MEXICO CITY - Much of Mexico has relaxed after swine flu first unleashed a wave of panic here and across the world three months ago, but cases are now soaring in the country's impoverished southeast.

Authorities insist that A(H1N1) is under control, despite a peak in Chiapas -- an area with poor indigenous communities, popular tourist sites, and heavy traffic of Central American immigrants heading to the United States.

Scientists have now identified the first known case as a female baby who tested positive on February 24 and survived. The girl from San Luis Potosi state in north Mexico had no known contact with pig farms.

Mexico is well placed to handle a rise in cases expected to coincide with colder temperatures from November, officials say.

"What could have been a disadvantage by being the first is now a strategic advantage, because now we know what to do (and) how to do it," government advisor and doctor Pablo Kuri told AFP.

The government is currently carrying out targeted health campaigns in the worst-affected areas.

Eight of the last 10 deaths -- bringing Mexico's total to 138 -- were in Chiapas, which has the country's highest caseload out of some 14,800 reported nationwide.

The situation in Chiapas is out of control, with between 100 and 130 cases reported daily, the federal health ministry said this month.

Local authorities have played down the situation, however, and have yet to clamp down on public gatherings as in other areas.

Initial panic in April led to strict measures, including shuttered schools, restaurants, tourist sites and sports venues in the sprawling capital.

Scientists now say that a handful of cases first appeared in northern and central Mexico in March, before the virus peaked in April.

"It's complicated to say where it originated but the earlier samples are not from rural areas," Celia Alpuche, head of the Institute of Epidemiological Diagnosis and Reference (INDRE), told AFP.

The economy -- already battered by the crisis in Mexico's main trading partner the United States -- was expected to show a big hit when figures take the outbreak into account. GDP already fell 8.2 percent in the first quarter.

The A(H1N1) outbreak hobbled tourism, which provides the country's third source of foreign income after oil and remittances. Authorities in May launched a multi-million-dollar campaign to bring tourists back.

After a virtual shutdown in parts of the country in April, few reminders of the disease are now apparent.

A handful wear surgical face masks while body thermometers and simple health questionnaires have joined other checks at airports.

The country of more than 100 million people has two million doses of Tamiflu in reserve and has ordered 20 million vaccines, if they are ready, to begin delivery in December, according to the health ministry.

Vaccination against seasonal flu will start for at risk groups on October 5.

A laboratory near Mexico City is meanwhile studying nationwide samples to identify the prevalence of virus and the biggest risk areas.

"It's very important to finish this study before the fall," Alpuche said.

Public awareness campaigns are due to return in October as a reminder that the flu has not disappeared.

"I think there are areas that have returned to completely normal life and you have to remind people that the new normality needs to include new habits" such as frequent hand washing, Kuri said.

But he added: "People can't live in a permanent state of stress."