Differential effects of antigens from L. braziliensis isolates from disseminated and cutaneous leishmaniasis on in vitro cytokine production

BACKGROUND: Disseminated leishmaniasis is an emerging infectious disease, mostly due to L. braziliensis, which has clinical and histopathological features distinct from cutaneous leishmaniasis. METHODS: In the current study we evaluated the in vitro production of the cytokines IFN-γ, TNF-α, IL-5 and IL-10 by peripheral blood mononuclear cells (PBMC) from 15 disseminated leishmaniasis and 24 cutaneous leishmaniasis patients upon stimulation with L. braziliensis antigens genotyped as disseminated leishmaniasis or cutaneous leishmaniasis isolates. RESULTS: Regardless of the source of L. braziliensis antigens, PBMC from cutaneous leishmaniasis patients produced significantly higher IFN-γ than PBMC from disseminated leishmaniasis patients. Levels of TNF-α by PBMC from cutaneous leishmaniasis patients were significantly higher than disseminated leishmaniasis patients only when stimulated by genotyped cutaneous leishmaniasis antigens. The levels of IL-5 and IL-10 production by PBMC were very low and similar in PBMCs from both disseminated leishmaniasis and cutaneous leishmaniasis patients. The immune response of each patient evaluated by the two L. braziliensis antigens was assessed in a paired analysis in which we showed that L. braziliensis genotyped as disseminated leishmaniasis isolate was more potent than L. braziliensis genotyped as cutaneous leishmaniasis isolate in triggering IFN-γ and TNF-α production in both diseases and IL-5 only in cutaneous leishmaniasis patients. CONCLUSION: This study provides evidence that antigens prepared from genotypically distinct strains of L. braziliensis induce different degrees of immune response. It also indicates that both parasite and host play a role in the outcome of L. braziliensis infection

Prevalence of and Factors Associated with Negative Microscopic Diagnosis of Cutaneous Leishmaniasis in Rural Peru.

Cutaneous leishmaniasis is endemic to South America where diagnosis is most commonly conducted via microscopy. Patients with suspected leishmaniasis were referred for enrollment by the Ministry of Health (MoH) in Lima, Iquitos, Puerto Maldonado, and several rural areas of Peru. A 43-question survey requesting age, gender, occupation, characterization of the lesion(s), history of leishmaniasis, and insect-deterrent behaviors was administered. Polymerase chain reaction (PCR) was conducted on lesion materials at the Naval Medical Research Unit No. 6 in Lima, and the results were compared with those obtained by the MoH using microscopy. Factors associated with negative microscopy and positive PCR results were identified using

Efficacy of Thermotherapy to Treat Cutaneous Leishmaniasis Caused by Leishmania tropica in Kabul, Afghanistan: A Randomized, Controlled Trial

BACKGROUND: Pentavalent antimony is the agent recommended for treatment of cutaneous leishmaniasis (CL). Its use is problematic, because it is expensive and because of the potential for drug-associated adverse effects during a lengthy and painful treatment course. METHODS: We tested the efficacy of thermotherapy for the treatment of CL due to Leishmania tropica in a randomized, controlled trial in Kabul, Afghanistan. We enrolled 401 patients with a single CL lesion and administered thermotherapy using radio-frequency waves (1 treatment of ≥1 consecutive application at 50°C for 30 s) or sodium stibogluconate (SSG), administered either intralesionally (a total of 5 injections of 25 mL every 57 days, depending on lesion size) or intramuscularly (20 mg/kg daily for 21 days). RESULTS: Cure, defined as complete reepithelialization at 100 days after treatment initiation, was observed in 75 (69.4%) of 108 patients who received thermotherapy, 70 (75.3%) of 93 patients who received intralesional SSG, and 26 (44.8%) of 58 patients who received intramuscular SSG. The OR for cure with thermotherapy was 2.80 (95% confidence interval [CI], 1.455.41), compared with intramuscular SSG treatment (P = .002). No statistically significant difference was observed in the odds of cure in comparison of intralesional SSG and thermotherapy treatments. The OR for cure with intralesional SSG treatment was 3.75 (95% CI, 1.867.54), compared with intramuscular SSG treatment (P 100 days, respectively; P = .003). CONCLUSIONS: Thermotherapy is an effective, comparatively well-tolerated, and rapid treatment for CL, and it should be considered as an alternative to antimony treatment

Forecasting temporal dynamics of cutaneous leishmaniasis in Northeast Brazil.

IntroductionCutaneous leishmaniasis (CL) is a vector-borne disease of increasing importance in northeastern Brazil. It is known that sandflies, which spread the causative parasites, have weather-dependent population dynamics. Routinely-gathered weather data may be useful for anticipating disease risk and planning interventions.Methodology/principal findingsWe fit time series models using meteorological covariates to predict CL cases in a rural region of Bahía, Brazil from 1994 to 2004. We used the models to forecast CL cases for the period 2005 to 2008. Models accounting for meteorological predictors reduced mean squared error in one, two, and three month-ahead forecasts by up to 16% relative to forecasts from a null model accounting only for temporal autocorrelation.SignificanceThese outcomes suggest CL risk in northeastern Brazil might be partially dependent on weather. Responses to forecasted CL epidemics may include bolstering clinical capacity and disease surveillance in at-risk areas. Ecological mechanisms by which weather influences CL risk merit future research attention as public health intervention targets

Control of mucocutaneous leishmaniasis, a neglected disease: results of a control programme in Satipo Province, Peru.

Mucocutaneous leishmaniasis (MCL) is an important health problem in many rural areas of Latin America, but there are few data on the results of programmatic approaches to control the disease. We report the results of a control programme in San Martin de Pangoa District, which reports one of the highest prevalences of MCL in Peru. For 2 years (2001--2002), the technicians at the health post were trained in patient case management, received medical support and were supplied with antimonials. An evaluation after 2 years showed the following main achievements: better diagnosis of patients, who were confirmed by microscopy in 34% (82/240) of the cases in 2001 and 60% of the cases (153/254) in 2002; improved follow-up during treatment: 237 of 263 (90%) patients who initiated an antimonial therapy ended the full treatment course; improved follow-up after treatment: 143 of 237 (60%) patients who ended their full treatment were correctly monitored during the required period of 6 (cutaneous cases) or 12 (mucosal cases) months after the end of treatment. These achievements were largely due to the human and logistical resources made available, the constant availability of medications and the close collaboration between the Ministry of Health, a national research institute and an international non-governmental organization. At the end of this period, the health authorities decided to register a generic brand of sodium stibogluconate, which is now in use. This should allow the treatment of a significant number of additional patients, while saving money to invest in other facets of the case management

Leishmania infantum AS A CAUSATIVE AGENT OF CUTANEOUS LEISHMANIASIS IN THE STATE OF MATO GROSSO DO SUL, BRAZIL

Cutaneous leishmaniasis is caused by different species of theLeishmania genus. Leishmania(Leishmania) infantum, causing cutaneous leishmaniasis, has been described in patients living in areas where visceral leishmaniasis is endemic. In this study, it was possible to characterize this species in seven slides from cutaneous tissue imprints from patients with cutaneous leishmaniasis in the State of Mato Grosso do Sul, Brazil

Leishmaniasis: new approaches to disease control.

The leishmaniases afflict the world's poorest populations. Among the two million new cases each year in the 88 countries where the disease is endemic (fig 1), it is estimated that 80% earn less than $2 a day. Human infections with Leishmania protozoan parasites, transmitted via the bite of a sandfly, cause visceral, cutaneous, or mucocutaneous leishmaniasis. The global burden of leishmaniasis has remained stable for some years, causing 2.4 million disability adjusted life years (DALYs) lost and 59 000 deaths in 2001. Neglected by researchers and funding agencies, leishmaniasis control strategies have varied little for decades, but in recent years there have been exciting advances in diagnosis, treatment, and prevention. These include an immunochromatographic dipstick for diagnosing visceral leishmaniasis; the licensing of miltefosine, the first oral drug for visceral leishmaniasis; and evidence that the incidence of zoonotic visceral leishmaniasis in children can be reduced by providing dogs with deltamethrin collars. There is also hope that the first leishmaniasis vaccine will become available within a decade. Here we review these developments and identify priorities for research

Molecular variation in Leishmania parasites from sandflies species of a zoonotic cutaneous leishmaniasis in northeast of Iran

Background & objectives: In the well-known zoonotic cutaneous leishmaniasis (ZCL) focus in Turkmen Sahara, border of Iran and Turkmenistan, ZCL has increased among humans in the past five years. The present study was undertaken to incriminate vectors of ZCL in the region, and to find molecular variation in Leishmania parasites. Methods: The sandflies were sampled using CDC light-traps and sticky papers. All the sandflies were identified using morphological characters of the head and abdominal terminalia. DNA was extracted from the dissected thorax and attached anterior abdomen of individual female sandfly. Leishmania detection and identification of sandflies were performed using PCR, digestion of BsuRI restriction enzyme and sequencing of ITS-rDNA gene and also by semi-nested PCR to amplify minicircle kinetoplast (k) DNA of Leishmania. Results: Leishmania infections were detected in 26 out of 206 female sandflies. Of the infected sandflies, 18 were Phlebotomus papatasi while eight were P. caucasicus/P. mongolensis. Two infections of L. turnica were detected, one in P. papatasi and other in P. caucasicus/P. mongolensis and the rest of the sandflies were found infected with L. major. Conclusion: Our finding showed that L. major had low diversity with only one common haplotype (GenBank Access No. EF413075). The novel haplotypes were discovered in L. major (GenBank Access No. KF152937) and in L. turanica (GenBank Access No. EF413079) in low frequency. These Leishmania parasites are circulating to maintain infections in the P. papatasi and P. caucasicus/P. mongolensis in Turkmen Sahara

Pupal surveys for Aedes aegypti surveillance and potential targeted control in residential areas of Mérida, México.

A mosquito larval-pupal survey was conducted in 1,160 households of the Mexican city of Mérida during the rainy season of 2003 to determine their differential productivity for Aedes aegypti. Larvae and pupae were detected in 15 broad categories of container types. All breeding sites were found in the patios (backyards) and were potentially rain filled. Ae. aegypti pupae were produced from all categories of breeding site, and no single container type was predominately responsible for pupal production. The most productive buckets comprised 42% of the pupae-positive containers and provided 34% of the total pupae collected. Pupal production in buckets, together with plastic rubbish, pet dishes and basins, utensils for cooking and washing, tires, and flowerpots, accounted for almost 87% of pupal production. However, the most important pupal producers had low infestation indices for immature forms, illustrating that the use of positive-container indices can underestimate the importance of certain breeding sites. Overall, 40% of containers that were observed harboring Ae. aegypti pupae were classified as disposable. The remaining containers were considered useful, although some were seldom used. The discussion focuses on the potential utility of the pupal survey for targeting control, and its resulting pupae-per-person entomological indicator, both for comparison with a theoretical threshold for dengue transmission and for targeting vector control in this Mexican city