A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions

The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions. The 1730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate and continental climate classes, and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a 'very high risk' of being or becoming invasive, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate 'rapid' management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement.

[Viral hepatitis A as an occupational disease in the city of Iaşi]

OBJECTIVES

Few studies have been carried out to evaluate the role of hepatitis A virus (HAV) as an occupational hazard. Our analysis of data on occupational diseases in Romania showed that hepatitis ranks as one of the first among infectious occupational diseases.

MATERIALS AND METHODS

Data on the role of hepatitis A, as occupational disease, were obtained by testing sera obtained from different occupational groups and compared results with the degree of immunity found among the normal population. An ELISA technique was used to determine the presence of each hepatitis marker (Murex kits for anti-HAV IgG).

RESULTS

The ratio of prevalence in each subset compared to the general population was used to express relative risk. The results of our study show that hepatitis A is an important hazard to sewerage workers. In view of these results, it should be considered whether the occupational differences alone account for the divergence in immunity between the groups or whether socioeconomic aspects and differences in the standard of hygiene are also responsible for HAV infections.