In May, 1,296 travel medicine specialists gathered in Quebec City, Canada, for the 14th biannual conference of the International Society of Travel Medicine. Several of the topics discussed are practically relevant to readers of Infectious Disease Alert, so we offer this Top 10 list of news items.
10. Big numbers imply big opportunity.
There were reportedly 3.5 billion air travelers last year and 1.14 billion international arrivals around the world in 2014. People traveled a total of 2.3 trillion air miles last year, with more than half of that being on international flights. Increasingly, travel originates in less-wealthy countries rather than from “developed” nations in Europe and North America. People are traveling from many places to many other places, and that means germs are on the move as well.
9. Ebola can be a sexually transmitted disease.
It seems that infectious Ebola virus can persist for months in semen. As reported in the May 8, 2015, MMWR, Ebola virus has been isolated from semen 82 days after the onset of symptoms, and viral RNA has been identified in semen up to 101 days after symptom onset. The “final” case of Ebola in Liberia presented 30 days after the prior “last” case — with the only identified risk factor being unprotected vaginal intercourse with someone who had long since recovered from Ebola virus disease.
8. Malaria is still an issue for nearly half of the people on our planet.
Worldwide, 3.3 billion people in 97 countries live at risk of getting sick with malaria. However, the numbers of cases and deaths due to malaria have dropped to just 30-40% of what they were 15 years ago. Still, though, millions of people living in malaria-free areas travel to malarial areas each year and come home with risks of being sick and/or introducing malaria to viable vectors still living in their home areas. In many areas, up to half of commercially available antimalarial medications are either substandard or blatantly falsified (containing little or none of the labeled product); labeling is also falsified and difficult to identify as counterfeit.
7. A popular vacation site in France is now endemic for schistosomiasis.
Tourists enjoy swimming in the Cavu River on the French island of Corsica. Unfortunately, the water is now contaminated with schistosomes. Of approximately 30,000 local residents, “only” 110 were seropositive for schistosomiasis, but half of the positive subjects were children. While control measures are being implemented, it is safer to enjoy the scenery of the Cavu River without getting wet.
6. Dengue vaccines are progressing down the development “pipeline.”
But, you already knew that if you have been reading Infectious Disease Alert regularly (see March 2014 issue). Huge phase 3 studies are in progress in South America and Asia. Licensing applications could be submitted during the current calendar year.
5. Europeans are not the same as Americans.
This has been clear for years as we watch our European colleagues support routine BCG vaccination for tuberculosis prevention. And, it is clear as we discuss malaria chemoprophylaxis for travelers to some “low”-risk areas such as parts of the Caribbean. European travel medicine specialists are more likely than their American counterparts to forego prophylaxis and send travelers off with a curative dose of a stand-by treatment for presumptive use.
4. Technology helps.
I’d missed it, but data reported last year showed that nano-bubble technology is leading toward a malaria test that requires no blood drawing and no reagents. The test is said to “detect and screen malaria in seconds,” and “can be realized as a compact, easy-to-use, inexpensive, and safe field technology.” (Lukianova-Hleb EY, et al. Proc Natl Acad Sci USA 2014;111:900-905)
3. Microbiomes matter.
For whatever reasons, 10% of irritable bowel syndrome (IBS) is linked to previous gastrointestinal infection, and 4-31% of acute gastroenteritis is followed by IBS. This seems to be a particular problem for travelers. Adding multiply-resistant Gram-negative rods to the intestinal flora is common with travel.
2. Vaccine refusers might not keep refusing.
Recent data suggest that the main reason international travelers who decline vaccines do so is because they are not convinced that they are personally at risk of the diseases for which vaccines help. There is less concern about safety or other “evils” of vaccines. We need to continue to provide culturally acceptable education about risks and benefits of travel.
1. You are “essential”!
Even when the CDC suggests that non-essential travel be limited to countries with active Ebola outbreaks, humanitarian aid-related travel is considered essential. The world needs you!