the first us case associated with the epidemic in hispaniola was laboratory confirmed on november 15 , 2010 , in a us resident who had traveled to haiti and returned to florida .
the first case in a patient with history of travel to dominican republic was laboratory confirmed on january 29 , 2011 .
as of april 4 , 2011 , a total of 23 cholera cases associated with the hispaniola epidemic had been confirmed ( figure 1 ) .
patients resided in florida ( 10 ) , massachusetts ( 4 ) , new york city ( 4 ) , kansas ( 1 ) , michigan ( 1 ) , north carolina ( 1 ) , virginia ( 1 ) , and texas ( 1 ) ( figure 2 ) .
illness onset dates ranged from october 23 , 2010 , to february 2 , 2011 .
median age was 38 years ( range 984 years ) , and 43% were female patients
. confirmed cholera cases ( n = 23 ) , by onset date and travel history , united states , october 21 , 2010february 4 , 2011 .
geographic distribution of cholera cases in the united states associated with hispaniola , october 21 , 2010april 4 , 2011 .
all patients were treated with antimicrobial agents , rehydration , or both ; 9 ( 39% ) were hospitalized , 6 ( 30% ) sought care at an emergency department , and none died .
six patients had illness onset before returning to the united states , 5 had illness onset on the day of return , and 12 had illness onset 111 days after return ( typical incubation period for cholera is 18 hours5 days ) ( 5 ) .
all 20 isolates matched the haiti isolate outbreak pattern by pulsed - field gel electrophoresis .
susceptibility results for antimicrobial drug tested showed that all isolates were resistant to trimethoprim / sulfamethoxazole , furazolidone , nalidixic acid , sulfisoxazole , and streptomycin , and 18 isolates showed intermediate resistance to chloramphenicol , ampicillin , or amoxicillin / clavulanic acid .
thirteen patients reported recent travel to haiti ( median length of stay 7 days , range 254 days ) and 9 to dominican republic ( median length of stay 4 days , range 29 days ) .
one patient reported no recent travel but consumed cooked conch brought to the united states from haiti by relatives .
travel was reported to the following departments in haiti : artibonite ( 2 ) , ouest ( 7 ) , centre ( 1 ) , nord ( 1 ) , and sud ( 1 ) .
one case - patient traveled to 2 departments , and 2 did not specify a destination .
all case - patients associated with the dominican republic had attended a wedding in la romana province on january 22 , 2010 ; an investigation conducted by the dominican republic ministry of health is ongoing . aside from 2 case - patients who traveled to this wedding together , no other case - patients reported traveling together .
visiting friends or relatives was the main reason for travel to haiti ( table 1 ) .
four patients traveled to haiti to participate in relief activities , 2 as medical volunteers , 1 on a mission trip , and 1 to distribute canned foods .
a wide range of exposures was reported ( table 2 ) ; 5 patients were exposed to persons with cholera or cholera - like illness and to other risk factors for cholera acquisition .
one volunteer reported no apparent lapses in safe water and food practices , although detailed information about food preparation was not available .
water exposures include local lake and stream of water running down a street in haiti ; a pool in the dominican republic ; ocean ( dominican republic ) ; unspecified location in port - au - prince , haiti ; and a tank at a medical center in haiti .
sources included newspaper articles ( 4 ) , friends ( 4 ) , cdc traveler s hotline ( 1 ) , and the world health organization website ( 1 ) ; 2 patients reported > 1 source .
two patients reported receiving a travel health alert notice upon arrival in the united states ( m. selent , unpub .
six months after the hispaniola cholera epidemic started in haiti , 23 associated cases were recognized in the united states .
all cases were associated with recent travel to hispaniola or with consumption of seafood from haiti .
the risk for cholera transmission in the united states is low because of improved water and sanitation , and there is no evidence of secondary transmission .
florida , new york , and massachusetts have the highest populations of persons of haitian or dominican ancestry ( 6 ) .
most cases were reported from florida , the state with the largest haitian population . however , case - patients also resided in states with small haitian and dominican populations .
travel between the united states and haiti is straightforward ; 4 us airports offer daily direct flights from florida and new york to port - au - prince .
many persons , including many of haitian descent , traveled from the united states to haiti to help with the response to the january 2010 earthquake in port - au - prince .
person - to - person transmission of cholera has only rarely been reported ; cases in medical workers are almost always attributable to consumption of contaminated food or water .
person - to - person transmission is not clearly supported for either of the cases we report in medical workers , although it can not be ruled out .
continued surveillance and detailed investigation of cases in medical workers is warranted to further define the risk , if any , of person - to - person transmission . echoing the latin american cholera epidemic in the 1990s ,
travelers to cholera - affected areas should be aware of the risk and should follow prevention measures to avoid infection
. in particular , travelers visiting friends or relatives may be at higher risk for travel - associated infection ( 7 ) .
few case - patients had received cholera prevention education ( educational materials available at www.cdc.gov/cholera/index.html ) ; no cholera vaccine is licensed in the united states . until cholera in haiti and dominican republic resolves
, clinicians , microbiologists , and public health workers in the united states should be prepared for more cases in travelers returning from hispaniola .
 cholera is rare in the united states ( annual average 6 cases ) . 
 since epidemic cholera began in hispaniola in 2010 , a total of 23 cholera cases caused by toxigenic vibrio cholerae o1 have been confirmed in the united states . 
 twenty - two case - patients reported travel to hispaniola and 1 reported consumption of seafood from haiti . 
The Study
Conclusions