Browsing by Autor "Ernesto Rojas"

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Assessment of a Leishmaniasis Reporting System in Tropical Bolivia Using the Capture-Recapture Method
(American Society of Tropical Medicine and Hygiene, 2017) Daniel Eid Rodríguez; Miguel Guzmán-Rivero; Ernesto Rojas; Isabel Goicolea; Anna‐Karin Hurtig; Daniel Illanes; Miguel San Sebastiån
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.
Clinical and immunological characteristics of tegumentary leishmaniasis cases in Bolivia
(Public Library of Science, 2021) Cristina Ballart; Mary Cruz Torrico; Gisela Vidal; Faustino Torrico; Daniel Lozano; Montserrat Gállego; Lilian Pinto; Ernesto Rojas; Ruth Aguilar; Carlota Dobaño
In Bolivia, parasitological diagnosis remains the reference standard in diagnosis of leishmaniasis because of its high specificity, whereas the sensitivity varies over a wide range leading to loss of cases. Until more accurate tools are implemented, all patients should be tested by both smears and culture of lesion aspirates to minimize the risk of false negatives. Our results showed higher concentrations of several cytokines in MCL compared to CL, but no differences were observed between CL and no-cases. In addition, none of the cytokines differed between primary and secondary infections. These results highlight the need of further research to identify biomarkers of susceptibility and disease progression, in addition to looking at the local cellular immune responses in the lesions.
Conocimientos, prácticas y seroprevalencia humana de brucelosis en la zona lechera central de Cochabamba, Bolivia
(Pan American Health Organization, 2025) Rosse Mary Yañez; Rocío Quitón; Ernesto Rojas; Tania Vargas; Daniel Eid Rodríguez; Jean‐Jacques Letesson; Patricia Rodríguez
This study revealed a high seroprevalence of brucellosis in the La Maica dairy-producing area in Cochabamba (Plurinational State of Bolivia), with many asymptomatic cases and a high number of false positives from IgG indirect ELISA. It is recommended to conduct awareness-raising campaigns on the risks of this disease and to discourage the consumption of raw milk.
Correction to: risk factors for cutaneous leishmaniasis in the rainforest of Bolivia: a cross-sectional study
(BioMed Central, 2018) Daniel Eid Rodríguez; Miguel Guzmán-Rivero; Ernesto Rojas; Isabel Goicolea; Anna‐Karin Hurtig; Daniel Illanes; Miguel San Sebastiån
Cutaneous leishmaniasis treatment and therapeutic outcomes in special populations: A collaborative retrospective study
(Public Library of Science, 2023) María del Mar Castro; Joelle Rode; Paulo Roberto Lima Machado; Alejandro Llanos‐Cuentas; Márcia Hueb; Gláucia Cota; Isis Valentina Rojas; Yenifer Orobio; Oscar Oviedo Sarmiento; Ernesto Rojas
Our findings support the need for greater availability and use of alternatives to systemic antimonials, particularly local therapies, and development of strategies to improve patient follow-up across the region, with special attention to pediatric populations.
Epidemiological monitoring of American tegumentary leishmaniasis: molecular characterization of a peridomestic transmission cycle in the Amazonian lowlands of Bolivia
(Oxford University Press, 2007) Ana Lineth García; Tatiana Tellez; Rudy Parrado; Ernesto Rojas; Hernán Bermúdez; Jean‐Claude Dujardin
Human-made and environmental changes constitute a major risk factor for the (re-)emergence and spread of leishmaniasis; surveillance of the transmission cycle is essential in this context. This study integrated entomological and molecular parasitological techniques to document the transmission pattern of a peridomestic focus of Leishmania in the Isiboro Secure area of Bolivia. First the spatial distribution and relative density of phlebotomine sand flies, genus Lutzomyia, were established. Lutzomyia shawi was the predominant species in domestic and peridomestic environments (90% from all collections). Second, direct application of the hsp70 PCR to sand fly extracts detected Leishmania infections in Lu. shawi only, and gave an estimated infection rate of 0.21 to 0.38%. The cleavage of the hsp70 amplicon with restriction enzymes (hsp70 PCR-RFLP) allowed identification of Le. (V.) braziliensis and Le. (V.) guyanensis in Lu. shawi captured in the same village. These two parasite species were also found in humans from the study region, supporting the co-existence of two transmission cycles involving the same sand fly species. This study demonstrated the use of PCR-RFLP in the identification of Leishmania in sand fly pools which could lead to the development of methods for screening large sand fly populations in Latin America.
Erratum—Vol. 15, No. 2
(Centers for Disease Control and Prevention, 2009) Ernesto Rojas; Rudy Parrado; Raúl Delgado; Richard Reithinger; Ana Cristina Bicharra García; Editor JAS; A Garca; R Parrado; E Rojas; R Delgado
Intralesional Antimony for Single Lesions of Bolivian Cutaneous Leishmaniasis: Table 1.
(Oxford University Press, 2013) Jaime Soto; Ernesto Rojas; Miguel A. Guzmán; Aleida Verduguez; Winne Nena; Maria Maldonado; M. I. González Cruz; Lineth Gracia; Darsi Villarroel; Isidoro Alavi
NCT01300975.
Leishmaniases in Bolivia: Comprehensive Review and Current Status
(American Society of Tropical Medicine and Hygiene, 2009) Ana Lineth García; Rudy Parrado; Ernesto Rojas; Raúl Delgado; Jean‐Claude Dujardin; Richard Reithinger
The leishmaniases are protozoan, zoonotic diseases transmitted to human and other mammal hosts by the bite of phlebotomine sandflies. Bolivia has the highest incidence of cutaneous leishmaniasis (CL) in Latin America (LA), with 33 cases per 100,000 population reported in 2006. CL is endemic in seven of the country's nine administrative departments. Visceral leishmaniasis (VL) is comparatively rare and is restricted to one single focus. Most CL cases are caused by Leishmania (Viannia) braziliensis (85% cases); VL is caused by L. (L.) infantum. Seven sandfly species are incriminated as vectors and Leishmania infections have been detected in several non-human mammal hosts. Transmission is associated with forest-related activities, but recently, cases of autochthonous, urban transmission were reported. Because most cases are caused by L. (V.) braziliensis, Bolivia reports the greatest ratio (i.e., up to 20% of all cases) of mucosal leishmaniasis to localized CL cases in LA. Per national guidelines, both CL and VL cases are microscopically diagnosed and treated with pentavalent antimony.
Nutritional status in patients with cutaneous leishmaniasis and a study of the effects of zinc supplementation together with antimony treatment
(Swedish Nutrition Foundation, 2014) Miguel Guzmán-Rivero; Ernesto Rojas; Aleida Verduguez-Orellana; Henry Sánchez Pardo; Mary Cruz Torrico; Lieselotte Cloetens; Björn Åkesson; Edgar Sejas
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.
Nutritional Status of Patients with Cutaneous Leishmaniasis from a Tropical Area of Bolivia, and Implications for Zinc Bioavailability
(Scientific Research Publishing, 2013) Claudia E. Lazarte; Claudia Alegre; Ernesto Rojas; Yvonne Granfeldt
Macro and micronutrient deficiencies are a significant problem among people in rural areas in developing countries. Deficiencies may lead to an impaired immune system making the organism vulnerable to infections and diseases. In this paper, the dietary intake, anthropometric measurements, zinc and copper levels in serum, of patients with cutaneous leishmaniasis (CL) are compared with a group of healthy controls and reference values. Results showed no significant differences in most nutrient intake or anthropometrics between patients and controls. However, serum zinc level of patients (80 g/dl) was significantly lower (P < 0.001) than in controls (85 g/dl), likely explained by the presence of leishmaniasis. The median serum zinc level in both groups was below the reference values, even though their median zinc intake met the zinc recommendations from WHO. Consequently, besides the presence of leishmaniasis, serum zinc levels may be compromised by inhibitory components in their diet, such as phytates, as it is shown by the molar ratio phytate:zinc (Phy:Zn) that was between 11 and 19, while 15 is the level said to compromise zinc status. There were significant (P < 0.05) negative correlations between serum zinc and Phy:Zn, for patients (r = -0.413) and controls (r = -0.410). In conclusion this study shows that patients with CL in Chapare, Bolivia had low serum zinc levels due to the leishmaniasis per se and the decreased zinc bioavailability in their diet. CL infection was not in direct association with the nutritional status indicated by the anthropometric or dietary assessments. However, dietary intake showed 5 essential nutrients below the nutrient recommendation in both groups.
Prevalence of Leishmania spp. infection in domestic dogs in Chapare, Bolivia
(Elsevier BV, 2010) Rudy Parrado; Ernesto Rojas; Raúl Delgado; Mary Cruz Torrico; Richard Reithinger; Ana Lineth García
Prevalencia de las infecciones por virus de las hepatitis B, C, D y E en Bolivia
(Pan American Health Organization, 1999) Pilar León; Evaristo Venegas; L. Bengoechea; Ernesto Rojas; J. A. López; Consuelo Elola; José Manuel Echevarría
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.
Risk factors for cutaneous leishmaniasis in the rainforest of Bolivia: a cross-sectional study
(BioMed Central, 2018) Daniel Eid Rodríguez; Miguel Guzmán-Rivero; Ernesto Rojas; Isabel Goicolea; Anna‐Karin Hurtig; Daniel Illanes; Miguel San Sebastiån
It 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.
Tegumentary leishmaniasis by Leishmania braziliensis complex in Cochabamba, Bolivia including the presence of L. braziliensis outlier
(Wiley, 2021) Mary Cruz Torrico; Anna Fernández‐Arévalo; Cristina Ballart; Marco Solano; Ernesto Rojas; Eva Ariza; Sílvia Tebar; Daniel Lozano; Alba Abràs; Joaquím Gascón
Leishmaniasis is caused by protozoans of the Leishmania genus, which includes more than 20 species capable of infecting humans worldwide. In the Americas, the most widespread specie is L. braziliensis, present in 18 countries including Bolivia. The taxonomic position of the L. braziliensis complex has been a subject of controversy, complicated further by the recent identification of a particular subpopulation named L. braziliensis atypical or outlier. The aim of this study was to carry out a systematic analysis of the L. braziliensis complex in Bolivia and to describe the associated clinical characteristics. Forty-one strains were analyzed by sequencing an amplified 1245 bp fragment of the hsp70 gene, which allowed its identification as: 24 (59%) L. braziliensis, 16 (39%) L. braziliensis outlier, and one (2%) L. peruviana. In a dendrogram constructed, L. braziliensis and L. peruviana are grouped in the same cluster, whilst L. braziliensis outlier appears in a separate branch. Sequence alignment allowed the identification of five non-polymorphic nucleotide positions (288, 297, 642, 993, and 1213) that discriminate L. braziliensis and L. peruviana from L. braziliensis outlier. Moreover, nucleotide positions 51 and 561 enable L. peruviana to be discriminated from the other two taxa. A greater diversity was observed in L. braziliensis outlier than in L. braziliensis-L. peruviana. The 41 strains came from 32 patients with tegumentary leishmaniasis, among which 22 patients (69%) presented cutaneous lesions (11 caused by L. braziliensis and 11 by L. braziliensis outlier) and 10 patients (31%) mucocutaneous lesions (eight caused by L. braziliensis, one by L. braziliensis outlier, and one by L. peruviana). Nine patients (28%) simultaneously provided two isolates, each from a separate lesion, and in each case the same genotype was identified in both. Treatment failure was observed in six patients infected with L. braziliensis and one patient with L. peruviana.
Tegumentary leishmaniasis by Leishmania braziliensis complex in Bolivia: the presence of L. braziliensis outlier
(2021) Mary Cruz Torrico; Anna Fernández‐Arévalo; Cristina Ballart; Marco Solano; Ernesto Rojas; Eva Ariza; Sílvia Tebar; Daniel Lozano; Alba Abràs; Joaquím Gascón
Leishmaniasis is caused by protozoans of the Leishmania genus, which includes more than 20 species capable of infecting humans worldwide. In the Americas, the most widespread specie is L. braziliensis , present in 18 countries, including Bolivia. The taxonomic position of the L. braziliensis complex has been a subject of controversy, complicated further by the recent identification of a particular subpopulation named L. braziliensis atypical or outlier. The aim of this study was to carry out a systematic analysis of the L. braziliensis complex in Bolivia and to describe the associated clinical characteristics. Forty-one strains were analyzed by sequencing an amplified 1245 bp fragment of the hsp70 gene, which allowed its identification as: 24 (59%) L. braziliensis , 16 (39%) L. braziliensis outlier and one (2%) L. peruviana . In a dendrogram constructed, L. braziliensis and L. peruviana are grouped in the same cluster, whilst L. braziliensis outlier appears in a separate branch. Sequence alignment allowed the identification of five non-polymorphic nucleotide positions (288, 297, 642, 993 and 1213) that discriminate L. braziliensis and L. peruviana from L. braziliensis outlier. Moreover, nucleotide positions 51 and 561 enable L. peruviana to be discriminated from the other two taxa. A greater diversity, was observed in L . braziliensis outlier than in L. braziliensis - L. peruviana . The 41 strains came from 32 patients with tegumentary leishmaniasis, among which 22 patients (69%) presented cutaneous lesions (11 caused by L. braziliensis and 11 by L. braziliensis outlier) and ten patients (31%) mucocutaneous lesions (eight caused by L. braziliensis , one by L. braziliensis outlier and one by L. peruviana ). Nine patients (28%) simultaneously provided two isolates, each from a separate lesion, and in each case the same genotype was identified in both. Treatment failure was observed in six patients infected with L. braziliensis and one patient with L. peruviana .
The immune response in patients with cutaneous leishmaniasis and the influence of zinc supplementation
(Elsevier BV, 2014) Miguel Guzmán-Rivero; Aleida Verduguez-Orellana; K Montaño; Lieselotte Cloetens; Ernesto Rojas; Björn Åkesson; Edgar Sejas
The need for culture in tegumentary leishmaniasis diagnosis in Bolivia: A comparative evaluation of four parasitological techniques using two sampling methods
(Elsevier BV, 2023) Mary Cruz Torrico; Cristina Ballart; Anna Fernández‐Arévalo; Marco Solano; Ernesto Rojas; Alba Abràs; Fabiola Gonzales; Yercin Mamani Ortiz; Albert Arnau; Daniel Lozano
Usefulness of Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry in the Characterization of Leishmania Strains Causing Tegumentary Leishmaniasis in Bolivia versus hsp70 Gene Sequencing
(American Society for Microbiology, 2023) Mary Cruz Torrico; Anna Fernández‐Arévalo; Cristina Ballart; Marco Solano; Ernesto Rojas; Alba Abràs; Fabiola Gonzales; Albert Arnau; Sílvia Tebar; Teresa Llovet
The objective of the study was to evaluate the usefulness of MALDI-TOF MS for the characterization of Leishmania species circulating in Bolivia, in comparison with the sequencing of the hsp70 gene. In our study, all of the isolates could be identified, and no misidentifications were observed at the complex level.