From owner-vect-bio@hgmp.mrc.ac.uk Tue Aug 6 22:34:17 2002 Return-Path: Received: from localhost (localhost [127.0.0.1]) by mercury.hgmp.mrc.ac.uk (Postfix) with SMTP id 4590717A73 for ; Tue, 6 Aug 2002 22:34:16 +0100 (BST) Received: from localhost (localhost [127.0.0.1]) by mercury.hgmp.mrc.ac.uk (Postfix) with ESMTP id EDCB817A7D for ; Tue, 6 Aug 2002 22:34:14 +0100 (BST) Received: by mercury.hgmp.mrc.ac.uk (Postfix, from userid 60001) id 8368F17A73; Tue, 6 Aug 2002 22:34:13 +0100 (BST) To: vect-bio@net.bio.net Newsgroups: bionet.biology.vectors Date: 30 Jul 2002 13:09:00 +0100 From: SSCHEINE Subject: Parasites of parasites Message-Id: <20020806213413.8368F17A73@mercury.hgmp.mrc.ac.uk> X-Razor-id: 8b709e3213943d635ec4d5943c92670534c5d89a Sender: owner-vect-bio@hgmp.mrc.ac.uk Precedence: bulk This may be a FAQ, but no one in a pretty knowledgable group of experts knew the answer for sure. We all know about lots of examples of viral diseases that are spread by external parasites (e.g., mosquitos, ticks, etc). However, does anyone know of an example of a viral disease spread by an _internal_ parasite (e.g., helmith, protozoan, etc)? We came up with two possible explanations. 1. Trivial: Such diseases exist, but the symptoms are always subscribed to the parasite. So no one has really looked. 2. Interesting: Evolutionary/ecological dynamics prevent such viral diseases from getting existing. Since the parasite needs the host to live long enough to complete its life cycle, and the virus would kill the host quickly, no such disease could ever get established. No one in the group (a workshop on infectious diseases) knew offhand of anything in the literature that addresses this question. So, does anyone know of an example or a reference on the topic? Thanks, Sam Scheiner Arizona State University ---