Cameron County outbreak of bacteria common during war time a mystery

BROWNSVILLE - The origin of drug-resistant bacteria's recent outbreak at Cameron County hospitals is stumping health officials.

Similar outbreaks of the opportunistic Acinetobacter baumannii have been possibly linked to war veterans.

But Dr. Brian Smith of the Texas Department of State Health Services said Friday that the source of the local AB outbreaks was still unknown. And while U.S. Center for Disease Control and Prevention studies suggests the bacteria could be linked to war veterans, there is no evidence that the local outbreak could have originated from a military veteran who served in Iraq or Afghanistan, Smith said.

In an article published in March by Drs. L. Silvia Muñoz-Price and Robert A. Weinstein in the New England Journal of Medicine, it is noted that AB infections have long been prominent in tropical countries, have been a recurrent problem during wars and natural disasters and have recently caused multi-hospital outbreaks in temperate climates.

AB causes a variety of diseases, ranging from pneumonia to serious blood or wound infections, according to the CDC. It may also "colonize" or live in a patient without causing infection or symptoms, typically occurring in very ill patients and either causing or contributing to death.

It can live on the skin and may survive in the environment for several days. Careful attention to infection control procedures such as keeping hands and common areas clean can reduce risk of transmission, CDC reported.

"Most alarming are the organism's ability to accumulate diverse mechanisms of resistance, the emergence of strains that are resistant to all commercially available antibiotics, and the lack of new antimicrobial agents in development," the New England article stated.

In November 2004, the CDC reported on AB infections at military medical facilities that treated service members from 2002 through 2004. Those patients were injured during Operation Iraqi Freedom or in Operation Enduring Freedom in Afghanistan.

Military health officials identified 102 patients with the bacteria at those military medical facilities between Jan. 1, 2002, and Aug. 31, 2004. Of these cases, 83 percent were associated with activities during the two military campaigns, researchers said.

The number of infections - and their resistance to medication - underscored the importance of controlling the infection during treatment in combat and healthcare settings, the CDC report noted. Also, the CDC cited a need to develop new anti-bacterial drugs.

The majority of the troops infected were active-duty members of the U.S. Armed Forces. Thirty-two patients, or 97 percent, were directly transferred to the Landstuhl Regional Medical Center Intensive Care Unit from a medical facility in a combat zone, according to the report.

The CDC also found that the LRMC and Walter Reed Army Medical Center were not the only facilities dealing with presence of the bacteria. Three other military treatment facilities also identified infections in service members injured in Iraq, Kuwait and Afghanistan: U.S. Navy hospital ship Comfort (11 patients); National Naval Medical Center in Bethesda, Maryland (eight); and Brooke Army Medical Center in San Antonio (five).

Some of the patients identified in the report had evidence of bloodstream infections at the time of admission to military medical facilities. However, the report noted it was not known where the infections were acquired, whether from in the field, during treatment or evacuation from other military medical facilities, such as field hospitals.

Outbreaks were also found during the Vietnam War. However, at more than 300 U.S. hospitals that the CDC has surveyed, the rate of resistance sharply increased from 1995 to 2004.

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CDC Facts

*From Jan. 1, 2002-Aug. 31, 2004, military health officials identified 102 patients with blood cultures that grew Acinetobacter baumannii bacteria at military medical facilities treating service members injured in the Iraq/Kuwait region and Afghanistan.

*Of these cases, 85 (83 percent) were associated with activities during Operation Iraqi Freedom and Operation Enduring Freedom.

*Most of the infections were reported from Landstuhl Regional Medical Center in Germany, 33 patients; and Walter Reed Army Medical Center in Washington D.C., 45 patients.

*This compares with one case reported in 2000-2002 at Landstuhl and two cases in 2001-2002 at Walter Reed.

Source: The Centers for Disease Control and Protection, November 2004.