American Society of Hirudotherapy

The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus

Vector biology study published in Virology (2004)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Safety & Infection ControlGreenblatt RJ et al. · Virology, 2004

Abstract

Fibropapillomatosis (FP) of marine turtles is a neoplastic disease of ecological concern. A fibropapilloma-associated turtle herpesvirus (FPTHV) is consistently present, usually at loads exceeding one virus copy per tumor cell. DNA from an array of parasites of green turtles (Chelonia mydas) was examined with quantitative PCR (qPCR) to determine whether any carried viral loads are sufficient to implicate them as vectors for FPTHV. Marine leeches (Ozobranchus spp.) were found to carry high viral DNA loads; some samples approached 10 million copies per leech. Isopycnic sucrose density gradient/qPCR analysis confirmed that some of these copies were associated with particles of the density of enveloped viruses. The data implicate the marine leech Ozobranchus as a mechanical vector for FPTHV. Quantitative RT-PCR analysis of FPTHV gene expression indicated that most of the FPTHV copies in a fibropapilloma have restricted DNA polymerase expression, suggestive of latent infection.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, U.S. Gov't, P.H.S.
Indexed MeSH termsAnimalsDNA, ViralDisease VectorsGene Expression Regulation, ViralHerpesviridaeLeechesMarine BiologyPapillomaPolymerase Chain ReactionReverse Transcriptase Polymerase Chain ReactionSkin NeoplasmsTurtles

Summary

Demonstrates Ozobranchus leeches as candidate mechanical vectors for fibropapilloma-associated turtle herpesvirus — landmark paper for leech-mediated viral transmission.

Why This Matters for Hirudotherapy

This study used quantitative PCR to examine whether parasites of green turtles (Chelonia mydas), including marine leeches of the genus Ozobranchus, carry fibropapilloma-associated turtle herpesvirus (FPTHV) at loads sufficient to implicate them as mechanical vectors. Ozobranchus leeches carried very high viral DNA loads (approaching 10 million copies per leech in some samples), and sucrose gradient analysis confirmed some copies were associated with enveloped virus-density particles. The authors concluded Ozobranchus is a candidate mechanical vector for FPTHV. For ASH's domain, this article concerns a leech genus (Ozobranchus) but has no connection to medicinal hirudotherapy or the therapeutic leech secretome; the relevance is entirely to marine turtle disease ecology and vector biology.

Citation

The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus.

Greenblatt RJ et al. · Virology, 2004

DOI

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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