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Biomedical subjects

A R Ronald

Publications and source records attributed to A R Ronald.

At least 217 records · Page 12Linked to original sources
PubMedDate not supplied

Long-term antimicrobial prophylaxis for recurrent urinary tract infection in women.

Thirteen women and two preadolescent girls who suffered recurrences after six months of prophylaxis with trimethoprim (TMP; 40 mg) and sulfamethoxazole (SMZ; 200 mg) taken thrice weekly at bedtime were enrolled in a 24-month study of prophylaxis with the same region. During 29.1 cumulative patient-years of prophylaxis, two infections due to Escherichia coli and one each due to Staphylococcus epidermidis and Streptococcus faecalis occurred (0.14 infection/patient-year). MICs for these isolates were less than or equal to 2 micrograms of TMP/ml and greater than 512 micrograms of SMZ/ml. During prophylaxis, 106 of 116 cultures from the periurethral area and 66 of 97 cultures from the anal and canal yielded no aerobic gram-negative bacilli. In three patients, the periurethral area was colonized with aerobic gram-negative bacilli with MICs of greater than or equal to 2 micrograms of TMP/ml. Thirteen patients were followed after the discontinuation of prophylaxis. Eight suffered recurrences, seven with organisms susceptible to TMP. After one year the remaining five had experienced no recurrences. It is concluded that long-term prophylaxis with 40 mg of TMP and 200 mg of SMZ thrice weekly is an effective, well-tolerated regimen that can maintain an infection-free state in women with histories of frequent urinary reinfections.

Adult↗
PubMedDate not supplied

Short-course and single-dose antimicrobial therapy for chancroid in Kenya: studies with rifampin alone and in combination with trimethoprim.

Tetracyclines and sulfonamides are no longer effective for the treatment of chancroid in many parts of the world. Rifampin and trimethoprim both possess in vitro activity against Haemophilus ducreyi, the causative agent of chancroid. In a randomized, controlled study, 22 patients with H. ducreyi-positive genital ulcers received 600 mg of rifampin once daily for three days, and 32 patients received 600 mg of rifampin plus 160 mg of trimethoprim once daily for three days. Both regimens rapidly eradicated H. ducreyi from ulcers, with subsequent healing of ulcers and buboes. Two relapses of ulcers and one therapeutic failure were observed in the rifampin-trimethoprim group, whereas no relapses or failures were noted in the rifampin group. In addition, all of 16 H. ducreyi-negative ulcers responded rapidly to treatment with either regimen. In an uncontrolled, open study, 22 H. ducreyi-positive ulcers were treated with a single dose of rifampin (600 mg) plus trimethoprim (160 mg). Ulcers and buboes resolved by day 14 in all but one patient. Thus, these short-course and single-dose regimens are effective against chancroid.

Adolescent↗
PubMedDate not supplied

Prospective randomized comparison of imipenem/cilastatin and cefotaxime for treatment of lung, soft tissue, and renal infections.

Thirty-one moderately or severely ill hospitalized patients with proved (25 patients) or suspected (six) bacterial infections were randomly allocated to receive imipenem/cilastatin (16) or cefotaxime (15). The median age, sex, duration of therapy, underlying disease, and types of infection were similar in both groups. Nineteen patients with pneumonia, eight with soft tissue infection, and four with acute pyelonephritis were included. The pathogens isolated included Escherichia coli (six), Streptococcus pneumoniae (five), Streptococcus pyogenes (five), Haemophilus species (four), Proteus species (three), Staphylococcus aureus (three), and Serratia marcescens (two). In the imipenem/cilastatin group, 13 patients were cured of their infections and three showed improvement. In the cefotaxime group, nine were cured, three showed improvement, and three showed no improvement. Nine patients treated with imipenem/cilastatin developed phlebitis, as compared with eight treated with cefotaxime. One patient treated with cefotaxime developed diarrhea. During therapy, potential pathogens were isolated from four patients in the imipenem/cilastatin group (Candida species [two] and Pseudomonas maltophilia [two]), as compared with eight in the cefotaxime group (enterococci [two], Pseudomonas aeruginosa [two], Candida species [two], Acinetobacter anitratus [one], and Pseudomonas fluorescens [one]). There were no recognized superinfections.

Adult↗
PubMedDate not supplied

Comparison of media for the primary isolation of Haemophilus ducreyi.

The rates of isolation of Haemophilus ducreyi from patients with presumed chancroid has been low, and improved cultural techniques are required. We determined the isolation rates of H. ducreyi from 38 patients with clinical chancroid and compared gonococcal agar supplemented with bovine hemoglobin to Mueller-Hinton agar supplemented with chocolated horse blood, each with and without 5% fetal calf serum. The rate of isolation and the qualitative and quantitative growth of strains was best on gonococcal agar with added fetal calf serum (GC-HgS). However, three strains were isolated only on Mueller-Hinton base (MH-base). GC-HgS was compared with MH-HB for the isolation of H. ducreyi from 201 patients with clinical chancroid. Seventy-one percent of cultures were positive on GC-HgS, and 61% were positive on MH-HB (P less than .005); however, 10% of cultures were positive only on MH-HB. The use of the two media together increased the yield of positive cultures to 81%. Thus maximal rates of isolation of H. ducreyi from clinical specimens requires the use of two media, GC-HgS and MH-HB.

Chancroid↗
PubMedDate not supplied

The clinical diagnosis of genital ulcer disease in men in the tropics.

Since the clinical diagnosis of genital ulcers without laboratory confirmation is not reliable in developed countries, we postulated that clinical diagnosis alone would be no more reliable in developing countries. A presumptive clinical diagnosis of chancroid, genital herpes, syphilis, or lymphogranuloma venereum was made for 100 male patients at the Special Treatment Clinic in Nairobi, Kenya. This diagnosis was then compared to the final diagnosis determined by laboratory identification of the pathogen, by culture, or by serologic response. In 64 patients, a final diagnosis of either chancroid, syphilis, or genital herpes was established. The diagnostic accuracy varied from 75% for chancroid to 42% for syphilis and 43% for herpes. The overall diagnostic accuracy was 66%. The predictive values of positive clinical diagnoses were 84% for chancroid, 60% for syphilis, and 75% for herpes. Thus, clinical diagnosis of genital ulcer disease was not sufficiently reliable in this study.

Chancre↗
PubMedDate not supplied

Cefotaxime treatment of Haemophilus ducreyi infection in Kenya.

The authors conducted a double-blind randomized clinical trial comparing single-dose cefotaxime (1 g im) plus daily placebo injections with cefotaxime (1 g im on each of three days). Each regimen was given with probenicid (1 g orally) for the treatment of chancroid. Twenty Haemophilus ducreyi culture-positive men received the single-dose cefotaxime regimen; in eight patients ulcers or buboes failed to respond to therapy. Nineteen H. ducreyi culture-positive men received cefotaxime on each of three days; H. ducreyi was eradicated from all patients, but one had a continuing ulcer and another had a bubo that failed to respond. Thus cefotaxime (1 g im daily for three days) plus probenicid (1 g orally) is effective therapy for chancroid. The lack of efficacy for chancroid of the single-dose cefotaxime regimen is surprising, given the remarkable susceptibility of H. ducreyi to cefotaxime; presumably the half-life of cefotaxime is too short for predictable eradication of H. ducreyi from the ulcer with a single-dose regimen.

Adolescent↗
PubMedDate not supplied

Prostitutes are a major reservoir of sexually transmitted diseases in Nairobi, Kenya.

Prostitutes are a major reservoir of sexually transmitted diseases in many developing nations. In Nairobi we found that 16%, 28%, and 46%, respectively, of upper-, middle-, and lower-social strata prostitutes were infected with Neisseria gonorrhoeae. Genital ulcers and infections with Haemophilus ducreyi were more prevalent among prostitutes of the middle and lower social strata. A group of 97 prostitutes of the lower social strata were followed longitudinally to determine the rate of reinfection with N. gonorrhoeae. The mean time to acquisition of a new infection was 12.0 +/- 9.2 days. These results show that in Nairobi prostitutes are a readily identifiable group of high-frequency transmitters of gonococcal infection. Strategies based on intervention in the prostitute reservoir could prove to be an effective means of control of gonococcal infections in developing nations.

Chancroid↗
PubMedDate not supplied

Clinical and microbiologic studies of genital ulcers in Kenyan women.

The etiology of genital ulcers in women in tropical regions is poorly understood. Eighty-nine women, presenting to a sexually transmitted disease clinic in Nairobi (Kenya) with a primary complaint of genital ulcers, were evaluated prospectively in a clinical and laboratory study. A final etiologic diagnosis was possible for 60 (67%) of the women. Culture for Haemophilus ducreyi was positive for 43 women, eight had secondary syphilis with ulcerated condyloma latum, three had primary syphilis, one had both chancroid and syphilis, two had moniliasis, two had herpetic ulceration, and one had a traumatic ulcer. The clinical characteristics that best distinguished chancroid from secondary syphilis were ulcer excavation and a rough ulcer base. No etiologic diagnosis was established for 29 patients. However, the clinical and epidemiologic features of these patients suggested that they were similar if not identical to the patients with H. ducreyi culture-positive chancroid. Further studies are necessary to determine the etiology of ulcers in females in whom no pathogen was identified.

Chancroid↗
PubMedDate not supplied

Transfer of plasmid-mediated ampicillin resistance from Haemophilus to Neisseria gonorrhoeae requires an intervening organism.

Haemophilus species have been implicated as the source of plasmid-mediated ampicillin resistance in Neisseria gonorrhoeae. Previous attempts to transfer conjugally the resistance plasmids from Haemophilus species to N. gonorrhoeae have met with limited success. Using both biparental and triparental mating systems, it was found that transfer will occur if the commensal Neisseria species, Neisseria cinerea, is used as a transfer intermediate. This organism stably maintains resistance plasmids of Haemophilus and facilitates transfer of these plasmids to N. gonorrhoeae, in a triparental mating system, at a transfer frequency of 10(-8). Both Haemophilus ducreyi and N. gonorrhoeae carry mobilizing plasmids capable of mediating conjugal transfer of the same resistance plasmids. However, restriction endonuclease mapping and DNA hybridization studies indicate that the mobilizing plasmids are distinctly different molecules. Limited homology is present within the transfer region of these plasmids.

Ampicillin↗
PubMedDate not supplied

Single-dose therapy with trimethoprim-sulfametrole for chancroid in females.

Women with genital ulcer disease who were culture-positive for Haemophilus ducreyi were treated with a single dose of the drug combination trimethoprim-sulfametrole; the dosage was 640 mg of trimethoprim and 3,200 mg of sulfametrole. All 27 women who were treated with this regimen and adequately followed were cured. Thus a single dose of trimethoprim-sulfametrole appears to be an effective treatment regimen for women with chancroid in Kenya.

Adult↗
PubMedDate not supplied

Advances in the diagnosis and management of chancroid.

Improved technologies for the cultural diagnosis of chancroid have resulted in increased interest in the management and control of genital ulcer disease. New treatment regimens have been identified, and new control strategies have evolved. These strategies now permit localized introductions of chancroid into developed countries to be contained rapidly. However, additional work is still necessary in developing countries.

Anti-Bacterial Agents↗
PubMedDate not supplied

Etiology of nonvesicular genital ulcers in Winnipeg.

Twenty-eight patients with recent onset of nonvesicular ulcerative genital lesions were studied prospectively to define the microbial etiology. Causative agents identified included herpes simplex virus (HSV), Chlamydia trachomatis, Haemophilus ducreyi, and Treponema pallidum. Three women and 25 men (seven of whom were homosexual) were studied. Ten patients did not have an etiology identified. Nine patients had syphilis, six had genital herpes, one had chancroid, one had granuloma inguinale, and one had a human bite injury. Six of seven homosexual men had syphilis, as compared with one of eight heterosexual men (P less than .002). Among heterosexual men, five had atypical HSV infections, three with extensive balanoposthitis and two with chancroidal ulcers. Of the clinical characteristics examined, induration of the ulcer base and tenderness on palpation were predictive of etiology, whereas numbers of ulcers and regional lymphadenopathy were not. H. ducreyi was not a common cause of genital ulcers in Winnipeg, and it was not found as a commensal or superinfecting organism in ulcers caused by other agents.

Adolescent↗
PubMedDate not supplied

A comparison of single-dose spectinomycin with five days of trimethoprim-sulfamethoxazole for the treatment of chancroid.

In a controlled trial 32 patients with ulcers culture-positive for Haemophilus ducreyi were treated with a single 2-g dose of spectinomycin, and 20 patients were treated with a five-day course of trimethoprim-sulfamethoxazole (TMP-SMZ; 160/800 mg) twice daily. Both regimens rapidly eradicated H. ducreyi from ulcers, with subsequent healing of ulcers and buboes. The cure rates 14 days after initiation of therapy were 94% for spectinomycin and 95% for TMP-SMZ. Patients with H. ducreyi-negative ulcers who were treated with the same regimens also healed and did not show a significantly different efficacy for either regimen. Thus we found that the one-day regimen of spectinomycin was as effective for the treatment of chancroid as was TMP-SMZ given for five days. Further studies on a larger number of patients are needed to confirm our findings.

Adult↗
PubMedDate not supplied

Comparison of Sheffield media with standard media for the isolation of Haemophilus ducreyi.

Isolation of Haemophilus ducreyi is the only method for the definitive diagnosis of chancroid. Culture on supplemented gonococcal base (GCHgs) or on supplemented Muller-Hinton agar (MHHb) has yielded the best isolation rates. Sheffield media is an alternative to standard media. We compared the isolation rate of H. ducreyi on GCHgs and MHHb to that on the Sheffield media with and without 5% horse blood. Vancomycin (3 mg/L) was added to all media. Of the 87 specimens cultured from patients with genital ulcer disease, 57 (66%) were positive on either GCHgs or MHHb or on both. Twenty six (30%) were positive on GCHgs only, 15 (17%) on MHHb only, and 15 (17%) on both. One culture was positive on Sheffield medium with 5% horse blood; none were positive on Sheffield medium without horse blood. Stock strains showed good growth at 48 hr on GCHgs and MHHb, but no growth at 48 hr and only minimally detectable growth at 72 hr on Sheffield media with horse blood. No growth was detected on Sheffield media without horseblood. Thus optimal culture of H. ducreyi in Kenya requires two media, supplemented gonococcal base and Muller-Hinton agar. Sheffield media is not useful for the primary isolation of H. ducreyi.

Agar↗
PubMedDate not supplied

Condom use prevents genital ulcers in women working as prostitutes. Influence of human immunodeficiency virus infection.

Control of genital ulcer disease (GUD) is a proposed intervention to slow the dissemination of human immunodeficiency virus (HIV) infection. Programs for the control of sexually transmitted diseases (STD) should focus on groups of high-frequency transmitters, such as prostitutes and their clientele. This study illustrates the interaction between the prevalence of chancroid, use of barrier prophylaxis against STDs, and HIV infection in a population of female prostitutes in Nairobi. Four hundred and twenty three women were evaluated. Despite the increased use of condoms, the prevalence of genital ulcers remained constant between 1986-87 and 1987-88. Genital ulcer disease was simultaneously associated with HIV infection (adjusted odds ratio: 3.7, P less than .01) whereas it was independently and inversely associated with more consistent condom use (P less than .01). The authors conclude that genital ulcer disease can be controlled in these populations but concurrent HIV infection increases the difficulty of this intervention.

Chancroid↗
PubMedDate not supplied

The association between lack of male circumcision and risk for HIV infection: a review of the epidemiological data.

BACKGROUND AND OBJECTIVES: Whether male circumcision reduces the risk of acquiring human immunodeficiency virus (HIV) infection remains controversial. STUDY DESIGN: As there have now been a number of studies conducted that have examined this issue, we undertook to review their findings. Thirty epidemiological studies identified in the literature that investigated the association between male circumcision status and risk for HIV infection were reviewed. RESULTS: Eighteen cross-sectional studies from six countries reported a statistically significant association, four studies from four countries found a trend toward an association. Four studies from two countries found no association. Two prospective studies reported significant associations, as did two ecological studies. In studies in which significant associations were demonstrated, measures of increased risk ranged from 1.5 to 8.4. The groups in which positive associations were found included sexually transmitted disease (STD) clinic and hospital patients, outpatient clinic and HIV screening clinic attenders, long-distance truck drivers, and general community members. CONCLUSION: Potential sources of error, assessment of causality, implications of the findings, and future research needs are discussed. Because a substantial body of evidence links noncircumcision in men with risk for HIV infection, consideration should be given to male circumcision as an intervention to reduce HIV transmission.

Bias↗
PubMedDate not supplied

Single dose azithromycin for the treatment of chancroid: a randomized comparison with erythromycin.

BACKGROUND AND OBJECTIVES: Chancroid is endemic in sub-Saharan Africa and enhances the sexual transmission of the human immunodeficiency virus Type 1 (HIV-1). Azithromycin is an orally absorbed macrolide antibiotic that is active against Haemophilus ducreyi, the causative agent of chancroid, and has pharmacokinetic properties that are suitable for single dosing. STUDY DESIGN: In a randomized single-blinded study of 127 men presenting to a referral STD clinic with culture proven chancroid, we compared the efficacy of azithromycin, administered as a single 1 g dose, with erythromycin 500 mg given 4 times daily for 7 days. RESULTS: Cure rates were 89% (73 of 82) in the azithromycin group and 91% (41 of 45) in the erythromycin group. A failure to respond to treatment was associated with HIV-1 seropositivity and a lack of circumcision. Both regimens were well tolerated. CONCLUSIONS: Azithromycin, given as a single 1 g oral dose, is an effective treatment for chancroid in men, and offers major prescribing advantages over erythromycin.

AIDS-Related Opportunistic Infections↗