Unless it is contained shortly, the Mexican swine flu outbreak that is sounding alarm bells across the world is likely to have long-term economic, law enforcement and political consequences on both sides of the U.S.-Mexican border.

Let’s start with the bad news.

• An extended swine flu will probably prolong the global recession. While most economists predict the recession may hit bottom late this year or early next year, a major reduction in world tourism, food and transportation industries could postpone the recovery.

The World Bank estimated last year that a flu pandemic could cause a 5 percent drop in world gross domestic product. The 2003 outbreak of severe acute respiratory syndrome (SARS) cost Asian countries an estimated $40 billion in tourism and trade revenues, it said.

• It will deepen Mexico’s economic downturn. Greater Mexico City, which accounts for more than 20 percent of the country’s economy, was virtually shut down this week as the city government ordered restaurants, movie theaters and other public places to suspend their activities until May 6. Meantime, U.S., European and other countries’ travel advisories asking their citizens to avoid nonessential travel to Mexico will affect Mexico’s $13.3 billion annual tourism industry, the country’s third-largest source of income after oil and family remittances.

On Wednesday, J.P. Morgan analyst Ben M. Laidler told me that, as a consequence of the swine flu outbreak, his research team may revise its economic projections for Mexico downward, from a 4 percent decline to a 4.5 percent decline this year.

• It will increase Mexican migration pressures. While a Homeland Security Department report two months ago said the number of undocumented Mexican migrants is declining for the first time in at least four years because of the U.S. recession, a serious economic downturn in Mexico is likely to drive the numbers of migrants up. Mexico’s economy needs to grow by about 5 percent a year to accommodate the nearly one million young people who join the labor force every year, and — if the economy contracts by 4.5 percent — it would not be farfetched to assume that more young Mexicans will seek better opportunities across the U.S. border.

• It will complicate President Barack Obama’s plans to pass a comprehensive U.S. immigration reform plan this year. The swine flu crisis will intensify pressures from anti-immigration groups to close the border, which may make it more difficult for U.S. legislators to vote for a bill that would include a path to citizenship for millions of undocumented migrants.

Already, conservative radio and cable television talking heads are blaming the swine flu cases in the United States on “illegal aliens,” despite the fact that most U.S. victims appear to be American tourists who returned from visits to Mexico.

• It will slow Mexico’s battle against drug cartel violence, which has caused more than 10,000 deaths in Mexico over the past two years, and has begun to spread across the border. Senior Mexican officials tell me that, since last Thursday, President Felipe Calderon’s Cabinet has been devoting 95 percent of its time to the swine flu crisis. The president’s daily meetings with his Cabinet’s anti-drug national security team have been temporarily suspended, and troops in Mexico City have been deployed to give out face masks on the streets.

The good news is that the Mexican government and Mexico City authorities are attacking the problem head on, international health officials tell me. Contrary to China’s slow and secretive response to the SARS crisis in 2002 — the Chinese government took four months, until February 2003, to openly admit the crisis — Mexico launched an aggressive education and mask distribution campaign last Friday, about six weeks after the first case was reported.

“We know that this is going to hurt us badly in the short term, but we want to focus on the medium and long term,” Rafael Fernandez de Castro, Calderon’s top foreign relations adviser, told me Wednesday. “In the medium term, we may actually come out strengthened from this crisis. This is an opportunity to show a transparent Mexico, a country that is trustworthy.”

My opinion: The Mexican government may have been slow to detect the crisis, but it is responding at full speed now. The U.S. government and international financial institutions should give the country all the help it needs. Otherwise, the economic and social consequences of this outbreak will reach far beyond the relatively small number of swine flu victims.

— Andres Oppenheimer is a Latin America correspondent for the Miami Herald.