ST 398 in New York City - via the Dominican Republic?

Here's a piece of MRSA news from the ICAAC meeting (see the post just below) that is intriguing enough to deserve its own post.

US and Caribbean researchers have found preliminary evidence of the staph strain ST 398, the animal-origin strain that has caused human illness in the Netherlands and has recently been found in Ontario and Iowa, in Manhattan. How it may have arrived: Via the Dominican Republic.

Th researchers (from Columbia University and Montefiore Medical Center in New York, three institutions in the Dominican Republic and one in Martinique) examine the influence of an "air bridge" — very frequent household travel — that is bringing MRSA and methicillin-sensitive staph back and forth between the Dominican Republic and the immigrant Dominican community at the north end of Manhattan. They compared 81 staph isolates from Dominican Republic residents and 636 from Manhattan residents and, among other findings, say that 6 Dominican strains and 13 Manhattan strains were ST398.

It is the first time ST398 has been found in Manhattan or in the Dominican Republic. (Most likely also the first time anyone has looked.)

The authors observe with some understatement:

Given the history of ST398's rapid dissemination in the Netherlands, its history of methicillin-resistance and its ability to cause infections in both hospital and community, it will be important to monitor its prevalence in these new regions.

It is important to note that these ST398s were not MRSA — they were MSSA, methicillin-sensitive. However: Earlier this year, the Dutch researchers who have delineated the emergence of ST398 in Holland commented on the diversity of ST398 they have found on different pig farms and hypothesized that the resistance element has been acquired several different times by methicillin-sensitive staph. (van Duijkeren, E. et al. Vet Microbiol 2008 Jan 25; 126(4): 383-9.)

So it is possible to hypothesize that this strain arrived in Manhattan from the more rural Dominican Republic, though with the growth of hobby urban farming in NYC, one could also make the case that transmission went the other way. And it is also possible — I emphasize possible — that this could be a precursor to ST398 MRSA emerging in Manhattan. An interesting thought.

(This research is not online, because it is a poster presented at a medical meeting. For reference, the cite is: C. DuMortier, B. Taylor, J. E. Sanchez et al. "Evidence of S. aureus Transmission Between the USA and the Dominican Republic." Poster C2-224. 48th ICAAC-46th IDSA, Washington DC, 24-28 Oct 2008.)