American Cutaneous Leishmaniasis in Panama: a historical review of entomological studies on anthropophilic Lutzomyia sand fly species

Abstract

We review existing information on the epidemiology of American Cutaneous Leishmaniasis (ACL) in Panama, with emphasis on the bionomics of anthropophilic Lutzomyia sand fly species. Evidence from Panamanian studies suggests that there are six anthropophilic species in the country: Lutzomyia trapidoi, Lu. panamensis, Lu. gomezi, Lu. ylephiletor, Lu. sanguinaria and Lu. pessoana (Henceforth Lu. carrerai thula). In general, these taxa are abundant, widespread and feed opportunistically on their hosts, which make them potential transmitters of pathogens to a broad range of wildlife, domesticated animals and humans. Furthermore, nearly all man-biting species in Panama (with the exception of Lu. gomezi) expand demographically during the rainy season when transmission is likely higher due to elevated Leishmania infection rates in vector populations. Despite this, data on the distribution and prevalence of ACL suggest little influence of vector density on transmission intensity. Apart from Lu. trapidoi, anthropophilic species seem to be most active in the understory, but vertical stratification, as well as their opportunistic feeding behavior, could vary geographically. This in turn seems related to variation in host species composition and relative abundance across sites that have experienced different degrees of human alteration (e.g., deforestation) in leishmaniasis endemic regions of Panama.

Forest disturbance and vector transmitted diseases in the lowland tropical rainforest of central Panama

“…We also argue that idiosyncratic findings show that the DEH was effectively applied to a narrow group of zoonotic diseases associated with rodents or tick vectors (e.g. hantaviruses and Lyme), leaving unsupported many other neglected zoonotic diseases, especially those transmitted by Neotropical dipterans . To achieve an integrated surveillance system for disease‐causing pathogen in Panama, it will be necessary to know beforehand which arthropod species are present and could play a role in disease transmission.…”

Intraspecific Genomic Divergence and Minor Structural Variations in Leishmania (Viannia) panamensis

“…Interestingly the genomes that fell into the Clade-2 are closer to Clade-1 (Panamanian genomes) than Clade-3; those results could indicate that in Colombia two different phylogroups of L. panamensis can be found. Comparing the transmission cycles of L. panamensis in Colombia and Panama; the epidemiological landscape in Panama is mainly enzootic and involves different sand fly vectors (Lutzomyia trapidoi and Lutzomyia panamensis) [45,46] and vertebrate reservoirs (Choloepus hoffmani and Bradypus griseus) [46,47], while in Colombia, the transmission cycles are predominantly intra and peridomiciliary [5,48,49]. In addition, considering that some studies describe that the high transmission rate of L. panamensis appears to be mainly related to high population densities of animal reservoirs (Choloepus hoffmani) in areas of the old-growth forest [46,50].…”

“…Comparing the transmission cycles of L. panamensis in Colombia and Panama; the epidemiological landscape in Panama is mainly enzootic and involves different sand fly vectors (Lutzomyia trapidoi and Lutzomyia panamensis) [45,46] and vertebrate reservoirs (Choloepus hoffmani and Bradypus griseus) [46,47], while in Colombia, the transmission cycles are predominantly intra and peridomiciliary [5,48,49]. In addition, considering that some studies describe that the high transmission rate of L. panamensis appears to be mainly related to high population densities of animal reservoirs (Choloepus hoffmani) in areas of the old-growth forest [46,50]. We believe that the presence of the new clade (Clade-2) in the Colombian territory could be due to (i) the migration of these reservoirs from Panamá to Colombia as result of landscape alteration which triggers demographic changes that lead to occasional migrations out of the territory [46,51], (ii) occupational exposure to infectious sandfly bites when humans enter the forest [52,53], or (iii) human migration from or to Colombia [54,55].…”

“…In addition, considering that some studies describe that the high transmission rate of L. panamensis appears to be mainly related to high population densities of animal reservoirs (Choloepus hoffmani) in areas of the old-growth forest [46,50]. We believe that the presence of the new clade (Clade-2) in the Colombian territory could be due to (i) the migration of these reservoirs from Panamá to Colombia as result of landscape alteration which triggers demographic changes that lead to occasional migrations out of the territory [46,51], (ii) occupational exposure to infectious sandfly bites when humans enter the forest [52,53], or (iii) human migration from or to Colombia [54,55].…”

Species of sand flies (Diptera: Psychodidae) collected from natural reserves in the Pacific and Darien regions of Colombia

“…trinidadensis, Lu. hartmani) (1), especialmente en ambientes rurales cercanos a reservas forestales asociadas con ecosistemas de bosque húmedo tropical (27)(28)(29). Entre los hallazgos más importantes se destaca, asimismo, la confirmación taxonómica de Lu.…”