Cost-effectiveness analysis of Mucosal Leishmaniasis diagnosis with PCR-based vs parasitological tests in Colombia.

To estimate the cost-effectiveness of available diagnosis alternatives for Mucosal Leishmaniasis (ML) in Colombian suspected patients. A simulation model of the disease's natural history was built with a decision tree and Markov models. The model´s parameters were identified by systematic review and validated by expert consensus. A bottom-up cost analysis to estimate the costs of diagnostic strategies and treatment per case was performed by reviewing 48 clinical records of patients diagnosed with ML. The diagnostic strategies compared were as follows: 1) no diagnosis; 2) parasite culture, biopsy, indirect immunofluorescence assay (IFA), and Montenegro skin test (MST) combined ; 3) parasite culture, biopsy, and IFA combined; 4) PCR-miniexon; and 5) PCR-kDNA. Three scenarios were modeled in patients with ML clinical suspicion, according to ML prevalence scenarios: high, medium and low. Adjusted sensitivity and specificity parameters of a combination of diagnostic tests were estimated with a discrete event simulation (DES) model. For each alternative, the costs and health outcomes were estimated. The time horizon was life expectancy, considering the average age at diagnosis of 31 years. Incremental cost-effectiveness ratios (ICERs) were calculated per Disability Life Year (DALY) avoided, and deterministic and probabilistic sensitivity analyses were performed. A threshold of willingness to pay (WTP) of three-time gross domestic product per capita (GDPpc) (US$ 15,795) and a discount rate of 3% was considered. The analysis perspective was the third payer (Health System). All costs were reported in American dollars as of 2015. PCR- kDNA was the cost-effective alternative in clinical suspicion levels: low, medium and high with ICERs of US$ 7,909.39, US$ 5,559.33 and US$ 4,458.92 per DALY avoided, respectively. ML diagnostic tests based on PCR are cost-effective strategies, regardless of the level of clinical suspicion. PCR-kDNA was the most cost-effective strategy in the competitive scenario with the parameters included in the present model.

Mucosal leishmaniasis: A forgotten disease, description and identification of species in 50 Colombian cases / Mucosal leishmaniasis: A forgotten disease, description and identification of species in 50 Colombian cases

INTRODUCTION: Mucosal leishmaniasis has a progressive course and can cause deformity and even mutilation in the affected areas. It is endemic in the American continent and it is mainly caused by Leishmania (Viannia) braziliensis. OBJECTIVE: To describe a series of mucosal leishmaniasis cases and the infectious Leishmania species. MATERIALS AND METHODS: We included 50 patients with a clinical diagnosis of mucosal leishmaniasis and parasitological confirmation, and we described their clinical and laboratory results. We performed species typing by PCR-RFLP using the miniexon sequence and hsp70 genes; confirmation was done by sequencing. RESULTS: The median time of disease evolution was 2.9 years (range: 1 month to 16 years). The relevant clinical findings included mucosal infiltration (94%), cutaneous leishmaniasis scar (74%), total loss of the nasal septum (24%), nasal deformity (22%), and mucosal ulceration (38%). The symptoms reported included nasal obstruction (90%), epistaxis (72%), rhinorrhea (72%), dysphonia (28%), dysphagia (18%), and nasal pruritus (34%). The histopathological study revealed a pattern compatible with leishmaniasis in 86% of the biopsies, and amastigotes were identified in 14% of them. The Montenegro skin test was positive in 86% of patients, immunofluorescence in 84%, and culture in 8%. Leishmania (V.) braziliensis was identified in 88% of the samples, L. (V) panamensis in 8%, and L. (V.) guyanensis and L. (L.) amazonensis in 2% respectively. CONCLUSION: In this study, we found a severe nasal disease with destruction and deformity of the nasal septum in 25% of the cases, probably associated with late diagnosis. Leishmania (V.) braziliensis was the predominant species. We described a case of mucosal leishmaniasis in Colombia caused by L. (L.) amazonensis for the first time.

Introducción. La leishmaniasis mucosa tiene un curso progresivo y puede causar deformidad e incluso mutilación de las zonas afectadas. Es endémica en el continente americano y es causada principalmente por Leishmania (Viannia) brasiliensis. Objetivo. Describir una serie de casos de leishmaniasis mucosa y las especies de Leishmania infecciosas. Materiales y métodos. Se estudiaron 50 pacientes con diagnóstico clínico de leishmaniasis mucosa y confirmación parasitológica. Se describieron sus características clínicas y los resultados de laboratorio. La tipificación de especies se hizo mediante reacción en cadena de la polimerasa de los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism Polymerase Chain Reaction, PCR-RFLP) en la secuencia del miniexon y el gen hsp70 y se confirmó por secuenciación. Resultados. La evolución de la enfermedad fue de un mes a dieciséis años (mediana de 2,8 años). Los hallazgos clínicos fueron los siguientes: infiltración mucosa (94 %), cicatriz de leishmaniasis cutánea (74 %), pérdida total del tabique nasal (24 %), deformidad nasal (22 %) y ulceración (38 %). Los síntomas reportados fueron: obstrucción nasal (90 %), epistaxis (72 %), rinorrea (72 %), disfonía (28 %), disfagia (18 %) y prurito nasal (34 %). La histopatología mostró un patrón compatible con leishmaniasis en 86 % de las biopsias y se identificaron amastigotes en 14 % de ellas. La prueba de Montenegro fue positiva en 86 % de los pacientes, la inmunofluorescencia en 84 %, y el cultivo en 8 %. Leishmania (V.) brasiliensis se identificó en 88 % de las muestras, L. (V) panamensis en 8 %, y L. (V.) guyanensis y L. (L.) amazonensis en 2 %, respectivamente. Conclusión. Se encontró enfermedad nasal grave con destrucción y deformidad del tabique nasal en una cuarta parte de los casos, probablemente debido a un diagnóstico tardío. Leishmania (V.) brasiliensis fue la especie predominante. Se describe por primera vez un caso de leishmaniasis mucosa causado por L. (L.) amazonensis en Colombia.

Mucosal leishmaniasis: A forgotten disease, description and identification of species in 50 Colombian cases / Leishmaniasis mucosa: una enfermedad olvidada, descripción e identificación de especies en 50 casos colombianos

Abstract Introduction: Mucosal leishmaniasis has a progressive course and can cause deformity and even mutilation in the affected areas. It is endemic in the American continent and it is mainly caused by Leishmania (Viannia) braziliensis. Objective: To describe a series of mucosal leishmaniasis cases and the infectious Leishmania species. Materials and methods: We included 50 patients with a clinical diagnosis of mucosal leishmaniasis and parasitological confirmation, and we described their clinical and laboratory results. We performed species typing by PCR-RFLP using the miniexon sequence and hsp70 genes; confirmation was done by sequencing. Results: The median time of disease evolution was 2.9 years (range: 1 month to 16 years). The relevant clinical findings included mucosal infiltration (94%), cutaneous leishmaniasis scar (74%), total loss of the nasal septum (24%), nasal deformity (22%), and mucosal ulceration (38%). The symptoms reported included nasal obstruction (90%), epistaxis (72%), rhinorrhea (72%), dysphonia (28%), dysphagia (18%), and nasal pruritus (34%). The histopathological study revealed a pattern compatible with leishmaniasis in 86% of the biopsies, and amastigotes were identified in 14% of them. The Montenegro skin test was positive in 86% of patients, immunofluorescence in 84%, and culture in 8%. Leishmania (V.) braziliensis was identified in 88% of the samples, L. (V) panamensis in 8%, and L. (V.) guyanensis and L. (L.) amazonensis in 2% respectively. Conclusion: In this study, we found a severe nasal disease with destruction and deformity of the nasal septum in 25% of the cases, probably associated with late diagnosis. Leishmania (V.) braziliensis was the predominant species. We described a case of mucosal leishmaniasis in Colombia caused by L. (L.) amazonensis for the first time.

Resumen Introducción. La leishmaniasis mucosa tiene un curso progresivo y puede causar deformidad e incluso mutilación de las zonas afectadas. Es endémica en el continente americano y es causada principalmente por Leishmania (Viannia) brasiliensis. Objetivo. Describir una serie de casos de leishmaniasis mucosa y las especies de Leishmania infecciosas. Materiales y métodos. Se estudiaron 50 pacientes con diagnóstico clínico de leishmaniasis mucosa y confirmación parasitológica. Se describieron sus características clínicas y los resultados de laboratorio. La tipificación de especies se hizo mediante reacción en cadena de la polimerasa de los polimorfismos de la longitud de los fragmentos de restricción (Restriction Fragment Length Polymorphism Polymerase Chain Reaction, PCR-RFLP) en la secuencia del miniexon y el gen hsp70 y se confirmó por secuenciación. Resultados. La evolución de la enfermedad fue de un mes a dieciséis años (mediana de 2,8 años). Los hallazgos clínicos fueron los siguientes: infiltración mucosa (94 %), cicatriz de leishmaniasis cutánea (74 %), pérdida total del tabique nasal (24 %), deformidad nasal (22 %) y ulceración (38 %). Los síntomas reportados fueron: obstrucción nasal (90 %), epistaxis (72 %), rinorrea (72 %), disfonía (28 %), disfagia (18 %) y prurito nasal (34 %). La histopatología mostró un patrón compatible con leishmaniasis en 86 % de las biopsias y se identificaron amastigotes en 14 % de ellas. La prueba de Montenegro fue positiva en 86 % de los pacientes, la inmunofluorescencia en 84 %, y el cultivo en 8 %. Leishmania (V.) brasiliensis se identificó en 88 % de las muestras, L. (V) panamensis en 8 %, y L. (V.) guyanensis y L. (L.) amazonensis en 2 %, respectivamente. Conclusión. Se encontró enfermedad nasal grave con destrucción y deformidad del tabique nasal en una cuarta parte de los casos, probablemente debido a un diagnóstico tardío. Leishmania (V.) brasiliensis fue la especie predominante. Se describe por primera vez un caso de leishmaniasis mucosa causado por L. (L.) amazonensis en Colombia.

La Lepra: una enfermedad vigente / Leprosy: an ongoing disease

El libro resalta que la lepra continúa siendo una enfermedad presente en Colombia y que aún constituye un problema de salud pública importante por los costos sociales, económicos y de sufrimiento humano que conlleva. Sabiendo que la literatura sobre el tema es escasa en nuestro medio, este libro surge como una herramienta de consulta creada para médicos y otros profesionales de salud, con la certeza de que es preciso mejorar la oportunidad del diagnóstico. Siendo fundamental que, durante su proceso formativo, todos los profesionales de la salud adquieran conocimientos sobre dicha enfermedad, que cada día se hace más visible por sus secuelas y diagnóstico tardío.

The book highlights the fact that leprosy continues to be a disease present in Colombia and that it is still a major public health problem due to the social, economic and human suffering costs it entails. Knowing that the literature on the subject is scarce in our country, this book is intended as a reference tool for doctors and other health professionals, in the knowledge that it is necessary to improve the timeliness of diagnosis. It is essential that, during their training process, all health professionals acquire knowledge about this disease, which is becoming more and more visible every day due to its sequelae and late diagnosis.

Polymerase chain reaction-miniexon: a promising diagnostic method for mucocutaneous leishmaniasis.

BACKGROUND: Mucocutaneous leishmaniasis is a chronic disease caused mainly by Leishmania species that belong to Viannia subgenus. It affects upper respiratory airways and may lead to deformity, dysphagia, and even death in severe cases. Diagnosis is a challenge because clinical and histopathologic changes are easily confused with other diseases, and conventional methods for parasite identification and culture have a low sensitivity. Molecular methods have been used in the last two decades. In 2007, we published a validation study using internal transcript spacers and kinetoplast DNA as molecular targets with satisfactory results. In this research, we tested miniexon gene as the target. METHODS: Mucosal tissue samples from 60 Colombian patients with clinical signs of mucocutaneous leishmaniasis were included. A composite reference standard defined 30 cases and 30 controls. Two blind observers performed patient classification and test application independently. Miniexon gene amplification generated: 226-230 bp fragment for subgenus Viannia; 308 bp fragment for L. amazonensis; 340 bp fragment for L. mexicana; and 418 bp fragment for L. infantum-chagasi. RESULTS: Polymerase chain reaction (PCR) sensitivity for fresh samples was 87.5% (95% confidence interval [CI] 72.2-100), specificity, 95% (95% CI 83.0-100), and positive likelihood ratio was 17.5 (95% CI 2.58-118.93), similar to results obtained with paraffin-embedded samples. Agreement between observers was 96% (kappa = 0.912; 95% CI 0.815-1.000) for both subgenus Viannia and Leishmania. CONCLUSIONS: We consider PCR-miniexon as a diagnostic method of first choice for mucocutaneous leishmaniasis due to its excellent diagnostic performance and its ability to discriminate between Leishmania and Viannia subgenera as well as between species belonging to Leishmania subgenus.

Noninferiority of miltefosine versus meglumine antimoniate for cutaneous leishmaniasis in children.

BACKGROUND: Children have a lower response rate to antimonial drugs and higher elimination rate of antimony (Sb) than adults. Oral miltefosine has not been evaluated for pediatric cutaneous leishmaniasis. METHODS: A randomized, noninferiority clinical trial with masked evaluation was conducted at 3 locations in Colombia where Leishmania panamensis and Leishmania guyanensis predominated. One hundred sixteen children aged 2-12 years with parasitologically confirmed cutaneous leishmaniasis were randomized to directly observed treatment with meglumine antimoniate (20 mg Sb/kg/d for 20 days; intramuscular) (n = 58) or miltefosine (1.8-2.5 mg/kg/d for 28 days; by mouth) (n = 58). Primary outcome was treatment failure at or before week 26 after initiation of treatment. Miltefosine was noninferior if the proportion of treatment failures was ≤15% higher than achieved with meglumine antimoniate (1-sided test, α = .05). RESULTS: Ninety-five percent of children (111/116) completed follow-up evaluation. By intention-to-treat analysis, failure rate was 17.2% (98% confidence interval [CI], 5.7%-28.7%) for miltefosine and 31% (98% CI, 16.9%-45.2%) for meglumine antimoniate. The difference between treatment groups was 13.8%, (98% CI, -4.5% to 32%) (P = .04). Adverse events were mild for both treatments. CONCLUSIONS: Miltefosine is noninferior to meglumine antimoniate for treatment of pediatric cutaneous leishmaniasis caused by Leishmania (Viannia) species. Advantages of oral administration and low toxicity favor use of miltefosine in children. CLINICAL TRIAL REGISTRATION: NCT00487253.

Relapses in multibacillary leprosy patients: a retrospective cohort of 11 years in Colombia.

OBJECTIVES: To determine the frequency and factors associated with relapse in multibacillary leprosy. DESIGN: We performed a retrospective cohort study on multibacillary leprosy patients treated at Centro Dermatologico Federico Lleras Acosta between January 1994 and December 2004. By survival analysis we studied the incidence density for recurrence and bacillary index conversion. The assessment of risk factors associated with the occurrence of relapse was constructed using a Cox regression model. RESULTS: We included 299 cases of which 243 received WHO-MB MDT on a regular basis, and followed them up to assess the frequency of relapses. We obtained 490 person-years of follow-up and an incidence density of 6.70 relapses/100 patient-years that was higher than most of the data reported in the literature. The relapse rate was 9.80 per 100 person-years when the initial bacillary index was > or = 2.0 and 5.60 relapses/100 patient-years when it was < 2 (P = 0.03). The relapse rate increased to 7.70/100 patient-years among those treated with WHO-MB 24 month fixed-dose, and it reduced to 5.70/100 patient-years when treated until smear negative. The variables that showed association with relapse were: initial bacillary index > or = 2.0, antireactional treatment and clinical classification of lepromatous leprosy. For each variable, the risk was four to five times more likely to present relapse. We also found that 21 patients' BI became negative per 100 treated for 1 year with WHO-MB MDT. CONCLUSIONS: We found a high relapse rate associated with initial high bacillary index in the Colombian population. Among the patients who received MDT on a regular basis 33 out of 165 (20%) relapsed.

Polymerase chain reaction with two molecular targets in mucosal leishmaniasis' diagnosis: a validation study.

We validated the polymerase chain reaction (PCR) with a composite reference standard in 61 patients clinically suspected of having mucosal leishmaniasis, 36 of which were cases and 25 were non-cases according to this reference standard. Patient classification and test application were carried out independently by two blind observers. One pair of primers was used to amplify a fragment of 120 bp in the conserved region of kDNA and another pair was used to amplify the internal transcript spacers (ITS) rDNA. PCR showed 68.6% (95% CI 59.2-72.6) sensitivity and 92% (95% CI 78.9-97.7) specificity; positive likelihood ratio: 8.6 (95% CI 2.8-31.3) and negative likelihood ratio: 0.3 (95% CI 0.3-0.5), when kDNA molecular target was amplified. The test performed better on sensitivity using this target compared to the ITS rDNA molecular target which showed 40% (95% CI 31.5-42.3) sensitivity and 96% (95% CI 84.1-99.3) specificity; positive likelihood ratio: 10 (95% CI 2.0-58.8) and negative likelihood ratio: 0.6 (95% CI 0.6-0.8). The inter-observer agreement was excellent for both tests. Based upon results obtained and due to low performance of conventional methods for diagnosing mucosal leishmaniasis, we consider PCR with kDNA as molecular target is a useful diagnostic test and the ITS rDNA molecular target is useful when the aim is to identify species.

Polymerase chain reaction with two molecular targets in mucosal leishmaniasis' diagnosis: a validation study

We validated the polymerase chain reaction (PCR) with a composite reference standard in 61 patients clinically suspected of having mucosal leishmaniasis, 36 of which were cases and 25 were non-cases according to this reference standard. Patient classification and test application were carried out independently by two blind observers. One pair of primers was used to amplify a fragment of 120 bp in the conserved region of kDNA and another pair was used to amplify the internal transcript spacers (ITS) rDNA. PCR showed 68.6 percent (95 percent CI 59.2-72.6) sensitivity and 92 percent (95 percent CI 78.9-97.7) specificity; positive likelihood ratio: 8.6 (95 percent CI 2.8-31.3) and negative likelihood ratio: 0.3 (95 percent CI 0.3-0.5), when kDNA molecular target was amplified. The test performed better on sensitivity using this target compared to the ITS rDNA molecular target which showed 40 percent (95 percent CI 31.5-42.3) sensitivity and 96 percent (95 percent CI 84.1-99.3) specificity; positive likelihood ratio: 10 (95 percent CI 2.0-58.8) and negative likelihood ratio: 0.6 (95 percent CI 0.6-0.8). The inter-observer agreement was excellent for both tests. Based upon results obtained and due to low performance of conventional methods for diagnosing mucosal leishmaniasis, we consider PCR with kDNA as molecular target is a useful diagnostic test and the ITS rDNA molecular target is useful when the aim is to identify species.