Hi ronR,
what you say is not completely true, health officials already said here in Belgium, back in '99 that HTLV was emerging.
When I became sick, I long believed I was infected with HIV. It took me years to believe I was not. Rightafter, I thought I was infected with HTLV, I had all reasons to believe: my sexual encounter was with someone where HTLV is believed to be endemic. It took me lots of ELISA tests to believe I was not infected with ...HTLV. After a few years, and no diagnosis I restarted thinking I might carry an HTLV infection. Finally I found a wonderful HTLV researcher, who performed a sensitive HTLV-test, which is used in research area. The test came back...negative. Note, that the antibody(ELISA) test on HTLV is not very sensitive(I think 96%). But, repeated tests will give you a 100% assurrance, they say.
Also, it looks like not everyone makes equally amounts of antibodies, and most tests out there are sensitive enough, but to catch a virus and bringing it to the test, is the hardest part. It's not all like HIV, where you might have thousands virus particles in a ml of blood. I think it's not all sorted out very well. And as long as it is not, you can't rule out anything.
HTLV seems indeed very hard to catch, and I personally think that this virus might use a bacteria as a transfer vector to humans. There you might have it: easy to catch, and as dessert, you get a nasty virus for free. All speculation of course...
But, my symptoms look very much like HTLV, therefore I think I might have a virus, which behaves like HTLV.
Best wishes,
OS.