NATIONAL CITY (CNS) - Public health officials from both sides of the border Friday signed an agreement for a joint effort to battle tuberculosis.

Nearly one third of San Diego County's TB patients have ties to Baja California, according to the county Health and Human Services Agency. In 2014, the HHSA reported 220 cases of the disease.

This comes as the annual number of cases in the region has dropped by around half over the past 20 years.

The HHSA says that, despite the reduction, the illness is more prevalent along the border than in other areas of California or Mexico. The San Diego rate is twice the national average, according to the agency.

The agreement by health officials from San Diego and Imperial counties formalizes a comprehensive strategy to combat TB along the border, with help from counterparts in Baja California. As part of the agreement, participants will receive referrals, lend technical support, accept lab specimens and assist with investigations.

The counties of San Diego and Imperial, the state of Baja California and the nonprofits International Community Foundation and Puentes de Esperanza Contra Tuberculosis, A.C., signed the deal.

"We live in a border region where thousands of people cross back and forth on a daily basis," said Dr. Wilma Wooten, San Diego County's public health officer. "In order to prevent and control the spread of tuberculosis, we must address this issue together."

Symptoms of active TB include persistent cough, fever, night sweats and unexplained weight loss, according to Wooten. She said most people who are exposed to TB do not develop the disease, but when it does occur, it can be treated and cured with medication.