Cruise ships carry thousands of passengers to ports in Mexico each week. With the deadly swine flu outbreak in that country and the Center for Disease Control’s new Mexico travel warning, many cruise lines are now modifying itineraries that include port calls in Mexico. Changes have been occuring constantly over the last day and port cancellations are beginning to take place.

Late yesterday evening, the Centers for Disease Control and Prevention (CDC) issued a travel warning for Mexico due to swine flu. The website states, "At this time, CDC recommends that U.S. travelers avoid all nonessential travel to Mexico." The United Kingdom Foreign & Commonwealth Office is recommending that its citizens avoid all nonessential travel to Mexico as well.

Yesterday, before the new CDC alert, both Carnival Cruise Lines and Royal Caribbean International stated that they were monitoring the situation, but neither planned to alter their sailings or cancel ports of call in Mexico. Royal Caribbean indicated that higher levels of sanitizing would take place on its ship and additional policies would be put in place to stop the potential spread of the illness.

Carnival issued their own statement, saying, "We do not anticipate that our guests' cruise experience will be impacted by this type of illness and will not be making any adjustments to our itineraries." Both Carnival and Royal Caribbean were not permitting Mexico cruise cancellations to be made without penalty.

Things have changed rapidly today, however. As of late this afternoon, both Carnival and Royal Caribbean suspended all calls at Mexico ports. Carnival's decision will affect 15 of its 22 ships. Princess and Holland America have also cancelled their visits to ports in Mexico. Links to cruise line updates and swine flu information are provided below. Check with your travel agent or the cruise line for further details, as this situation is constantly in flux.

Several Alabama media outlets have reported that federal agents in Mobile will be meeting a Carnival cruise ship returning from Mexico on Thursday of this week to check arriving passengers for signs of swine flu.

If you are booked on a cruise to Mexico and have purchased travel insurance, check with your insurance provider to see if you are covered. Calls to TravelGuard today indicated that the insurer was not currently covering policyholders for Mexico travel cancellations, even in light of the current CDC warning against nonessential travel. The TravelGuard representative indicated that the company does not cover against government warnings against travel or fears about traveling to a particular country. If travelers became ill before leaving or came down with the flu or were quarantined during travel, however, those costs would be covered. Flight cancellations are generally covered as well.

Most, if not all, airlines are waiving re-booking fees for passengers traveling to Mexico, but that doesn't help cruise line passengers as ships leave from domestic ports. In light of these relaxed airline policies, however, some cruise passengers are wondering why cruise lines aren't amending their cancellation rules as well. These changes are now beginning to take place. If you're booked on a Mexico cruise, it's important to check with your travel agent and stay informed.

Here are the latest updates:

UPDATE: 4/28 5:15 p.m. - Holland America has cancelled all calls to Mexican ports in April and early May. http://www.hollandamerica.com/news/Main.action?tabName=Travel+Advisories

UPDATE: 4/28 6:15 p.m. - Carnival has cancelled all calls to Mexican ports for all current sailings and all sailings departing on April 30th through May 4th. Continue to check back for futher updates on this situation. For more information, visit: http://www.carnival.com/cms/fun/cruise_control/Travel_Advisory.aspx?cid=So_Twitter_103

UPDATE: 4/28 6:35 p.m. - Royal Caribbean International and Celebrity Cruises have temporarily halted all port calls in Mexico. No date for resuming Mexico calls has been provided. Visit www.royalcaribbean.com and www.celebrity.com for more information and contact your travel agent for further details.

UPDATE: 4/28 9:40 p.m. - NCL has cancelled the Norwegian Pearl's Mexico calls this week. The cruise line will not be visiting Mexico again until late September.

UPDATE: 4/28 9:55 p.m. - Royal Caribbean has released itinerary updates for its ships affected by the suspension of Mexico ports of call. Make sure to fill out the form to get updates for your sailing: http://www.royalcaribbean.com/beforeyouboard/itineraryUpdates.do.

UPDATE: 4/28 10:10 p.m. - Fred. Olsen Cruise Lines cancels its Mexico call next week: http://www.fredolsencruises.com/news/fred-olsen-cancels-call-into-mexico

UPDATE: 4/28 10:40 p.m. - Princess cancels stops at all Mexico ports of call. Six Princess ships (8 itineraries, 22 calls) are affected: http://www.princess.com/news/article.jsp?newsArticleId=na1010

Here are some good resources for cruise passengers and travelers interested in more information on the swine flu:

Centers for Disease Control and Prevention (CDC): www.cdc.gov

World Health Organization: http://www.who.int/csr/disease/swineflu/en/index.html

US Department of State: http://www.travel.state.gov

Basic Information About The Swine Flu (NPR): http://www.npr.org/templates/story/story.php?storyId=103506962

Swine Flu Q&A (USA TODAY): http://www.usatoday.com/news/health/2009-04-26-swine-flu-questions-answers_N.htm

Swine Flu Precautions: http://www.cnn.com/2009/HEALTH/04/26/swin.flu.risks/index.html

Carnival Cruise Lines: www.carnival.com

Royal Caribbean International: www.royalcaribbean.com

Holland America Line: www.hollandamerica.com

Princess Cruises: www.princess.com

Cruise Lines International Association (CLIA): www.cruising.org