American Society of Hirudotherapy

The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas)

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 NeoplasmsTurtlesViral LoadVirus Latency

Summary

Quantitative PCR of green-turtle parasites showed marine leeches (Ozobranchus spp.) carry high fibropapilloma-associated turtle herpesvirus DNA loads, some near 10 million copies per leech, implicating them as mechanical vectors.

Context

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. The article concerns a leech genus (Ozobranchus), marine turtle disease ecology, and vector biology.

Citation

Reference (Vancouver style)

Greenblatt RJ, Work TM, Balazs GH, Sutton CA, Casey RN, Casey JW. The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas). Virology. 2004;321(1):101-110. doi:10.1016/j.virol.2003.12.026. PMID: 15033569

Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.

DOIPubMed

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

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.