Washington - Trachoma has been eliminated as a public health problem in Mexico, the World Health Organization (WHO) announced this week. Mexico becomes the first country in the Americas and the third in the world after Oman and Morocco to receive validation from WHO for having eliminated this disease.

Trachoma is the leading infectious cause of blindness worldwide. It is transmitted by contact with bacteria in the eye and nasal discharges of infected persons, especially young children. It affects poor, isolated populations in 41 countries around the world. In the Americas, trachoma is still endemic in Brazil, Guatemala, and Colombia.

"Mexico has managed to eliminate trachoma as a public health problem," said WHO Director-General Margaret Chan in a letter to the Mexican Government congratulating the country on the achievement. WHO's conclusion is "based on the data presented in the country record and on the recommendation of the review group of independent experts which visited the country last November, she added.

"This is a historic moment for public health in Mexico and the Americas," said Carissa F. Etienne, Director of the Pan American Health Organization (PAHO), WHO regional office for the Americas. "Eliminating a disease is not achieved every day," she said, acknowledging "the decades-long efforts of Mexican authorities, health workers and communities to improve their health and quality of life, and end this disease of poverty."

In Mexico, the disease has been endemic in 246 communities in five municipalities in the state of Chiapas, affecting a total of 146,207 people. Actions to combat trachoma were strengthened in 2004 with the creation of the Trachoma Prevention and Control Program of the Ministry of Health of Chiapas and the strengthening of the WHO SAFE strategy.

This strategy consists of a comprehensive package of interventions including surgery for advanced disease, antibiotics to clear C. trachomatis infection, facial cleanliness and environmental improvement to reduce transmission.

The Trachoma Brigades, a group of doctors, nurses and specially trained technical personnel to combat trachoma, worked locally to reduce the number of cases from 1,794 in 2004 to zero cases in 2016, according to data from the Chiapas Trachoma Prevention and Control Program.

Using this approach, the country met the international criteria for elimination of trachoma as a public health problem, which are: Prevalence of less than 5 percent in children aged 1 to 9, and less than one case of trachomatous trichiasis (inverted eyelashes) per 1,000 inhabitants.

In 2012, there were only thirty-six cases of infection among children from 1 to 9 years of age (less than 5 percent) and less than 1 case of trachomatous trichiasis per 1,000 inhabitants. These numbers met the international criteria for elimination of trachoma as a public health problem.

The Secretary of Health of Mexico, Jose Narro, said he was excited at the achievement of elimination. The accomplishment, he said, was due to "A long history of hard work and efforts by many persons, over the course of generations."

To maintain elimination and prevent a resurgence of the disease, PAHO / WHO recommends continuous monitoring of trachoma and delivery of care to affected patients.

To date, five other countries (China, Gambia, Ghana, Iran and Myanmar) have reported on the achievement of elimination targets. Most countries with trachoma are using the SAFE strategy to eliminate the disease by 2020. In 2015, more than 185,000 people with trichiasis received corrective surgery worldwide, and 56 million were treated with antibiotics for trachoma.

This elimination in Mexico adds to another important achievement reached by the country in 2015, when it received the verification of the elimination of onchocerciasis from WHO. Onchocerciasis is a parasitic disease that can also cause blindness and disability and, like trachoma, mainly affects people living in poverty.