BackgroundParasite prevalence and diversity are determined by the distribution of hosts and vectors and by the interplay among a suite of environmental factors. Distributions of parasite lineages vary based on host susceptibility and geographical barriers. Hemoparasites of the genera Haemoproteus and Plasmodium have wide distributions, and high prevalence and genetic diversity within perching birds (Order Passeriformes). The rufous-collared sparrow (Zonotrichia capensis) is widely distributed in Central and South America across an immense diversity of environments from sea level to more than 4000 meters above sea level. It therefore provides an excellent model to investigate whether altitudinal and latitudinal gradients influence the distribution, prevalence and diversity of haemosporidian parasites, their population structure and the biogeographical boundaries of distinct parasite lineages.ResultsWe assembled samples from 1317 rufous-collared sparrows spanning 75 locales from across Central and South America (between 9.5°N and 54°S; 10–4655 meters above sea level). We used DNA sequence data from a fragment of the mitochondrial cytochrome b gene (cytb) of Haemoproteus and Plasmodium from 325 positive samples and found prevalences of 22 and 3%, respectively. Haemoproteus exhibited a higher prevalence than Plasmodium but with comparatively lower genetic diversity. We detected a relationship of Plasmodium and Haemoproteus prevalence with altitude and latitude; however, altitude and latitude did not influence parasite diversity.ConclusionsParasite lineages showed a phylogeographical boundary coincident with the Andes Mountains, although we also observed a north-south disjunction in Peru for Haemoproteus. Haemosporidian distribution was not homogeneous but differed based on latitude and altitude. This is most probably due to environmental factors that have influenced both vector distribution and abundance, as well as parasite development. Our study provides key insights on the distribution of haemoparasite lineages and parasite dynamics within hosts.Electronic supplementary materialThe online version of this article (10.1186/s13071-018-3243-4) contains supplementary material, which is available to authorized users.

Background Rickettsial diseases are considered important in public health due to their dispersal capacity determined by the particular characteristics of their reservoirs and/or vectors. Among the latter, fleas play an important role, since the vast majority of species parasitize wild and invasive rodents, so their detection is relevant to be able to monitor potential emerging diseases. The aim of this study was to detect, characterize, and compare Rickettsia spp. from the fleas of micromammals in areas with different human population densities in Chile. Methods The presence of Rickettsia spp. was evaluated by standard polymerase chain reaction (PCR) and sequencing in 1315 fleas collected from 1512 micromammals in 29 locations, with different human population densities in Chile. A generalized linear model (GLM) was used to identify the variables that may explain Rickettsia prevalence in fleas. Results DNA of Rickettsia spp. was identified in 13.2% (174 of 1315) of fleas tested. Fifteen flea species were found to be Rickettsia-positive. The prevalence of Rickettsia spp. was higher in winter, semi-arid region and natural areas, and the infection levels in fleas varied between species of flea. The prevalence of Rickettsia among flea species ranged between 0–35.1%. Areas of lower human density showed the highest prevalence of Rickettsia. The phylogenetic tree showed two well-differentiated clades with Rickettsia bellii positioned as basal in one clade. The second clade was subdivided into two subclades of species related to Rickettsia of the spotted fever group. Conclusions To our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 15 flea species of micromammals in Chile. In this study, fleas were detected carrying Rickettsia DNA with zoonotic potential, mainly in villages and natural areas of Chile. Considering that there are differences in the prevalence of Rickettsia in fleas associated with different factors, more investigations are needed to further understand the ecology of Rickettsia in fleas and their implications for human health.

The objective of this study was to describe the developmental biology of the tick Ornithodoros peruvianus Kohls, Clifford and Jones under laboratory conditions. A total of 174 live specimens of O. peruvianus at different stages were collected from caves located on Pan de Azúcar Island (26°09’S, 70°41’W) and Tal Tal (25°15’S, 70°15’W). In the laboratory, ticks were fed on rabbits (Oryctolagus cuniculus) and kept in acrylic tubes under controlled conditions of humidity and temperature (average of 75% +/- 5 and 23 +/- 1°C, respectively), and a 12 hour photoperiod. The minimum period between stages were: oviposition to egg hatching: 9 days; larva to nymph one: 44 days (44-56); nymph one to nymph two: 10 days (10-20); nymph two to male: 66 days (66-84); nymph two to nymph three: 68 days, and nymph three to female: 42 days. Oviposition occurred in 24 females, with an average of 70 (15-133) eggs per female after the first bloodmeal. The total time to complete the cycle under laboratory conditions was 185 days on average (SD = 17.43). O. peruvianus may require three nymphal stages to molt into an adult female and only two to molt into an adult male. The selected environmental conditions, host and photoperiod are important factors that must now be considered to better understand the factors that affect developmental times of this tick.

La modificación del uso de suelo ha provocado la pérdida, fragmentación y degradación del escaso remanente de bosque nativo presente en el centro-sur de Chile, hábitat de marsupiales del género Dromiciops (Microbiotheria). En este estudio, exploramos la presencia de Dromiciops a través de cámaras trampa en una zona relicta de bosque esclerófilo mediterráneo costero. Se registró la presencia de Dromiciops en cuatro de los nueve sitios evaluados. Este hallazgo corresponde al primer registro formal de Dromiciops en esta área.