Spatial distribution and effects of land use and cover on cutaneous leishmaniasis vectors in the municipality of Paracambi, Rio de Janeiro, Brazil

ABSTRACT The municipality of Paracambi (Rio de Janeiro, Brazil) reports sporadic cases of American cutaneous leishmaniasis (ACL). Previous studies detected Nyssomyia intermedia (Diptera: Psychodidae) as the main vector in the region, but its spatial distribution and the presence of other vector species have not been evaluated. This study aims at filling this knowledge gap, by studying the ecology of sand flies, their spatiotemporal distribution, and correlation with land use/cover. Two campaigns of monthly sand fly collections using light traps and manual captures were conducted in 1992-1994 and 2001-2003. Females were dissected to detect natural Leishmania infections. The spatial distribution of sand flies was assessed using kernel density maps. Correlations with land use/cover were evaluated by extracting satellite imagery data around the capture points. A total of 17,232 sand flies from 13 species were captured. Medically important species included Ny. intermedia, Migonemyia migonei, Pintomyia fischeri and Ny. whitmani. No Leishmania-infected females were detected. Highest densities were detected in the peri-urban areas Cascata and Sabugo, and in rural areas São José and Mutirão. Ny. intermedia had statistically significant correlations with pasture and agricultural areas. Present results strengthened that Ny. intermedia and Mg. migonei are the main local ACL vectors. Correlations with land use evidence the association between ACL and anthropic environmental change.

Low versus high dose of antimony for American cutaneous leishmaniasis: A randomized controlled blind non-inferiority trial in Rio de Janeiro, Brazil.

BACKGROUND: Although high dose of antimony is the mainstay for treatment of American cutaneous leishmaniasis (ACL), ongoing major concerns remain over its toxicity. Whether or not low dose antimony regimens provide non-inferior effectiveness and lower toxicity has long been a question of dispute. METHODS: A single-blind, non-inferiority, randomized controlled trial was conducted comparing high dose with low dose of antimony in subjects with ACL treated at a referral center in Rio de Janeiro, an endemic area of Leishmania (Viannia) braziliensis transmission. The primary outcome was clinical cure at 360 days of follow-up in the modified-intention-to-treat (mITT) and per-protocol (PP) populations. Non-inferiority margin was 15%. Secondary objectives included occurrence of epithelialization, adverse events and drug discontinuations. This study was registered in ClinicalTrials.gov: NCT01301924. RESULTS: Overall, 72 patients were randomly assigned to one of the two treatment arms during October 2008 to July 2014. In mITT, clinical cure was observed in 77.8% of subjects in the low dose antimony group and 94.4% in the high dose antimony group after one series of treatment (risk difference 16.7%; 90% CI, 3.7-29.7). The results were confirmed in PP analysis, with 77.8% of subjects with clinical cure in the low dose antimony group and 97.1% in the high dose antimony group (risk difference 19.4%; 90% CI, 7.1-31.7). The upper limit of the confidence interval exceeded the 15% threshold and was also above zero supporting the hypothesis that low dose is inferior to high dose of antimony after one series of treatment. Nevertheless, more major adverse events, a greater number of adverse events and major adverse events per subject, and more drug discontinuations were observed in the high dose antimony group (all p<0.05). Interestingly, of all the subjects who were originally allocated to the low dose antimony group and were followed up after clinical failure, 85.7% achieved cure after a further treatment with local therapy or low dose of antimony. CONCLUSIONS: Compared with high dose, low dose of antimony was inferior at the pre-specified margin after one series of treatment of ACL, but was associated with a significantly lower toxicity. While high dose of antimony should remain the standard treatment for ACL, low dose antimony treatment might be preferred when toxicity is a primary concern.

PANCREATIC TOXICITY AS AN ADVERSE EFFECT INDUCED BY MEGLUMINE ANTIMONIATE THERAPY IN A CLINICAL TRIAL FOR CUTANEOUS LEISHMANIASIS.

American tegumentary leishmaniasis is an infectious disease caused by a protozoan of the genus Leishmania. Pentavalent antimonials are the first choice drugs for cutaneous leishmaniasis (CL), although doses are controversial. In a clinical trial for CL we investigated the occurrence of pancreatic toxicity with different schedules of treatment with meglumine antimoniate (MA). Seventy-two patients were allocated in two different therapeutic groups: 20 or 5 mg of pentavalent antimony (Sb5+)/kg/day for 20 or 30 days, respectively. Looking for adverse effects, patients were asked about abdominal pain, nausea, vomiting or anorexia in each medical visit. We performed physical examinations and collected blood to evaluate serum amylase and lipase in the pre-treatment period, and every 10 days during treatment and one month post-treatment. Hyperlipasemia occurred in 54.8% and hyperamylasemia in 19.4% patients. Patients treated with MA 20 mg Sb5+ presented a higher risk of hyperlipasemia (p = 0.023). Besides, higher MA doses were associated with a 2.05 higher risk ratio (p = 0.003) of developing more serious (moderate to severe) hyperlipasemia. The attributable fraction was 51% in this group. Thirty-six patients presented abdominal pain, nausea, vomiting or anorexia but only 47.2% of those had hyperlipasemia and/ or hyperamylasemia. These findings suggest the importance of the search for less toxic therapeutic regimens for the treatment of CL.

Factors associated to adherence to different treatment schemes with meglumine antimoniate in a clinical trial for cutaneous leishmaniasis.

The favorable outcome of the treatment of a disease is influenced by the adherence to therapy. Our objective was to assess factors associated with adherence to treatment of patients included in a clinical trial of equivalence between the standard and alternative treatment schemes with meglumine antimoniate (MA) in the treatment of cutaneous leishmaniasis (CL), in the state of Rio de Janeiro. Between 2008 and 2011, 57 patients with CL were interviewed using a questionnaire to collect socioeconomic data. The following methods were used for adherence monitoring: counting of vial surplus, monitoring card, Morisky test and modified Morisky test (without the question regarding the schedule); we observed 82.1% (vial return), 86.0% (monitoring card), 66.7% (Morisky test) and 86.0% (modified Morisky test) adherence. There was a strong correlation between the method of vial counting and the monitoring card and modified Morisky test. A significant association was observed between greater adherence to treatment and low dose of MA, as well as with a lower number of people sleeping in the same room. We recommend the use of the modified Morisky test to assess adherence to treatment of CL with MA, because it is a simple method and with a good performance, when compared to other methods.

Factors associaeed to adherence to different tratment schemes with meglumine aantimoniate in a clinical trial for cutaneous leishmaniasis / Fatores associados à adesão a diferentes esquemas de tratamento com antimoniato de meglumina em ensaio clínico para leishmaniose cutânea

The favorable outcome of the treatment of a disease is influenced by the adherence to therapy. Our objective was to assess factors associated with adherence to treatment of patients included in a clinical trial of equivalence between the standard and alternative treatment schemes with meglumine antimoniate (MA) in the treatment of cutaneous leishmaniasis (CL), in the state of Rio de Janeiro. Between 2008 and 2011, 57 patients with CL were interviewed using a questionnaire to collect socioeconomic data. The following methods were used for adherence monitoring: counting of vial surplus, monitoring card, Morisky test and modified Morisky test (without the question regarding the schedule); we observed 82.1% (vial return), 86.0% (monitoring card), 66.7% (Morisky test) and 86.0% (modified Morisky test) adherence. There was a strong correlation between the method of vial counting and the monitoring card and modified Morisky test. A significant association was observed between greater adherence to treatment and low dose of MA, as well as with a lower number of people sleeping in the same room. We recommend the use of the modified Morisky test to assess adherence to treatment of CL with MA, because it is a simple method and with a good performance, when compared to other methods.

O desfecho favorável ao tratamento de uma enfermidade é influenciado pela adesão à terapia. Objetivamos avaliar fatores associados à adesão ao tratamento dos pacientes incluídos em ensaio clínico de equivalência entre o esquema de tratamento padrão e alternativos com antimoniato de meglumina (AM) no tratamento da leishmaniose cutânea (LC) no estado do Rio de Janeiro. Entre 2008 e 2011, 57 pacientes com LC foram entrevistados através de questionário para coleta de dados socioeconômicos. Para monitorização da adesão foram utilizados os seguintes métodos: contagem de ampolas excedentes, cartão de acompanhamento, teste de Morisky e teste de Morisky modificado (sem a pergunta referente ao horário). Observou-se adesão de 82,1% (devolução de ampolas), 86,0% (cartão de acompanhamento), 66,7% (teste de Morisky) e 86,0% (teste de Morisky modificado). Houve forte concordância entre o método contagem de ampolas e cartão de acompanhamento, bem como teste de Morisky modificado. Verificou-se associação significativa entre maior adesão ao tratamento e baixa dose de AM, bem como com menor número de pessoas dormindo no mesmo quarto. Recomendamos a utilização do teste de Morisky modificado na avaliação da adesão ao tratamento da LC com AM por ser método simples e com bom desempenho quando comparado aos outros testes.

[Prevalence of canine infection from endemic areas of American cutaneous leishmaniasis in Paracambi District, Rio de Janeiro State, between 1992 and 1993]. / Prevalência da infecção canina em áreas endêmicas de leishmaniose tegumentar americana, do município de Paracambi, Estado do Rio de Janeiro, no período entre 1992 e 1993.

In the district of Paracambi, State of Rio de Janeiro an epidemiological survey for American tegumentary leishmaniasis in canine population was carried out in endemic localities. A total of 179 dogs was registered and 138 (77.1%) examined for their clinical aspects, development of delayed hypersensitivity (DHS) with Imunoleish(R) antigen and serological responses by indirect immunofluorescent reaction and enzyme-linked immunosorbent assay. In 9 (6.5%) dogs with active cutaneous lesions or suspect scars, 66.7% were caused by Leishmania sp; 44.4% produced infection in hamsters and showed growth in culture media, which was considered to be compatible with the species of Leishmania braziliensis complex. The molecular characterization (isoenzyme and KDNA restriction profiles) defined two strains with similar profiles for L. (Viannia) braziliensis. The prevalence of canine infection estimated by the cutaneous test, IFR and ELISA was 10.1%, 16.7% and 27.8%, respectively. The presence of clinical / sub-clinical form of ATL in canine population associated with human infections suggested that the dog can act as source of infection as well as for dissemination of the disease.

Prevalência da infecção canina em áreas endêmicas de leishmaniose tegumentar americana, do município de Paracambi, Estado do Rio de Janeiro, no período entre 1992 e 1993 / Prevalence of canine infection from endemic areas of American cutaneous leishmaniasis in Paracambi District, Rio de Janeiro State, between 1992 and 1993

No município de Paracambi, Estado do Rio de Janeiro, foi realizado um inquérito epidemiológico sobre a leishmaniose tegumentar americana na população canina residente em áreas endêmicas rural e semiurbana. Foram cadastrados 179 cães e 138 (77,1 por cento) foram examinados, segundo seus aspectos clínicos e desenvolvimento de hipersensibilidade tardia ao antígeno Imunoleish® e respostas sorológicas à reação de imunofluorescência indireta e ao ensaio imunoenzimático. Dos 9 (6,5. por cento) animais portadores de lesões/cicatrizes suspeitas, 66,7 por cento foram causadas por Leishmania sp; 44,4 por cento produziram infecção em hamsters e apresentaram crescimento em meio de cultura, compatíveis com o comportamento de Leishmania do complexo braziliensis. A caracterização molecular (análises isoenzimáticas e do perfil de restrição do KDNA) identificou 2 amostras como similares à Leishmania (Viannia) braziliensis. A prevalência da infecção canina observada através do teste cutâneo, RIFI e ELISA foi, respectivamente, 10,1 por cento, 16,7 por cento e 27,8 por cento. A presença das formas clínica/subclínica da LTA na população canina associada à infecção humana sugere que o cão pode atuar como possível fonte de infecção, assim como na disseminação da doença.