Nations need common rules for responding to flu outbreaks to prevent discrimination and unfair trade restrictions, Mexico's U.N. envoy said today, complaining that Mexican citizens and exports were being unfairly singled out, according to AP. Some countries have «developed some attitudes which I will straightforward qualify as discriminatory against Mexicans,» Luis Alfonso De Alba said. The World Health Organization is compiling reports on what measures countries are taking, and what justification they are giving, said spokesman Gregory Hartl. These reports are provided to other countries, he said, but there are no plans to make them publicly available. Mexico will press for a debate on the issue when the World Health Organization's 193 member countries hold their annual meeting starting May 18, De Alba told reporters at U.N. headquarters in Geneva. «Nobody intends to limit the sovereignty of the state, but at the same time we need to be certain that there are common understandings of what are justifiable measures,» he said. Mexico has complained that its citizens and exports are being shunned by some countries, such as China, that are fearful about the spread of the swine flu virus, even though cases have been reported in 25 nations, including the United States, Canada and Spain. Brazil became the latest country to acknowledge the presence of the disease Friday, when it formally declared four cases to WHO. China has quarantined travelers from Mexico and Canada, and imposed a ban on pork imports from North America. Beijing defends the steps as necessary to block swine flu from entering the world's most populous nation. At least 15 other countries have restricted imports of pork or pork products from affected nations, drawing angry responses from pig farmers who say the animals are not to blame for the outbreak. Mexico on Tuesday sent a letter to all members of the 153-nation World Trade Organization, urging its trading partners to «withdraw any restrictive measure imposed on Mexican products that is not consistent with the scientific information available.» Singapore is now requiring that Mexican nationals get visas and that travelers arriving from Mexico be confined for seven days on arrival. No such rules apply to the U.S., which has the second highest number of cases. Some European governments have been telling their citizens to delay nonessential travel to Mexico without making similar recommendations for the United States or Canada. «Having a Mexican passport has become a problem,» De Alba said. Misleading media reporting of the outbreak was partly to blame, he added, citing a trailer for a Swiss television program that showed a man in traditional Mexican dress wearing a face mask. «It hurts very much the self-esteem of a country,» De Alba said. The U.N.'s human rights office in Geneva weighed in on the issue as well Friday. «No one should be put in quarantine solely on the basis of their nationality,» spokesman Rupert Colville said. «That would be an unacceptable and clear-cut case of discrimination with tangible negative effects on the rights of the person in question.» The World Health Organization has spoken out against travel restrictions, saying there is no scientific justification for them at this point. In its latest update on the outbreak Friday, WHO said there have been some 2,500 confirmed human cases of swine flu. Mexico accounts for about half of all cases, and all but two of 44 confirmed deaths.