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Valderrama A.,Federal University of Viçosa | Valderrama A.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | Tavares M.G.,Federal University of Viçosa | Filho J.D.A.,Instituto Rene Rachou Fiocruz
Memorias do Instituto Oswaldo Cruz | Year: 2011

In Panama, species of the genus Lutzomyia are vectors of American cutaneous leishmaniasis (ACL). There is no recent ecological information that may be used to develop tools for the control of this disease. Thus, the goal of this study was to determine the composition, distribution and diversity of Lutzomyia species that serve as vectors of ACL. Sandfly sampling was conducted in forests, fragmented forests and rural environments, in locations with records of ACL. Lutzomyia gomezi, Lutzomyia panamensis and Lutzomyia trapidoi were the most widely distributed and prevalent species. Analysis of each sampling point showed that the species abundance and diversity were greatest at points located in the fragmented forest landscape. However, when the samples were grouped according to the landscape characteristics of the locations, there was a greater diversity of species in the rural environment locations. The Kruskal Wallis analysis of species abundance found that Lu. gomezi and Lu. trapidoi were associated with fragmented environments, while Lu. panamensis, Lutzomyia olmeca bicolor and Lutzomyia ylephiletor were associated with forested environments. Therefore, we suggest that human activity influences the distribution, composition and diversity of the vector species responsible for leishmaniasis in Panama.

Lanzas F.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | Karakousis P.C.,Johns Hopkins University | Sacchettini J.C.,Texas A&M University | Ioerger T.R.,Texas A&M University
Journal of Clinical Microbiology | Year: 2013

Multidrug-resistant tuberculosis (MDR-TB) is a significant health problem in Panama. The extent to which such cases are the result of primary or acquired resistance and the strain families involved are unknown. We performed whole-genome sequencing of a collection of 66 clinical MDR isolates, along with 31 drug-susceptible isolates, that were isolated in Panama between 2001 and 2010; 78% of the MDR isolates belong to the Latin American-Mediterranean (LAM) family. Drug resistance mutations correlated well with drug susceptibility profiles. To determine the relationships among these strains and to better understand the acquisition of resistance mutations, a phylogenetic tree was constructed based on a genome-wide single-nucleotide polymorphism analysis. The phylogenetic tree shows that the isolates are highly clustered, with a single strain (LAM9-c1) accounting for nearly one-half of the MDR isolates (29/66 isolates). The LAM9-c1 strain was most prevalent among male patients of working age and was associated with high mortality rates. Members of this cluster all share identical mutations conferring resistance to isoniazid (KatG S315T mutation), rifampin (RpoB S531L mutation), and streptomycin (rrs C517T mutation). This evidence of primary resistance supports a model in which MDR-TB in Panama is driven by clonal expansion and ongoing transmission of several strains in the LAM family, including the highly successful MDR strain LAM9-c1. The phylogenetic analysis also shows that the LAM9-c1 strain is closely related to the KwaZulu-Natal (KZN) extensively drug-resistant TB strain identified in KwaZulu-Natal, South Africa. The LAM9-c1 and KZN strains likely arose from a recent common ancestor that was transmitted between Panama and South Africa and had the capacity to tolerate an accumulation of multiple resistance mutations. Copyright © 2013, American Society for Microbiology.

Saldana A.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud
PloS one | Year: 2012

Chagas disease was originally reported in Panama in 1931. Currently, the best knowledge of this zoonosis is restricted to studies done in historically endemic regions. However, little is known about the distribution and epidemiology of Chagas disease in other rural areas of the country. A cross-sectional descriptive study was carried out between May 2005 - July 2008 in four rural communities of the Santa Fe District, Veraguas Province. The study included an entomologic search to collect triatomines, bloodmeal type identification and infection rate with trypanosomes in collected vectors using a dot- blot and PCR analysis, genotyping of circulating Trypanosoma cruzi (mini-exon gene PCR analysis) and the detection of chagasic antibodies among inhabitants. The vector Rhodnius pallescens was more frequently found in La Culaca and El Pantano communities (788 specimens), where it was a sporadic household visitor. These triatomines presented darker coloration and larger sizescompared with typical specimens collected in Central Panama. Triatoma dimidiata was more common in Sabaneta de El Macho (162 specimens). In one small sub-region (El Macho), 60% of the houses were colonized by this vector. Of the examined R. pallescens, 54.7.0% (88/161) had fed on Didelphis marsupialis, and 24.6% (34/138) of T. dimidiata specimens collected inside houses were positive for human blood. R. pallescens presented an infection index with T. cruzi of 17.7% (24/136), with T. rangeli of 12.5% (17/136) and 50.7% (69/136) were mixed infections. In 117 T. dimidiata domestic specimens the infection index with T. cruzi was 21.4%. Lineage I of T. cruzi was confirmed circulating in these vectors. A T. cruzi infection seroprevalence of 2.3% (24/1,056) was found in this population. This is the first report of Chagas disease endemicity in Santa Fe District, and it should be considered a neglected public health problem in this area of Panama.

Bermudez S.C.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | Miranda R.C.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud
Revista MVZ Cordoba | Year: 2011

Objetive. To determine the distribution of ectoparasites in dogs in Panama. Materials and methods. There were surveyed 720 canines belonging to 57 communities. Results. The results showed that 84% of the dogs were infested with at least one species of ectoparasite. Dogs from lowlands showed a higher percentage of parasitism and a greater biodiversity of parasites than dogs from highlands. There were found seven species of ticks, four species of fleas, two species of lice, and one specie of botfly. The ticks Rhipicephalus sanguineus, Amblyomma cajennense, A. ovale and the flea Ctenocephalides felis were widespread; however Ixodes boliviensis and Pulex simulans showed a much narrower geographic distribution and they were found only in dogs from highlands. The flea species Rhopalopsyllus cacicus and the tick Haemaphysalis juxtakochi were found for the first time in panamanian dogs. Conclusions. The environmental situation in Panama, can encourage that wildlife ectoparasites parasitized dogs in absence of their native hosts. This condition may increase transmission risk of some diseases where the ticks and fleas are vectors.

Obaldia N.,Harvard University | Obaldia N.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud
Malaria Journal | Year: 2015

Background: Identification of risk factors is important for the establishment of malaria elimination programmes tailored to specific regions. Type of house construction had been associated with increasing risk of acquiring malaria. This study aimed at establishing the association between determinants of low socio-economic status (SES) and type of house construction with the likelihood of living in a Plasmodium vivax malarious corregimiento (smallest political division) in Panama during 2009-2012. Methods: To determine the association between type-2 houses (build with deciduous materials) and other determinants of low SES, with living in a malarious corregimiento, this study analyzed demographic and housing census data (2010), and malaria incidence aggregated at the corregimiento level (2009-2012), using a Spearman's non-parametric correlation test to explore for associations, followed by a case-control study and a reduced multivariate logistic regression approach for confirmation. Results: A descriptive temporal and spatial analysis indicated that P. vivax in Panama was associated with Amerindian reservations. Moreover, this study demonstrated that a strong correlation (deleterious effect) existed between living in a malarious corregimiento and being exposed to a type-2 house (OR = > 1.0) (p < 0.001), while, it showed an inverse correlation for exposure to type-1 houses (protective effect) (build with permanent materials) (OR = < 1.0) (p < 0.001). In the same way, a significant association between exposure to type-2 houses and the outcome of living in a malarious corregimiento was found using a case-control study approach (Chi2 test = p < 0.001), that was confirmed applying a reduced multivariate logistic regression fitted model. Conclusions: This study demonstrated that living in a P. vivax malarious corregimiento in Panama during 2009-2012 was strongly correlated with those corregimientos having a high proportion of type-2 houses. A multivariate logistic regression approach at the house and corregimiento level indicated a strong association of type-2 houses, dirt floors and illiteracy with the likelihood of living in a malarious corregimiento. It is expected that these findings will help implement a multi-sectorial approach for the elimination of malaria in poor areas of Panama where malaria is endemic, which emphasizes house improvements such as mosquito-proofing and socio-economic development. © 2015 Obaldia; licensee Biomed Central.

Gottdenker N.L.,University of Georgia | Calzada J.E.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | Saldana A.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | Carroll C.R.,University of Georgia
American Journal of Tropical Medicine and Hygiene | Year: 2011

Anthropogenic disturbance is associated with increased vector-borne infectious disease transmission in wildlife, domestic animals, and humans. The objective of this study was to evaluate how disturbance of a tropical forest landscape impacts abundance of the triatomine bug Rhodnius pallescens, a vector of Chagas disease, in the region of the Panama Canal in Panama. Rhodnius pallescens was collected (n = 1,186) from its primary habitat, the palm Attalea butyracea, in five habitat types reflecting a gradient of anthropogenic disturbance. There was a high proportion of palms infested with R. pallescens across all habitat types (range = 77.1-91.4%). Results show that disturbed habitats are associated with increased vector abundance compared with relatively undisturbed habitats. Bugs collected in disturbed sites, although in higher abundance, tended to be in poor body condition compared with bugs captured in protected forest sites. Abundance data suggests that forest remnants may be sources for R. pallescens populations within highly disturbed areas of the landscape. Copyright © 2011 by The American Society of Tropical Medicine and Hygiene.

Bermudez C. S.E.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | Miranda C. R.J.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | Smith C. D.,Summit Municipal Park
Experimental and Applied Acarology | Year: 2010

From September 2007 to September 2009, we studied the species of ticks present in the Summit Municipal Park. Ticks were extracted from zoo animals, free-living wild mammals and reptiles trapped, dead mammals on the roads and environment (ground and zoo burrows). A total of 2,649 ticks were collected: 2,167 immature stages (1,345 larvae and 822 nymphs) and 482 adults. Seventeen species were identified: Ornithodoros puertorricensis (Argasidae), Amblyomma auricularium, A. cajennense, A. calcaratum, A. dissimile, A. geayi, A. naponense, A. nodosum, A. oblongoguttatum, A. ovale, A. pecarium, A. sabanerae, A. tapirellum, A. varium, Ixodes luciae, Haemaphysalis juxtakochi and Rhipicephalus sanguineus (Ixodidae), representing 36% of the species reported in Panama. Amblyomma ovale was the species most commonly infesting animals from the zoo. © 2010 Springer Science+Business Media B.V.

Apanaskevich D.A.,Georgia Southern University | Bermudez S.E.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud
Journal of Medical Entomology | Year: 2013

A new tick species belonging to the genus Dermacentor Koch, 1844, Dermacentor panamensis n. sp., is described. All stages of this species are similar to those of Dermacentor halli McIntosh, 1931, with which it was confused for a long time. Males of D. panamensis can be distinguished from those of D. halli by the following suite of characters: narrower conscutum, broader basis capituli, shorter dorsal cornua, narrower palpi, palpal segment III tapering to its apex, legs poorly ornate: ivory colored patches present only on dorsal aspects of leg segments (mostly on legs III and IV), and internal spur of coxae I narrower and more tapering. Females of D. panamensis can be distinguished from those of D. halli by the following suite of characters: narrower and less ornate scutum, broader basis capituli, shorter dorsal cornua, larger porose areas, narrower palpi, palpal segment III tapering to its apex, legs poorly ornate: ivory colored patches present only on dorsal aspects of leg segments (mostly on legs III and IV), and internal spur of coxae I narrower and more tapering. Nymphs of D. panamensis can be distinguished from those of D. halli by clear posterolateral projections of scutum and by absence of coxal "pore" on coxae I-IV, while larvae of D. panamensis can be distinguished from those of D. halli by shorter and less sharp lateral projections of basis capituli dorsally and slightly sharp anterior angle of basis capituli. D. panamensis is known from highlands of Costa Rica, Guatemala, Honduras, Nicaragua, and Panama where the adults were collected from porcupines and unidentified sloth and mouse while nymphs and larvae were found on various rodents and a bat. © 2013 Entomological Society of America.

Gottdenker N.L.,University of Georgia | Chaves L.F.,Hokkaido University | Chaves L.F.,National University of Costa Rica | Calzada J.E.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud | And 2 more authors.
PLoS Neglected Tropical Diseases | Year: 2012

Background: Anthropogenic land use may influence transmission of multi-host vector-borne pathogens by changing diversity, relative abundance, and community composition of reservoir hosts. These reservoir hosts may have varying competence for vector-borne pathogens depending on species-specific characteristics, such as life history strategy. The objective of this study is to evaluate how anthropogenic land use change influences blood meal species composition and the effects of changing blood meal species composition on the parasite infection rate of the Chagas disease vector Rhodnius pallescens in Panama. Methodology/Principal Findings: R. pallescens vectors (N = 643) were collected in different habitat types across a gradient of anthropogenic disturbance. Blood meal species in DNA extracted from these vectors was identified in 243 (40.3%) vectors by amplification and sequencing of a vertebrate-specific fragment of the 12SrRNA gene, and T. cruzi vector infection was determined by pcr. Vector infection rate was significantly greater in deforested habitats as compared to contiguous forests. Forty-two different species of blood meal were identified in R. pallescens, and species composition of blood meals varied across habitat types. Mammals (88.3%) dominated R. pallescens blood meals. Xenarthrans (sloths and tamanduas) were the most frequently identified species in blood meals across all habitat types. A regression tree analysis indicated that blood meal species diversity, host life history strategy (measured as rmax, the maximum intrinsic rate of population increase), and habitat type (forest fragments and peridomiciliary sites) were important determinants of vector infection with T. cruzi. The mean intrinsic rate of increase and the skewness and variability of rmax were positively associated with higher vector infection rate at a site. Conclusions/Significance: In this study, anthropogenic landscape disturbance increased vector infection with T. cruzi, potentially by changing host community structure to favor hosts that are short-lived with high reproductive rates. Study results apply to potential environmental management strategies for Chagas disease. © 2012 Gottdenker et al.

Motta J.A.,Instituto Conmemorativo Gorgas Of Estudios Of La Salud
Revista panamericana de salud pública = Pan American journal of public health | Year: 2013

To estimate mortality from diabetes mellitus (DM) for the period 2001-2011 in the Republic of Panama, by province/indigenous territory, and determine its relationship with biological and socioeconomic risk factors. Cases for the years 2001-2011 with DM listed as the principal cause of death were selected from Panama's National Mortality Registry. Crude and adjusted mortality rates were generated by sex, age, and geographic area. Linear regression analyses were performed to determine the relationship between DM mortality and biological and socioeconomic risk factors. A composite health index (CHI) calculated from biological and socioeconomic risk factors was estimated for each province/indigenous territory in Panama. DM mortality rates did not increase for men or women during 2001-2011. Of the biological risk factors, being overweight had the strongest association with DM mortality. Of the socioeconomic risk factors, earning less than US$ 100 per month had the strongest association with DM mortality. The highest socioeconomic CHI scores were found in a province that is predominantly rural and in areas with indigenous populations. The highest biological CHI scores were found in urban-rural provinces and those with the highest percentage of elderly people. Regional disparities in the association between DM mortality and DM risk factors reaffirm the heterogeneous composition of the Panamanian population and the uneven distribution of biological and social determinant risk factors in the country and point to the need to vary management strategies by geographic area for this important cause of disability and death in Panama.

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