Self-application of aminoglycoside-based creams to treat cutaneous leishmaniasis in travelers

BACKGROUND

In endemic foci, the use of an aquaphilic cream containing paromomycin with/without gentamicin to treat cutaneous leishmaniasis (CL) is safe, painless and cures 78-82% of patients with New and Old World CL. Self-application in travelers requires evaluation.

METHODS

Travelers with 1-10 lesions of confirmed CL were prospectively treated with the paromomycin-gentamicin formulation (WR279396, 2012-2017, Group 1) and carefully follow up, or treated with a locally produced paromomycin-only cream (2018-2022, Group 2). The cream was applied once under supervision, then self-applied daily for 20-30 days. A cured lesion was defined as 100% re-epithelialization at day 42 without relapse at three months.

RESULTS

Medical features were similar in Group 1 (17 patients), and Group 2 (23 patients). Patients were infected with either Leishmania major, L. infantum, L. killicki, L. guyanensis, L. braziliensis, or L. naiffi. Intention-to-treat and per-protocol cure rates were 82% (95% confidence interval (CI) [64.23;100.00]) and 87% (95% CI [71,29;100.00]) in Group 1, and 69% (95% CI [50.76; 88.37]) and 76% (95% CI [57.97; 94.41]) in Group 2. In the pooled Group 1&2, 75% (95% CI [61.58;88.42]) (30/40) and 81% (95% CI [68,46;93.6]) (30/37) of patients were cured in intention-to-treat and per-protocol, respectively. There were no significant differences observed in the success rates between Old World and New World CL (83.3% vs. 60%, p = 0.14). Prospective observations in Group 1 showed that adverse events were mainly pruritus (24%) and pain (18%) on lesions (all mild or moderate). No mucosal involvement was observed in either group.

DISCUSSION

In this representative population of travelers who acquired CL either in the Old or New World, the 81% per-protocol cure rate of a self-applied aminoglycoside cream was similar to that observed in clinical trials.

Hydroxychloroquine to prevent SARS-CoV-2 infection among healthcare workers: early termination of a phase 3, randomised, open-label, controlled clinical trial

OBJECTIVE

To assess the effectiveness and safety of hydroxychloroquine (HCQ) prophylaxis for the prevention of SARS-CoV-2 infection in healthcare workers (HCW) on duty during the COVID-19 pandemic.

RESULTS

A total of 68 HCWs met the eligibility criteria were randomly allocated to receive HCQ (n = 36) or not (n = 32). There were no significant differences between groups in respects to age, gender, or medical history. Eight participants met the primary efficacy endpoint of SAR-CoV-2 infection during the study period; there was no difference in incidence of SARS-CoV-2 infections between both study arms (HCQ: 5 vs Control: 3, p = 0.538). The relative risk of SARS-CoV-2 infection in the HCQ arm was 1.69 compared to the control group (95%CI 0.41-7.11, p = 0.463); due to poor participant accrual, the resulting statistical power of the primary efficacy outcome was 11.54%. No serious adverse events occurred; however, two (2/36, 5.6%) participants no longer wished to participate in the study and withdrew consent due to recurring grade 1 and 2 adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04414241. (Registered on June 4, 2020).

Effectiveness of Whole-Virus COVID-19 Vaccine among Healthcare Personnel, Lima, Peru

In February 2021, Peru launched a COVID-19 vaccination campaign among healthcare personnel using an inactivated whole-virus vaccine. The manufacturer recommended 2 vaccine doses 21 days apart. We evaluated vaccine effectiveness among an existing multiyear influenza vaccine cohort at 2 hospitals in Lima. We analyzed data on 290 participants followed during February-May 2021. Participants completed a baseline questionnaire and provided weekly self-collected nasal swab samples; samples were tested by real-time reverse transcription PCR. Median participant follow-up was 2 (range 1-11) weeks. We performed multivariable logistic regression and adjusted for preselected characteristics. During the study, 25 (9%) participants tested SARS-CoV-2-positive. We estimated adjusted vaccine effectiveness at 95% (95% CI 70%-99%) among fully vaccinated participants and 100% (95% CI 88%-100%) among partially vaccinated participants. These data can inform the use and acceptance of inactivated whole-virus vaccine and support vaccination efforts in the region.

Clinical evaluation of the BioFire Global Fever Panel for the identification of malaria, leptospirosis, chikungunya, and dengue from whole blood: a prospective, multicentre, cross-sectional diagnostic accuracy study

BACKGROUND

Acute febrile illness is a common presentation for patients at hospitals globally. Assays that can diagnose a variety of common pathogens in blood could help to establish a diagnosis for targeted disease management. We aimed to evaluate the performance of the BioFire Global Fever Panel (GF Panel), a multiplex nucleic acid amplification test performed on whole blood specimens run on the BioFire FilmArray System, in the diagnosis of several pathogens that cause acute febrile illness.

METHODS

We did a prospective, multicentre, cross-sectional diagnostic accuracy study to evaluate the GF Panel. Consenting adults and children older than 6 months presenting with fever in the previous 2 days were enrolled consecutively in sub-Saharan Africa (Ghana, Kenya, Tanzania, Uganda), southeast Asia (Cambodia, Thailand), central and South America (Honduras, Peru), and the USA (Washington, DC; St Louis, MO). We assessed the performance of six analytes (chikungunya virus, dengue virus [serotypes 1-4], Leptospira spp, Plasmodium spp, Plasmodium falciparum, and Plasmodium vivax or Plasmodium ovale) on the GF Panel. The performance of the GF Panel was assessed using comparator PCR assays with different primers followed by bidirectional sequencing on nucleic acid extracts from the same specimen. We calculated the positive percent agreement and negative percent agreement of the GF Panel with respect to the comparator assays. This study is registered with ClinicalTrials.gov, NCT02968355.

FINDINGS

From March 26, 2018, to Sept 30, 2019, 1965 participants were enrolled at ten sites worldwide. Of the 1875 participants with analysable results, 980 (52·3%) were female and the median age was 22 years (range 0-100). At least one analyte was detected in 657 (35·0%) of 1875 specimens. The GF Panel had a positive percent agreement for the six analytes evaluated as follows: chikungunya virus 100% (95% CI 86·3-100), dengue virus 94·0% (90·6-96·5), Leptospira spp 93·8% (69·8-99·8), Plasmodium spp 98·3% (96·3-99·4), P falciparum 92·7% (88·8-95·6), and P vivax or P ovale 92·7% (86·7-96·6). The GF Panel had a negative percent agreement equal to or greater than 99·2% (98·6-99·6) for all analytes.

INTERPRETATION

This 1 h sample-to-answer, molecular device can detect common causative agents of acute febrile illness with excellent positive percent agreement and negative percent agreement directly in whole blood. The targets of the assay are prevalent in tropical and subtropical regions globally, and the assay could help to provide both public health surveillance and individual diagnoses.

FUNDING

BioFire Defense, Joint Project Manager for Medical Countermeasure Systems and US Army Medical Materiel Development Activity, and National Institute of Allergy and Infectious Diseases.

375. High Laboratory-confirmed SARS-CoV-2 Attack Rate in Lima Health Care Personnel During August 2020-March 2021 Suggests Role for Improved Infection Control

Background

Peru has one of the highest per capita SARS-CoV-2 death rates in Latin America. Healthcare workers (HCW) are a critical workforce during the COVID-19 pandemic but are themselves often at increased risk of infection. We evaluated SARS-CoV-2 attack rate and risk factors among frontline HCWs.

Methods

We performed a prospective cohort study of HCW serving two acute care hospitals in Lima, Peru from Aug 2020 to Mar 2021. Participants had baseline SARS-CoV-2 serology using the CDC ELISA, active symptom monitoring, and weekly respiratory specimen collection with COVID-19 exposure/risk assessment for 16-weeks regardless of symptoms. Respiratory specimens were tested by real-time reverse transcriptase PCR (rRT-PCR).

Results

Of 783 eligible, 667 (85%) HCW were enrolled (33% nurse assistants, 29% non-clinical staff, 26% nurses, 7% physicians, and 6% other). At baseline and prior to COVID-19 vaccine introduction, 214 (32.1%; 214/667) were reactive for SARS-CoV-2 antibodies. In total, 72 (10.8%; 72/667) HCWs were found to be rRT-PCR positive during weekly follow-up. Of the rRT-PCR positive HCWs, 37.5% (27/72) did not report symptoms within 1-week of specimen collection. During follow up, HCW without detectable SARS-CoV-2 antibodies at baseline were significantly more likely to be rRT-PCR positive (65/453, 14.3%) compared to those with SARS-CoV-2 antibodies at baseline (4/214, 1.9%) (p-value: < 0.001). Three HCW were both serologically reactive and rRT-PCR positive at baseline. Looking only at HCW without SARS-CoV-2 antibodies, nurse assistants (rRT-PCR positive: 18.6%; 27/141) and non-clinical healthcare workers (16.5%; 21/127) were at greater risk of infection compared to nurses (8.5%; 10/118), physicians (7.9%; 3/38), and other staff (10.3%; 4/29) (RR 1.95;95%CI 1.2,3.3; p-value: 0.01).

Conclusion

Baseline SARS-CoV-2 prevalence and 16-week cumulative incidence were substantial in this pre-vaccination Peruvian HCW cohort. Almost 40% of new infections occurred in HCW without complaint of symptoms illustrating a limitation of symptom-based HCW screening for COVID-19 prevention. Nurse assistants and non-clinical healthcare workers were at greater risk of infection indicating a role for focused infection prevention and risk reduction strategies for some groups of HCW.

Disclosures

Fernanda C. Lessa, MD, MPH, Nothing to disclose

Guillain-Barré Syndrome Outbreak in Peru 2019 Associated With Campylobacter jejuni Infection

OBJECTIVE

To identify the clinical phenotypes and infectious triggers in the 2019 Peruvian Guillain-Barré syndrome (GBS) outbreak.

METHODS

We prospectively collected clinical and neurophysiologic data of patients with GBS admitted to a tertiary hospital in Lima, Peru, between May and August 2019. Molecular, immunologic, and microbiological methods were used to identify causative infectious agents. Sera from 41 controls were compared with cases for antibodies to Campylobacter jejuni and gangliosides. Genomic analysis was performed on 4 C jejuni isolates.

RESULTS

The 49 included patients had a median age of 44 years (interquartile range [IQR] 30-54 years), and 28 (57%) were male. Thirty-two (65%) had symptoms of a preceding infection: 24 (49%) diarrhea and 13 (27%) upper respiratory tract infection. The median time between infectious to neurologic symptoms was 3 days (IQR 2-9 days). Eighty percent had a pure motor form of GBS, 21 (43%) had the axonal electrophysiologic subtype, and 18% the demyelinating subtype. Evidence of recent C jejuni infection was found in 28/43 (65%). No evidence of recent arbovirus infection was found. Twenty-three cases vs 11 controls (OR 3.3, confidence interval [CI] 95% 1.2-9.2, p < 0.01) had IgM and/or IgA antibodies against C jejuni. Anti-GM1:phosphatidylserine and/or anti-GT1a:GM1 heteromeric complex antibodies were strongly positive in cases (92.9% sensitivity and 68.3% specificity). Genomic analysis showed that the C jejuni strains were closely related and had the Asn51 polymorphism at cstII gene.

CONCLUSIONS

Our study indicates that the 2019 Peruvian GBS outbreak was associated with C jejuni infection and that the C jejuni strains linked to GBS circulate widely in different parts of the world.

Topical paromomycin for New World cutaneous leishmaniasis

Background

Paromomycin-based topical treatments were shown to be effective in curing cutaneous leishmaniasis (CL) lesions caused by Leishmania major in Tunisia. Cure rates of an index lesion were approximately 80%. As a follow on, we conducted a similar Phase 3 trial in Panama to demonstrate the efficacy of these treatments against New World species. The primary objective was to determine if a combination topical cream (paromomycin-gentamicin) resulted in statistically superior final clinical cure rates of an index lesion compared to a paromomycin alone topical cream for the treatment of CL, primarily caused by Leishmania panamensis.

Methods

We conducted a randomized, double blind, Phase 3 trial of topical creams for the treatment of CL caused by Leishmania spp. Three hundred ninety nine patients with one to ten CL lesions were treated by topical application once daily for 20 days. The primary efficacy endpoint was percentage of subjects with clinical cure of an index lesion confirmed to contain Leishmania with no relapse.

Results

The clinical cure of the index lesion for paromomycin-gentamicin was 79% (95% CI; 72 to 84) and for paromomycin alone was 78% (95% CI; 74 to 87) (p = 0.84). The most common adverse events considered related to study cream application were mild to moderate dermatitis, pain, and pruritus.

Conclusions

Superiority of paromomycin-gentamicin was not demonstrated. However, the approximately 80% cure rates for both topical creams were similar to those demonstrated in Tunisia and previously reported with parenteral antimonials.

Leishmaniasis, a neglected parasitic infection transmitted by the bite of a female sand fly, is endemic in 98 countries or territories with approximately 0.7 to 1.2 million cutaneous leishmaniasis (CL) cases occurring each year. In Panama, most of the CL cases are caused by L. panamensis and, the first line of treatment is pentavalent antimony, given parenterally for 20 days. These systemic regimen is associated with toxicities that can limit the patient from receiving a full course of treatment. Alternative therapies are needed particularly for patients with mild disease, no mucosal involvement, no immunosuppression, and for patients living in areas with scarce infrastructure. Therefore, less toxic, non-parenteral new therapies against CL are urgently needed. We conducted a comparative clinical study that evaluated Paromomycin topical creams (Paromomycin alone versus Paromomycin+Gentamicin) for the treatment of cutaneous leishmaniasis (n = 399) in three sites of country. Our study demonstrated the efficacy of these preparations against New World leishmanial species (mostly L. panamensis) with a cure rate close to 80%.

Our trial supports Paromomycin as a viable alternative treatment for CL caused for the New World Leishmania species.

Harmonized clinical trial methodologies for localized cutaneous leishmaniasis and potential for extensive network with capacities for clinical evaluation

Introduction

Progress with the treatment of cutaneous leishmaniasis (CL) has been hampered by inconsistent methodologies used to assess treatment effects. A sizable number of trials conducted over the years has generated only weak evidence backing current treatment recommendations, as shown by systematic reviews on old-world and new-world CL (OWCL and NWCL).

Materials and methods

Using a previously published guidance paper on CL treatment trial methodology as the reference, consensus was sought on key parameters including core eligibility and outcome measures, among OWCL (7 countries, 10 trial sites) and NWCL (7 countries, 11 trial sites) during two separate meetings.

Results

Findings and level of consensus within and between OWCL and NWCL sites are presented and discussed. In addition, CL trial site characteristics and capacities are summarized.

Conclusions

The consensus reached allows standardization of future clinical research across OWCL and NWCL sites. We encourage CL researchers to adopt and adapt as required the proposed parameters and outcomes in their future trials and provide feedback on their experience. The expertise afforded between the two sets of clinical sites provides the basis for a powerful consortium with potential for extensive, standardized assessment of interventions for CL and faster approval of candidate treatments.

The term ‘cutaneous leishmaniasis’ (CL) includes a range of manifestations affecting the skin caused by Leishmania parasites across several continents. While not life-threatening, CL can be invalidating and disfiguring, or become complicated. Today, there is no satisfactory treatment for CL that is effective and safe. Faced with no investments into developing drugs for CL, clinical researchers have tried many treatments over the years, but little progress has been made. One of the reasons is the lack of standardized methodologies in conducting these trials which makes it difficult to collate and compare results. Clinical researchers now realize that their efforts can be brought to fruition if common methodologies are available and applied. This paper summarizes the principles and parameters agreed upon by researchers of how to identify patients and how to measure treatment effects in a way that will make it possible to gather convincing evidence of whether a treatment works or not. Adhering to these principles will allow faster progress towards offering better care to patients with this neglected disease.

Accelerating to Zero: Strategies to Eliminate Malaria in the Peruvian Amazon

AbstractIn February 2014, the Malaria Elimination Working Group, in partnership with the Peruvian Ministry of Health (MoH), hosted its first international conference on malaria elimination in Iquitos, Peru. The 2-day meeting gathered 85 malaria experts, including 18 international panelists, 23 stakeholders from different malaria-endemic regions of Peru, and 11 MoH authorities. The main outcome was consensus that implementing a malaria elimination project in the Amazon region is achievable, but would require: 1) a comprehensive strategic plan, 2) the altering of current programmatic guidelines from control toward elimination by including symptomatic as well as asymptomatic individuals for antimalarial therapy and transmission-blocking interventions, and 3) the prioritization of community-based active case detection with proper rapid diagnostic tests to interrupt transmission. Elimination efforts must involve key stakeholders and experts at every level of government and include integrated research activities to evaluate, implement, and tailor sustainable interventions appropriate to the region.

Antileishmanial Activity of Compounds Derived from the Medicines for Malaria Venture Open Access Box Against Intracellular Leishmania major Amastigotes

Leishmaniasis is a complex tropical disease caused by kinetoplastid parasitic protozoa of the genus Leishmania and is transmitted by the sand fly insect vector. Cutaneous leishmaniasis (CL) is the most common form of this disease, and CL infections often result in serious skin lesions and scars. CL remains a public health problem in many endemic countries worldwide because of the absence of effective, safe, and cost-effective drugs for treatment. One of the strategies we chose to use to find novel chemical entities worthy of further development as antileishmanials involved screening synthetic and natural products libraries. In our study, we developed a Leishmania major intracellular amastigote assay that uses the activity of luciferase as a measure of parasite proliferation and used this assay to screen a collection of 400 compounds obtained from Medicines for Malaria Venture (MMV) for their antileishmanial activity. Our results showed that 14 compounds identified by MMV as antimalarial drugs have antileishmanial activity and can potentially be optimized for CL drug development.

Direct comparison of the efficacy and safety of oral treatments with oleylphosphocholine (OlPC) and miltefosine in a mouse model of L. major cutaneous leishmaniasis

Background

Cutaneous leishmaniasis (CL) represents a range of skin diseases caused by infection with Leishmania parasites and associated with tissue inflammation and skin ulceration. CL is clinically widespread in both the Old and New World but lacks treatments that are well tolerated, effective and inexpensive. Oleylphosphocholine (OlPC) is a new orally bioavailable drug of the alkylphosphocholine family with potent antileishmanial activity against a broad range of Leishmania species/strains.

Methodology/principal findings

The potential of OlPC against Old World CL was evaluated in a mouse model of Leishmania (L.) major infection in BALB/c mice. Initial dose-response experiments showed that an oral daily dose of 40 mg/kg of OlPC was needed to impact time to cure and lesion sizes. This dose was then used to directly compare the efficacy of OlPC to the efficacy of the antileishmanial drugs miltefosine (40 mg/kg/day), fluconazole (160 mg/kg/day) and amphotericin B (25 mg/kg/day). OlPC, miltefosine and fluconazole were given orally for 21 days while amphotericin B was administered intraperitoneally for 10 days. Ulcer sizes and animal weights were followed up on a weekly basis and parasitemia was determined by means of a real-time in vivo imaging system which detects luminescence emitted from luciferase-expressing infecting L. major parasites. Amphotericin B and OlPC showed excellent efficacy against L. major lesions in terms of reduction of parasitic loads and by inducing complete healing of established lesions. In contrast, treatment with miltefosine did not significantly affect parasitemia and lesion sizes, while fluconazole was completely ineffective at the dose regimen tested.

Conclusions/Significance

Given the data showing the outstanding efficacy and tolerability of OlPC, our results suggest that OlPC is a promising new drug candidate to improve and simplify current clinical management of L. major CL.

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease transmitted to humans by sandflies and characterized by local ulcerative skin lesions. The disease is linked to poverty in the Middle-East, North and East Africa, South-Central Asia and South America, with 0.7 to 1.2 million new annual cases estimated. In most endemic regions CL treatment relies on injections with pentavalent antimonials, old generation drugs with considerable side effects and long treatment regimens. CL is therefore a highly undertreated disease in need of easy-to-administer, orally bioavailable and well-tolerated agents with broad clinical activity. To date, the only oral drug with acceptable efficacy against leishmaniasis is miltefosine, an alkylphosphocholine with a narrow therapeutic window that limits its use. Given the existing clinical need for CL, we tested the efficacy of oleylphosphocholine (OlPC) in a validated mouse model of Old World (Leishmania major) CL. OlPC is a new orally bioavailable drug of the same family as miltefosine with potent and broad leishmanicidal activity. In direct comparison with miltefosine, our results indicate that OlPC induces higher parasite clearance and lesion healing with measurable improved tolerance. These promising observations warrant further research on OlPC as a new drug to improve clinical management of CL.

Randomized, double-blinded, phase 2 trial of WR 279,396 (paromomycin and gentamicin) for cutaneous leishmaniasis in Panama

In this randomized, double-blinded Phase 2 trial, 30 patients with Leishmania panamensis cutaneous leishmaniasis were randomly allocated (1:1) to receive once daily topical treatment with WR 279,396 (15% paromomycin + 0.5% gentamicin) or Paromomycin Alone (15% paromomycin) for 20 days. The index lesion cure rate after 6 months follow-up was 13 of 15 (87%) for WR 279,396 and 9 of 15 (60%) for Paromomycin Alone (P = 0.099). When all treated lesions were included, the final cure rate for WR 279,398-treated patients was again 87%, but the final cure rate for Paromomycin Alone-treated patients was 8 of 15 (53.3%; P = 0.046). Both creams were well tolerated with mild application site reactions being the most frequent adverse event. The increased final cure rate in the WR 279,396 group in this small Phase 2 study suggests that the combination product may provide greater clinical benefit than paromomycin monotherapy against L. panamensis cutaneous leishmaniasis.

Contributions of the Global Emerging Infections Surveillance and Response System Network to global health security in 2011

In its 15th year, the Global Emerging Infections Surveillance and Response System (GEIS) continued to make significant contributions to global public health and emerging infectious disease surveillance worldwide. As a division of the US Department of Defense's Armed Forces Health Surveillance Center since 2008, GEIS coordinated a network of surveillance and response activities through collaborations with 33 partners in 76 countries. The GEIS was involved in 73 outbreak responses in fiscal year 2011. Significant laboratory capacity-building initiatives were undertaken with 53 foreign health, agriculture and/or defense ministries, as well as with other US government entities and international institutions, including support for numerous national influenza centers. Equally important, a variety of epidemiologic training endeavors reached over 4,500 individuals in 96 countries. Collectively, these activities enhanced the ability of partner countries and the US military to make decisions about biological threats and design programs to protect global public health as well as global health security.

Drug discovery algorithm for cutaneous leishmaniasis

Cutaneous leishmaniasis is clinically widespread but lacks treatments that are effective and well tolerated. Because all present drugs have been grandfathered into clinical use, there are no examples of a pre-clinical product evaluation scheme that lead to new candidates for formal development. To provide oral agents for development targeting cutaneous leishmaniasis, we have implemented a discovery scheme that incorporates in vitro and in vivo testing of efficacy, toxicity, and pharmacokinetics/metabolism. Particular emphasis is placed on in vivo testing, progression from higher-throughput models to those with most clinical relevance, and efficient use of resources.

An in vivo drug screening model using glucose-6-phosphate dehydrogenase deficient mice to predict the hemolytic toxicity of 8-aminoquinolines

Anti-malarial 8-aminoquinolines drugs cause acute hemolytic anemia in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDD). Efforts to develop non-hemolytic 8-aminoquinolines have been severely limited caused by the lack of a predictive in vivo animal model of hemolytic potential that would allow screening of candidate compounds. This report describes a G6PDD mouse model with a phenotype closely resembling the G6PDD phenotype found in the African A-type G6PDD human. These G6PDD mice, given different doses of primaquine, which used as a reference hemolytic drug, display a full array of hemolytic anemia parameters, consistently and reproducibly. The hemolytic and therapeutic indexes were generated for evaluation of hemotoxicity of drugs. This model demonstrated a complete hemolytic toxicity response to another known hemolytic antimalarial drug, pamaquine, but no response to non-hemolytic drugs, chloroquine and mefloquine. These results suggest that this model is suitable for evaluation of selected 8-AQ type candidate antimalarial drugs for their hemolytic potential.

Methodology of clinical trials aimed at assessing interventions for cutaneous leishmaniasis

The current evidence-base for recommendations on the treatment of cutaneous leishmaniasis (CL) is generally weak. Systematic reviews have pointed to a general lack of standardization of methods for the conduct and analysis of clinical trials of CL, compounded with poor overall quality of several trials. For CL, there is a specific need for methodologies which can be applied generally, while allowing the flexibility needed to cover the diverse forms of the disease. This paper intends to provide clinical investigators with guidance for the design, conduct, analysis and report of clinical trials of treatments for CL, including the definition of measurable, reproducible and clinically-meaningful outcomes. Having unified criteria will help strengthen evidence, optimize investments, and enhance the capacity for high-quality trials. The limited resources available for CL have to be concentrated in clinical studies of excellence that meet international quality standards.

Solid evidence is needed to decide how to treat conditions. In the case of cutaneous leishmaniasis, the diversity of clinical conditions, combined with the heterogeneity and weaknesses of the methodologies used in clinical trials, make it difficult to derive robust conclusions as to which treatments should be used. There also other imperatives - ethical (not exposing patients to treatments that cannot be assessed adequately) and financial (optimize use of limited resources for a neglected condition). This paper is meant to provide clinical investigators with guidance for the design, conduct, analysis and report of clinical trials to assess the efficacy and safety of treatments of this condition.

Topical paromomycin with or without gentamicin for cutaneous leishmaniasis

BACKGROUND

There is a need for a simple and efficacious treatment for cutaneous leishmaniasis with an acceptable side-effect profile.

METHODS

We conducted a randomized, vehicle-controlled phase 3 trial of topical treatments containing 15% paromomycin, with and without 0.5% gentamicin, for cutaneous leishmaniasis caused by Leishmania major in Tunisia. We randomly assigned 375 patients with one to five ulcerative lesions from cutaneous leishmaniasis to receive a cream containing 15% paromomycin-0.5% gentamicin (called WR 279,396), 15% paromomycin alone, or vehicle control (with the same base as the other two creams but containing neither paromomycin nor gentamicin). Each lesion was treated once daily for 20 days. The primary end point was the cure of the index lesion. Cure was defined as at least 50% reduction in the size of the index lesion by 42 days, complete reepithelialization by 98 days, and absence of relapse by the end of the trial (168 days). Any withdrawal from the trial was considered a treatment failure.

RESULTS

The rate of cure of the index lesion was 81% (95% confidence interval [CI], 73 to 87) for paromomycin-gentamicin, 82% (95% CI, 74 to 87) for paromomycin alone, and 58% (95% CI, 50 to 67) for vehicle control (P<0.001 for each treatment group vs. the vehicle-control group). Cure of the index lesion was accompanied by cure of all other lesions except in five patients, one in each of the paromomycin groups and three in the vehicle-control group. Mild-to-moderate application-site reactions were more frequent in the paromomycin groups than in the vehicle-control group.

CONCLUSIONS

This trial provides evidence of the efficacy of paromomycin-gentamicin and paromomycin alone for ulcerative L. major disease. (Funded by the Department of the Army; ClinicalTrials.gov number, NCT00606580.).

Treatment of cutaneous leishmaniasis with a topical antileishmanial drug (WR279396): phase 2 pilot study

We studied the efficacy of WR279396, a topical formulation of aminoglycosides that cures 100% of cutaneous leishmaniasis lesions in mice. We conducted what is to our knowledge the first controlled study of WR279396 therapy for clinical cutaneous leishmaniasis. A total of 45 Colombian soldiers, all men, were randomly assigned to treatment with WR279396 (33 patients) or placebo (12 patients). Each lesion was treated twice daily for 20 days. Lesions were measured at the end of therapy and at 45, 90, and 180 days after treatment began. A total of 17 (61%) of 28 assessable WR279396-treated patients were cured, and 5 (55%) of 9 assessable placebo-treated patients were cured (P = 0.9). For the 36 lesions treated with WR279396 that were cured, cure took a mean of 35 days, whereas for the 6 lesions that were cured in the group of patients receiving placebo, cure time took a mean of 56 days (P = 0.04). WR279396 is a nontoxic topical formulation that significantly accelerated cure time in patients with Leishmania panamensis cutaneous leishmaniasis.

Phase 2 trial of WR6026, an orally administered 8-aminoquinoline, in the treatment of visceral leishmaniasis caused by Leishmania chagasi

There are no recognized orally administered treatments for any of the leishmaniases. The 8-aminoquinoline WR6026 is an orally administered analog of primaquine that cured 50% of patients with kala-azar in Kenya at a dose of 1 mg/kg/day for 28 days. A further phase 2, open-label, dose-escalating safety and efficacy study was performed for kala-azar in Brazil. Cure rates for Brazilian patients treated for 28 days were as follows: 1 mg/kg/day: 0 of 4 (0%); 1.5 mg/kg/day: 1 of 6 (17%); 2.0 mg/kg/day: 4 of 6 (67%); 2.5 mg/kg/day: 1 of 5 (20%); and 3.25 mg/kg/day: 0 of 1 (0%). Nephrotoxicity that was not anticipated from preclinical animal studies or from phase 1 studies was seen at 2.5 mg/kg/day in 2 patients and in the single patient administered 3.25 mg/kg/day. WR6026 demonstrated the unusual clinical features of lack of increased efficacy against Brazilian kala-azar with increased dosing above 2 mg/kg/day and toxicity that was not present in previous investigations.

Malaria in Brazilian military personnel deployed to Angola

BACKGROUND

Malaria represents one of the most important infectious disease threats to deployed military forces; most personnel from developed countries are nonimmune personnel and are at high risk of infection and clinical malaria. This is especially true for forces deployed to highly-endemic areas in Africa and Southeast Asia where drug-resistant malaria is common.

METHODS

We conducted an outbreak investigation of malaria cases in Angola where a total of 439 nonimmune Brazilian troops were deployed for a 6-month period in 1995-1996. A post-travel medical evaluation was also performed on 338 (77%) of the 439 soldiers upon return to Brazil. Questionnaire, medical record, thick/thin smear, and serum anti-Plasmodium falciparum antibody titer (by IFA) data were obtained. Peak serum mefloquine (M) and methylmefloquine (MM) metabolite levels were measured in a subsample of 66 soldiers (42 cases, 24 nonmalaria controls) who were taking weekly mefloquine prophylaxis (250 mg).

RESULTS

Seventy-eight cases of malaria occurred among the 439 personnel initially interviewed in Angola (attack rate = 18%). Four soldiers were hospitalized, and 3 subsequently died of cerebral malaria. Upon return to Brazil, 63 (19%) of 338 soldiers evaluated were documented to have had clinical symptoms and a diagnosis of malaria while in Angola. In addition, 37 (11%) asymptomatically infected individuals were detected upon return (< 1% parasitemia). Elevated, post-travel anti-P. falciparum IFA titers (> or = 1:64) were seen in 101 (35%) of 292 soldiers tested, and was associated with a prior history of malaria in-country (OR = 3.67, 95% CI 1.98-6.82, p <.001). Noncompliance with weekly mefloquine prophylaxis (250 mg) was associated with a malaria diagnosis in Angola (OR = 3.75, 95% CI 0.97-17.41, p =.03) but not with recent P. falciparum infection (by IFA titer). Mean peak levels (and ratios) of serum M and MM were also found to be lower in those who gave a history of malaria while in Angola.

CONCLUSIONS

Malaria was a significant cause of morbidity among Brazilian Army military personnel deployed to Angola. Mefloquine prophylaxis appeared to protect soldiers from clinical, but not subclinical, P. falciparum infections. Mefloquine noncompliance and an erratic chemoprophylaxis prevention policy contributed to this large outbreak in nonimmune personnel. This report highlights the pressing need for development of newer, more efficacious and practical, prophylactic drug regimens that will reduce the malaria threat to military forces and travelers.

Humoral immune responses among mucosal and cutaneous leishmaniasis patients caused by Leishmania braziliensis

Mucosal leishmaniasis is arguably the most morbid sequelae of cutaneous leishmaniasis. The importance of early diagnosis for effective therapy, coupled with the difficulty of diagnosing the disease parasitologically, prompted this investigation of humoral immune markers of mucosal disease. Promastigote soluble antigens of Leishmania braziliensis, isolated from cutaneous and mucosal lesions, were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis; antigens were identified by immunoblotting with parasite-specific IgG antibody-positive sera of patients with mucosal disease (n = 18) and cutaneous disease (n = 23). For antigens of the cutaneous parasite WR 2095, mucosal sera generally reacted intensely to antigens of 75, 66, and 45 kDa and weakly to 48-50-kDa antigens, whereas cutaneous sera generally detected weakly the first 3 antigens and intensely the latter doublet. The data suggest that the transition from the cutaneous antigenic profile to a mucosal antigenic profile could be used to predict mucosal disease in approximately half of mucosal patients. An additional finding was that antibodies present in the sera of patients with mucosal disease labeled a 66-kDa peptide of normal human lip mucosa more intensely than did cutaneous sera. Autoimmune processes stimulated by the reaction of IgG, originally directed against the 66-kDa of L. braziliensis, to the 66-kDa antigen of mucosal tissue may contribute to the clinical presentation of mucosal leishmaniasis.

Successful topical treatment of murine cutaneous leishmaniasis with a combination of paromomycin (Aminosidine) and gentamicin

Cutaneous leishmaniasis is presently treated with 20 days of parenteral therapy with a frequently toxic drug (antimony). Topical formulations of paromomycin (15%) plus methylbenzethonium chloride (MBCL, 12%) or plus urea (10%) in soft white paraffin have been tested for Old and New World disease in humans. We compared the efficacy of a new topical formulation, WR 279,396 (paromomycin [15%] plus gentamicin [0.5%]) to the clinical formulations in the treatment of cutaneous disease in BALB/c mice. Sixty-day-old lesions were treated twice a day for 10 days, and the response to therapy was determined over a further 70 days. For ulcers due to Leishmania major or to Leishmania mexicana, 100% of lesions in the WR 279,396 group healed by day 20 after therapy and did not relapse by day 70; 83% of lesions healed without relapse in the paromomycin-MBCL group. In the paromomycin-urea group, 100% of L. major lesions healed by day 30 but 30% relapsed. For ulcers due to Leishmania panamensis or Leishmania amazonensis, all lesions treated with WR 279,396 healed and did not relapse; < 50% of lesions treated with paromomycin-MBCL healed by day 30, and all lesions relapsed by day 70. In addition to being active, WR 279,396 was not toxic in this model and appears to have a cosmetic effect (promoting hair growth, healing, and limiting the size of the scar).

Safety and efficacy of intravenous sodium stibogluconate in the treatment of leishmaniasis: recent U.S. military experience

The efficacy and toxicity of sodium stibogluconate (SSG) at a dosage of 20 mg/(kg.d) for either 20 days (for cutaneous disease) or 28 days (for visceral, mucosal, or viscerotropic disease) in the treatment of leishmaniasis is reported. Ninety-six U.S. Department of Defense health care beneficiaries with parasitologically confirmed leishmaniasis were prospectively followed for 1 year. One patient was infected with human immunodeficiency virus; otherwise, comorbidity was absent. Clinical cure occurred in 91% of 83 cases of cutaneous disease and 93% of 13 cases of visceral/viscerotropic disease. Adverse effects were common and necessitated interruption of treatment in 28% of cases, but they were generally reversible. These included arthralgias and myalgias (58%), pancreatitis (97%), transaminitis (67%), headache (22%), hematologic suppression (44%), and rash (9%). No subsequent mucosal leishmaniasis was identified, and there were no deaths attributable to SSG or leishmaniasis.

An axenic amastigote system for drug screening

Currently available primary screens for selection of candidate antileishmanial compounds are not ideal. The choices include screens that are designed to closely reflect the situation in vivo but are labor-intensive and expensive (intracellular amastigotes and animal models) and screens that are designed to facilitate rapid testing of a large number of drugs but do not use the clinically relevant parasite stage (promastigote model). The advent of successful in vitro culture of axenic amastigotes permits the development of a primary screen which is quick and easy like the promastigote screen but still representative of the situation in vivo, since it uses the relevant parasite stage. We have established an axenic amastigote drug screening system using a Leishmania mexicana strain (strain M379). A comparison of the 50% inhibitory concentration (IC50) drug sensitivity profiles of M379 promastigotes, intracellular amastigotes, and axenic amastigotes for six clinically relevant antileishmanial drugs (sodium stibogluconate, meglumine antimoniate, pentamidine, paromomycin, amphotericin B, WR6026) showed that M379 axenic amastigotes are a good model for a primary drug screen. Promastigote and intracellular amastigote IC50s differed for four of the six drugs tested by threefold or more; axenic amastigote and intracellular amastigote IC50s differed by twofold for only one drug. This shows that the axenic amastigote susceptibility to clinically used reference drugs is comparable to the susceptibility of amastigotes in macrophages. These data also suggest that for the compounds tested, susceptibility is intrinsic to the parasite stage. This contradicts previous hypotheses that suggested that the activities of antimonial agents against intracellular amastigotes were solely a function of the macrophage.

Inefficacy of allopurinol as monotherapy for Colombian cutaneous leishmaniasis. A randomized, controlled trial

BACKGROUND

Hundreds of thousands of cases of cutaneous leishmaniasis occur each year worldwide. Available therapies are parenteral, moderately toxic, and costly.

OBJECTIVE

To determine the efficacy of and tolerance for oral allopurinol as monotherapy for cutaneous leishmaniasis.

DESIGN

Randomized, controlled trial.

SETTING

Outpatient clinics in 11 regions of Colombia in which cutaneous leishmaniasis is endemic.

PATIENTS

187 otherwise healthy adults with cutaneous leishmaniasis. Eighty-four percent of patients were infected with or were from regions with Leishmania panamensis; 16% were infected or were from regions with L. braziliensis.

INTERVENTION

Patients were randomly assigned to one of three treatment groups. The first group received allopurinol, three 100-mg tablets four times daily (20 mg/kg of body weight per day) for 28 days. The second group received three placebo tablets four times daily for 28 days. The third group received Glucantime, 20 mg of intramuscular antimony/kg per day for 20 days.

MEASUREMENT

Complete cure was defined as complete clinical reepithelialization of all lesions at 3 months and no relapse during 12 months of follow-up.

RESULTS

Of 182 patients whose data could be analyzed, 157 (86%) were evaluated. In the allopurinol group, 18 of 55 (33% [95% CI, 21% to 47%]) patients were cured; in the placebo group, 17 of 46 patients (37% [CI, 23% to 52%]) were cured (difference, 4% [CI, -14% to 22%]; P = 0.68); and in the Glucantime group, 52 of 56 patients (93% [CI, 83% to 98%]) were cured (P < 0.001 compared with the allopurinol and placebo groups combined). In most cases, therapy was considered to have failed because the lesion did not reepithelialize by 1.5 months after the end of therapy. Three cases of relapse (two in the allopurinol group and one in the placebo group) at the nasal mucosa (mucosal leishmaniasis) had occurred by the end of 12 months of follow-up.

CONCLUSIONS

Allopurinol monotherapy has no effect on Colombian cutaneous disease primarily caused by L. panamensis and therefore is unlikely to be effective against cutaneous leishmaniasis in other endemic regions.

Leishmania spp: temperature sensitivity of promastigotes in vitro as a model for tropism in vivo

Since in humans, skin temperature is lower than internal temperature, the temperature sensitivity of Leishmania may influence the tropism of Leishmania in the human host; temperature-sensitive parasites may remain in the skin, temperature-resistant parasites may go to the viscera. In order to pursue the genetic factors controlling Leishmania tropism, we have developed an in vitro promastigote temperature model. Promastigote growth is measured at 30, 32, and 34 degrees C and compared with growth at the control temperature (25 degrees C). The results from tests of the promastigote temperature sensitivity of eight species (33 different strains) show that visceral species (L. donovani and L. chagasi) are more temperature resistant than cutaneous species (L. major, L. tropica, L. mexicana, L. braziliensis, L. panamensis, and L. amazonensis), that Old World species are more temperature-resistant than New World species, and that within the New World cutaneous species there are three distinct temperature sensitivity groupings (L. mexicana > L. braziliensis and L. panamensis > L. amazonensis). Interestingly, viscerotropic L. tropica from Operation Desert Storm and L. donovani complex strains isolated from cutaneous lesions are more and less temperature-sensitive, respectively, than strains of the same species with the expected tropism in vivo.

Microtubule inhibitors: structure-activity analyses suggest rational models to identify potentially active compounds

Trifluralin, a dinitroaniline microtubule inhibitor currently in use as an herbicide, has been shown to inhibit the proliferation of Plasmodium falciparum, Trypanosoma brucei, and several species of Leishmania, in vitro. As a topical formulation, trifluralin is also effective in vivo (in BALB/c mice) against Leishmania major and Leishmania mexicana. Although trifluralin and other dinitroaniline herbicides show significant activity as antiparasitic compounds, disputed indications of potential carcinogenicity will probably limit advanced development of these substances. However, researchers have suggested that the activity of trifluralin is due to an impurity or contaminant, not to trifluralin itself. We have pursued this lead and identified the structure of the active impurity. This compound, chloralin, is 100 times more active than trifluralin. On the basis of its structure, we developed a rational structure-activity model for chloralin. Using this model, we have successfully predicted and tested active analogs in a Leishmania promastigote assay; thus, we have identified the putative mechanism of action of this class of drugs in Leishmania species. Potentially, this will allow the design of noncarcinogenic, active drugs.

Efficacy of the herbicide trifluralin against four P-glycoprotein-expressing strains of Leishmania

Drug resistance has emerged as a major obstacle to chemotherapy for many infectious diseases. Trifluralin, an antimicrotubule herbicide, is a new experimental drug for treatment of leishmaniasis. Here, we found that it was effective against two strains of Leishmania that express the multidrug-resistant genes ldmdr1 and lmpgpA and two strains that express proteins that are immunologically cross-reactive with mammalian P glycoproteins. These results suggest that trifluralin is not subject to counteractions of these multidrug resistance mechanisms of Leishmania species.

Evaluation of a direct immunofluorescent antibody (DIFMA) test using Leishmania genus-specific monoclonal antibody in the routine diagnosis of cutaneous leishmaniasis

A direct immunofluorescent antibody (DIFMA) test using a Leishmania genus-specific monoclonal antibody was evaluated in the routine diagnosis of cutaneous leishmaniasis (CL) in Ecuador. This test was compared with the standard diagnostic techniques of scrapings, culture and histology. Diagnostic samples were taken from a total of 90 active dermal ulcers from patients from areas of Ecuador known to be endemic for cutaneous leishmaniasis. DIFMA was positive in all lesions. It was shown to be significantly superior to standard diagnostic methods either alone or in combination. The sensitivity of DIFMA did not diminish with chronicity of lesions. This test proved to be extremely useful in the routine diagnosis of CL because it is highly sensitive, is easy to use and produces rapid results.

Diagnosis of symptomatic visceral leishmaniasis by use of the polymerase chain reaction on patient blood

To diagnose symptomatic visceral leishmaniasis (kala-azar) using peripheral blood rather than tissue aspirates, a polymerase chain reaction (PCR) technique was developed for which the detection limit is 1 Leishmania-infected macrophage in 8 mL of blood. For Indian, Kenyan, or Brazilian patients with parasitologically confirmed kala-azar, 57 of 63 cases before treatment had blood that was PCR-positive (90% sensitivity). None of 40 clinically healthy persons had PCR-positive blood (100% specificity). Twelve (92%) of 13 clinically cured Indian patients had negative PCR reactions 1-6 months after treatment. This PCR procedure can provide a parasitologic diagnosis for the vast majority of kala-azar cases before therapy, may identify patients who have been successfully treated by chemotherapy, and should substantially reduce the need for invasive tests.

Successful treatment of New World cutaneous leishmaniasis with a combination of topical paromomycin/methylbenzethonium chloride and injectable meglumine antimonate

Colombian patients with New World cutaneous leishmaniasis were treated with a combination of a topical formulation (15% paromomycin sulfate/5% methylbenzethonium chloride, twice a day) and parenteral meglumine antimonate (20 mg of antimony [Sb]/kg.d]). Cohort 1 received topical therapy for 10 days and Sb for 7 days; 18 (90%) of the 20 patients were cured (follow-up, 12 months). Other clinical data suggested that neither the topical formulation alone nor the 7-day regimen of Sb alone would have cured many patients. In a subsequent cohort, which received topical therapy for 10 days and Sb for 3 days, the cure rate was 42% (eight of 19 patients). In Colombian cohorts (historical controls) treated with Sb alone for 10-15 days, the cure rate was 31%-36%. Side effects in cohort 1 patients consisted of local reactions to the topical formulation: burning and pruritus in 25% of patients and vesicle formation in 15% of patients. This is the first report that a regimen partially composed of topical antimicrobial agents can be highly effective for treatment of New World cutaneous leishmaniasis.

Paromomycin resistance in Leishmania tropica: lack of correlation with mutation in the small subunit ribosomal RNA gene

The aminoglycoside antibiotic paromomycin is a potentially useful anti-leishmanial chemotherapeutic agent. Resistance to this antibiotic was studied using Leishmania tropica. Promastigotes resistant to 210 micrograms/ml of paromomycin were selected by exposing them to gradual increments of this drug. Previous work in Escherichia coli, Tetrahymena, and yeast mitochondrial mutants has demonstrated mutations in the E. coli small subunit ribosomal RNA at the 1409:1491 basepair position, or equivalent positions in other organisms, resulting in basepair disruption. When the nucleotide sequence at both the DNA and RNA levels of the resistant L. tropica promastigotes cultured in the presence of paromomycin was compared with those of the drug-sensitive parent, there was no sequence change at the putative mutation site. Paromomycin resistance in L. tropica is apparently due to other mechanisms.

Limited efficacy of injectable aminosidine as single-agent therapy for Colombian cutaneous leishmaniasis

Ninety military patients with cutaneous leishmaniasis in Colombia were randomly allocated to 3 treatment regimens of parenteral aminosidine sulphate: (i) 12 mg aminosidine base/kg/d for 7 d, (ii) 12 mg/kg/d for 14 d, and (iii) 18 mg/kg/d for 14 d. With the 89 evaluable patients, the cure rates 12 months after the end of treatment were 10%, 45%, and 50%, respectively. Fifty-eight of the 66 patients who were not cured had lesions that enlarged or were unchanged by 1.5 months after treatment follow up. The other 8 patients had lesions that relapsed between 3 and 12 months after therapy. Even in group (iii) the cure rate was inferior to that (> 90%) with antimony or pentamidine previously reported in this patient population. This study indicates that parenteral aminosidine alone is less likely to be successful in the treatment of cutaneous lesihmaniasis than visceral leishmaniasis, for which a 74% cure rate has been reported. Further trials might consider the combination of aminosidine with other antileishmanial drugs.

Evidence of sexual reproduction in the protozoan parasite Leishmania (Kinetoplastida: Trypanosomatidae)

Parasitic protozoa of the genus Leishmania (Kinetoplastida: Trypanosomatidae) are generally thought to multiply by binary fission; however, data from quantitative microspectrophotometry indicate that nuclear fusion or sexual reproduction takes place in the intracellular amastigote form. Among several different Leishmania species, the mean +/- SD nuclear DNA content of all promastigotes (extracellular form) and of some amastigotes (intracellular form) in macrophages was 0.098 +/- 0.032 relative units; in contrast, other amastigotes within the same macrophage had a mean +/- SD nuclear DNA content of 0.219 +/- 0.050. The latter population of amastigotes are apparently produced when the nuclei of a pair of 0.098 amastigotes fuse. These 0.219 amastigotes later go through what is probably the typical meiotic cycle to reform the 0.098 condition we observed among promastigotes. The demonstration of sexual reproduction in Leishmania has important implications for the future direction of research on this medically important parasite.

Successful treatment of Colombian cutaneous leishmaniasis with four injections of pentamidine

We previously found that 2 mg of pentamidine isethionate/kg, administered every other day in seven injections, was 95% curative for Colombian cutaneous leishmaniasis. However, 17% of the patients had to prematurely terminate therapy due to drug toxicity and another 30% had mild-to-moderate toxic clinical reactions. In this report, we show that the same daily dose of drug, 2 mg/kg, but administered in only four every-other-day injections, resulted in an 84% cure rate in 38 patients. Twenty-one patients (55%) experienced side effects, three of which were moderate to severe. A higher daily dose of drug, 3 mg/kg, administered in four every-other-day injections, resulted in a 96% cure rate in 51 evaluable patients. Thirty-six of the treated patients (64%) experienced side effects, five of which were moderate to severe. Although hypotension and hypoglycemia were looked for in all patients, only one patient experienced hypoglycemia and it had normalized by follow-up. We propose that the regimen of 3 mg of pentamidine/kg every other day in four injections is optimal for Colombian cutaneous leishmaniasis and competitive with standard Glucantime therapy, in terms of cure rate, toxicity, length of time the patient has to be under medical supervision, and cost of drug plus medical attention. We suggest that such a short course of injectable agent be studied for the treatment of patients with cutaneous leishmaniasis from other endemic areas.

Treatment of Brazilian kala-azar with a short course of amphocil (amphotericin B cholesterol dispersion)

Amphotericin B is an effective but toxic antileishmanial agent. Lipid-encapsulated amphotericin B should have a high therapeutic index for visceral leishmaniasis because reticuloendothelial cells, the sole site in which Leishmania is found, will phagocytize and concentrate the complex. Amphotericin B cholesterol dispersion (Amphocil; 2 mg/[kg.d] intravenously) was administered to 10 Brazilians with kala-azar for 10 days (cohort 1) and to 10 Brazilians with kala-azar for 7 days (cohort 2). All patients were successfully treated: 19 of the 20 patients were without visible parasites in the bone marrow; the mean time to afebrility was 4.2 days; spleen size regressed by a mean of 79% 2 months after therapy; and no patient had clinical or laboratory abnormalities by the end of 6-12 months of follow-up. Side effects were fever and chills accompanied by respiratory distress, but not nephrotoxicity, in children < 3 years of age.

Identification and genetic comparison of leishmanial parasites causing viscerotropic and cutaneous disease in soldiers returning from Operation Desert Storm

Six Leishmania major and seven L. tropica parasites were isolated and identified from participants in Operation Desert Shield/Storm. A complete enzyme analysis (21 enzymes) revealed that there was enzyme polymorphism among the isolates of each species group. Any one Desert Storm L. major isolate could differ from any other for 1-3 enzymes, and any L. tropica isolate could differ from any one other for up to eight enzymes. Enzyme polymorphism data from other L. major and L. tropica isolates from Africa and the Middle East region were obtained and combined with the Desert Storm data to produce population enzyme polymorphism estimates. Results from these population data indicated that L. major parasites could be expected to differ from each other for as many as eight enzymes and still be L. major, and similarly, L. tropica isolates could differ for as many as 14 enzymes. These expected isolate variation extremes have not been observed among the isolates studied. All L. major and most L. tropica isolates were from patients who, as expected, presented with cutaneous disease, but the Desert Storm and two Kenyan patients infected with L. tropica presented with a viscerotropic disease, the symptoms of which are unlike those of classic visceral leishmaniasis. Such unrecognized presentation for these L. tropica-infected patients indicates that both parasite and patient can play critical roles in disease manifestations. The Desert Storm isolates are, as indicated, either L. major or L. tropica.

Survivability and infectivity of viscerotropic Leishmania tropica from Operation Desert Storm participants in human blood products maintained under blood bank conditions

To assess the potential for leishmaniasis being transmitted through blood transfusion, we studied the survival of Leishmania in blood products under blood bank storage conditions. We report that L. tropica- or L. donovani-contaminated transfusable blood products are a risk to the blood supply for at least 25 days postdonation under blood bank general conditions. The blood components that have been implicated are whole blood, packed red blood cells, platelet concentrate, and frozen-deglycerolized red blood cells, but not, as would be expected, fresh frozen plasma. Blood units containing four infected monocytes per milliliter of blood with a mean of three amastigotes per monocyte contain viable parasites for 15 days under blood bank storage conditions. Furthermore, animal studies showed the presence of parasites in the blood of cutaneously infected animals and the possibility of transmitting the disease to healthy experimental animals by blood transfusion from infected animal donors. Three of three BALB/C mice showed metastasis to the lower extremities and face after they received 0.25 ml of blood from a CPDA-1 bag seeded with 1.5 x 10(5) amastigotes per ml of blood kept under blood bank conditions for 30 days. This proves that Leishmania not only survives blood banking procedures and storage conditions but that the parasite retains its infectivity. The results of this study and the recent demonstration of L. tropica-infected monocytes in the blood of a patient returning from Southwest Asia suggests that transfusion-associated leishmaniasis can occur.

Herbicides to curb human parasitic infections: in vitro and in vivo effects of trifluralin on the trypanosomatid protozoans

Leishmaniasis is a major tropical disease for which current chemotherapies, pentavalent antimonials, are inadequate and cause severe side effects. It has been reported that trifluralin, a microtubule-disrupting herbicide, is inhibitory to Leishmania amazonensis. In this study, the in vitro effect of trifluralin on different species of trypanosomatid protozoans was determined. In addition to L. amazonensis, trifluralin is effective against Leishmania major and Leishmania tropica, which cause cutaneous infections, Leishmania donovani, which causes visceral disease, Leishmania panamensis, which may cause mucocutaneous infection, and Trypanosoma brucei, an important human and veterinary pathogen. Moreover, most encouragingly, trifluralin is effective in vivo as a topical ointment against L. major and Leishmania mexicana murine cutaneous leishmaniasis. Thus, trifluralin is a promising lead drug for several related, prevalent tropical diseases: leishmaniasis, trypanosomiasis of animals, and, possibly, African trypanosomiasis in humans.

Isolation of Leishmania mexicana (Kinetoplastida: Trypanosomatidae) from Lutzomyia anthophora (Diptera: Psychodidae) collected in Texas

Three of 27 female Lutzomyia anthophora (Addis) collected in Texas from the nest of a southern plains woodrat, Neotoma micropus Baird, during October 1991 were infected with flagellate protozoans. Isolates were grown in Schneider's Drosophila medium supplemented with 20% fetal bovine serum, and isozyme analysis of two of the isolates determined the parasites to be Leishmania mexicana (Biagi). These are the first isolations of Leishmania from field-collected sand flies in North America north of Mexico. Possible reasons for the lack of human cases near the focus are presented.

Evaluation of pentamidine for the treatment of cutaneous leishmaniasis in Colombia

Ninety-two patients in Colombia with cutaneous leishmaniasis were randomly assigned to groups to be treated with meglumine antimonate (infected control subjects; 10 mg of antimony/kg intramuscularly, twice a day for 20 days), pentamidine (2 mg/kg every other day intramuscularly, for a total of seven injections), or itraconazole (200 mg orally, twice a day for 28 days) or to receive no treatment (negative control subjects). In the group treated with meglumine antimonate, 21 of 23 patients healed by the first follow-up visit, 1.5 months after the end of therapy, and did not relapse (91% cure rate). In the pentamidine-treated group, 23 of 24 patients healed and did not relapse (96%). Four of the 23 pentamidine-treated patients who ultimately were cured had terminated therapy prematurely (after receiving 4-6 injections) because of hypotension (2 patients), hypoglycemia (1 patient), or headache and myalgias (1 patient). In a subsequent group of 19 patients who were administered 2 mg of pentamidine/kg every other day for a total of only four injections, 14 healed without relapse (74% cure rate). The itraconazole-treated group was similar to the no-treatment control group in terms of the number of patients for whom therapy failed (75% and 64%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Drug resistance in leishmaniasis: its implication in systemic chemotherapy of cutaneous and mucocutaneous disease

We report that in vitro sensitivity to pentavalent antimony (Sb5) of 35 Leishmania isolates as determined by the semiautomated microdilution technique (SAMT) showed an 89% and 86% correlation with clinical outcome after Pentostam and Glucantime treatment, respectively. These results suggest that in over 85% of the cases, the clinical outcome of treatment (cure or failure) could have been predicted by using the SAMT technique. Furthermore, the results clearly indicate that drug resistance is a problem, and that at least in some instances, failure to respond to treatment is due to the parasite as well as patient factors. Strains from Sb5-treated patients with American cutaneous and mucocutaneous disease who fail at least one complete course of Pentostam are as highly nonresponsive to this drug as laboratory-proven drug-resistant Leishmania strains. It was determined that some Leishmania isolates are innately less susceptible to Sb5 than others, and that moderate resistance to Sb5 exists in nature. A 10- and 17-fold increase was detected in the 50% inhibitory concentration (IC50) of Sb5 for L. mexicana and L. braziliensis isolates after subcurative treatment of the patients, when compared with the mean IC50 of seven and six isolates from the same endemic areas in Guatemala and Peru, respectively. Thus, we have correlated subcurative treatment to a decrease in drug sensitivity in at least these two cases. Collectively, these results indicate that under Sb5 pressure from undermedication, the parasites inherently most drug resistant are favored. The degree of resistance of a strain to antimony in association with host-specific factors will determine whether the clinical response to treatment with this drug is a total cure or a partial response followed by relapse(s), and possibly secondary unresponsiveness resulting in total resistance to antimony. It is evident from our in vitro test data that the SAMT is an extremely powerful and highly accurate technique for the prediction and determination of drug sensitivity of leishmanial isolates, as well as a means to screen for anti-leishmanial agents.

Characterization of a Leishmania isolate from the rodent host Neotoma micropus collected in Texas and comparison with human isolates

We report the biological and biochemical parameters of Leishmania parasites (MNEO/US/90/WR972) isolated from a rodent host, Neotoma micropus, collected in Texas. Footpad inoculations of WR972 promastigotes into BALB/c mice and Syrian hamsters resulted in ulcerating lesions six and eight weeks post-inoculation, respectively. Using monoclonal antibody-stained touch preparations, amastigotes were found in the liver of both laboratory hosts. Infection of J774 macrophages with WR972 promastigotes supported the growth of amastigotes for 12 days at 35 degrees C. The WR972 parasite was identified by enzyme electrophoresis as L. mexicana. Isozyme comparison of WR972 with 42 L. mexicana isolates (from humans and rodents) from four different endemic areas, including Texas, suggest that these parasite populations are identical for approximately 97% of their genetic loci. Pulse field gel electrophoresis (PFGE) of WR972 resolved 18 chromosomes with a size range of 300- greater than 2,000 kb. The karyotype strongly resembles that of two other Texas L. mexicana isolates from humans. Taken together, the PFGE, hybridization, and isoenzyme data suggest that the wood rat isolate (WR972) is identical to parasites from human cutaneous lesions isolated in Texas and Central America. In addition, the biological characteristics of WR972, its infectivity of BALB/c mice and the Syrian hamster, and the potential of the isolate to infect, transform, and divide in J774 macrophages indicate that WR972 will be pathogenic in humans if transmission occurs. Health care providers should consider this possibility when studying the epidemiology and control of cutaneous leishmaniasis in Texas.