Fecal pollution source tracking and thalassogenic diseases: The temporal-spatial concordance between maximum concentrations of human mitochondrial DNA in seawater and Hepatitis A outbreaks among a coastal population

Fecal pollution source tracking (FST) studies the origin of fecal contamination and promotes action to eliminate it to improve human health and environmental sustainability. This work presents the temporal and spatial relations of human mitochondrial DNA (HmtDNA), fecal coliforms (FC) and live microbial biomass (ATP) in seawater during a hepatitis A outbreak among a human coastal population. The study area is approximately 100 km along the coastline of the Biobío Region in the southeastern Pacific (Humboldt Current System, Chile). Total data from the swash zone from summer 2015 to autumn 2016 show there were significant positive log-log correlations between FC and HmtDNA (R = 0.32) and ATP (R = 0.31). These correlations were highest during the austral spring of 2015 (R = 0.53 and 0.58 respectively), when HmtDNA also correlated significantly with ATP (R = 0.86). Maximum average values of the parameters measured in this season showed a temporal-spatial concordance with the peak in the number of hepatitis A cases among the nearby coastal population. FC correlated significantly with HmtDNA (R = 0.98) in the water column of the coastal zone close to Concepción Bay during the austral summer of 2016 and in the swash zone of the bay (R = 0.68) throughout the study period. Hepatitis A virus (HAV) has also been detected in organisms and seawater in Concepción Bay, which is consistent with the high incidence of hepatitis A among the coastal population. The concordance between human fecal pollution in the study area and a seasonal hepatitis A outbreak strongly suggests that HmtDNA and its relation with FC and ATP in the coastal zone of marine environments can be used as a proxy to evaluate the risk of outbreaks of thalassogenic diseases.

Two new species of the Liolaemuselongatus-kriegi complex (Iguania, Liolaemidae) from Andean highlands of southern Chile

The elongatus-kriegi complex is one of the most diverse clades of the Liolaemus (sensu stricto) subgenus of lizards. There are currently 29 species recognized in this group distributed between Chile and Argentina. Based on molecular evidence, there seem to be five main clades nested within this complex: the elongatus, leopardinus, kriegi, petrophilus and punmahuida clades. Liolaemusbuergeri and Liolaemuskriegi, both of the kriegi clade, were believed to inhabit the surroundings of the Laja Lagoon, in the Biobío Region of Chile. Moreover, this Chilean population of Liolaemuskriegi was recently recognized as an undescribed taxon called “Liolaemus sp. A” based on molecular phylogenetics. In this work, we studied these two populations of the Laja Lagoon and provided the morphological diagnosis to describe them as two new species: Liolaemusscorialissp. n. and Liolaemuszabalaisp. n., previously considered Liolaemusbuergeri and “Liolaemuskriegi/Liolaemus sp. A” respectively. Additionally, we identified another population of Liolaemusscorialis in the vicinity of La Mula Lagoon in the Araucanía Region of Chile. Liolaemusscorialis differs from almost all of the species of the elongatus-kriegi complex by its considerably smaller size. Nevertheless, without molecular data we cannot assign it to any particular subclade. Liolaemuszabalai belongs to the kriegi clade based on published molecular phylogenies. Finally, we provide some natural history data on both species and we document for the first time the presence of Liolaemusneuquensis in Chile from a museum specimen from La Mula Lagoon.