Non-invasive biomonitoring of infant exposure to environmental organic pollutants in north-western Spain based on hair analysis. Identification of potential sources

Recent years have seen growing interest in hair sample analysis to detect organic pollutants (OPs). This biological matrix can be analysed non-invasively for biomonitoring of OPs over a wide exposure window. Obtaining hair sample amounts that meet the needs of the analytical methodology required for the determination of the POs of interest can be challenging, especially in infants. As a result, studies assessing organic pollutants in infant hair have been very scarce. We quantified levels of about 60 OPs, including persistent organic pollutants (POPs), in 110 hair samples from a patient cohort (60 mothers and 50 infants) from Santiago de Compostela (north-western Spain). For each participant we examined relationship between OP levels and corresponding epidemiological parameters using correlations, principal component analysis (PCA), hierarchical cluster analysis, and Multivariate analysis of variance (MANOVA). For many OPs we observed significant correlations with place of residence, parity, and maternal age, as well as pet ownership. Evaluation of dietary habits showed significant associations between levels some OPs and the consumption of fish, molluscs, and cereal. There were significant associations between chlorpyrifos and deltamethrin levels and infant birth characteristics such as birthweight and head circumference. Relations between OP levels in the hair of mothers and their infants were also examined, revealing common sources of exposure for dioxin-like polychlorinated biphenyls (DLPCBs), non-dioxin-like polychlorinated biphenyls (NDLPCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs). Levels of fluoranthene (F), pyrene (P), endrin, and some PBDEs in maternal hair were significantly correlated with those in infant hair. Our findings identified common sources of exposure to OPs of distinct chemical classes.

The role of healthy dog carriers of Babesia microti-like piroplasms

BACKGROUND

While in Europe Babesia canis has been traditionally held responsible for canine piroplasmosis, Babesia microti-like piroplasm (Bml) infection is being ever more observed in dogs, with the first clinical cases reported in northwestern Spain. This study examines the epidemiological role of healthy dogs living in endemic areas of Bml infection in Spain. The data obtained were used to describe the clinical status and map the geographical distribution of Bml infection in healthy dogs in northwestern Spain.

RESULTS

Blood samples and ticks were taken from 756 healthy dogs representatively across the whole Galicia region (northwestern Spain): stray (n = 211), hunting dogs (n = 333) and pets (n = 212). Blood samples were tested by microscopy parasite observation, nested PCR-RFLP and sequencing. Piroplasm infection prevalences in healthy dogs from northwestern Spain were 17.1% (129/756) by PCR and 3.4% (26/756) by microscopy observation. The species found by PCR were: 2.2% (17/756) for B. canis and 15.1% (114/756) for Bml. Co-infection with B. canis and Bml was noted in 2 dogs. The higher prevalences detected were Bml in hunting dogs (25.5%; 85/333) and B. canis in stray dogs (6.6%; 14/211). In fox-hunting dogs from any area and dogs from the A Coruña Province, significantly higher prevalences of Bml infection were detected (P < 0.001). Upon physical examination, tick infestation was observed: 130 ticks in 18 hunting and three pet dogs. These were subsequently identified as Rhipicephalus sanguineus (s.l.) (49.2%), Ixodes hexagonus (38.5%), Ixodes ricinus (6.9%) and Dermacentor reticulatus (5.4%). Among the more prevalent ticks infesting healthy carrier dogs were I. hexagonus, followed by D. reticulatus and I. ricinus.

CONCLUSIONS

Babesia canis and Bml were the only piroplasm species found infecting healthy dogs in Galicia, the prevalence of Bml being higher than of B. canis. Factors correlated with a higher Bml infection risk were being a hunting dog and living in the A Coruña Province. Healthy dogs travelling to other countries could act as carriers and probably contribute to the spread of Bml infection in dogs and wild carnivores throughout Europe.

Prevalence and identity of Sarcocystis spp. in roe deer (Capreolus capreolus) in Spain: a morphological study

Muscular samples from the oesophagus, diaphragm and heart of 101 roe deer (Capreolus capreolus) hunted in Galicia (Northwestern Spain) were examined, by the compression method, for the presence of Sarcocystis spp. infection. The structure of the cyst wall was examined by light (LM) and transmission electron microscopy (TEM). The overall prevalence of infection was very high (99%), with a density of 404 cysts/sample (SD 812). The prevalence was very similar in the different examined muscle types (99% heart and diaphragm, and 98.9% oesophagus). A significantly higher intensity of infection was found in the heart (831; SD 1281), followed by the diaphragm (197; SD 190) and the oesophagus (180; SD 205). Macrocysts (>1500 μm long) were only detected in the oesophagus of 48.5% of the examined roe deer; their mean size was 2055.4 μm (SD 632.46). Cysts localised in the myocardium were significantly shorter (371.5 μm; SD 160.47) than those found in the diaphragm (678.2; SD 546) and the oesophagus (973.4 μm; SD 667.87). By LM, most of the cysts (98.8%) displayed a thin wall, which was consistent with those of Sarcocystis sp., S. gracilis and S. capreolicanis; only 1.2% of the cysts had a thick striated wall, consistent with Sarcocystis silva. Three morphological distinct sarcocysts were observed by TEM: the unnamed species Sarcocystis sp., S. capreolicanis and S. gracilis. The wall ultrastructure of the examined macrocysts was consistent with S. gracilis. This study has revealed that Spanish roe deer harbours 4 morphologically distinct types of sarcocysts; being the first record of S. gracilis in roe deer from Spain.