Molecular screening of tick-borne microorganisms in ticks from rural areas of Panama, with the first record of Ehrlichia minasensis in Rhipicephalus microplus from Central America.

During a molecular screening of rickettsial, borrelial and protozoal agents in ticks from rural areas of Panama, we detected DNA of Rickettsia amblyommatis in four Amblyomma mixtum collected from horses in a locality in Los Santos province. Ehrlichia minasensis and Anaplasma marginale were identified from three and two Rhipicephalus microplus, respectively, collected on cows from Chiriqui province. No DNA from other tick-borne agents was found. These results increase the information of R. amblyommatis and A. marginale in Panama, and also mark the first record of E. minasensis in Central America.

Ticks infesting humans in Central America: A review of their relevance in public health.

Ticks are blood-sucking arthropods that parasitize most groups of terrestrial or semiaquatic vertebrates. Humans are accidental hosts to the ticks; however, in humans the ticks can cause damages varying from simple irritation to severe allergies, toxicosis, paralysis, and the transmission of pathogens, some of which can be fatal. Central America represents a narrow isthmus between North and South America and is considered a biodiversity hotspot. The importance of tick-borne diseases in this region is manifested by fatal outbreaks caused by Rickettsia rickettsii, severe and mild cases of other rickettsioses, ehrlichiosis, and tick-borne relapsing fevers, in addition to cases paralysis and strong allergic reactions. Even so, this information is scarce in most countries of this region, and there are no epidemiological data. In this article we present a review of the ticks that parasitize humans in Central America, covering data from the 19th Century to the present day. Of nearly 80 tick species reported in Central America, 28 species are reported on humans. This list includes species that thrive within homes, grazing areas and, to a lesser extent, in wild environments, both in lowland and high mountain forests. The most important genus in this region is Amblyomma, followed by Rhipicephalus and Ornithodoros, and to a lesser extent Haemaphysalis, Ixodes and Dermacentor. These data provide information on the tick species most commonly associated with humans in Central America, and highlight the potential for tick-borne diseases in wild, rural and urban regions.

Molecular screening for tick-borne bacteria and hematozoa in Ixodes cf. boliviensis and Ixodes tapirus (Ixodida: Ixodidae) from western highlands of Panama.

The first molecular screening for Rickettsia, Anaplasma, Ehrlichia, Borrelia, Babesia and Hepatozoon was carried out in questing Ixodes cf. boliviensis and Ixodes tapirus from Talamanca Mountains, Panama, using specific primers, sequencing and phylogeny. Phylogenetic analyses for the microorganisms in Ixodes cf. boliviensis confirmed the presence of Rickettsia sp. strain IbR/CRC endosymbiont (26/27 ticks), three genotypes of the Borrelia burgdorferi (sensu lato) complex (4/27 ticks), Babesia odocoilei (1/27 ticks), and Hepatozoon sp. (2/27 ticks), tentatively designated Hepatozoon sp. strain Chiriquensis. Phylogenetic analyses for the microorganisms in I. tapirus revealed an undescribed Rickettsia sp., tentatively designated Rickettsia sp. strain Itapirus LQ (6/6 ticks), and Anaplasma phagocytophilum (2/6 ticks). To the best of our knowledge, this is the first report of B. burgdorferi (s.l.) complex, A. phagocytophilum, B. odocoilei, and Hepatozoon sp. in Ixodes ticks from Central America, and also the first detection of Rickettsia spp. in Ixodes species in Panama. In light of the importance of these findings, further studies are needed focusing on the role of I. tapirus and I. cf. boliviensis as vectors, and the vertebrates acting as reservoirs.

Rickettsia amblyommatis isolated from Amblyomma mixtum (Acari: Ixodida) from two sites in Panama.

Rickettsia amblyommatis is widely distributed in the Americas, and has been reported to infect different species of ticks within its distribution. In Panama, R. amblyommatis is the most common Rickettsia and its presence was molecularly detected in nine species of ticks and one flea species. This work described the isolation of R. amblyommatis in Vero cells by shell vial technique, from Amblyomma mixtum ticks collected from a captive tapir from Gamboa (Colon province), and a horse from El Valle de Antón (Cocle province). These represent the first isolations of R. amblyommatis in Panama.

Ornithodoros capensis sensu stricto (Ixodida: Argasidae) in Coiba National Park: first report for Panama, with notes on the O. capensis group in Panamanian shores and Costa Rica.

Ornithodoros capensis sensu lato (s.l.) is a morphologically similar group of soft ticks that parasitizes mostly seabirds in continental and offshore territories worldwide. Ornithodoros capensis sensu stricto (s.s.) has been previously recorded in many islands and coastal localities along the American continent; however, some records from Central America remain obscure. In this work we performed morphological and molecular analyses on soft ticks collected in Coiba National Park, an archipelago located in the Pacific Ocean off the coast of Panama, confirming the occurrence of O. capensis s.s. in this country for the first time. In addition, a morphological examination of museum specimens collected in Costa Rica, and a further locality in Panama, confirmed that O. capensis s.l. is established in the former country, and that its distribution along Panamanian shores is likely larger.

A review of the genus Rickettsia in Central America.

In this paper, we present a historical review of rickettsiosis in Central America and also the most recent findings of Rickettsia in ectoparasites. All countries of Central America have records of rickettsiosis. Regarding the typhus group rickettsioses, there is clinical or serological evidence of Rickettsia prowazekii in Guatemala, Rickettsia typhi in Panama, Guatemala, and Costa Rica and unidentified species of the typhus group in El Salvador. Concerning spotted fever group rickettsiosis, there is serological evidence of infection by Rickettsia akari in Costa Rica and confirmed cases involving Rickettsia rickettsii in Panama and Costa Rica. There are also reports of spotted fever group rickettsiosis in acute patients from Guatemala, Honduras, and Nicaragua. Serological studies in Central America show reactivity of Rickettsia ambyommatis, Rickettsia bellii, Rickettsia felis, Rickettsia rhipicephali, and R. rickettsii in domestic and wild mammals. Eight species of Rickettsia have been detected in ectoparasites from Central America: R. africae (or very similar), R. amblyommatis, R. asembonensis, R. bellii, R. felis, R. parkeri, R. rhipicephali, and R. rickettsii, in addition to undescribed strains such as Atlantic Rainforest, Colombianensi, IbR/CRC, Barva, Aragaoi, and Candidatus "Rickettsia nicoyana;" the latter being the only one associated with Argasidae (Ornithodoros knoxjonesi). R. amblyommatis is the most common species in Central America, seeing as it has been reported in 10 species of ticks and one of fleas in five of the seven countries of the region. In this study, we demonstrate that the genus Rickettsia is widely distributed in Central America and that rickettsiosis could be an underestimated problem in the absence of greater diagnostic efforts in undetermined febrile cases.

Hard ticks (Acari: Ixodidae) of livestock in Nicaragua, with notes about distribution.

We document the species of ticks that parasitize livestock in Nicaragua. The study was based on tick collection on cattle and horses from 437 farms in nine departments. Of 4841 animals examined (4481 cows and 360 horses), 3299 were parasitized, which represent 68 % of the bovines and 67 % of the equines in study: 59 cows and 25 horses were parasitized by more than one species. In addition, 280 specimens of the entomological museum in León were examined. The ticks found on cattle were Rhipicephalus microplus (75.2 % of the ticks collected), Amblyomma mixtum (20.8 %), A. parvum (2.6 %), A. tenellum (0.7 %), A. maculatum (0.7 %). While the ticks collected from the horses were: Dermacentor nitens (41.5 %), A. mixtum (31.7 %), R. microplus (13.8 %), A. parvum (6.5 %), A. tenellum (3.3 %), D. dissimilis (2.4 %) and A. maculatum (0.8 %).

Questing Amblyomma mixtum and Haemaphysalis juxtakochi (Acari: Ixodidae) Infected with Candidatus "Rickettsia amblyommii" from the Natural Environment in Panama Canal Basin, Panama.

This work emphasizes the detection of Candidatus "Rickettsia amblyommii" in questing Haemaphysalis juxtakochi and Amblyomma mixtum. From February 2009 to December 2012, questing ticks were collected from the vegetation and leaf-litter of four protected forests and two grassy areas around the Panama Canal basin. DNA was extracted from Amblyomma mixtum, Amblyomma naponense, Amblyomma oblongoguttatum, Amblyomma pecarium, Amblyomma tapirellum, Haemaphysalis juxtakochi, and unidentified immature Amblyomma. Specific primers of citrate synthase gene gltA were used to detect and identify the rickettsiae. Amplicons with the expected band size were purified and sequenced. DNA of C. "R. amblyommii" was found in A. mixtum, H. juxtakochi and Amblyomma immatures. To our knowledge, these finding represent the first report of C. "R. amblyommii" in free-living ticks in the wilderness of Central America.

Some ecological aspects of free-living Haemaphysalis juxtakochi Cooley, 1946 (Acari: Ixodidae) in Panama / Algunos aspectos ecológicos de fases de vida libre de Haemaphysalis juxtakochi Cooley, 1946 (Acari: Ixodidae) en Panamá

Objective. To describe the seasonal variation and perform a comparative analysis on habitat preference of Haemaphysalis juxtakochi in Panama. Materials and methods. Ticks were collected from the vegetation, using a white cloth, between January 2009 and March 2010, in four site located in Summit Municipal Park (SMP), two in wooded area (WA) and two in grasslands (GR).The ticks were determined as larvae, nymphs and adults of H. juxtakochi. The number of ticks collected in each area was employed to describe the seasonal distribution of both immature and adult stages, and the non-parametric Mann-Whitney U test. Results. A total of 2.338 ticks in WA and 560 ticks in GR were collected. The major peak of adults from May to July, nymphs peaked from January to April and the peak of larvae abundance from December and January. There was a significant difference in the number of ticks collected in the two areas for each tick stage (larvae, mean number (MN) in WA 120.14, MN in GR 57.07, P: 0.02; nymphs, MN in WA 46.42, MN in GR 16.38, P: 0.018; adults, MN in WA 6.64, MN in GR 1.78, P: 0.02). Conclusions. The results suggest that H. juxtakochi maintains a one-year cycle in the study areas. This cycle would be characterized by the immature population peaks in the dry season; while adults are distributed throughout year, with a peak in the transition from the rainy and dry. Moreover, H. juxtakochi was more abundant in forests than in grasslands, which could lead to a better adaptation to forested conditions.

Objetivo. Describir la variación estacional y realizar un análisis comparativo de la preferencia de hábitat de H. juxtakochi en Panamá. Materiales y métodos. Se recolectaron mensualmente garrapatas de la vegetación utilizando una tela blanca, entre enero de 2009 y marzo de 2010 en cuatro sitios establecidos en el Parque Municipal Summit (PMS), dos en área de pastizales (AP) y dos en área boscosa (AB). Las garrapatas fueron identificadas como larva, ninfa y adulto de H. juxtakochi. El número de garrapatas recolectadas en cada área fue empleado para describir la distribución estacional de ambos estadios inmaduros y adultos, y se compararon con la prueba no paramétrica Mann-Whitney U. Resultados. Se recolectó un total de 2.338 garrapatas en AP y 560 garrapatas en AB. El mayor pico de garrapatas adultas fue de mayo hasta julio, los picos de ninfas fueron de enero hasta abril y los picos de abundancia de larvas desde diciembre hasta enero. Hubo diferencias significativas en el número de garrapatas recolectadas en las dos áreas para cada estadio (número promedio de larvas en AB 120.14, en AP 57.07, P: 0.02; número promedio de ninfas en AB 46.42, en AP 16.38, P:0.018; número promedio de adultos en AB 6.64, en AP 1.78, P: 0.02). Conclusiones. Los resultados sugieren que H. juxtakochi mantiene un ciclo de un año en las áreas de estudio. Este ciclo estaría caracterizado por picos poblacionales de ejemplares inmaduros en la época seca; mientras que los adultos se distribuyen a lo largo de todo año, con un pico en la transición entre la época lluviosa y seca. Por otra parte, H. juxtakochi fue más abundante en bosques que en pastizales, lo cual podría suponer mejores adaptaciones a condiciones boscosas.

Ticks (Ixodida) on humans from central Panama, Panama (2010-2011).

From January 2010 to December 2011, a total of 138 cases of ticks feeding on humans were reported from 11 locations in central Panama. Five of these locations were situated in forest environments, three in rural landscapes and three in urban areas. The ticks were submitted to the Gorgas Memorial Institute, where nine species were identified among 65 specimens: Amblyomma cajennense s.l., A. dissimile, A. naponense, A. oblongoguttatum, A. ovale, A. sabanerae, A. tapirellum, Haemaphysalis juxtakochi and Rhipicephalus sanguineus s.l. The remaining 73 specimens consisted of unidentified immature ticks, all belonging to the genus of Amblyomma. Rhipicephalus sanguineus s.l. was the species most frequently associated with humans, particularly in urban environments. In rural landscapes, tick bites were most often caused by A. cajennense s.l., whereas A. tapirellum was the species most often found parasitizing humans in forest environments. These data provide information on the tick species most commonly associated with humans in forested environments, rural areas and cities around the Panama Canal.

Distribución de los ectoparásitos de Canis lupus familiaris L. (Carnivora: Canidae) de Panamá / Distribution of ectoparasites of Canis lupus familiaris L. (Carnivora: Canidae) from Panama

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.

Rickettsial infection in domestic mammals and their ectoparasites in El Valle de Antón, Coclé, Panamá.

The present research evaluated the presence of Rickettsia spp. on ectoparasites of horses and dogs (using PCR techniques), and their sera (using immunofluorescence assay) in El Valle de Antón town in Panama. A total of 20 horses and 20 dogs were sampled, finding four species of ectoparasites on dogs (the ticks Rhipicephalus sanguineus, Amblyomma ovale, Amblyomma oblongoguttatum, and the flea Ctenocephalides felis), and two tick species on horses (Amblyomma cajennense and Dermacentor nitens). DNA of Rickettsia amblyommii was found in pools of A. cajennense, D. nitens, and R. sanguineus, while Rickettsia felis was detected in C. felis pools. Overall, 70% (14/20) and 65% (13/20) of the horses and dogs, respectively, were seroreactive (titer ≥ 64) to spotted fever group rickettsiae. Sera from six dogs and five horses reacted to R. amblyommii antigens with titers at least four-fold higher than those for the other antigens tested (Rickettsia bellii, Rickettsia parkeri, Rickettsia rhipicephali, R. felis, and R. rickettsii). These serological results, coupled with our molecular findings, suggest that these dogs and horses were infected by Rickettsia amblyommii. More studies need to be realized afford to identify the Rickettsia species responsible for other serological and molecular positive results, and their ecological importance.