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

Single-Dose Azithromycin for the Treatment of Haemophilus ducreyi Skin Ulcers in Papua New Guinea

Background

Haemophilus ducreyi (HD) and Treponema pallidum subspecies pertenue (TP) are major causative agents of cutaneous ulcer (CU) in the tropics. Azithromycin is recommended to treat sexually transmitted HD infections and has good in vitro activity against HD strains from both genital and skin ulcers. We investigated the efficacy of oral single-dose azithromycin on HD-CU.

Methods

We conducted a community-based cohort study in Lihir Island, Papua New Guinea, from October 2014 through May 2016. Consenting patients with skin ulcers >1 cm in diameter were eligible for this study and had collected a lesional swab for polymerase chain reaction (PCR). All participants were treated with single-dose azithromycin (30 mg/kg) and were followed up for assessment of clinical resolution. We retrospectively classified patients according to PCR results into HD, TP, and PCR-negative groups. The primary endpoint was healing rates of HD-CU at 14 days after treatment.

Results

We obtained full outcome data from 246 patients; 131 (53.3%) were HD PCR positive, 37 (15.0%) were TP positive, and 78 (31.7%) were negative for all tests. Healing rates were 88.5% (95% confidence interval [CI], .82-.93) in the HD group, 78.4% [95% CI, .63-.89] in the TP group, and 74.4% (95% CI, .64-.83) in the PCR-negative group. If we included the participants with improved ulcers, the healing rates increased to 94.7%, 97.3%, and 89.7% respectively. HD cases classified as not healed all converted to HD-negative PCR.

Conclusions

Based upon clinical resolution and PCR conversion to HD negative, a single oral dose of azithromycin is efficacious for the treatment of HD-CU. These results have implications for the treatment of individual patients and for the use of antibiotics in public health strategies to control CU in the tropics.

Macrolides for treatment of Haemophilus ducreyi infection in sexually active adults

BACKGROUND

Chancroid is a genital ulcerative disease caused by Haemophilus ducreyi. This microorganism is endemic in Africa, where it can cause up to 10% of genital ulcers. Macrolides may be an effective alternative to treat chancroid and, based on their oral administration and duration of therapy, could be considered as first line therapy.

OBJECTIVES

To assess the effectiveness and safety of macrolides for treatment of H ducreyi infection in sexually active adults.

SEARCH METHODS

We searched the Cochrane STI Group Specialized Register, CENTRAL, MEDLINE, Embase, LILACS, WHO ICTRP, ClinicalTrials.gov and Web of Science to 30 October 2017. We also handsearched conference proceedings and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing macrolides in different regimens or with other therapeutic alternatives for chancroid.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted data and assessed risk of bias. We resolved disagreements through consensus. We used the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

Seven RCTs (875 participants) met our inclusion criteria, of which four were funded by industry. Five studies (664 participants) compared macrolides with ceftriaxone, ciprofloxacin, spectinomycin or thiamphenicol. Low quality evidence suggested there was no difference between the groups after treatment in terms of clinical cure (risk ratio (RR) 1.09, 95% confidence interval (CI) 0.97 to 1.21; 2 studies, 340 participants with syndromic approach and RR 1.06, 95% CI 0.98 to 1.15; 5 studies, 348 participants with aetiological diagnosis) or improvement (RR 0.89, 95% CI 0.52 to 1.52; 2 studies, 340 participants with syndromic approach and RR 0.80, 95% CI 0.42 to 1.51; 3 studies, 187 participants with aetiological diagnosis). Based on low and very low quality evidence, there was no difference between macrolides and any other antibiotic treatments for microbiological cure (RR 0.93, 95% CI 0.74 to 1.16; 1 study, 45 participants) and minor adverse effects (RR 1.34, 95% CI 0.24 to 7.51; 3 studies, 412 participants).Two trials (269 participants) compared erythromycin with any other macrolide type. Low quality evidence suggested that, compared with azithromycin or rosaramicin, long courses of erythromycin did not increase clinical cure (RR 1.00, 95% CI 0.91 to 1.10; 2 studies, 269 participants with syndromic approach and RR 1.04, 95% CI 0.93 to 1.16; 2 studies, 211 participants with aetiological diagnosis), with a similar frequency of minor adverse effects between the groups (RR 1.14, 95% CI 0.63 to 2.06; 1 trial, 101 participants). For this comparison, subgroup analysis found no difference between HIV-positive participants (RR 1.02, 95% CI 0.73 to 1.43; 1 study, 38 participants) and HIV-negative participants (RR 1.04, 95% CI 0.94 to 1.14; 1 study, 89 participants). We downgraded the quality of evidence to low, because of imprecision, some limitations on risk of bias and heterogeneity.None of the trials reported serious adverse events, cost effectiveness and participant satisfaction.

AUTHORS' CONCLUSIONS

At present, the quality of the evidence on the effectiveness and safety of macrolides for treatment of H ducreyi infection in sexually active adults is low, implying that we are uncertain about the estimated treatment effect. There is no statistically significant difference between the available therapeutic alternatives for the treatment of sexually active adults with genital ulcers compatible with chancroid. Low quality evidence suggests that azithromycin could be considered as the first therapeutic alternative, based on their mono-dose oral administration, with a similar safety and effectiveness profile, when it is compared with long-term erythromycin use.Due to sparse available evidence about the safety and effectiveness of macrolides to treat H ducreyi infection in people with HIV, these results should be taken with caution.

Epidemiology, clinical features, diagnosis and treatment of Haemophilus ducreyi - a disappearing pathogen?

Chancroid, caused by Haemophilus ducreyi, has declined in importance as a sexually transmitted pathogen in most countries where it was previously endemic. The global prevalence of chancroid is unknown as most countries lack the required laboratory diagnostic capacity and surveillance systems to determine this. H. ducreyi has recently emerged as a cause of chronic skin ulceration in some South Pacific islands. Although no antimicrobial susceptibility data for H. ducreyi have been published for two decades, it is still assumed that the infection will respond successfully to treatment with recommended cephalosporin, macrolide or fluoroquinolone-based regimens. HIV-1-infected patients require careful follow-up due to reports of treatment failure with single dose regimens. Buboes may need additional treatment with either aspiration or excision and drainage.

Genital ulcer disease treatment for reducing sexual acquisition of HIV

BACKGROUND

Genital ulcer disease by virtue of disruption of the mucosal surfaces may enhance HIV acquisition. Genital ulcer disease treatment with resolution of the ulcers may therefore contribute in reducing the sexual acquisition of HIV.

OBJECTIVES

To determine the effects of treatment of genital ulcer disease on sexual acquisition of HIV.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, LILACS, NLM Gateway, Web of Science, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov, and reference lists of relevant publications for eligible studies published between 1980 and August 2011.

SELECTION CRITERIA

Randomized controlled trials of any treatment intervention aimed at curing genital ulcer disease compared with an alternative treatment, placebo, or no treatment. We included only trials whose unit of randomization was the individual with confirmed genital ulcer.

DATA COLLECTION AND ANALYSIS

We independently selected studies and extracted data in duplicate; resolving discrepancies by discussion, consensus, and arbitration by third review author. We expressed study results as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

There were three randomized controlled trials that met our inclusion criteria recruited HIV-negative participants with chancroid (two trials with 143 participants) and primary syphilis (one trial with 30 participants). The syphilis study, carried out in the US between 1995 and 1997, randomized participants to receive a single 2.0 g oral dose of azithromycin (11 participants); two 2.0 g oral doses of azithromycin administered six to eight days apart (eight participants); or benzathine penicillin G administered as either 2.4 million units intramuscular injection once or twice seven days apart (11 participants). No participant in the trial seroconverted during 12 months of follow-up. The chancroid trials, conducted in Kenya by 1990, found no significant differences in HIV seroconversion rates during four to 12 weeks of follow-up between 400 and 200 mg single oral doses of fleroxacin (one trial, 45 participants; RR 3.00; 95% CI 0.29 to 30.69), or between 400 mg fleroxacin and 800 mg sulfamethoxazole plus 160 mg trimethoprim (one trial, 98 participants; RR 0.33; 95% CI 0.04 to 3.09). Adverse events reported were mild to moderate in severity, and included Jarisch-Herxheimer reactions and gastrointestinal symptoms. The differences between the treatment arms in the incidence of adverse events were not significant. The quality of this evidence on the effectiveness of genital ulcer disease treatment in reducing sexual acquisition of HIV, according to GRADE methodology, is of very low quality.

AUTHORS' CONCLUSIONS

At present, there is insufficient evidence to determine whether curative treatment of genital ulcer disease would reduce the risk of HIV acquisition. The very low quality of the evidence implies that the true effect of genital ulcer disease treatment on sexual acquisition of HIV may be substantially different from the effect estimated from currently available data. However, genital ulcer diseases are public health problems in their own right and patients with these conditions should be treated appropriately; whether the treatment reduces the risk of HIV infection or not.

Current concepts in bacterial sexually transmitted diseases

Sexually transmitted diseases (STDs) are the most common infectious diseases worldwide, with over 350 million new cases occurring each year, and have far-reaching health, social, and economic consequences. Failure to diagnose and treat STDs at an early stage may result in serious complications and sequelae. STDs are passed from person to person primarily by sexual contact and are classified into varied groups. Some cause mild, acute symptoms and some are life-threatening. They are caused by many different infectious organisms and are treated in different ways. Syphilis and gonorrhea are ancient afflictions. Now, however, Chlamydia is prevalent and has become the most common bacterial STD. Antimicrobial resistance of several sexually transmitted pathogens is increasing, rendering some regimens ineffective, adding to therapeutic problems. A standardized treatment protocol for STDs is recommended to ensure that all patients receive adequate treatment. Appropriate treatment of STDs is an important public health measure.

Recent advances in management of genital ulcer disease and anogenital warts

Genital ulcer disease (GUD) constitutes a major public health problem. Most of them are the result of sexually transmitted diseases. Genital herpes, syphilis, lymphogranuloma venereum, granuloma venereum, or chancroid are the commonly encountered GUD. The treatment modalities for these disorders have changed with advent and use of drugs such as azithromycin. The treatment modalities differ in patients with HIV disease. Further vaccines for herpes genitalis and human papilloma virus has opened new avenues in management of these diseases. In regions where there are no diagnostic facilities or where the costs of diagnostic tests are prohibitive, syndromic management of GUD is preferred.

Treatment of chancroid in resource-poor countries

Chancroid, formerly a major cause of the genital ulcer disease syndrome, remains an important cofactor in both the transmission and acquisition of HIV-1 infection. Those countries with the greatest burden of HIV also have some of the highest prevalence rates of chancroid worldwide. The diagnosis of chancroid, caused by the fastidious bacterium Haemophilus ducreyi, is both expensive and difficult in many resource-poor areas. These areas of the world use syndromic management to treat genital ulcers and such an approach has proven effective in reducing rates of bacterial genital ulcer diseases. There are currently inexpensive and effective single-dose therapies available to treat chancroid. Single-dose regimens, given at first presentation, improve compliance and reduce the risk of sexually transmitted infections. Bacterial resistance to several antimicrobial agents has increased over the years and remains a continued threat to effective antimicrobial therapy. Follow-up of cases, and partner notification and treatment is carried out to limit reinfection and onward transmission of chancroid. Patients with coexistent HIV may be particularly at risk of failing single-dose therapy and should therefore be reviewed wherever possible.

In vitro and in vivo activity of combination antimicrobial agents on Haemophilus ducreyi

OBJECTIVES

Development of single dose antibiotic treatments for chancroid has been followed by drug-resistant Haemophilus ducreyi in endemic areas. We examined the activity and interactions of antimicrobial agents and combinations against H. ducreyi.

METHODS

We evaluated the in vitro susceptibility of three virulent strains of H. ducreyi to ceftriaxone, azithromycin, rifabutin and streptomycin, and each two-drug combination by the agar dilution method. We then tested each two-antibiotic combination for activity by the chequerboard method. Lastly, we chose the antibiotic combination with the lowest fractional inhibitory concentration index (FICI) and tested combined sub-therapeutic doses, the highest doses which had no effect alone on lesion healing compared with controls, for in vivo interaction in the temperature-dependent rabbit model of H. ducreyi infection.

RESULTS

Each H. ducreyi strain was susceptible in vitro to each antibiotic and two-antibiotic combination, and combined ceftriaxone and streptomycin had the lowest FICI at 0.63. In five treated animals versus three untreated controls, combined sub-therapeutic doses of ceftriaxone (0.05 mg/kg) and streptomycin (10 mg/kg) reduced mean (SD) duration of culture positivity from 7.3 (1.1) to 2.6 (1.7) days (P<0.001), time to 50% reduction in lesion size from 9.7 (1.5) to 5.8 (0.8) days (P<0.005), and time to resolution of ulcer from 11.7 (2.3) to 6.6 (1.7) days (P<0.05).

CONCLUSIONS

Ceftriaxone and streptomycin have in vivo synergic interaction against H. ducreyi lesions in the temperature-dependent rabbit model of infection. Antibiotic combinations may be evaluated clinically as single-dose therapy for chancroid.

Selected sexually transmitted diseases and their relationship to HIV

Although sexually transmitted diseases (STDs) are underreported and underrecognized, they are a major source of morbidity, mortality, and represent a major socioeconomic cost in developing and industrialized nations. Individuals who develop STDs are often coinfected with human immunodeficiency virus (HIV). Coinfection with HIV both facilitates the natural history of STDs and worsens the clinical picture. The objective of this article is to provide a review to the practicing clinician on the epidemiology, clinical manifestations, methods of diagnosis, and treatment for four cutaneous STDs--chancroid, genital herpes, granuloma inguinale, and lymphogranuloma venereum--in coinfected HIV patients.

Chancroid: clinical manifestations, diagnosis, and management

Chancroid is a sexually transmitted disease (STD) caused by the Gram negative bacterium Haemophilus ducreyi and is characterised by necrotising genital ulceration which may be accompanied by inguinal lymphadenitis or bubo formation. H ducreyi is a fastidious organism which is difficult to culture from genital ulcer material. DNA amplification techniques have shown improved diagnostic sensitivity but are only performed in a few laboratories. The management of chancroid in the tropics tends to be undertaken in the context of syndromic management of genital ulcer disease and treatment is usually with erythromycin. A number of single dose regimens are also available to treat H ducreyi infection. Genital ulceration as a syndrome has been associated with increased transmission of human immunodeficiency virus (HIV) infection in several cross sectional and longitudinal studies. Effective and early treatment of genital ulceration is therefore an important part of any strategy to control the spread of HIV infection in tropical countries.

A systematic review of the epidemiologic interactions between classic sexually transmitted diseases and HIV: how much really is known?

BACKGROUND

Many studies have explored the role of "classic" sexually transmitted diseases (STDs) in determining the pattern of HIV epidemics. However, the many different STDs may contribute in different ways, at different magnitudes.

GOAL

To review available studies on the bidirectional interactions of HIV and STDs to explore the extent of current knowledge on the different influences of the varied STDs in heterosexual HIV epidemics.

METHODS

Longitudinal studies on susceptibility and controlled studies on infectiousness and duration of disease identified on electronic databases through reference lists and citation indices up to the end of 1999 were systematically reviewed, including meta-analyses assessing the influence of STDs on susceptibility to HIV.

RESULTS

Studies have a clear publication bias with a significant result that hinders robust interpretation. However, genital ulcerative disease appears to have a greater impact than nonulcerative disease, and men are more affected than women by the effects of STDs on susceptibility to HIV. There is evidence that STDs increase the infectiousness of HIV from men to women, whereas the evidence is more equivocal for the infectiousness of women. Few studies identify the impact of different STDs, and there is a marked lack of studies investigating the impact of HIV infection on the transmission of other STDs.

CONCLUSIONS

A large body of work has measured the association between STDs and HIV. However, publication bias and gaps in the focus of studies mean that a detailed, quantitative understanding of the interaction requires much more attention.

An overview of sexually transmitted diseases. Part III. Sexually transmitted diseases in HIV-infected patients

The HIV epidemic has dramatically altered the field of sexually transmitted diseases (STDs). HIV infection is unique among sexually transmitted diseases because it can modify the clinical presentation and features of other STDs. Conversely, other STDs can affect the transmission of HIV. This review is the third part of a series that has provided a general overview of STDs. In this article, genital ulcer diseases (genital herpes, syphilis, chancroid, lymphogranuloma venereum, and granuloma inguinale), human papillomavirus infection (anogenital warts and subclinical infections), molluscum contagiosum, human herpesvirus 8 infection, viral hepatitis, and ectoparasitic infestations (scabies and pediculosis pubis) are discussed as they occur in HIV-infected hosts. Additional features as they relate to HIV-infected patients, such as epidemiology and transmission, are discussed when applicable.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should improve their understanding of sexually transmitted diseases in the HIV-infected host.

Chancroid: from clinical practice to basic science

Chancroid is a sexually transmitted disease caused by the bacterium Haemophilus ducreyi. It usually presents as a genital ulcer and may be associated with regional lymphadenopathy and bubo formation. H. ducreyi infection is predominantly seen in tropical resource-poor regions of the world where it is frequently the most common etiological cause of genital ulceration. Genital ulcer disease has been shown to be an extremely important co-factor in HIV transmission. With the advent of the AIDS epidemic, there has been increased research effort to elucidate those factors involved in the pathogenesis of chancroid. Several putative virulence factors have now been identified and isogenic H. ducreyi mutants constructed by mutagenesis of their encoding genes. This approach has facilitated investigations into the role each of these putative virulence factors may play in H. ducreyi pathogenesis through the use of in vitro and in vivo model systems. One major goal of current chancroid research is to identify antigens which are immunogenic and could form the basis of a vaccine against H. ducreyi infection. Such a vaccine, if shown to be effective in decreasing the prevalence of chancroid, could have the added benefit of slowing down the HIV incidence rates in those populations where chancroid is a major co-factor for HIV transmission.

The macrolides: erythromycin, clarithromycin, and azithromycin

In addition to erythromycin, macrolides now available in the United States include azithromycin and clarithromycin. These two new macrolides are more chemically stable and better tolerated than erythromycin, and they have a broader antimicrobial spectrum than erythromycin against Mycobacterium avium complex (MAC), Haemophilus influenzae, nontuberculous mycobacteria, and Chlamydia trachomatis. All three macrolides have excellent activity against the atypical respiratory pathogens (C. pneumoniae and Mycoplasma species) and the Legionella species. Azithromycin and clarithromycin have pharmacokinetics that allow shorter dosing schedules because of prolonged tissue levels. Both azithromycin and clarithromycin are active agents for MAC prophylaxis in patients with late-stage acquired immunodeficiency syndrome (AIDS), although azithromycin may be the preferable agent because of fewer drug-drug interactions. Clarithromycin is the most active MAC antimicrobial agent and should be part of any drug regimen for treating active MAC disease in patients with or without AIDS. Although both azithromycin and clarithromycin are well tolerated by children, azithromycin has the advantage of shorter treatment regimens and improved tolerance, potentially improving compliance in the treatment of respiratory tract and skin or soft tissue infections. Intravenously administered azithromycin has been approved for treatment of adults with mild to moderate community-acquired pneumonia or pelvic inflammatory diseases. An area of concern is the increasing macrolide resistance that is being reported with some of the common pathogens, particularly Streptococcus pneumoniae, group A streptococci, and H. influenzae. The emergence of macrolide resistance with these common pathogens may limit the clinical usefulness of this class of antimicrobial agents in the future.

Macrolide antibiotics

This article is an extensive review of current information available on the macrolide antibiotics. This includes antimicrobial spectrum, pharmacology, complications and side effects, and pediatric use of these drugs. These are important antibiotics, but careful selection of patients must be made and the physician must be alert for evidence of drug-drug interactions, which are not uncommon with several members of this class.

Comparison of E-test with agar dilution methods in testing susceptibility of N. gonorrhoeae to azithromycin

BACKGROUND AND OBJECTIVES

The antimicrobial susceptibility pattern of Neisseria gonorrhoeae varies from one country to another and may also change with time. To monitor these variations and changes, it is desirable to have a method that is simple and reproducible. This study was undertaken to determine the in vitro susceptibility of N. gonorrhoeae to azithromycin and to assess the reliability of results obtained using E-test methodology for determination of the minimum inhibitory concentration (MIC) of azithromycin.

STUDY DESIGN

The MICs for 135 clinical isolates of N. gonorrhoeae were determined by a modified Kirby-Bauer method recommended by the National Committee for Clinical Laboratory Standards against penicillin, cefuroxime, ceftriaxone, norfloxacin, tetracycline, kanamycin, spectinomycin, and azithromycin. The MIC of azithromycin was determined by both the E-test and agar dilution method. All tests were done simultaneously.

RESULTS

The MIC of azithromycin to all 135 isolates ranged from 0.078 to 0.25 microgram/ml with the agar dilution method and from 0.016 to 0.50 microgram/ml with the E-test. The MIC50 and MIC90 of azithromycin were 0.064 microgram/ml and 0.125 microgram/ml, respectively, by the agar dilution method, whereas they are slightly higher by the E-test method. Seventy-six of the isolates were beta-lactamase producers and 69 were high-level tetracycline-resistant N. gonorrhoeae. There was no difference in the MIC50 and MIC90 of azithromycin in these groups of isolates. The percentage agreement within the acceptable +/-1 log2 dilution difference between MICs obtained by E-test and those obtained by the agar dilution method was 97.8%.

CONCLUSIONS

Azithromycin has a very good in vitro antigonococcal activity, and the E-test is a reliable method to determine the MIC of azithromycin against N. gonorrhoeae.

Update on chancroid: an important cause of genital ulcer disease

Chancroid is a major cause of genital ulcer disease worldwide, and occurred at epidemic rates in the United States in the late 1980s. Though the recent epidemic in the U.S. appears to be waning, a number of areas continue to report significant numbers of cases. Chancroid is a particular concern, because, like other diseases that cause genital ulceration, it is associated with an increased risk for transmission or acquisition of human immunodeficiency virus (HIV). Recent studies have advanced the understanding of chancroid epidemiology, and new diagnostic tests may improve the ability to recognize and appropriately treat chancroid. Increased awareness of chancroid, with appropriate treatment for suspected lesions, along with public health efforts to implement prevention in high-risk populations, will be critical to prevent ongoing transmission of chancroid, and potentially ongoing transmission of HIV.

Treatment of syphilis with azithromycin

The efficacy of oral azithromycin (500 mg daily for 10 days or 500 mg on alternate days for 11 days) in 100 patients with seropositive syphilis was studied. Clinical manifestations regressed more rapidly in azithromycin-treated patients compared with patients who received erythromycin or penicillin, and there was also a more rapid reduction in serum antibody levels. In 90.3% of patients, the complete resolution of classic serological tests was observed within 4 months of completion of the azithromycin treatment. The immobilization (TPI) test and absorbed fluorescent treponema antibody tests became negative 12 months after treatment in 40% of patients. After 4 years of follow-up, no symptoms of neurosyphilis or syphilitic changes of visceral organs were observed.

Treatment of chancroid with azithromycin

A randomized, comparative study undertaken in Nairobi, Kenya and a non-comparative evaluation undertaken in Carletonville, South Africa have both shown that a single oral dose of azithromycin 1 g is effective in the treatment of the genital ulcer disease (GUD), chancroid, with cure rates of 89% and 92% recorded respectively. While treatment failure was associated with human immunodeficiency virus seropositivity and lack of circumcision in Kenya, no such association could be found in the South African study. In both series, azithromycin treatment resulted in cure of both Haemophilus ducreyi culture-positive and culture-negative cases of GUD, including two cases subsequently diagnosed as lymphogranuloma venereum. A combination of single-dose azithromycin with single-dose benzathine penicillin may provide effective 'single-visit' syndromic treatment for GUD in many developing countries.