Aflatoxin Exposure and Associated Human Health Effects, a Review of Epidemiological Studies

flatoxins are fungal toxins that possess acute life threatening toxicity, carcinogenic properties and other potential chronic adverse effects. Dietary exposure to aflatoxins is considered a major public health concern, especially for subsistence farming communities in sub-Saharan Africa and South Asia, where dietary staple food crops such as groundnuts and maize are often highly contaminated with aflatoxin due to hot and humid climates and poor storage, together with low awareness of risk and lack of enforcement of regulatory limits. Biomarkers have been developed and applied in many epidemiological studies assessing aflatoxin exposure and the associated health effects in these high-risk population groups. This review discusses the recent epidemiological evidence for aflatoxin exposure, co-exposure with other mycotoxins and associated health effects in order to provide evidence on risk assessment, and highlight areas where further research is necessary. Aflatoxin exposure can occur at any stage of life and is a major risk factor for hepatocellular carcinoma, especially when hepatitis B infection is present. Recent evidence suggests that aflatoxin may be an underlying determinant of stunted child growth, and may lower cell-mediated immunity, thereby increasing disease susceptibility. However, a causal relationship between aflatoxin exposure and these latter adverse health outcomes has not been established, and the biological mechanisms for these have not been elucidated, prompting further research. Furthermore, there is a dearth of information regarding the health effects of co-exposure to aflatoxin with other mycotoxins. Recent developments of biomarkers provide opportunities for important future research in this area.

Review of the genus Bursaphelenchus Fuchs, 1937 (Nematoda, Aphelenchida) with some conclusions on the host-parasite and vector-parasite evolution.

INTRODUCTION AND GOALS: Genus Bursaphelenchus includes several pests of the world importance for the rural economy, the most dangerous are the Bursaphelenchus xylophilus (the pinewood nematode caused decline of the pine trees in south Asia and in one spot area in Europe, Portugal, Peninsula de Setubal) and the Bursaphelenchus cocophilus, causing the decline of coco-palm plantations in Carribean and Latin American regions. The peculiarity of the host-parasite association of the genus that the nematode life cycle includes three trophic components: plant (mostly a tree), insect vector and a fungus. Goals of the presentation is to list all species of the world fauna and all efficient diagnostic characters, then create the identification tool and analyze the similarity of species and possible ways and causes of the host-parasite evolution of the group. RESULTS: Complete list of species with synonymy and a catalogue of all efficient diagnostic characters with their states, selected from papers of the most experienced taxonomists of the genus, are given for the genus Bursaphelenchus. List of known records of Bursaphelenchus species with names of natural vectors and plants and their families is given (for world pests the most important groups of trees and insects are listed). The tabular, traditional and computer-aided keys are presented. Dendrograms of species relationships (UPGMA, standard distance: mean character difference) based on all efficient taxonomic characters and separately on the spicule characters only, are given. Discussion whether the species groups are natural or purely diagnostic ones is based on the relationships dendrograms and the vector and associated plant ranges of Bursaphelenchus species; the xylophilus species group (B. xylophilus, B. abruptus, B. baujardi, B. conicaudatus, B. eroshenkii, B. fraudulentus, B. kolymensis, B. luxuriosae; B. mucronatus), the hunti group (B. hunti, B. seani, B. kevini and B. fungivorus) are probably the natural ones. CONCLUSIONS: The parasitic nematode association includes three trophic components: plant, insect vector and fungus. The initial insect-plant complex Scolytidae-Pinaceae is changeable and only in rare occasions the change of the preferred vector to Cerambycidae (the xylophilus group), Hymenoptera (the hunti group) led to formation of the natural species-groups. From the analysis it is clear that although the vector range is changeable it is comparatively more important for the evolution of the genus Bursaphelenchus than associations with plants at the family level. Data on the fungi species (3rd component in natural Bursaphelenchus associations) are insufficient for the detailed comparative analysis.

Bull Creek/May River PSG-R-008

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Bull Creek/May River PSG-R-008 Recreational Shellfish Ground in Beaufort County.

Last End Point / Pinckney Island PSG - R036/R037

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Last End Point / Pinckney Island PSG - R036/R0378 Recreational Shellfish Ground in Beaufort County.

Chechessee Point PSG - R061

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Chechessee Point PSG - R061 Recreational Shellfish Ground in Beaufort County.

Station Creek PSG - R089

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Station Creek PSG - R089 Recreational Shellfish Ground in Beaufort County.

Ashe Island PSG - R132

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Ashe Island PSG - R132 Recreational Shellfish Ground in Colleton County.

Leadenwah Creek PSG - R173, R174, R181

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Leadenwah Creek PSG - R173, R174, R181 Recreational Shellfish Ground in Charleston County.

Leadenwah Creek PSG - R175

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Leadenwah Creek PSG - R175 Recreational Shellfish Ground in Charleston County.

Kiawah River PSG - R186

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Kiawah River PSG - R186 Recreational Shellfish Ground in Charleston County.

Green Creek PSG - R193

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Green Creek PSG - R193 Recreational Shellfish Ground in Charleston County.

Folly River PSG - R201

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Folly River PSG - R201 Recreational Shellfish Ground in Charleston County.

Gray Bay PSG - R234

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Gray Bay PSG - R234 Recreational Shellfish Ground in Charleston County.

Hamlin Creek PSG - R252

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Hamlin Creek PSG - R252 Recreational Shellfish Ground in Charleston County.

Hamlin Creek PSG - R252

The South Carolina Department of Natural Resources provides maps to recreational and state shellfish grounds, available to the public for recreational harvesting or to commercial harvest. This map shows the location of Hamlin Creek PSG - R252 Recreational Shellfish Ground in Charleston County.