Managing Travel Health Risks, Behaviors, & Outcomes: Best Practices - Seminar, April 28, 2000

Jay S Keystone, MD, Professor of Medicine, Tropical Disease Unit, Toronto General Hospital

DR. GRIZZARD: Jay?

DR. KEYSTONE: Well, it's remarkable. We have three travel medicine experts, none of whom do travel medicine, including myself. I'll explain that in just a minute.

My name is Jay Keystone, and I guess I have been doing tropical disease medicine for the last 24 years and have been teaching travel medicine for almost as long. I'm at the Tropical Disease Unit at Toronto General, which is an affiliated University of Toronto hospital, and we are involved in the clinical aspects of post-travel medicine, not pre-travel, teaching and research.

And as I said, I teach it but I don't do it. Over the last—up until about a year ago, we were strongly partnered with a pre-travel clinic at the Toronto General Hospital and saw about 6,000 new patients a year, run by Dr. Phil Scapaturra, who is here today. I always like to say that the knows more about pre-travel medicine than I'll ever know. And our area, however, is on the other side of the coin, and that is, the post-travel side. We see the travelers coming home. We see about 1,000 consultations a year, of which about 75 percent of those are in travelers and about 25 percent are in immigrants.

Let me just tell you, before I show you a clinical slide, about the kinds of research that we've been doing. We do both clinical research and molecular biology basic research. Our clinical research has been really focused more on the pre-travel side, a little bit on the post-travel, but mostly looking at perception of need for travel advice, studies on the accuracy of advice e have published in areas looking at embassies, family practitioners, and travel medicine clinics, looking at the issue of compliance and recognition of disease in the community, particularly malaria, where we did a very interesting study with very disturbing results about how poorly malaria is diagnosed in our community, which is a 3.5-million-person city, that is highly multicultural. For those who don't know it, in Toronto by the year 2000, which I guess is about now, about 50 percent of our population will be visible minority, which is now our visible majority. And so we have a very large multicultural group of individuals that we see who travel to and from all over the world.

The other thing we do is vaccine trials, antimalarial trials and drugs, drug studies. It's my kids who do the drugs. I just do the studies. Anybody that doesn't think their kids do drugs, come and talk to me at the end of this.

We also do molecular biological studies on rapid diagnostics for malaria, the new dip-stick tests, the antigen detection tests for malaria, and most of this basic science stuff and much of the clinical is done by our primary researcher, Dr. Kevin Kain, who is now my director. Now we can diagnose drug-resistant malaria within four days. We don't have to wait 28 days to see if there iss going to be a relapse. By using PCR, we can actually tell you within three or four days whether that strain is likely to be sensitive or not. And Dr. Kain is also working on the pathogenesis of malaria and has an amazing new theory that's going to shake up some of the biological world in malaria.

But if you were to ask me what our major business is, my twin brother once sent me a T-shirt that said, "Number two is our number one business," and that refers—for those of you who don't know what number two is, it's stool. And if you ask a child, do you have to go number one or number two, number two is our number one business because traveler's diarrhea makes up a very big part of our business, and in particular, not acute traveler's diarrhea but persistent, chronic GI problems in travelers, which probably is an issue for World Bank employees—I don't know how many of you here are from the World Bank and travel. I would suspect that's a major problem for you. And we've been looking at that issue for a number of years, estimated about 2 percent of travelers have chronic, persistent diarrhea or GI upset, constipation alternating with diarrhea.

So let me just show you some data just very briefly in one minute that was accumulated by the ISTM at a Geosentinel surveillance site. Now, we are one of 23 sites for surveillance. This is about 1,700 patients over time. Geosentinel is a surveillance network by the International Society of Travel Medicine with 23 different sites around the world. And the purpose is to carry out surveillance for emerging infectious diseases. And the hope is that as people arrive from different countries at different sites, all that information is collated weekly at CDC. And so if someone comes in with a rash from X country and someone else from that same country goes to another travel clinic, very quickly we can determine that there's something new going on in different sites around the world. And that's the Geosentinel network.

Well, we're one of those 23 sites, and without the numbers, you will see diarrhea, acute or chronic, mostly chronic, makes up about 25 percent of our consultations, at least 25 percent. We screen a number of travelers, that is, the long-stay travelers, missionaries, government, Peace Corps, or in Canada it's CUSO. We screen them when they come back for tropical and parasitic diseases.

Skin conditions make up probably about 10 percent— of our problems. Malaria, again, another 4 or 5 percent. Anxiety and fatigue, usually related to stress—I don't know. We lose a number to follow-up. Why that should be a diagnostic criteria I haven't figured out. Viral syndromes, larva migrans, respiratory. Then at the bottom here you have the dreaded Blastocystis hominis, which is this single-cell parasite that is eluding anyone knowing what to do with. Post-infectious lactose intolerance, milk intolerance, which we think is one of the major components of post-travel bowel problems, and a variety of other things, all the other parasites.

So that's just kind of an overview of the kinds of things we see, but number one, two and—well, number two, number two, number two is chronic or persistent bowel symptoms after travel.

Thank you.

Disclaimer: These Proceedings have been produced from transcripts made from audio tapes. Efforts were made to check the accuracy of information with the various authors, but this accuracy is not guaranteed. If there is information that you believe requires correction, please send a message to our e-mail address.