Ernesto Rojas

Intralesional Antimony for Single Lesions of Bolivian Cutaneous Leishmaniasis

BACKGROUND Cutaneous leishmaniasis is an ultimately self-curing disease for which systemic therapy with pentavalent antimony (Sb) is effective but with side effects. We evaluated 2 local treatments, intralesional (IL) Sb and cryotherapy, for single lesions due to Bolivian Leishmania (v.) braziliensis in a placebo-controlled study. METHODS Patients were randomized between IL Sb (650 µg/mm(2) of lesion area on days 1, 3, and 5), cryotherapy (days 1 and 14), and placebo cream (daily for 20 days) in a 3:2:3 allocation. Lesion area was measured prior to therapy, and at 1, 3, and 6 months after therapy. The criteria for lesion cure were as follows: not doubling in size at 1 month, at least 50% diminution in size at 3 months, and complete reepithelialization at 6 months. Local adverse effects were recorded. RESULTS Cure rates were 21 of 30 (70%; 95% confidence interval [CI], 52%-83%) for IL Sb, 4 of 20 (20%; 95% CI, 8%-42%) for cryotherapy, and 5 of 30 (17%; 95% CI, 7%-34%) for placebo cream (P < .001 for IL Sb vs each other group). IL Sb adverse events were limited to injection site pain, with a mean value of 1.0 (mild). CONCLUSIONS The comparative cure rate, small amount of drug administered, and tolerance data for IL Sb suggest that if local therapy for single L. braziliensis lesions is chosen, this treatment is attractive. Given the difficulties of performing placebo-controlled trials in the New World, the combined placebo and cryotherapy cure rate (18%; 95% CI, 10%-31%) is likely to become the standard against which future interventions for L. braziliensis are compared. CLINICAL TRIALS REGISTRATION NCT01300975.

Prevalencia de las infecciones por virus de las hepatitis B, C, D y E en Bolivia

En Bolivia no se han realizado estudios especificos sobre los virus de la hepatitis, por lo que su prevalencia y patrones de circulacion son practicamente desconocidos. De 1992 a 1996 se realizo un estudio seroepidemiologico con el fin de adquirir una primera vision de conjunto sobre las prevalencias de las infecciones por virus de la hepatitis B (VHB), C (VHC), D (VHD) y E (VHE) en distintas poblaciones de Bolivia. Sobre la base de los datos obtenidos en otros lugares de America Latina, se presto atencion especial al estudio de las comunidades autoctonas de la region amazonica. En las zonas rurales del altiplano andino, la infeccion por VHB presento una prevalencia general que corresponderia a una situacion de endemia media o baja (11,2%) y no se encontro ningun portador de anticuerpos contra VHC o VHD. En dos poblaciones de alto riesgo de la ciudad de Cochabamba (ninos sin hogar y trabajadoras del sexo), la prevalencia de infeccion por VHB fue similar (11,6%) y podria considerarse baja en comparacion con la de otras poblaciones analogas de nucleos urbanos en America Latina. La correspondiente al VHC (un caso positivo, 0,5%) seria parecida a la descrita en esas mismas poblaciones, si bien el escaso numero de muestras estudiadas no permite extraer conclusiones mas firmes. En concordancia con observaciones anteriores de comunidades similares de zonas tropicales de Suramerica, en las poblaciones autoctonas de la Amazonia boliviana la infeccion por VHB es sumamente endemica (prevalencia general de 74,0%), pero no se ha detectado la circulacion de VHC. Se sabe que la transmision de VHB es horizontal y tiene lugar desde edades muy tempranas, pero se desconocen los mecanismos de esa actividad. A los 10 anos de edad, mas de la mitad de la poblacion ya ha experimentado la infeccion natural que, 10 anos mas tarde, se habra difundido a practicamente toda la poblacion. La tasa muy baja de individuos positivos al HbsAg (1,6%), la ausencia de ADN virico en las muestras con reactividad aislada a anti-HBc y la alta prevalencia de anti-HBs entre los individuos que presentan marcadores de infeccion natural (92,4%) excluyen la participacion de la transmision vertical en el mantenimiento de la endemia. Hasta el momento, no se ha documentado ningun brote de infeccion por VHD en estas comunidades, pero la alta endemia de infeccion por VHB alerta sobre el riesgo de posibles brotes en el futuro. Los resultados obtenidos con las pruebas de anticuerpos contra VHE sugieren que este virus circula ampliamente en Bolivia y que podria haber producido brotes recientes en el departamento de Cochabamba. Se recomienda vacunar contra VHB en las poblaciones endemicas como medida de corto plazo; buscar activamente en todo el pais brotes y casos esporadicos de hepatitis E y continuar realizando estudios que permitan evaluar las repercusiones sanitarias de la situacion documentada en este estudio.In Bolivia, no studies have been carried out specifically on hepatitis viruses. Thus, their prevalence and circulation patterns are virtually unknown. A seroepidemiologic study was performed from 1992 to 1996 to generate a preliminary idea of the overall prevalence of infection from hepatitis B, C, D, and E viruses (HBV, HCV, HDV, and HEV, respectively) in different Bolivian population groups. Prompted by the data obtained in other areas of Latin America, the study focused on indigenous communities in the Amazon region. In rural areas of the high Andean plateau, HBV infection showed an overall prevalence compatible with medium to low endemicity (11.2%), and no carriers of HCV or HDV antibodies were found. In two high-risk groups in the city of Cochabamba (homeless children and sexual workers), the prevalence of HBV infection was similar (11.6%) and could be considered low by comparison to that of similar population groups in Latin American urban centers. The prevalence of HCV (one positive case, or 0.5%) was similar to that found in similar population groups, although the small number of samples precludes drawing more definite conclusions. As has been noted previously with similar communities in tropical areas of South America, HBV infection is highly endemic in indigenous populations of the Bolivian Amazon (with an overall prevalence of 74.0%), but circulation of HCV has not been detected. It is a well-known fact that HBV is horizontally transmitted and that transmission can take place very early in life, but the mechanisms involved are unknown. By 10 years of age, more than half the population has already had the natural infection that, in approximately 10 more years will have affected virtually the entire population. The very low rate of positivity to HBsAg (1.6%), the absence of viral DNA in samples showing isolated positivity to anti-HBc, and the high prevalence of anti-HBs among individuals who show markers for natural infection (92.4%) suggest vertical transmission plays no role in persistent endemicity. So far, no outbreak of HDV infection has been documented in these communities, but the high endemicity shown by HBV points to the possibility of future outbreaks. Results obtained with tests for the detection of antibodies against HEV suggest that this virus is circulating widely in Bolivia and that it could have caused recent outbreaks in Cochabamba state. Vaccination against HBV in endemic populations is recommended as a short-term measure. Also recommended are actively searching for outbreaks and sporadic cases of hepatitis E in the entire country and performing additional research that will help in assessing the public health consequences of the situation described in this article.

Leishmaniasis in Chaparé, Bolivia

To the Editor: In Bolivia, most cases of leishmaniasis are caused by Leishmania (Viannia) braziliensis (1). The parasite is transmitted zoonotically by several sandfly species and, when transmitted to humans, may cause cutaneous leishmaniasis (CL), and potentially, mucosal leishmaniasis (ML) (2). Data on the prevalence and effects of CL in Bolivia have been scarce, even though anecdotal and official reports indicate a dramatic increase in the number of human CL cases in Bolivia in the past decade (1,3). Also, although CL was originally a sylvatic disease in Bolivia, some evidence indicates that the transmission cycle has adapted to the peridomestic habitat. However, this evidence is largely based on individual case reports. No information is available on parasite species, vectors, and reservoirs in such a peridomestic transmission cycle. A preliminary study to guide future research focus and assist in immediate leishmaniasis prevention and control policy decision making is underway in Isiboro-Secure National Park, Chapare, Bolivia. Our objectives were to collect data on the prevalence of leishmaniasis in that area and evidence for peridomestic Leishmania transmission. A survey was carried out during April–July 2007 in 2 communities in Isiboro-Secure National Park, San Gabriel (16°40′31′′S and 65°37′38′′W) and San Julian (16°41′59′′S and 65°38′10′′W). These 2 communities were selected because of local knowledge of disease in the community, their moderate degree of urbanization (i.e., ≈50% of the communities’ houses are clustered around the main access road), and the accessibility of the sites to the field team. In this area, CL is transmitted from April through October. Households in both communities were visited by a team of experienced medical staff who interviewed heads of household to collect demographic data (sex, age) and diagnose the clinical condition of all present household members (presence/absence of CL lesions or scars, number of lesions, date of lesion onset) by using a standardized, pretested questionnaire. The study protocol was approved by the Ethical Committee Review Board of the World Health Organization (WHO). All patients with active cases were treated with meglumine antimoniate according to the standard protocol (2). We surveyed 133 and 52 households in San Gabriel and San Julian, which represented 86% and 80% of the total households of the respective communities; 21 and 13 households, respectively, were visited but did not participate because the owners refused or were not present. Of the 965 persons surveyed, 488 (50.6%) were male and 476 (49.3%) were female; 9 (0.9%) had active CL lesions and 62 (6.4%) had CL scars. One person had ML, and 3 had evidence of past ML; all ML patients were male. Of those with CL lesions, all had 1 lesion only. The mean lesion size was 2.3 cm (range 1.5–3 cm), and the mean lesion duration (to survey date) was 5.6 months (range 1–11 months). The clinical CL lesions were parasitologically confirmed by microscopy (n = 4) or PCR (n = 8). Parasite culture was performed on patient isolates (n = 6), and L. (V.) braziliensis was identified and characterized as the etiologic agent of these CL cases. Active lesion and scar prevalence were associated with male sex (lesions: Fisher exact test, odds ratio [OR] = 7.90 [95% confidence interval (CI) 1.01–169.09], p 15 years (lesions: Fisher exact test, OR = 0.19 [95% CI 0.01–1.46], p = 0.094; scars: Yates-corrected χ2 test, OR = 0.09 [95% CI 0.03–0.27], p<0.001) (Figure). Active lesion and scar prevalence were also associated with prolonged migration into the forest before the survey (lesions: Fisher exact test, OR = 28.10 [95% CI 3.49–184.29], p<0.01; scars: Fisher exact test, OR = 35.76 [95% CI 13.49–93.53], p<0.001). Figure Age prevalence curve of persons with lesions (white bars) and scars (black line) from cutaneous leishmaniasis, Bolivia, 2007. Whether the surveyed population is representative of the total population living in the study area is debatable. However, on the basis of current population figures (i.e., 16,000) and observed prevalence of CL, we estimate up to 1,440 CL cases in Isiboro-Secure currently. The low prevalence of active disease and scars indicates that L. (V.) braziliensis was introduced into Isiboro-Secure fairly recently, which is corroborated by the short median time since the cure of persons with CL scars (i.e., 7.5 years, range 0.4–30.5 years). Combined with the association of CL with male sex, age, and migration to the forest, we conclude that in Isiboro-Secure, most L. (V.) braziliensis transmission is sylvatic rather than peridomestic. This transmission pattern implies that prevention and control approaches that focus on the person (e.g., use of repellents, early treatment seeking) will most likely be more effective than approaches that focus on the household (e.g., indoor residual spraying with insecticides, insecticide-treated bednets). Current analyses are underway to establish CL risk factors. Additionally, a prevention and control strategy adapted to the local context is being planned to minimize the population’s exposure to sandflies, prepare health professionals for adequate (per protocol) management of cases, and minimize the likelihood that L. (V.) braziliensis transmission becomes peridomestic.

Prevalence of Leishmania spp. infection in domestic dogs in Chapare, Bolivia

Data on Leishmania spp. infection in dogs in Bolivia is scarce. Dogs from an area where 90% of human cutaneous leishmaniasis (CL) cases are due to Leishmania (Viannia) braziliensis were screened for Leishmania infection using established enzyme-linked immunosorbent antibody test (ELISA) protocols. Although none of the 51 dogs surveyed had clinical lesions indicative of CL, 6 out of 51 (11.8%) sampled dogs tested positive by ELISA.

Risk factors for cutaneous leishmaniasis in the rainforest of Bolivia: a cross-sectional study

BackgroundCutaneous leishmaniasis (CL) is an endemic disease in Bolivia, particularly in the rainforest of Cochabamba, in the municipality of Villa Tunari. The precarious, dispersed, and poorly accessible settlements in these farming communities make it difficult to study them, and there are no epidemiological studies in the area. The aim of the present study was to identify the risk factors associated with cutaneous leishmaniasis.MethodsA cross-sectional study was conducted in August 2015 and August 2016 in two communities of Villa Tunari, Cochabamba. The cases were diagnosed through clinical examinations, identification of the parasite by microscopic examination, and the Montenegro skin test. Risk factors were identified through logistic regression.ResultsA total of 274 participants (40.9% female and 59.1% male) were surveyed, of which 43% were CL positive. Sex was the only factor associated with CL with three times more risk for men than for women; this finding suggests a sylvatic mechanism of transmission in the area.ConclusionsIt is advisable to focus on education and prevention policies at an early age for activities related to either leisure or work. Further research is needed to assess the influence of gender-associated behavior for the risk of cutaneous leishmaniasis.

Nutritional status in patients with cutaneous leishmaniasis and a study of the effects of zinc supplementation together with antimony treatment.

Background The role of micronutrient status for the incidence and clinical course of cutaneous leishmaniasis is not much studied. Still zinc supplementation in leishmaniasis has shown some effect on the clinical recovery, but the evidence in humans is limited. Objective To compare biochemical nutritional status in cutaneous leishmaniasis patients with that in controls and to study the effects of zinc supplementation for 60 days. Design Twenty-nine patients with cutaneous leishmaniasis were treated with antimony for 20 days. Fourteen of them got 45 mg zinc daily and 15 of them got placebo. Biomarkers of nutritional and inflammatory status and changes in size and characteristics of skin lesions were measured. Results The level of transferrin receptor was higher in patients than in controls but otherwise no differences in nutritional status were found between patients and controls. No significant effects of zinc supplementation on the clinical recovery were observed as assessed by lesion area reduction and characteristics or on biochemical parameters. Conclusions It is concluded that nutritional status was essentially unaffected in cutaneous leishmaniasis and that oral zinc supplementation administered together with intramuscular injection of antimony had no additional clinical benefit.

Correction to: risk factors for cutaneous leishmaniasis in the rainforest of Bolivia: a cross-sectional study

In the original publication of this article [1], the authors noted that some data were incorrect in Table 4.

Assessment of a Leishmaniasis Reporting System in Tropical Bolivia Using the Capture-Recapture Method.

This study evaluates the level of underreporting of the National Program of Leishmaniasis Control (NPLC) in two communities of Cochabamba, Bolivia during the period 2013-2014. Montenegro skin test-confirmed cases of cutaneous leishmaniasis (CL) were identified through active surveillance during medical campaigns. These cases were compared with those registered in the NPLC by passive surveillance. After matching and cleaning data from the two sources, the total number of cases and the level of underreporting of the National Program were calculated using the capture-recapture analysis. This estimated that 86 cases of CL (95% confidence interval [CI]: 62.1-110.8) occurred in the study period in both communities. The level of underreporting of the NPLC in these communities was very high: 73.4% (95% CI: 63.1-81.5%). These results can be explained by the inaccessibility of health services and centralization of the NPLC activities. This information is important to establish priorities among policy-makers and funding organizations as well as implementing adequate intervention plans.

Combined treatment of mucocutaneous leishmaniasis after therapeutic failure: Case report

Results: All patients showed telangiectasias (100%) and dermoscopy revealed linear, tortuous and polygonal vessels.72% of the patients had dermoscopic features for Demodex folliculorum-follicular plugs and Demodex tails. All the 29% patients with clinical spinulosus had Demodex dermoscopic features.76% of the patients had clinically visible pustules but by dermoscopy the tiny infraclinical pustules could be seen better and earlier. 77% of the patients had visible erythema on the face and by dermoscopy all they had red diffuse areas. The white hairs derived from hypertrichosis were observed at 13% with the naked eye and at 43% by dermoscopy. The atrophy was clinically visible at 12% patients as a severe skin thinning but dermoscopy revealed also atrophic areas at another 2 patients as white structure less areas or patches between vessels. The patients with dermoscopic atrophy were using mometasonefuroat and clobetasol propionate.