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Velez ID, Tanamas SK, Arbelaez MP, Kutcher SC, Duque SL, Uribe A, Zuluaga L, Martínez L, Patiño AC, Barajas J, Muñoz E, Mejia Torres MC, Uribe S, Porras S, Almanza R, Pulido H, O’Neill SL, Santacruz-Sanmartin E, Gonzalez S, Ryan PA, Denton JA, Jewell NP, Dufault SM, Simmons CP, Anders KL. Reduced dengue incidence following city-wide wMel Wolbachia mosquito releases throughout three Colombian cities: Interrupted time series analysis and a prospective case-control study. PLoS Negl Trop Dis 2023; 17:e0011713. [PMID: 38032857 PMCID: PMC10688673 DOI: 10.1371/journal.pntd.0011713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 10/10/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND The introduction of Wolbachia (wMel strain) into Aedes aegypti mosquitoes reduces their capacity to transmit dengue and other arboviruses. Randomised and non-randomised studies in multiple countries have shown significant reductions in dengue incidence following field releases of wMel-infected Ae. aegypti. We report the public health outcomes from phased, large-scale releases of wMel-Ae. aegypti mosquitoes throughout three contiguous cities in the Aburrá Valley, Colombia. METHODOLOGY/PRINCIPAL FINDINGS Following pilot releases in 2015-2016, staged city-wide wMel-Ae. aegypti deployments were undertaken in the cities of Bello, Medellín and Itagüí (3.3 million people) between October 2016 and April 2022. The impact of the Wolbachia intervention on dengue incidence was evaluated in two parallel studies. A quasi-experimental study using interrupted time series analysis showed notified dengue case incidence was reduced by 95% in Bello and Medellín and 97% in Itagüí, following establishment of wMel at ≥60% prevalence, compared to the pre-intervention period and after adjusting for seasonal trends. A concurrent clinic-based case-control study with a test-negative design was unable to attain the target sample size of 63 enrolled virologically-confirmed dengue (VCD) cases between May 2019 and December 2021, consistent with low dengue incidence throughout the Aburrá Valley following wMel deployments. Nevertheless, VCD incidence was 45% lower (OR 0.55 [95% CI 0.25, 1.17]) and combined VCD/presumptive dengue incidence was 47% lower (OR 0.53 [95% CI 0.30, 0.93]) among participants resident in wMel-treated versus untreated neighbourhoods. CONCLUSIONS/SIGNIFICANCE Stable introduction of wMel into local Ae. aegypti populations was associated with a significant and sustained reduction in dengue incidence across three Colombian cities. These results from the largest contiguous Wolbachia releases to-date demonstrate the real-world effectiveness of the method across large urban populations and, alongside previously published results, support the reproducibility of this effectiveness across different ecological settings. TRIAL REGISTRATION NCT03631719.
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Affiliation(s)
- Ivan Dario Velez
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | | | | | | | - Sandra L. Duque
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | - Alexander Uribe
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | - Lina Zuluaga
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | - Luis Martínez
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | | | - Jovany Barajas
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | - Estefanía Muñoz
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | | | - Sandra Uribe
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | - Sandra Porras
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | | | | | | | | | - Sandra Gonzalez
- World Mosquito Program, Universidad de Antioquia, Medellín, Colombia
| | - Peter A. Ryan
- World Mosquito Program, Monash University, Melbourne, Australia
| | - Jai A. Denton
- World Mosquito Program, Monash University, Melbourne, Australia
| | - Nicholas P. Jewell
- Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Suzanne M. Dufault
- Division of Biostatistics, Department of Epidemiology and Biostatistics, University of California, San Francisco, California, United States of America
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Posada-López L, Rodrigues BL, Velez ID, Uribe S. Improving the COI DNA barcoding library for Neotropical phlebotomine sand flies (Diptera: Psychodidae). Parasit Vectors 2023; 16:198. [PMID: 37308979 DOI: 10.1186/s13071-023-05807-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/10/2023] [Indexed: 06/14/2023] Open
Abstract
Sand fly species are traditionally identified using morphological traits, though this method is hampered by the presence of cryptic species. DNA barcoding is a widely used tool in the case of insects of medical importance, where it is necessary to know quickly which species are present in a transmission area. Here, we assess the usefulness of mitochondrial cytochrome c oxidase subunit I (COI) DNA barcoding as a practical tool for species identification, correct assignment of isomorphic females, and to evaluate the detection of cryptic diversity that occurs in the same species. A fragment of the COI gene was used to generate 156 new barcode sequences for sand flies from different countries of the Neotropical region, mainly Colombia, which had been identified morphologically as 43 species. The sequencing of the COI gene allowed the detection of cryptic diversity within species and correctly associated isomorphic females with males identified by morphology. The maximum intraspecific genetic distances ranged from 0 to 8.32% and 0 to 8.92% using uncorrected p distances and the Kimura 2-parameter (K2P) model, respectively. The minimum interspecific distance (nearest neighbor) for each species ranged from 1.5 to 14.14% and 1.51 to 15.7% using p and K2P distances, respectively. Three species had more than 3% maximum intraspecific distance: Psychodopygus panamensis, Micropygomyia cayennensis cayennensis, and Pintomyia evansi. They also were split into at least two molecular operational taxonomic units (MOTUs) each, using different species delimitation algorithms. Regarding interspecific genetic distances, the species of the genera Nyssomyia and Trichophoromyia generated values lower than 3% (except Nyssomyia ylephiletor and Ny. trapidoi). However, the maximum intraspecific distances did not exceed these values, indicating the presence of a barcode gap despite their proximity. Also, nine sand fly species were DNA barcoded for the first time: Evandromyia georgii, Lutzomyia sherlocki, Ny. ylephiletor, Ny. yuilli pajoti, Psathyromyia punctigeniculata, Sciopemyia preclara, Trichopygomyia triramula, Trichophoromyia howardi, and Th. velezbernali. The COI DNA barcode analysis enabled the correct delimitation of several Neotropical sand fly species from South and Central America and raised questions about the presence of cryptic species for some taxa, which should be further assessed.
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Affiliation(s)
- Laura Posada-López
- PECET (Programa de Estudio y Control de Enfermedades Tropicales), Universidad de Antioquia, Medellín, Colombia.
- Programa de Pós-graduação em Saúde Pública, Faculdade de Saúde Pública (FSP/USP), São Paulo, SP, Brasil.
| | - Bruno Leite Rodrigues
- Programa de Pós-graduação em Saúde Pública, Faculdade de Saúde Pública (FSP/USP), São Paulo, SP, Brasil
| | - Ivan Dario Velez
- PECET (Programa de Estudio y Control de Enfermedades Tropicales), Universidad de Antioquia, Medellín, Colombia
| | - Sandra Uribe
- Grupo de Investigación en Sistemática Molecular, Universidad Nacional de Colombia, Campus, Medellín, Colombia
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Cardona-G W, Robledo S, Alzate F, Yepes AF, Hernandez C, Velez ID, Calderon JC, Tabares IV. Antileishmanial and cytotoxic activities of four Andean plant extracts from Colombia. Vet World 2020; 13:2178-2182. [PMID: 33281353 PMCID: PMC7704314 DOI: 10.14202/vetworld.2020.2178-2182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/11/2020] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND AIM Licania salicifolia (L.S) Cuatrec., Persea ferruginea (P.F) Kunth, Oreopanax floribundus (O.F), and Psychotria buchtienii (P.B) belong to the families Chrysobalanaceae, Lauraceae, Araliaceae, and Rubiaceae, respectively, which have been used as medicines by communities in the Andes. This study evaluated the leishmanicidal and cytotoxic activities of alcohol and non-alcohol extracts from four Andean plant extracts (L.S, O.F, P.F, and P.B). MATERIALS AND METHODS Extracts were obtained by percolation with solvents of different polarities - hexane, dichloromethane, ethyl acetate, and ethanol. Phytochemical screening was conducted based on reported methods. All products were evaluated in vitro to determine the leishmanicidal activity against amastigotes of Leishmania panamensis and cytotoxicity against U937 cells. RESULTS Flavonoids, triterpenes, and tannins were the main secondary metabolites found. From the results, dichloromethane extracts from O.F and P.B, ethanol extract from P.B, and ethyl acetate extracts of all plants were active, with EC50 <30 μg/mL. Ethyl acetate was the most active extract, which showed EC50 values of 9.8, 14.1, 23.7, and 25.5 μg/mL, for L.S, P.B, O.F, and P.F, respectively. Hexane extracts from P.B and O.F exhibited moderate activity with EC50 values of 84.8 and 87.4 μg/mL, respectively. Hexane and ethanol extracts from O.F, ethyl acetate, and ethanol extracts from L.S, and all extracts from P.F were not toxic. Alternatively, hexane and dichloromethane extracts from L.S and P.B as well as dichloromethane and ethyl acetate extracts from O.F displayed high toxicity. CONCLUSION Based on the activity we observed, ethyl acetate extract can continue in its usage in the search for new antileishmanial drugs, mainly ethyl acetate extract from L.S showed activity comparable to meglumine antimoniate and was not cytotoxic.
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Affiliation(s)
- Wilson Cardona-G
- Chemistry of Colombian Plants, Institute of Chemistry, Natural and Exact Sciences Faculty, Universidad de Antioquia, Colombia
| | - Sara Robledo
- Group of Botanical Studies, Institute of Biology, Natural and Exact Sciences Faculty, Universidad de Antioquia, Colombia
| | - Fernando Alzate
- PECET, Medical Research Institute, School of Medicine, Universidad de Antioquia, Colombia
| | - Andrés F. Yepes
- Chemistry of Colombian Plants, Institute of Chemistry, Natural and Exact Sciences Faculty, Universidad de Antioquia, Colombia
| | - Cristian Hernandez
- Chemistry of Colombian Plants, Institute of Chemistry, Natural and Exact Sciences Faculty, Universidad de Antioquia, Colombia
| | - Ivan Dario Velez
- Group of Botanical Studies, Institute of Biology, Natural and Exact Sciences Faculty, Universidad de Antioquia, Colombia
| | - Juan Carlos Calderon
- Chemistry of Colombian Plants, Institute of Chemistry, Natural and Exact Sciences Faculty, Universidad de Antioquia, Colombia
| | - Isabel Vásquez Tabares
- Chemistry of Colombian Plants, Institute of Chemistry, Natural and Exact Sciences Faculty, Universidad de Antioquia, Colombia
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Lim JK, Carabali M, Camacho E, Velez DC, Trujillo A, Egurrola J, Lee KS, Velez ID, Osorio JE. Epidemiology and genetic diversity of circulating dengue viruses in Medellin, Colombia: a fever surveillance study. BMC Infect Dis 2020; 20:466. [PMID: 32615988 PMCID: PMC7331258 DOI: 10.1186/s12879-020-05172-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 06/17/2020] [Indexed: 12/29/2022] Open
Abstract
Background Dengue fever is a major public health problem in Colombia. A fever surveillance study was conducted for evaluation of the clinical, epidemiological, and molecular patterns of dengue, prior to Chikungunya and Zika epidemics. Methods In November 2011–February 2014, a passive facility-based surveillance was implemented in Santa Cruz Hospital, Medellin, and enrolled eligible febrile patients between 1 and 65 years-of-age. Acute and convalescent blood samples were collected 10–21 days apart and tested for dengue using IgM/IgG ELISA. RNA was extracted for serotyping using RT-PCR on acute samples and genotyping was performed by sequencing. Results Among 537 febrile patients enrolled during the study period, 29% (n = 155) were identified to be dengue-positive. Only 7% of dengue cases were hospitalized, but dengue-positive patients were 2.6 times more likely to be hospitalized, compared to non-dengue cases, based on a logistic regression. From those tested with RT-PCR (n = 173), 17 were dengue-confirmed based on PCR and/or virus isolation showing mostly DENV-3 (n = 9) and DENV-4 (n = 7) with 1 DENV-1. Genotyping results showed that: DENV-1 isolate belongs to the genotype V or American/African genotype; DENV-3 isolates belong to genotype III; and DENV-4 isolates belong to the II genotype and specifically to the IIb sub-genotype or linage. Conclusions Our surveillance documented considerable dengue burden in Santa Cruz comuna during non-epidemic years, and genetic diversity of circulating DENV isolates, captured prior to Chikungunya epidemic in 2014 and Zika epidemic in 2015. Our study findings underscore the need for continued surveillance and monitoring of dengue and other arboviruses and serve as epidemiological and molecular evidence base for future studies to assess changes in DENV transmission in Medellin, given emerging and re-emerging arboviral diseases in the region.
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Affiliation(s)
- Jacqueline Kyungah Lim
- Dengue Vaccine Initiative, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
| | - Mabel Carabali
- Dengue Vaccine Initiative, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.,Department of Epidemiology, Biostatistics and Occupational Health, McGill University, 845 Sherbrooke St., W, Montreal, Quebec, H3A 0G4, Canada
| | - Erwin Camacho
- Investigaciones Biomedicas, Universidad de Sucre, Cra 28 # 5-267, Barrio Puerta Roja, Sincelejo, Sucre, Colombia
| | - Diana Carolina Velez
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, calle 67 No. 53, 108, Medellín, Antioquia, Colombia
| | - Andrea Trujillo
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, calle 67 No. 53, 108, Medellín, Antioquia, Colombia
| | - Jorge Egurrola
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, calle 67 No. 53, 108, Medellín, Antioquia, Colombia
| | - Kang-Sung Lee
- Dengue Vaccine Initiative, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Ivan Dario Velez
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, calle 67 No. 53, 108, Medellín, Antioquia, Colombia
| | - Jorge E Osorio
- Department of Pathobiological Sciences, University of Wisconsin, 500 Lincoln Dr, Madison, WI, 53706, USA
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Carabali M, Lim JK, Velez DC, Trujillo A, Egurrola J, Lee KS, Kaufman JS, DaSilva LJ, Velez ID, Osorio JE. Dengue virus serological prevalence and seroconversion rates in children and adults in Medellin, Colombia: implications for vaccine introduction. Int J Infect Dis 2017; 58:27-36. [PMID: 28284914 PMCID: PMC5421161 DOI: 10.1016/j.ijid.2017.02.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 02/17/2017] [Accepted: 02/20/2017] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Dengue is an important public health problem worldwide. A vaccine has recently been licensed in some countries of Latin America and Asia. Recommendations for dengue vaccine introduction include endemicity and a high serological prevalence of dengue in the territories considering its introduction. METHODS A community-based survey was conducted to estimate dengue seroprevalence and age-specific seroconversion rates in a community in Medellin, Colombia, using a dengue serological test (IgG indirect ELISA). Residents were selected at random and were first screened for dengue infection; they were then followed over 2.5 years. RESULTS A total of 3684 individuals aged between 1 and 65 years participated in at least one survey. The overall dengue seroprevalence was 61%, and only 3.3% of seropositive subjects self-reported a past history of dengue. Among dengue virus (DENV)-naïve subjects with more than two visits (n=1002), the overall seroconversion rate was 8.7% (95% confidence interval 7.3-10.4) per 1000 person-months, over the study period. Overall, the mean age of DENV prevalent subjects was significantly higher than the mean age of seroconverted subjects. Specifically, DENV seropositivity over 70% was observed in participants over 21 years old. Serotype-specific plaque-reduction neutralization tests (PRNT) revealed that all four dengue serotypes were circulating, with DENV4 being most prevalent. CONCLUSIONS These laboratory-based findings could inform dengue vaccine decisions, as they provide age-specific seroprevalence and seroconversion data, evidencing permanent and ongoing dengue transmission in the study area. This study provides evidence for the existing rates of secondary and heterotypic responses, presenting a challenge that must be addressed adequately by the new vaccine candidates.
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Affiliation(s)
- Mabel Carabali
- Dengue Vaccine Initiative, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, South Korea; Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada.
| | - Jacqueline Kyungah Lim
- Dengue Vaccine Initiative, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, South Korea
| | - Diana Carolina Velez
- Program for the Study and Control of Tropical Diseases, Universidad de Antioquia, Medellín, Colombia
| | - Andrea Trujillo
- Program for the Study and Control of Tropical Diseases, Universidad de Antioquia, Medellín, Colombia
| | - Jorge Egurrola
- Program for the Study and Control of Tropical Diseases, Universidad de Antioquia, Medellín, Colombia
| | - Kang Sung Lee
- Dengue Vaccine Initiative, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, South Korea
| | - Jay S Kaufman
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada
| | - Luiz Jacinto DaSilva
- Dengue Vaccine Initiative, International Vaccine Institute, SNU Research Park, 1 Gwanak-ro, Gwanak-gu, Seoul, 151-742, South Korea
| | - Ivan Dario Velez
- Program for the Study and Control of Tropical Diseases, Universidad de Antioquia, Medellín, Colombia
| | - Jorge E Osorio
- Program for the Study and Control of Tropical Diseases, Universidad de Antioquia, Medellín, Colombia; Department of Pathobiological Sciences, University of Wisconsin, Madison, Wisconsin, USA
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Aliota MT, Peinado SA, Velez ID, Osorio JE. The wMel strain of Wolbachia Reduces Transmission of Zika virus by Aedes aegypti. Sci Rep 2016; 6:28792. [PMID: 27364935 PMCID: PMC4929456 DOI: 10.1038/srep28792] [Citation(s) in RCA: 198] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 06/10/2016] [Indexed: 11/09/2022] Open
Abstract
Zika virus (ZIKV) is causing an explosive outbreak of febrile disease in the Americas. There are no effective antiviral therapies or licensed vaccines for this virus, and mosquito control strategies have not been adequate to contain the virus. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against other arboviruses. At present, it is unknown whether or not ZIKV can infect, disseminate, and be transmitted by Wolbachia-infected Ae. aegypti. Using Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for ZIKV. These results support the use of Wolbachia biocontrol as a multivalent strategy against Ae. aegypti-transmitted viruses.
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Affiliation(s)
- Matthew T. Aliota
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Stephen A. Peinado
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Ivan Dario Velez
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, Medellin, A1226, Colombia
| | - Jorge E. Osorio
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
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Aliota MT, Walker EC, Uribe Yepes A, Dario Velez I, Christensen BM, Osorio JE. The wMel Strain of Wolbachia Reduces Transmission of Chikungunya Virus in Aedes aegypti. PLoS Negl Trop Dis 2016; 10:e0004677. [PMID: 27124663 PMCID: PMC4849757 DOI: 10.1371/journal.pntd.0004677] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/08/2016] [Indexed: 12/04/2022] Open
Abstract
Background New approaches to preventing chikungunya virus (CHIKV) are needed because current methods are limited to controlling mosquito populations, and they have not prevented the invasion of this virus into new locales, nor have they been sufficient to control the virus upon arrival. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, evidence suggests Wolbachia infections confer protection for Ae. aegypti against CHIKV. Although this approach holds much promise for limiting virus transmission, at present our understanding of the ability of CHIKV to infect, disseminate, and be transmitted by wMel-infected Ae. aegypti currently being used at Wolbachia release sites is limited. Methodology/Principal Findings Using Ae. aegypti infected with the wMel strain of Wolbachia that are being released in Medellin, Colombia, we report that these mosquitoes have reduced vector competence for CHIKV, even with extremely high viral titers in the bloodmeal. In addition, we examined the dynamics of CHIKV infection over the course of four to seven days post feeding. Wolbachia-infected mosquitoes remained non-infective over the duration of seven days, i.e., no infectious virus was detected in the saliva when exposed to bloodmeals of moderate viremia, but CHIKV-exposed, wild type mosquitoes did have viral loads in the saliva consistent with what has been reported elsewhere. Finally, the presence of wMel infection had no impact on the lifespan of mosquitoes as compared to wild type mosquitoes following CHIKV infection. Conclusions/Significance These results could have an impact on vector control strategies in areas where Ae. aegypti are transmitting both DENV and CHIKV; i.e., they argue for further exploration, both in the laboratory and the field, on the feasibility of expanding this technology beyond DENV. New approaches to preventing chikungunya virus (CHIKV) infection are needed because the endemic range of this virus is expanding and because current methods are limited to controlling mosquito populations, and this approach has not effectively controlled this virus. A promising candidate for arbovirus control and prevention relies on the introduction of the intracellular bacterium Wolbachia into Aedes aegypti mosquitoes. Wolbachia biocontrol has advanced from laboratory experiments demonstrating that Wolbachia reduces virus replication to small-scale field trials demonstrating that Wolbachia are capable of spreading through wild Ae. aegypti populations. This primarily has been proposed as a tool to control dengue virus (DENV) transmission; however, Wolbachia infections confer protection for their insect hosts against a range of pathogens including CHIKV in Ae. aegypti. Medium-scale Wolbachia deployments are imminent or in certain instances have commenced. Therefore, assessing whether or not Wolbachia-infected Ae. aegypti are effective against CHIKV will help inform the viability of Wolbachia biocontrol for CHIKV control. Our study provides valuable evidence that could justify expanding this type of control program to other Ae. aegypti-transmitted arboviruses, primarily CHIKV.
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Affiliation(s)
- Matthew T. Aliota
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
| | - Emma C. Walker
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Alexander Uribe Yepes
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, Medellin, Colombia
| | - Ivan Dario Velez
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Universidad de Antioquia, Medellin, Colombia
| | - Bruce M. Christensen
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Jorge E. Osorio
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Sirivichayakul C, Barranco-Santana EA, Esquilin-Rivera I, Oh HML, Raanan M, Sariol CA, Shek LP, Simasathien S, Smith MK, Velez ID, Wallace D, Gordon GS, Stinchcomb DT. Safety and Immunogenicity of a Tetravalent Dengue Vaccine Candidate in Healthy Children and Adults in Dengue-Endemic Regions: A Randomized, Placebo-Controlled Phase 2 Study. J Infect Dis 2015; 213:1562-72. [PMID: 26704612 DOI: 10.1093/infdis/jiv762] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 12/11/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A safe, effective tetravalent dengue vaccine is a global health priority. The safety and immunogenicity of a live attenuated, recombinant tetravalent dengue vaccine candidate (TDV) were evaluated in healthy volunteers from dengue-endemic countries. METHODS This multicenter, double-blind, phase 2 study was conducted in Puerto Rico, Colombia, Singapore, and Thailand. During stage I, 148 volunteers aged 1.5-45 years were sequentially enrolled into 4 age-descending groups and randomized at a ratio of 2:1 to receive TDV or placebo. In stage II (group 5), 212 children aged 1.5-11 years were randomized at a ratio of 3:1 to receive TDV or placebo. Participants received a subcutaneous injection of TDV or placebo on days 0 and 90 and were followed for analysis of safety, seropositivity, and neutralizing antibodies to DENV-1-4. RESULTS Injection site pain, itching, and erythema (mostly mild) were the only solicited adverse events more frequently reported with TDV than with placebo in all age groups. After 2 TDV doses, seropositivity was >95% in all 5 groups for DENV-1-3 and 72.7%-100% for DENV-4; geometric mean titers ranged from 582 to 1187 for DENV-1, from 582 to 1187 for DENV-2, from 196 to 630 for DENV-3, and from 41 to 210 for DENV-4 among the 5 groups. CONCLUSIONS TDV was well tolerated and immunogenic in volunteers aged 1.5-45 years, irrespective of prevaccination dengue exposure.
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Affiliation(s)
| | | | | | - Helen M L Oh
- Division of Infectious Disease, Changi General Hospital
| | | | - Carlos A Sariol
- Department of Microbiology and Medical Zoology Department of Internal Medicine, University of Puerto Rico School of Medicine Latin Clinical Trial Center, San Juan, Puerto Rico
| | - Lynette P Shek
- Department of Paediatrics, National University of Singapore
| | | | | | - Ivan Dario Velez
- Program for the Study and Control of Tropical Diseases, Universidad de Antioquia, Medellín, Colombia
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9
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Ruiz-Lopez F, Wilkerson RC, Ponsonby DJ, Herrera M, Sallum MAM, Velez ID, Quiñones ML, Flores-Mendoza C, Chadee DD, Alarcon J, Alarcon-Ormasa J, Linton YM. Systematics of the oswaldoi complex (Anopheles, Nyssorhynchus) in South America. Parasit Vectors 2013; 6:324. [PMID: 24499562 PMCID: PMC3843595 DOI: 10.1186/1756-3305-6-324] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 09/10/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Effective malaria control relies on accurate identification of those Anopheles mosquitoes responsible for the transmission of Plasmodium parasites. Anopheles oswaldoi s.l. has been incriminated as a malaria vector in Colombia and some localities in Brazil, but not ubiquitously throughout its Neotropical range. This evidence together with variable morphological characters and genetic differences supports that An. oswaldoi s.l. compromises a species complex. The recent fully integrated redescription of An. oswaldoi s.s. provides a solid taxonomic foundation from which to molecularly determine other members of the complex. METHODS DNA sequences of the Second Internal Transcribed Spacer (ITS2 - rDNA) (n = 192) and the barcoding region of the Cytochrome Oxidase I gene (COI - mtDNA) (n = 110) were generated from 255 specimens of An. oswaldoi s.l. from 33 localities: Brazil (8 localities, including the lectotype series of An. oswaldoi), Ecuador (4), Colombia (17), Trinidad and Tobago (1), and Peru (3). COI sequences were analyzed employing the Kimura-two-parameter model (K2P), Bayesian analysis (MrBayes), Mixed Yule-Coalescent model (MYC, for delimitation of clusters) and TCS genealogies. RESULTS Separate and combined analysis of the COI and ITS2 data sets unequivocally supported four separate species: two previously determined (An. oswaldoi s.s. and An. oswaldoi B) and two newly designated species in the Oswaldoi Complex (An. oswaldoi A and An. sp. nr. konderi). The COI intra- and inter-specific genetic distances for the four taxa were non-overlapping, averaging 0.012 (0.007 to 0.020) and 0.052 (0.038 to 0.064), respectively. The concurring four clusters delineated by MrBayes and MYC, and four independent TCS networks, strongly confirmed their separate species status. In addition, An. konderi of Sallum should be regarded as unique with respect to the above. Despite initially being included as an outgroup taxon, this species falls well within the examined taxa, suggesting a combined analysis of these taxa would be most appropriate. CONCLUSIONS Through novel data and retrospective comparison of available COI and ITS2 DNA sequences, evidence is shown to support the separate species status of An. oswaldoi s.s., An. oswaldoi A and An. oswaldoi B, and at least two species in the closely related An. konderi complex (An. sp. nr. konderi, An. konderi of Sallum). Although An. oswaldoi s.s. has never been implicated in malaria transmission, An. oswaldoi B is a confirmed vector and the new species An. oswaldoi A and An. sp. nr. konderi are circumstantially implicated, most likely acting as secondary vectors.
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Affiliation(s)
- Freddy Ruiz-Lopez
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Museum Support Center, Suitland, MD 20746, USA
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Richard C Wilkerson
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Museum Support Center, Suitland, MD 20746, USA
- Walter Reed Biosystematics Unit, Smithsonian Institution, Museum Support Center, Suitland, MD 20746, USA
| | - David J Ponsonby
- Department of Geographical and Life Sciences, Canterbury Christ Church University, Kent, UK
| | - Manuela Herrera
- Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | - Maria Anice Mureb Sallum
- Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidad de São Paulo, São Paulo, SP, Brazil
| | - Ivan Dario Velez
- Programa de Estudio y Control de Enfermedades Tropicales (PECET), Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Martha L Quiñones
- Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, Colombia
| | | | - Dave D Chadee
- Department of Life Science, Faculty of Science and Technology, University of the West Indies, St. Augustine Campus, West Indies, Trinidad and Tobago
| | - Joubert Alarcon
- Servicio Nacional de Control de Enfermedades Transmitidas por Vectores Artrópodos, Ministerio Salud Publica, Guayaquil, Ecuador
| | - Joubert Alarcon-Ormasa
- Servicio Nacional de Control de Enfermedades Transmitidas por Vectores Artrópodos, Ministerio Salud Publica, Guayaquil, Ecuador
| | - Yvonne-Marie Linton
- Walter Reed Biosystematics Unit, Smithsonian Institution, Museum Support Center, Suitland, MD 20746, USA
- Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD 20910, USA
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10
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Abreu Velez AM, Yepes Naranjo MM, Avila IC, Luz Londoño M, Googe Jr. PB, Velásquez Velez JE, Velez ID, Upegui YA, Jimenez- Echavarria A, Mesa-Herrera NR, Yi H, Calle-Isaza J, Howard MS. Tissue inhibitor of metalloproteinase 1, matrix metalloproteinase 9, αlpha-1 antitrypsin, metallothionein and urokinase type plasminogen activator receptor in skin biopsies from patients affected by autoimmune blistering diseases. Our Dermatol Online 2013. [DOI: 10.7241/ourd.20133.67] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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11
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Sierra DM, Velez ID, Linton YM. Malaria vector anopheles (Nyssorhynchus) nuneztovari comprises one genetic species in colombia based on homogeneity of nuclear ITS2 rDNA. J Med Entomol 2004; 41:302-307. [PMID: 15185929 DOI: 10.1603/0022-2585-41.3.302] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Previous studies indicated that two distinct chromosomal forms of Anopheles nuneztovari Gabaldón, cytotypes B and C, occurred on the west and east of the Latin American Andes Mountains, respectively. To determine the taxonomic status ofAnopheles (Nyssorhynchus) nuneztovari in Colombia, link-reared specimens were collected from four sites: in the departments of Chocó (La Pacurita) and Valle (Sitronella) in the west, and Norte de Santander (Guaramito andl Tibú) in the east. Nuclear ITS2 sequences were generated for 46 individuals. Only two specimens (4.4%) showed divergent haplotypes, varying from the consensus by a single-base polymorphism (0.18%). These results suggest that populations of An. nuneztovari corresponding to cytotypes (B and C) are conspecific.
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Affiliation(s)
- Diana M Sierra
- Programa de Estudio y Control de Enfermedades Tropicales, Facultad de Medicina, Universidad de Antioquia, Medellin, Colombia
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12
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Alvarez N, Robledo S, Velez ID, Robert JM, Le Baut G, Le Pape P. Inhibition of parasite protein kinase C by new antileishmanial imidazolidin-2-one compounds. J Enzyme Inhib Med Chem 2002; 17:443-7. [PMID: 12683682 DOI: 10.1080/1475636021000005749] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The protein kinase C (PKC) family of isoenzymes mediate a wide range of signal transduction pathways in many different cells lines. Little is known regarding the presence and functional roles of PKC in Leishmania spp. Here we report the inhibition of parasite PKC by new imidazolidinone compounds. The most active derivative 7 showed an important activity (IC50 = 9.9 microM) against the clinical relevant stage of parasites in comparison with Glucantime (IC50 = 464.5 microM), without inducing toxicity on human fibroblast cells (IC50 = 102 microM). Pretreatment of intact parasites with 10 microM of compound 7 inhibited 80% of PKC activity. At the same concentration, this compound inhibited 70% of the parasite-host cell invasion process. An in vivo model showed that compound 7 reduced the liver parasite burden by 25% and spleen parasite burden by 44%. These results provide the first evidence that PKC plays a critical role in the invasion process. Thus Leishmania PKC activity could be a relevant therapeutic target and the imidazolidinones novel antileishmanial candidates.
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Affiliation(s)
- Nidia Alvarez
- Unité de Parasitologie UPRES EA 1155, Faculté de Pharmacie de Nantes, France
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13
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Trujillo CM, Robledo SM, Franco JL, Velez ID, Erb KJ, Patiño PJ. Endemically exposed asymptomatic individuals show no increase in the specific Leishmania (Viannia) panamensis-Th1 immune response in comparison to patients with localized cutaneous leishmaniasis. Parasite Immunol 2002; 24:455-62. [PMID: 12654087 DOI: 10.1046/j.1365-3024.2002.00488.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In Colombia, most cases of human cutaneous leishmaniasis are caused by Leishmania (Viannia) panamensis. Interestingly, up to 30% of the exposed population do not suffer from clinical leishmaniasis although it is likely that they are continuously infected with Leishmania parasites. Since it is believed that the induction of efficient Th1 immune responses protects against Leishmania infections both in humans and in animal models, we determined if endemically exposed asymptomatics showed stronger Leishmania-specific Th1 immune responses than patients with active localized cutaneous leishmaniasis (LCL). We found that Montenegro skin test responses were slightly higher among asymptomatic individuals compared to patients suffering from LCL. However, PBMC from patients with LCL showed similar Leishmania-specific proliferative responses compared to PBMC from asymptomatic individuals. Furthermore, PBMC from both groups also secreted similar amounts of IFN-gamma, IL-12p40 and IL-10 after in vitro exposure to L. panamensis. No IL-4 was detected in the supernatants. Taken together our results suggest that lack of LCL development in endemically exposed asymptomatics cannot be explained by stronger systemic anti-Leishmania Th1 immune responses or decreased Th2 responses in these individuals in comparison to individuals who develop LCL. It may be possible that other mechanisms are responsible for resistance to cutaneous leishmaniasis in Colombia in endemically exposed asymptomatics.
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Affiliation(s)
- C M Trujillo
- Programa de Estudio y Control en Enfermedades Tropicales - PECET, Universidad de Antioquia, Medellín, Colombia.
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14
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Abstract
Leishmaniasis in Colombia has traditionally been seen as a health risk for adult males, as they become infected when they enter the vector's biotopes to tap natural resources. National health statistics seem to confirm this theory. However, during field studies, the Program for the Study and Control of Tropical Diseases (PECET) observed both equal proportions of men and women with active leishmaniasis and delayed hypersensitivity skin tests and equal proportions of males and females having had contact with the parasite from early childhood. Several factors that have not been analyzed in depth in Colombia thus far appear to distort the disease's epidemiological pattern in the country, and gender-linked differences in access to health care appear to exist. As a consequence, no relief is provided for this source of human suffering, and socioeconomic repercussions for households are significant. Preventive measures by the Colombian Ministry of Health (MOH) systematically underestimate the magnitude of intra- and peridomiciliary transmission, and female patients are excluded from active case detection. Further research should be devoted to this phenomenon. The MOH should be encouraged to improve leishmaniasis control programs, especially with regard to active case detection, training, and teaching, so that quicker diagnosis can be performed. Meanwhile, the MOH should retrain its health personnel.
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Affiliation(s)
- I D Velez
- Programa de Estudio y Control de Enfermedades Tropicales, Universidad de Antioquia, Medellín, Colombia.
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15
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Abstract
Canine dirofilariasis is widespread in urban areas of central and northern Colombia. Previously we detected specific antibodies against complex antigens from Dirofilaria immitis adult worms in individuals from an isolated Tikuna Indian community in the Colombian Amazon. In this study a 56 kDa polypeptide from the adult D. immitis excretory/secretory (E/S) products is identified by Western blot, isolated by elution from polyacrilamide gels and applied in an ELISA-based test for the detection of specific IgG. Eleven of 74 serum samples analysed were positive by ELISADi56. Positive individuals came from five different areas of Colombia. The highest number of positives was found in the Amazon (4), followed by Bogotà (3). The physicians of the area must be alerted regarding the existence of human D. immitis infections and include dirofilariasis in the differential diagnosis of pulmonary nodules.
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Affiliation(s)
- C Vieira
- Laboratorio de Parasitología, Facultad de Farmacia, Universidad de Salamanca, Spain
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16
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Mesa NR, Mondragón MC, Soto ID, Parra MV, Duque C, Ortíz-Barrientos D, García LF, Velez ID, Bravo ML, Múnera JG, Bedoya G, Bortolini MC, Ruiz-Linares A. Autosomal, mtDNA, and Y-chromosome diversity in Amerinds: pre- and post-Columbian patterns of gene flow in South America. Am J Hum Genet 2000; 67:1277-86. [PMID: 11032789 PMCID: PMC1288567 DOI: 10.1016/s0002-9297(07)62955-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2000] [Accepted: 09/06/2000] [Indexed: 11/29/2022] Open
Abstract
To evaluate sex-specific differences in gene flow between Native American populations from South America and between those populations and recent immigrants to the New World, we examined the genetic diversity at uni- and biparental genetic markers of five Native American populations from Colombia and in published surveys from native South Americans. The Colombian populations were typed for five polymorphisms in mtDNA, five restriction sites in the beta-globin gene cluster, the DQA1 gene, and nine autosomal microsatellites. Elsewhere, we published results for seven Y-chromosome microsatellites in the same populations. Autosomal polymorphisms showed a mean G(ST) of 6.8%, in agreement with extensive classical marker studies of South American populations. MtDNA and Y-chromosome markers resulted in G(ST) values of 0.18 and 0.165, respectively. When only Y chromosomes of confirmed Amerind origin were used in the calculations (as defined by the presence of allele T at locus DYS199), G(ST) increased to 0.22. G(ST) values calculated from published data for other South American natives were 0.3 and 0.29 for mtDNA and Amerind Y chromosomes, respectively. The concordance of these estimates does not support an important difference in migration rates between the sexes throughout the history of South Amerinds. Admixture analysis of the Colombian populations suggests an asymmetric pattern of mating involving mostly immigrant men and native women.
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Affiliation(s)
- N R Mesa
- Laboratorio de Genética Molecular, Departamento de Fisiología y Bioquímica, Medellín, Colombia
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17
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Ramírez JR, Agudelo S, Muskus C, Alzate JF, Berberich C, Barker D, Velez ID. Diagnosis of cutaneous leishmaniasis in Colombia: the sampling site within lesions influences the sensitivity of parasitologic diagnosis. J Clin Microbiol 2000; 38:3768-73. [PMID: 11015400 PMCID: PMC87473 DOI: 10.1128/jcm.38.10.3768-3773.2000] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2000] [Accepted: 06/30/2000] [Indexed: 11/20/2022] Open
Abstract
Parasitologic confirmation of cutaneous leishmaniasis is obligatory before chemotherapy can be considered. Direct microscopic examination of scrapings taken from indurated borders of ulcers has been routinely used as primary method of diagnosis. In this report we compared the sensitivity of examination of dermal scrapings taken from the bottoms of ulcers (BDS) with that of dermal scrapings taken from indurated active margins of lesions (MDS) in a total of 115 patients. The sensitivities of the microscopic examination were 90.4 and 78.3% for BDS and MDS samples, respectively. When the PCR method was used with a group of 40 patients, we also observed a higher sensitivity when BDS samples were examined (80.8% in BDS samples versus 57.7% in MDS samples). The improvement of the diagnostic sensitivity in the BDS samples appears to be related to the higher parasite load and more easily detectable morphology of amastigotes in the centers of the ulcers. Other parasitologic diagnostic methods, such as culture and histopathologic examination of biopsies, are less sensitive (67.5 and 64.3%, respectively). Aspirate culture, however, was shown to be the most sensitive method for the diagnosis of patients with chronic ulcers. When microscopic examinations of both MDS and BDS samples are combined, the sensitivity of diagnosis may rise up to 94%. We therefore recommend this method as a primary routine procedure for diagnosis of cutaneous leishmaniasis.
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Affiliation(s)
- J R Ramírez
- Programa de Estudio y Control de Enfermedades Tropicales, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia.
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18
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Anderson TJ, Haubold B, Williams JT, Estrada-Franco JG, Richardson L, Mollinedo R, Bockarie M, Mokili J, Mharakurwa S, French N, Whitworth J, Velez ID, Brockman AH, Nosten F, Ferreira MU, Day KP. Microsatellite markers reveal a spectrum of population structures in the malaria parasite Plasmodium falciparum. Mol Biol Evol 2000; 17:1467-82. [PMID: 11018154 DOI: 10.1093/oxfordjournals.molbev.a026247] [Citation(s) in RCA: 573] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Multilocus genotyping of microbial pathogens has revealed a range of population structures, with some bacteria showing extensive recombination and others showing almost complete clonality. The population structure of the protozoan parasite Plasmodium falciparum has been harder to evaluate, since most studies have used a limited number of antigen-encoding loci that are known to be under strong selection. We describe length variation at 12 microsatellite loci in 465 infections collected from 9 locations worldwide. These data reveal dramatic differences in parasite population structure in different locations. Strong linkage disequilibrium (LD) was observed in six of nine populations. Significant LD occurred in all locations with prevalence <1% and in only two of five of the populations from regions with higher transmission intensities. Where present, LD results largely from the presence of identical multilocus genotypes within populations, suggesting high levels of self-fertilization in populations with low levels of transmission. We also observed dramatic variation in diversity and geographical differentiation in different regions. Mean heterozygosities in South American countries (0.3-0.4) were less than half those observed in African locations (0. 76-0.8), with intermediate heterozygosities in the Southeast Asia/Pacific samples (0.51-0.65). Furthermore, variation was distributed among locations in South America (F:(ST) = 0.364) and within locations in Africa (F:(ST) = 0.007). The intraspecific patterns of diversity and genetic differentiation observed in P. falciparum are strikingly similar to those seen in interspecific comparisons of plants and animals with differing levels of outcrossing, suggesting that similar processes may be involved. The differences observed may also reflect the recent colonization of non-African populations from an African source, and the relative influences of epidemiology and population history are difficult to disentangle. These data reveal a range of population structures within a single pathogen species and suggest intimate links between patterns of epidemiology and genetic structure in this organism.
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Affiliation(s)
- T J Anderson
- Wellcome Trust Centre for the Epidemiology of Infectious Disease, Department of Zoology, University of Oxford, Oxford, England.
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Thomaz-Soccol V, Velez ID, Pratlong F, Agudelos S, Lanotte G, Rioux JA. Enzymatic polymorphism and phylogenetic relationships in Leishmania Ross, 1903 (Sarcomastigophora: Kinetoplastida): a case study in Colombia. Syst Parasitol 2000; 46:59-68. [PMID: 10803436 DOI: 10.1023/a:1006379309576] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Leishmaniasis is widespread in Colombia and is found in 30 of 32 Departments. More than 200 infection zones have been reported from different regions, which vary from sea-level to an altitude of 2,300 m along the Atlantic Coast, Pacific coast, Amazon basin, Cauca and Magdalena valleys. We report 76 Leishmania stocks isolated from humans, dogs and phlebotomine hosts. Isoenzyme electrophoresis revealed 16 zymodemes, which could be divided into four phylogenetic complexes, i.e., L. braziliensis, L. amazonensis, L. guyanensis/panamensis and L. infantum. Three zymodemes became integrated into the subgenus Leishmania and the other zymodemes into the subgenus Viannia. Cutaneous infections were due to the L. braziliensis (9.2%) and L. guyanensis/panamensis (85.54%) complexes. Mucous secondary involvement was due to the L. braziliensis and L. guyanensis/panamensis complexes. In this work the specific status of L. (V.) guyanensis and L. (V.) panamensis is discussed.
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Affiliation(s)
- V Thomaz-Soccol
- Parasitology Section, University Federal of Parana, Curitiba, Pr, Brazil
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20
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Abstract
Hexane, ethyl acetate and methanol extracts of Annona muricata pericarp were tested in vitro against Leishmania braziliensis and L. panamensis promastigotes, and against cell line U-937. The ethyl acetate extract was more active than the other extracts and even of Glucantime used as reference substance. Its fractionation led to the isolation of three acetogenins--annonacin, annonacin A and annomuricin A.
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Affiliation(s)
- M C Jaramillo
- Facultad de Química Farmacéutica, Universidad de Antioquia, A. A. 1226 Medellín, Colombia
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Gallardo T, Saez J, Granados H, Tormo JR, Velez ID, Brun N, Torres B, Cortes D. 10-Oximeguanacone, the first nitrogenated acetogenin derivative found to be a potent inhibitor of mitochondrial complex I. J Nat Prod 1998; 61:1001-1005. [PMID: 9722484 DOI: 10.1021/np980079+] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A new 10-keto bis-tetrahydrofuran acetogenin, guanacone (1), has been isolated from a cytotoxic extract of Annona aff. spraguei seeds. The 10-oximeguanacone derivative 1f is the first bioactive nitrogenated acetogenin found to be a very potent inhibitor of complex I. In addition, a SAR study of guanacone analogues is reported based on the titration of the NADH oxidase and NADH:ubiquinone oxidoreductase activities.
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Affiliation(s)
- T Gallardo
- Departamento de Farmacología, Universidad de Valencia, 46100 Burjassot, Valencia, Spain
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22
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Chouicha N, Lanotte G, Pratlong F, Cuba Cuba CA, Velez ID, Dedet JP. Phylogenetic taxonomy of Leishmania (Viannia) braziliensis based on isoenzymatic study of 137 isolates. Parasitology 1997; 115 ( Pt 4):343-8. [PMID: 9364560 DOI: 10.1017/s0031182097001376] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Biochemical characterization of 137 Leishmania braziliensis isolates from South and Central America, and from selected endemic foci in Bolivia, Brazil and Colombia, performed by isoenzymatic electrophoresis using 10 enzymatic systems, showed a high enzymatic polymorphism (44 zymodemes obtained) based on the variation of a small number of enzymes. Cladistic analysis showed close links between the zymodemes within the L. braziliensis s.s. cluster. The position of 2 Colombian zymodemes obtained (MON*204 and MON*205) justify the inclusion of L. peruviana within the L. braziliensis cluster.
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Affiliation(s)
- N Chouicha
- Laboratoire d'Ecologie Médicale et Pathologie Parasitaire, Faculté de Médecine, Montpellier, France
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Travi BL, Montoya J, Gallego J, Jaramillo C, Llano R, Velez ID. Bionomics of Lutzomyia evansi (Diptera: Psychodidae) vector of visceral leishmaniasis in northern Columbia. J Med Entomol 1996; 33:278-285. [PMID: 8667372 DOI: 10.1093/jmedent/33.3.278] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The feeding behavior, seasonality, and natural infection rate of Lutzomyia evansi (Nuñez-Tovar) with Leishmania chagasi (Cuna & Chagas) was studied during a 12-mo period at 2 hamlets, El Contento and Vidales. Sand fly abundance in extra-, peri-, and intradomestic habitats was evaluated with sticky traps and CDC light traps, whereas human bait and Shannon trap collections were made only in peridomestic habitats. All trapping methods showed a clear predominance of L. evansi throughout the year. Sand flies were present during most of the year, with the exception of the driest months (February and March). Although the total number of sand flies was higher in El Contento than in Vidales, a larger proportion of L. evansi was found in intradomestic habitat than in the peri- and extradomestic habitats at Vidales. Also, sand flies from Vidales had a higher infection rate with L. chagasi than did those from El Contento. Although 2 of 9 promastigote infections detected in L. evansi were identified as L. chagasi, the difficulty of isolating and propagating leishmania strains from this visceral leishmaniasis focus precluded characterization of most parasite samples. Parous and infected sand flies were most abundant toward the end of the rainy season (October-December). For this reason, control strategies based on reducing sand fly populations or avoiding human-vector contact should be concentrated during the October-December period.
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Affiliation(s)
- B L Travi
- Centro Internacional de Entrenamiento e Investigaciones Médicas-CIDEIM, Cali, Colombia
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Travi BL, Jaramillo C, Montoya J, Segura I, Zea A, Goncalves A, Velez ID. Didelphis marsupialis, an important reservoir of Trypanosoma (Schizotrypanum) cruzi and Leishmania (Leishmania) chagasi in Colombia. Am J Trop Med Hyg 1994; 50:557-65. [PMID: 8203703 DOI: 10.4269/ajtmh.1994.50.557] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The role of Didelphis marsupialis as a reservoir of zoonotic hemoflagellates was examined in two ecologically distinct settings in Colombia. While 72% (12 of 18) of the opossums collected in the tropical rain forest harbored Trypanosoma cruzi, other mammals in the area had lower infection rates: 1.3% (Proechymis semispinosus [spiny rat]; 13% Tylomys mirae [climbing rat]; and 6% Rattus rattus). Trypanosoma cruzi isolates from D. marsupialis were similar to zymodeme 1 (Z1), and two of four phenotypes were shared with Tylomys mirae, which is also predominantly arboreal. Terrestrial (P. semispinosus) and peridomestic (R. rattus) animals were infected with Z3 or other Z1 phenotypes, respectively. Schizodeme analysis showed polymorphisms among isolates from mammals, reflecting diverse modes of transmission, and a complex epidemiologic situation. Despite the lower infection rate of the opossum (14%) found in our study in the tropical dry forest as compared with the tropical wet forest, Chagas' disease has been reported only in the former area. This suggests that the lack of alternative blood sources for triatomines of the tropical dry forest, where mammals are less abundant than in the wet forest, may increase the risk of human infection. Among several species of mammals captured in the tropical dry forest, Leishmania chagasi was isolated from 22.7% (5 of 22) D. marsupialis. This finding confirms the important role of opossums in Colombian foci of visceral leishmaniasis, including those where the phlebotomine species involved in transmission is Lutzomyia evansi, an alternative vector to the more common Lutzomyia longipalpis.
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Affiliation(s)
- B L Travi
- Fundacion Centro Internacional de Entrenamiento e Investigaciones Medicas, Cali, Colombia
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Medrano FJ, Hernández-Quero J, Jiménez E, Pineda JA, Rivero A, Sánchez-Quijano A, Velez ID, Viciana P, Castillo R, Reyes MJ. Visceral leishmaniasis in HIV-1-infected individuals: a common opportunistic infection in Spain? AIDS 1992; 6:1499-503. [PMID: 1362880 DOI: 10.1097/00002030-199212000-00013] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the epidemiological, clinical and biological features of visceral leishmaniasis (VL) in patients with HIV-1 infection. DESIGN Retrospective study. SETTING Three university hospitals in southern Spain. PATIENTS Forty-seven adult patients with VL and HIV-1 infection diagnosed between January 1986 and November 1991. RESULTS Forty-five out of the 47 (96%) cases were diagnosed in the last 2 years. Fever (87%), hepatomegaly (74%), splenomegaly (72%) and pancytopenia (77%) were the most common presenting features. Most patients (79%) were strongly immunocompromised when VL was diagnosed, and were in stage IV of the Centers for Disease Control classification; 87% had a CD4 lymphocyte count < 200 x 10(6)/l. However, VL was the first severe infection diagnosed in 10 cases. Significant titres (> 1:40) of antileishmanial antibodies were detected by indirect immunofluorescence in five out of 16 (31%) cases only. Clinical response to the therapy was difficult to assess. Microbiological response was achieved in only 38% of the patients evaluated. CONCLUSIONS Leishmaniasis is a relatively common infection in HIV-1-infected individuals in southern Spain. Its clinical picture is quite uniform and it can be the first opportunistic infection in individuals with HIV-1. In endemic areas, a high index of clinical suspicion should be maintained in order to avoid underdiagnosis of leishmaniasis.
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Affiliation(s)
- F J Medrano
- Viral Hepatitis and AIDS Study Group, Virgen del Rocio University Hospital, Sevilla, Spain
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Rioux JA, Velez ID, Denial M, Dereure J, Perières J, Lanotte G, el Mellouki W. [Presence in Morocco of Phlebotomus (Paraphlebotomus) kazeruni Theodor and Mesghali, 1964]. Ann Parasitol Hum Comp 1986; 61:473-81. [PMID: 3813429 DOI: 10.1051/parasite/1986614473] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A report is made of Phlebotomus kazeruni on southern Marocco (Tata and Ouarzazate Provinces). This sandflies was previously known only from Afghanistan, Iran and Saudi Arabia.
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