with pseudomonas infection randomized to cefazolin/tobramycin, ticarcillin (3 g iv 4-hourly) was used instead of cefazolin. One hundred and ten of 129 patients were evaluable (ceftazidime = 52, cefazolin/tobramycin = 58). Seventy five cases (68%) had documented pathogens of which 81% were aerobic Gram-negative bacilli. Analysis of clinical response showed no difference in overall results (P = 0.77), or separate outcomes: cured (P = 0.85), improved (P = 0.62), failed (P = 0.53), or relapsed (P = 0.50). No differences in bacteriological response were noted either: eradication (P greater than 0.10), elimination with recurrence (P greater than 0.10), persistence (P greater than 0.10). The incidence of enterococcal and fungal colonization and superinfection was the same for both regimens. There was a greater incidence of Coombs' test positivity with ceftazidime (P less than 0.01) but greater nephrotoxicity with cefazolin/tobramycin (P less than 0.02). Ceftazidime appears to be as efficacious as cefazolin/tobramycin in the treatment of hospitalized patients with pneumonia, and is less nephrotoxic.

Adolescent↗
PubMed1987

Relationship between lipopolysaccharide composition and virulence of Haemophilus ducreyi.

The relationship between lipopolysaccharide (LPS) composition and virulence of Haemophilus ducreyi strains was investigated. Glycoses identified in LPS by gas-liquid chromatography were glucose, galactose, and their amino derivatives glucosamine and galactosamine. Fucose was found in trace amounts but mannose and rhamnose, characteristic of the O-side chain of LPS in many species, were not detected. Qualitatively, the LPS composition of the eight strains examined was similar and differences were mainly quantitative. The total glycose:KDO ratio of the LPS of virulent strains exceeded that of avirulent strains. All strains had similar fatty-acid composition but lacked lauric acid. SDS-polyacrylamide gel electrophoresis of the LPS of virulent and avirulent strains also revealed differences in their electrophoretic mobilities. The LPS profiles of avirulent strains were similar, but differed from those of virulent strains. These profiles lacked high mol. wt bands representing O-side chain repeating units. Thus, differences in the electrophoretic mobilities of the LPS of virulent and avirulent strains may reflect differences in the amount of carbohydrates associated with the core polysaccharide.

Electrophoresis, Polyacrylamide Gel↗
PubMed1987

Single-dose ceftriaxone for chancroid.

Men with genital ulcers that were culture positive for Haemophilus ducreyi were treated with intramuscular ceftriaxone and randomized to three different dose regimens. All but 1 of 50 men treated with 1 g of intramuscular ceftriaxone were cured. Similarly, 0.5 and 0.25 g cured 43 of 44 men and 37 of 38 men, respectively. A single dose of 250 mg of intramuscular ceftriaxone is an effective treatment for chancroid.

Adult↗
PubMed1987

In vitro activity of ceftriaxone, cefetamet (Ro 15-8074), ceftetrame (Ro 19-5247; T-2588), and fleroxacin (Ro 23-6240; AM-833) versus Neisseria gonorrhoeae and Haemophilus ducreyi.

We examined 300 strains of Neisseria gonorrhoeae and 100 strains of Haemophilus ducreyi to determine their in vitro susceptibility to two new cephalosporins, cefetamet (Ro 15-8074) and ceftetrame (Ro 19-5247; T-2588), and a new fluroquinolone, fleroxacin (Ro 23-6240; AM-833). Their activity was compared with that of ceftriaxone, penicillin, spectinomycin, tetracycline, and erythromycin. Cefetamet, ceftetrame, and fleroxacin had excellent in vitro activity against both groups of microorganisms. beta-Lactamase production did not significantly affect the MICs of these agents. The Mtr phenotype of N. gonorrhoeae raised the MICs two- to fourfold, but the MICs remained within the range of achievable levels in serum. These newer compounds have a distinct advantage over existing therapeutic agents in that they can be administered orally. Clinical trials are warranted to assess their usefulness in the therapy of gonorrhea and chancroid.

Cefmenoxime↗
PubMed1987

Recurrent urinary tract infection in adult women: diagnosis and treatment.

Recurrent urinary infection may be either relapse or reinfection. The majority of women experiencing recurrent infection have normal genitourinary tracts. For recurrent cystitis, single-dose therapy is optimal and symptomatic episodes are effectively prevented with continuous low-dose antimicrobial prophylaxis. For upper tract infection, or relapse after single dose therapy, two-week therapy is generally adequate. Investigation for abnormalities of the genitourinary tract should be reserved for women who fail to respond to therapy or with relapsing or bacteremic infection.

Adult↗
PubMed1986

Single-dose therapy of gonococcal ophthalmia neonatorum with ceftriaxone.

We conducted a randomized clinical trial comparing a single intramuscular dose of 125 mg of ceftriaxone with a single intramuscular dose of 75 mg of kanamycin followed by topical gentamicin for seven days, and with a single intramuscular dose of 75 mg of kanamycin followed by topical tetracycline for seven days, in the treatment of gonococcal ophthalmia neonatorum in Nairobi, Kenya. Of 122 newborns with culture-proved gonococcal ophthalmia neonatorum, 105 returned for follow-up. Sixty-one infants (54 percent) received ceftriaxone, 32 received kanamycin plus topical gentamicin, and 29 received kanamycin plus topical tetracycline. Sixty-six (54 percent) of the Neisseria gonorrhoeae isolates were penicillinase producing. All 55 newborns who received ceftriaxone and returned for follow-up were clinically and microbiologically cured. One of 26 returning newborns who received kanamycin plus tetracycline and 2 of 24 returning newborns who received kanamycin plus gentamicin had persistent or recurrent gonococcal conjunctivitis. Ceftriaxone also eradicated oropharyngeal gonococcal infection in 18 newborns, whereas oropharyngeal infection persisted in 2 of 8 newborns who had received kanamycin (P not significant). We conclude that 125 mg of ceftriaxone as a single intramuscular dose is very effective therapy for gonococcal ophthalmia neonatorum, with marked efficacy against extraocular infection and without the need for concomitant topical antimicrobial therapy.

Ceftriaxone↗
PubMed1986

Epidemiology of ophthalmia neonatorum in Kenya.

In a Nairobi hospital where ocular prophylaxis against ophthalmia neonatorum has been discontinued, 1,019 women were screened for Neisseria gonorrhoeae and Chlamydia trachomatis during labour and 7 and 28 days postpartum. The prevalence of gonococcal infection was 7% and that of chlamydial was 29%. 52.4% of gonococcal isolates produced penicillinase. The incidence of ophthalmia neonatorum was 23.2 per 100 live births, and incidences of gonococcal and chlamydial ophthalmia were 3.6 and 8.1 per 100 live births, respectively. Of 181 cases of neonatal conjunctivitis, 31% were caused by C trachomatis, 12% by N gonorrhoeae, and 3% by both. In 67 babies exposed to maternal gonococcal infection and 201 exposed to maternal chlamydial infection, rates of transmission to the eye were 42% and 31%, respectively, and to the throat were 7% and 2%. Gonococcal transmission rate was higher in mothers with concomitant chlamydial infection (68%; p = 0.01). Postpartum endometritis was associated with ophthalmia neonatorum (p less than 0.001). Ocular prophylaxis at birth for gonococcal ophthalmia should be reintroduced.

Adult↗