Leishmanaisis

Leishmanaisis

Date: 
01/11/2007
Investigation Line: 

Abstract

New therapeutic alternatives against leishmaniasis remain a priority. The activity of azithromycin against Leishmania (Leishmania) major has been previously demonstrated. Different responses among species of Leishmania make species-specific drug screening necessary. The activity of azithromycin against Leishmania (Viannia) braziliensis and Leishmania (Leishmania) amazonensis was evaluated in golden hamsters infected through footpad injections of metacyclic promastigotes, and compared with untreated controls and animals treated with meglumine antimoniate. Footpad thickness, lesion cultures and dissemination sites were analyzed. Treatment of golden hamsters with oral azithromycin at 450mg/kg had no activity against infections with Leishmania (Leishmania) amazonensis. For infections due to Leishmania (Viannia) braziliensis, azithromycin demonstrated significant activity relative to untreated controls, but inferior to meglumine antimoniate, for controlling lesion size. Neither drug was able to totally eliminate parasites from the lesions. It was concluded that azithromycin has activity against Leishmania (Viannia) braziliensis but not against Leishmania (Leishmania) amazonensis in this model.

Date: 
01/10/2007
Investigation Line: 

Abstract

Azithromycin was compared with meglumine antimoniate for treatment of patients with cutaneous leishmaniasis. Patients were randomized to receive oral azithromycin, 500 mg/day (22 patients) or intramuscular meglumine antimoniate, 10 mg Sb/kg/day (23 patients), both for 28 days, with a second cycle of 15 days if necessary, and followed-up for one year after completion of treatment. Efficacy, defined as complete re-epithelization without relapse for 12 months after completing therapy, was 82.6% (95% confidence interval [CI] = 67-98%) for meglumine antimoniate and 45.5% (95% CI = 25-66%) for azithromycin. All patients who failed treatment with azithromycin were treated with meglumine antimoniate and clinically cured. Azithromycin was well tolerated; meglumine antimoniate caused arthralgias and local symptoms in 78% of the patients. In 17 cases, species identification was obtained; Leishmania (Viannia) braziliensis was identified in all of them. For the treatment of American cutaneous leishmaniasis caused by L. (V.) braziliensis, meglumine antimoniate is significatively more efficacious than azithromycin, which was clinically curative in almost half of the patients and well-tolerated.

Date: 
01/05/2005
Investigation Line: 

Abstract

Sixteen Leishmania stocks, 15 isolated from patients with cutaneous (CL), mucocutaneous (MCL), or recurrent cutaneous leishmaniasis, plus one from a dog with CL in Salta and Corrientes Provinces, Argentina, were studied by multilocus enzyme electrophoresis. Thirteen of the stocks from humans were grouped in two zymodemes; nine termed as KMS 1, four as KMS 2, and assigned to Leishmania (Viannia) braziliensis. Two additional stocks from CL cases expressed a KMS 4 enzyme profile, corresponding to L. (V.) guyanensis. Although the parasites from the dog were also assigned to L. (V.) braziliensis, its zymodeme, KMS 3, was not expressed in any of the current human isolates. The characterization of Leishmania from a dog was done for the first time in Argentina. The importance of the intraspecific polymorphism in the induction of clinical forms and in the host-reservoir concept is briefly discussed, based on the zymodeme data of isolates from humans and dogs. The presence of L. (V.) guyanensis was confirmed in the country.

Date: 
01/01/2004
Investigation Line: 

Abstract

Migration of HIV infected individuals from cities to small towns and rural areas spreads AIDS among non urban population, superimposing HIV with other endemic or epidemic infections as parasitoses. This situation is a big challenge to public health because in most cases the association between these infections worsens both prognoses. We present here the first case in Argentina of AIDS associated to a mucocutaneous form of American tegumentary leishmaniasis. The patient was from Orán, an area where in the middle eighties, an epidemic outbreak took place. By now more than 2000 cases have been parasitologically confirmed in our Institute and the causing species were identified as Leishmania (V.) braziliensis and L. (L.) amasonensis. Considering the existence of co-infection of HIV and Leishmania, it is recommended that in patients from endemic areas with records of cutaneous or mucocutaneous ulcers, even healed, leishmaniasis must be investigated, among other diseases.

Date: 
01/01/2003
Investigation Line: 

Abstract

The aims of this study were to characterize human American tegumentary leishmaniasis, which includes cutaneous, mucocutaneous and mucosal leishmaniasis, in Northwest Argentina, to determine the prevalence of double infection with Trypanosoma cruzi and to identify the species of Leishmania in this area. Most of the 330 leishmaniasis patients presented cutaneous ulcers (96.1%), 2.4% mucocutaneous and 1.5% the mucosal form ('espundia'). The aetiological agents, determined by isoenzyme electrophoresis, were identified as Leishmania (Viannia) braziliensis in 16 out of 20 isolates and in the remaining 4 as Leishmania (Leishimania) amazonensis, the first ever-documented in Argentina. Sera analysed by ELISA and IFA using complex antigen from both T. cruzi and L. braziliensis showed a very high percentage of positives (66.3-78.2%). When antigens for specific diagnosis of Chagas' disease were used, 40.9% of the leishmaniasis patients were also found to be infected by T. cruzi. These results indicate that the strong immune response against T. cruzi gave no protection to Leishmania, in spite of the serological cross-reaction between these parasites. In addition, we showed that more than 40% of the patients would be misdiagnosed as chagasic if complex antigens, as epimastigotes or soluble fraction from epimastigotes, were used in IFA or ELISA. This is of paramount importance not only because patients' treatment would be associated to misdiagnosis but the fact that in many countries in Central and South America, a positive test for Chagas' disease means a rejection for those seeking employment.

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