The World Health Organization (WHO) on Monday raised the pandemic swine flu alert level from phase 3 to 4, two levels below the declaration of a full pandemic. The elevated alert means there has been sustained human-to-human transmission of the new A/H1N1 swine flu virus and that scientists now believe government efforts should focus on slowing the spread of the virus rather than containing it at its source.
"We have taken a step in that direction, but a pandemic is not considered inevitable," said Keiji Fukuda, the WHO's interim director-general for health, safety and environment. "The situation is fluid and continues to evolve."
Hoping for Help
Lazaro Gonzalez, 40, wears a protective mask as he waits for passersby to donate money to him. Health experts said the virus comes from the same strain that causes seasonal outbreaks in humans. But they claim this newly-detected version contains genetic material from versions of flu which usually affect pigs and birds.
In Sickness and In Health
Erika Cruz, left, helps her husband Miguel Anguel Esquivel walk toward the emergency entrance of Mexico City's National Institute of Respiratory Illnesses. Esquivel was grunting, sweating and wearing tissue paper in his ears as the couple hurried to the hospital with him showing symptoms of the influenza virus that has plagued the city.
Taking Cover
A soldier hands out masks in central Mexico City. The E.U.'s health commissioner urged Europeans on Monday to postpone non-essential travel to Mexico and the U.S. The illness has claimed at least 152 lives, confined hundreds to hospital and brought Mexico City, one of the world's largest cities, to a virtual standstill.
The Mask of Mexico
A Mexican policeman patrols Mexico City's historic Zocalo square. José Ángel Córdova, the Mexican health secretary, said suspected swine flu cases in his country had risen to 1,614.
Quick Embrace
A couple attempts to kiss. Across Mexico more than 1,300 people were tested for suspected swine flu infection and 400 were taken to hospital for checks. Health officials believe that tens of thousands, and possibly more, have been infected but have since recovered.
Fears of a Clown
A clown wears a surgical mask as a precaution against infection. "[We are] monitoring, minute by minute, the evolution of this problem across the whole country," said the Mexican president, Felipe Calderón. The World Bank approved $205m in loans Sunday to fight the outbreak in Mexico.
Praying for Better Times
People wearing protective masks pay respects to Our Lady of Guadalupe as they passed Guadalupe's shrine at the Basilica de Guadalupe. Mexico's biggest Catholic church was shut down and masses canceled as a precaution to keep large crowds away. Many public buildings, including schools, have also been closed.
