Free recycling classes
Registration today, 7-8 a.m. or with Gabriela Rodríguez or Nancy Valverde at 2257-4250, 2221-0123, corredorbiologico@ice.co.cr.

Little Theatre Group open house
Special EGM and preview Nunsense (musical comedy) in English, Aug. 4, 7 p.m., Laurence Olivier Theater, next to Sala Garbo, Av. 2, Ca. 28, 8355-1623, www.littletheatregroup.org.

Santos y Zurdo in concert
Electronic, world, rock, 10 p.m., Jazz Café, San Pedro. http://jazzcafecostarica.com/agenda.php.

Expresso in concert
Pop, 10 p.m., Jazz Café, Escazú.

Drivers heading to Costa Rica's northwest Guanacaste province hit a roadblock this weekend that could persist through tomorrow. Road authorities closed a bridge on the Inter-American Highway North Saturday after it cracked, according to the Public Works and Transport Ministry (MOPT).

The bridge crosses the Guacimal River at Kilometer 145, between Puntarenas and Guanacaste, the daily Al Día reported.

MOPT spokesman Omar Segura said the transport authorities today will offer more information on the closure and alternate routes.

Al Día reported that possible alternatives include the Paquera and Playa Naranjo ferries across the Gulf of Nicoya; up toward Tilarán, Guanacaste, through San Ramón and around Lake Arenal; or the route to Upala, a town near the northern border in the Alajuela province, to connect to La Cruz, Guanacaste.

A massive fire blazed through the night and into the morning Friday in Nicaragua's largest market.

Authorities are investigating the cause of the fire, which burned as many as four blocks of the sprawling Oriental market in Managua, said to be Central America's largest open-air market.

Burning thousands of shops, the blaze put a damper on Managua's celebrations of the capital's patron saint, Santo Domingo de Guzmán.

Police Chief Aminta Granera told TV Channel 2 the fire was controlled as of mid-day Friday after burning for 14 hours with a thick gray plume of smoke over Managua.

MEXICO CITY – More than 25,000 people from around the world have descended on Mexico's sprawling urban capital this week to participate in the 17th International AIDS Conference, which has brought together leading researchers, activists and health and development experts.

The world conference, the first of its kind to be held in Latin America, was inaugurated yesterday afternoon and will run throughout the week, featuring presentations and speeches by participants from 188 countries.

Despite some heartening advances in treatment coverage for people living with HIV/AIDS, and a 10 percent global decrease in new infections last year, this week's conference is expected to focus on several emerging challenges that could threaten recent progress. Those challenges include a resurgence in HIV infection rates among gay men, the threat posed by a mutated and transmittable version of the HIV virus that is resistant to drug treatment, and other obstacles associated with providing universal coverage and treatment by 2010 – an internationally agreed-on goal that appears increasingly lofty.

Since first being discovered in the early 1980s, HIV has infected 58 million people, and AIDS has killed 25 million.

Craig McClure, executive director of the International AIDS Society, the group responsible for organizing the conference, says he expects the event to focus on human-rights promotion, treatment, prevention and the strengthening of health systems.

Some of the more contentious topics that will be addressed are male circumcision as a useful prevention measure, the future of a possible HIV vaccine and using antiretroviral drug treatment to prevent the virus' transmission.

One of the most controversial issues is expected to be the claim made earlier this year by the Swiss AIDS Commission that people with HIV who are being treated with antiretrovirals, to the point that they now have an undetectable viral load, are no longer able to transmit the virus to others. The claim has caused great concern and criticism in the international AIDS community, where many argue it is unwise and counterproductive to green-light unsafe sex practices after years of preaching protection.

An average of 6,800 people are infected every day with HIV, though drugs have proved effective in controlling the virus and preventing it from progressing to AIDS.

To date, no vaccine for the virus has been found.