Distribution of Spotted Fever Group Rickettsiae in Hard Ticks (Ixodida: Ixodidae) from Panamanian Urban and Rural Environments (2007-2013).

Tick-borne rickettsiosis is an important emerging disease in Panama; to date, there have been 12 confirmed cases, including eight fatalities. To evaluate the distribution of rickettsiae in Panamanian ticks, we collected questing and on-host ticks in urban and rural towns in elevations varying between 0 and 2300 m. A total of 63 sites (13 urban and 50 rural towns) were used to develop models of spatial distributions. We found the following tick species: Rhipicephalus sanguineus s.l. (present in 54 of 63 towns and cities), Amblyomma mixtum (45/63), Dermacentor nitens (40/63), A. ovale (37/63), Rhipicephalus microplus (33/63), A. oblongoguttatum (33/63), Ixodes affinis (3/63), and Ixodes boliviensis (2/63). Rhipicephalus sanguineus s.l. was present in urban and rural towns, and other species were present only in rural towns. DNA was extracted from 408 R. sanguineus s.l., 387 A. mixtum, 103 A. ovale, and 11 A. oblongoguttatum and later tested for rickettsiae genes using PCR. Rickettsia DNA was detected in ticks from 21 of 63 localities. Rickettsia rickettsii was detected in five A. mixtum (1.29%), and Candidatus "Rickettsia amblyommii" was found in 138 A. mixtum (35%), 14 R. sanguineus (3.4%), and one A. ovale (0.9%). These results suggest that much of rural Panama is suitable for the expansion of tick populations and could favor the appearance of new tick-borne rickettsiosis outbreaks.

Serologic evidence of human Rickettsia infection found in three locations in Panamá / Evidencia serológica de infecciones de Rickettsia en humanos provenientes de tres localidades de Panamá

Introduction: Since the middle of last century, cases of rickettsiosis have been found in Panamá when outbreaks of murine typhus and spotted fever were reported. Since then, little information exists about its prevalence in this country, since it is most often is misdiagnosed as another disease. Objectives: The aim of this paper is to demonstrate the presence of Rickettsia infections in humans in three locations in Panamá. These locations are agricultural areas, near forested areas or those who work in zoo. Materials and methods: Three locations where chosen for this study: Tortí, El Valle de Antón and workers in the Summit Municipal Park in Panamá City. All volunteers signed an informed consent and answered a questionnaire. The samples were analyzed for the detection of rickettsial spotted fever and typhus group by the indirect immunofluorescence (using commercial kits) and antigens of Rickettsia rickettsii and R. amblyommii. Results: Blood samples were taken from 97 volunteers in Tortí (25), El Valle de Anton (37) and Summit Municipal Park (35). Of these, a total of 38 (39%) samples reacted to one of the two methods: eight (32%) in Tortí, 18 (48%) in El valle and 12 (34%) in Summit Municipal Park. Conclusion: The results show a high prevalence of antibodies to Rickettsia belonging to the spotted fever group in each of the three study areas, in addition to presenting evidence of the typhus group Rickettsia in El Valle de Anton. These areas could be considered endemic for rickettsiosis as there are conditions for maintaining them.

Introducción. Desde mediados del siglo pasado, se conocen en Panamá casos de rickettsiosis, cuando fueron reportados brotes de tifus en ratones y de fiebres manchadas. A partir de entonces, poca información se tiene sobre su prevalencia en este país, lo cual se debe principalmente a que son confundidos con otras enfermedades. Objetivos. El objetivo de este trabajo fue demostrar la presencia de rickettsiosis en humanos provenientes de tres localidades de Panamá, que corresponden a zonas agropecuarias, cercanas a bosques, o que trabajaban en zoológicos. Materiales y métodos. Se escogieron tres localidades para este estudio: Tortí (provincia de Panamá), El Valle de Antón (provincia de Coclé) y el Parque Municipal Summit en Ciudad de Panamá. Los voluntarios firmaron un consentimiento informado, además de responder un cuestionario. De cada voluntario se extrajo sangre venosa, la que fue analizada por medio de inmunoflorescencia indirecta, utilizando kits comerciales y láminas sensibilizadas con antígenos cultivados de Rickettsia rickettsii y Rickettsia amblyommii . Resultados. Se tomaron muestras de 97 voluntarios, 25 en Tortí, 37 en El Valle de Antón y 35 en el Parque Municipal Summit. De estos, 38 (39 %) de las muestras fueron positivas en algunas de las dos técnicas practicadas: 8 (32 %) en Tortí, 18 (48 %) en El Valle y 12 (34 %) en el Parque Municipal Summit. Conclusión. Se demuestra una alta prevalencia de anticuerpos contra Rickettsia del grupo de las fiebres manchadas en las tres áreas de estudio, además de presentarse evidencia de títulos para Rickettsia del grupo tifus en El Valle de Antón. Estas zonas podrían considerarse como endémicas por rickettsiosis, ya que existen condiciones que permiten el mantenimiento de las mismas.

Serologic evidence of human Rickettsia infection found in three locations in Panamá.

INTRODUCTION: Since the middle of last century, cases of rickettsiosis have been found in Panamá when outbreaks of murine typhus and spotted fever were reported. Since then, little information exists about its prevalence in this country, since it is most often is misdiagnosed as another disease. OBJECTIVES: The aim of this paper is to demonstrate the presence of Rickettsia infections in humans in three locations in Panamá. These locations are agricultural areas, near forested areas or those who work in zoo. MATERIALS AND METHODS: Three locations where chosen for this study: Tortí, El Valle de Antón and workers in the Summit Municipal Park in Panamá City. All volunteers signed an informed consent and answered a questionnaire. The samples were analyzed for the detection of rickettsial spotted fever and typhus group by the indirect immunofluorescence (using commercial kits) and antigens of Rickettsia rickettsii and R. amblyommii. RESULTS: Blood samples were taken from 97 volunteers in Tortí (25), El Valle de Anton (37) and Summit Municipal Park (35). Of these, a total of 38 (39%) samples reacted to one of the two methods: eight (32%) in Tortí, 18 (48%) in El valle and 12 (34%) in Summit Municipal Park. CONCLUSION: The results show a high prevalence of antibodies to Rickettsia belonging to the spotted fever group in each of the three study areas, in addition to presenting evidence of the typhus group Rickettsia in El Valle de Anton. These areas could be considered endemic for rickettsiosis as there are conditions for maintaining them.

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.