Health

Mexico has some very fine hospitals that offer excellent care, and also for considerably less in terms of cost. Unless you plan to travel off the beaten track, for example, take jungle tours, or plan to travel in rural and/or remote areas of Mexico, or places that are not well established, the likelihood is, you won't need to immunize yourself.

All travelers should visit either their doctor or a travel health clinic 4-8 weeks before departure.

Summary of recommendations

Malaria:  Prophylaxis with chloroquine is recommended for rural areas in the states of Oaxaca, Chiapas, Sinaloa, Michoahan, Nayarit, Guerrero, Tabasco, Quintana Roo, and Campeche; for the mountainous northern areas of Jalisco; and for an area between 24 degrees N and 28 degrees N latitude and 106 degrees W and 110 degrees W longitude which includes parts of the states of Sonora, Chihuahua, and Durango. There is no malaria risk in the major resorts along the Pacific and Gulf Coasts or along the United States-Mexico border.

Vaccinations

Medications

Travelers' diarrhea is the most common travel-related ailment. The cornerstone of prevention is food and water precautions, as outlined below. All travelers should bring along an antibiotic and an antidiarrheal drug to be started promptly if significant diarrhea occurs, defined as three or more loose stools in an 8-hour period or five or more loose stools in a 24-hour period, especially if associated with nausea, vomiting, cramps, fever or blood in the stool. A quinolone antibiotic is usually prescribed: either ciprofloxacin (Cipro) (PDF) 500 mg twice daily or levofloxacin (Levaquin) (PDF) 500 mg once daily for a total of three days. Quinolones are generally well-tolerated, but occasionally cause sun sensitivity and should not be given to children, pregnant women, or anyone with a history of quinolone allergy. Alternative regimens include a three day course of rifaximin (Xifaxan) 200 mg three times daily or azithromycin (Zithromax) 500 mg once daily. Rifaximin should not be used by those with fever or bloody stools and is not approved for pregnant women or those under age 12. Azithromycin should be avoided in those allergic to erythromycin or related antibiotics. An antidiarrheal drug such as loperamide (Imodium) or diphenoxylate (Lomotil) should be taken as needed to slow the frequency of stools, but not enough to stop the bowel movements completely. Diphenoxylate (Lomotil) and loperamide (Imodium) should not be given to children under age two.

Most cases of travelers' diarrhea are mild and do not require either antibiotics or antidiarrheal drugs. Adequate fluid intake is essential.

If diarrhea is severe or bloody, or if fever occurs with shaking chills, or if abdominal pain becomes marked, or if diarrhea persists for more than 72 hours, medical attention should be sought.

Though effective, antibiotics are not recommended prophylactically (i.e. to prevent diarrhea before it occurs) because of the risk of adverse effects, though this approach may be warranted in special situations, such as immunocompromised travelers.

Malaria in Mexico: prophylaxis is recommended for rural areas (including resorts) in the states of Oaxaca, Chiapas, Sinaloa, Michoahan, Nayarit, Guerrero, Tabasco, Quintana Roo, and Campeche; for the mountainous northern areas of Jalisco; and for an area between 24 degrees N and 28 degrees N latitude and 106 degrees W and 110 degrees W longitude which includes parts of the states of Sonora, Chihuahua, and Durango. The drug of choice is choloroquine, taken once weekly in a dosage of 500 mg, starting one-to-two weeks before arrival and continuing through the trip and for four weeks after departure. Chloroquine may cause mild adverse reactions, including gastrointestinal disturbance, headache, dizziness, blurred vision, and itching, but severe reactions are uncommon. Insect protection measures are also essential for these areas.

There is no malaria risk in the major resorts along the Pacific and Gulf Coasts or along the United States-Mexico border.

Immunizations

The following are the recommended vaccinations for Mexico:

Measles vaccine is recommended for any traveler born after 1956 who does not have either a history of two documented measles immunizations or a blood test showing immunity. A measles outbreak was reported from Distrito Federal, Estado de Mexico, and Hidalgo in early 2004. Although measles immunization is usually begun at age 12 months, consider giving an initial dose of measles vaccine to children between the ages of 6 and 11 months who will be traveling to Mexico. Many adults who had only one vaccination show immunity when tested and do not need the second vaccination. Those born before 1957 are presumed to be immune to measles. Measles vaccine should not be given to pregnant or severely immunocompromised individuals.

Hepatitis A vaccine is recommended for all travelers over one year of age. It should be given at least two weeks (preferably four weeks or more) before departure. A booster should be given 6-12 months later to confer long-term immunity.

Travelers who are less than one year of age, are pregnant, or have less than two weeks before departure should receive a single intramuscular dose of gammaglobulin instead of vaccine.

Typhoid vaccine is recommended for all travelers. It is generally given in an oral form (Vivotif Berna) consisting of four capsules taken on alternate days until completed. The capsules should be kept refrigerated and taken with cool liquid. Side-effects are uncommon and may include abdominal discomfort, nausea, rash or hives. The alternative is an injectable polysaccharide vaccine, given as a single dose. Adverse reactions, which are uncommon, may include discomfort at the injection site, fever and headache. The oral vaccine is approved for travelers at least six years old, whereas the injectable vaccine is approved for those over age two. There are no data concerning the safety of typhoid vaccine during pregnancy. The injectable vaccine (Typhim Vi) is probably preferable to the oral vaccine in pregnant and immunocompromised travelers.

Hepatitis B vaccine is recommended for travelers who will have intimate contact with local residents or potentially need blood transfusions or injections while abroad, especially if visiting for more than six months. It is also recommended for all health care personnel. A full series consists of three intramuscular doses given at 0, 1 and 6 months. Engerix-B is also approved for administration at 0, 1, 2, and 12 months, which may be appropriate for travelers departing in less than 6 months. Side-effects are generally mild and may include discomfort at the injection site and low-grade fever. Severe allergic reactions (anaphylaxis) occur rarely.

Rabies vaccine is recommended only for those at high risk for animal bites, such as veterinarians and animal handlers, and for long-term travelers who may have contact with animals and may not have access to medical care. Most cases in Mexico are related to dog bites, but bats and other wild species remain important sources of infection. A complete preexposure series consists of three doses of vaccine injected into the deltoid muscle on days 0, 7, and 21 or 28. Side-effects may include pain at the injection site, headache, nausea, abdominal pain, muscle aches, dizziness, or allergic reactions.

Any animal bite or scratch should be thoroughly cleaned with large amounts of soap and water and local health authorities should be contacted immediately for possible post-exposure treatment, whether or not the person has been immunized against rabies.

All travelers should be up-to-date on routine immunizations, including

• Tetanus - Diphteria vaccine (recommended for all travelers who have not received a tetanus-diphtheria immunization within the last 10 years.)
• Varicella (chickenpox) vaccine (recommended for any international traveler over one year of age who does not have either a history of documented chickenpox or a blood test showing immunity. Many people who believe they never had chickenpox show immunity when tested and do not need the vaccine. Varicella vaccine should not be given to pregnant or immunocompromised individuals.)

Cholera vaccine is not recommended. Only one case of cholera was reported for the year 2001 and none for 2002.

Polio vaccine is not recommended for any adult traveler who completed the recommended childhood immunizations. Polio has been eradicated from the Americas, except for a small outbreak of vaccine-related poliomyelitis in the Dominican Republic and Haiti in late 2000.

Other infections

Gnathostomiasis has been reported in Acapulco and other parts of Mexico. The disease, which is caused by a helminth known as Gnathostoma spinigerum, is usually acquired by eating raw or undercooked freshwater fish, including ceviche, a popular lime-marinated fish salad. The chief symptom is intermittent, migratory swellings under the skin, sometimes associated with joint pains, muscle pains, or gastrointestinal symptoms. The symptoms may not begin until many months after exposure.

Rubella (German measles) infections were reported in elevated frequency from Chihuahua and Tamaulipas states, across the border from Texas, in 1998. Rubella may cause birth defects and miscarriages if acquired by pregnant women. Rubella vaccine, which is included among routine childhood immunizations, is thought to provide lifelong immunity. A booster is not generally recommended for anyone immunized as a child. Pregnant women should have a blood test to confirm that they're immune.

HIV (human immunodeficiency virus) infection is reported, but travelers are not at risk unless they have unprotected sexual contacts or receive injections or blood transfusions.

Food and water precautions

Do not drink tap water unless it has been boiled, filtered, or chemically disinfected. Do not drink unbottled beverages or drinks with ice. Do not eat fruits or vegetables unless they have been peeled or cooked. Avoid cooked foods that are no longer piping hot. Cooked foods that have been left at room temperature are particularly hazardous. Avoid unpasteurized milk and any products that might have been made from unpasteurized milk, such as ice cream. Avoid food and beverages obtained from street vendors. Do not eat raw or undercooked meat or fish, including ceviche. Some types of fish may contain poisonous biotoxins even when cooked. Barracuda in particular should never be eaten. Other fish that may contain toxins include red snapper, grouper, amberjack, and sea bass.

All travelers should bring along an antibiotic and an antidiarrheal drug to be started promptly if significant diarrhea occurs, defined as three or more loose stools in an 8-hour period or five or more loose stools in a 24-hour period, especially if accompanied by nausea, vomiting, cramps, fever or blood in the stool. Antibiotics which have been shown to be effective include ciprofloxacin (Cipro), levofloxacin (Levaquin), rifaximin (Xifaxan) or azithromycin (Zithromax). Either loperamide (Imodium) or diphenoxylate (Lomotil) should be taken in addition to the antibiotic to reduce diarrhea and prevent dehydration.

If diarrhea is severe or bloody, or if fever occurs with shaking chills, or if abdominal pain becomes marked, or if diarrhea persists for more than 72 hours, medical attention should be sought.

Insect and tick protection

Wear long sleeves, long pants, hats and shoes (rather than sandals). For rural and forested areas, boots are preferable, with pants tucked in, to prevent tick bites. Apply insect repellents containing 20-35% DEET (N,N-diethyl-3-methylbenzamide) or 20% picaridin (Bayrepel) to exposed skin (but not to the eyes, mouth, or open wounds). DEET may also be applied to clothing. Products with a lower concentration of either repellent need to be repplied more frequently. Products with a higher concentration of DEET carry an increased risk of neurologic toxicity, especially in children, without any additional benefit. Do not use either DEET or picaridin on children less than two years of age.

For additional protection, apply permethrin-containing compounds to clothing, shoes, and bed nets. Permethrin-treated clothing appears to have little toxicity. Don't sleep with the window open unless there is a screen. If sleeping outdoors or in an accomodation that allows entry of mosquitoes, use a bed net, preferably impregnated with insect repellent, with edges tucked in under the mattress. The mesh size should be less than 1.5 mm. If the sleeping area is not otherwise protected, use a mosquito coil, which fills the room with insecticide through the night. In rural or forested areas, perform a thorough tick check at the end of each day with the assistance of a friend or a full-length mirror.

Ticks should be removed with tweezers, grasping the tick by the head. Many tick-borne illnesses can be prevented by prompt tick removal.

Pollution

Air pollution in Mexico City and Guadelajara may be severe, especially from December to May. Air pollution reached unacceptable levels in Mexico City in 1998 due to smoke from forest fires in southern Mexico and low rainfall. Travelers with respiratory or cardiac conditions and those who are elderly or extremely young are at greatest risk for complications from air pollution, which may include cough, difficulty breathing, wheezing, or chest pain. The risk may be minimized by staying indoors, avoiding outdoor exercise, and drinking plenty of fluids.

General advice

Bring adequate supplies of all medications in their original containers, clearly labeled. Carry a signed, dated letter from the primary physician describing all medical conditions and listing all medications, including generic names. If carrying syringes or needles, be sure to carry a physician's letter documenting their medical necessity. Pack all medications in hand luggage. Carry a duplicate supply in the checked luggage. If you wear glasses or contacts, bring an extra pair. If you have significant allergies or chronic medical problems, wear a medical alert bracelet.

Make sure your health insurance covers you for medical expenses abroad. If not, supplemental insurance for overseas coverage, including possible evacuation, should be seriously considered. If illness occurs while abroad, medical expenses including evacuation may run to tens of thousands of dollars. Bring your insurance card, claim forms, and any other relevant insurance documents. Before departure, determine whether your insurance plan will make payments directly to providers or reimburse you later for overseas health expenditures.

Pack a personal medical kit, customized for your trip (see description). Take appropriate measures to prevent motion sickness and jet lag, discussed elsewhere. On long flights, be sure to walk around the cabin, contract your leg muscles periodically, and drink plenty of fluids to prevent blood clots in the legs. For those at high risk for blood clots, consider wearing compression stockings.

Avoid contact with stray dogs and other animals. If an animal bites or scratches you, clean the wound with large amounts of soap and water and contact local health authorities immediately. Wear sun block regularly when needed. Use condoms for all sexual encounters. Ride only in motor vehicles with seat belts. Do not ride on motorcycles.