Mosquitoes
Alike the rest of West Indies, mosquitoes are present in Martinique, especially during rainy periods. They may transmit nasty diseases such as dengue, chikungunya or zika, for which there is no exiting vaccine. Therefore, mosquito repellent, plug-in and burning coil devices repelling mosquitoes are strongly advised. While purchasing a repellent for mosquitoes or ticks, only chose products containing one of the following active agents : 20% or more DEET for protection against mosquitoes and ticks, so it will last several hours ; for mosquitoes repellent make sure they contain DEET, picaridin (also known as KBR 3023, Bayrepel and icaridin), oil of lemon eucalyptus (OLE or PMD) or IR3535.
Vaccines
Two vaccines are recommended of you are traveling to Martinique : typhoid and hepatitis A, which you can get through contaminated water or food, regardless where you are staying. Typhoid vaccine is particularly important if you plan on going to small villages or rural areas, or if you are an adventurous eater.
Rabies is present in bats in Martinique. However, it is not a major risk to most traveler. Vaccine is recommended for travelers involved in activities that put them at risk of bat bites (caving), and for people who will be working with or around bats. Yellow fever is not present in Martinique, therefore you don’t need a vaccine.
Animals
There are no dangerous animals in Martinique, except the rare fer-de-lance snake. If you notice trees marked with a red paint, it is Manchineel tree, which green berries are very toxic : you should never stand under one in the rain or eat its berries. Thus, the most common danger for travelers may be the sun, in the case of overexposure.
Water Animals
While swimming in the turquoise waters of Martinique, watch out for sea urchins, jellyfishes and sharp coral. Wearing fins or waterproof sandals is usually an answer to those dangers. Swim only in designated areas, and obey warning flags and lifeguards on beaches. Avoid swallowing water when swimming, cause it may carry germs that can make you sick. Do not swim in freshwater in developing areas or where sanitation is poor. Schistosomiasis is a parasitic infection that can be spread in fresh water and that is present in Martinique. Thus, it is advised not to swim in fresh, unchlorinated water, such as lakes, ponds or rivers.
Safety
Martinique does not have history of unsafety. In Fort-de-France, video cameras as well as an increased police presence have helped reduce the crime rate. However, you should keep the same safety precautions you would exercise in any large city : never leave jewelry, money nor any valuables unattended on the beach or in your car, put valuables in safes, and preferably, if you go downtown by night, be accompanied.
If you are a US citizen, you may enroll in the Smart Traveler Enrollment Program, allowing travelers to enroll their trip with the nearest US Embassy or Consulate. It is also advised to leave a copy of your passport, credit cards, contact information and itinerary with someone at home, or to email it to yourself. While in Martinique, it is better to leave your real passport at the place where you are staying at.