For questions concerning disease risk in Haiti there are many great resources. International Association for Medical Assistance to Travelers (IAMAT), has non-government sourced information on local disease risk. Their Haiti specific page for disease risk: http://iamat.org/country_profile.cfm?id=48.
You need immunization against tetanus, diphtheria, and pertussis which consists of a primary series plus booster within the last ten years. Similarly, you should be immunized against measles, mumps and rubella. Obtain a current seasonal influenza immunization. You should have two varicella doses if you were born after 1979.
Specific to your trip to Haiti you should have a typhoid immunization. There are two preparations available in the US: an oral and an injectable form. The injectable consists of one shot which requires boosting every two years. The oral form consists of 4 capsules taken every other day. This form of immunization will need boosting in 5 years. Both forms of typhoid protection should be completed at least 10 days before departure.
As medical students and professionals you should have received your hepatitis B series. If not at least get started with your first, and preferably your second, in the series before your trip. This is a three shot series that lasts many years. The normal sequence is received at 0, 1 month, 6 months.
Everyone going should have a hepatitis A immunization. This is a shot that can be taken almost as you walk out the door and it will be effective. The full series is two shots taken 6 months apart, but at least the first shot needs to be taken before your trip.
In select locations, such as Canada, there is an oral immunization against cholera (Dukoral). This is unavailable in the United States, however, Vaxchora is now available in the US. When traveling in Haiti you should have access to rehydration salts and azithromycin, which we will carry in our medical kits. One may consider taking doxycycline as a prophylactic. This can also be used as a malaria prophylaxis taken 1 day before going, daily while there, and daily for 4 weeks after leaving. Our advice is use the chloroquine for the malaria and to just take doxycycline while there and maybe three days afterwards to help prevent cholera when working in the cholera treatment units or centers.
Malaria prophylaxis. You should all start chloroquine 500 mg weekly at least two weeks before you depart, weekly while in Haiti, and for four weeks after departing. One hundred percent of the malaria in this country is P falciparum, the most deadly form. Transmission occurs throughout the year with peaks of incidence November through January and May through July.
Dengue fever and chikungunya virus is a significant risk in urban and rural areas. The only preventative is mosquito protection. Learn more about Dengue fever here.
It is mandatory that you treat your clothing with permethrin prior to the trip. Please see our suggestions on clothing treatment and skin protection.
Tuberculosis is a common disease with an incidence of over 100 cases per 100,000 population, the highest risk category. As members of the health care community, you should have yearly TB screens.