San Diego Health Officials Brace for Arrival of Cholera : Disease: Experts fear that migrant camps along the border may be vulnerable to the epidemic raging in the Americas. A major outbreak in the United States is not expected.

Health officials here are alerting doctors as they brace for the arrival of cholera, an epidemic that has spread north through the Americas and struck a new nation each month since it was first discovered in Peru in January.

Federal and local health officials stress that a major outbreak of cholera is not expected to hit the United States. But there might be poor areas along border states--particularly colonias in Texas and migrant camps in San Diego County--that are vulnerable to the disease, they say.

Cholera, known as a disease of the poor, flourishes in areas with inadequate water and sewage systems and unsanitary food storage. The life-threatening disease, which is easily treated, is caused by a bacterium transmitted through contaminated water or food. Symptoms include dehydration, diarrhea, vomiting and cramps.

“For John Q. Public who lives in a house, the risk is very, very minimal,” said Dr. Donald G. Ramras, deputy director of the San Diego County Department of Health Services. “Except travelers (in cholera-stricken countries) must be careful.”

Health experts worry about cholera invading the numerous North County camps of migrant workers, a group that numbers from 3,000 to 20,000, who have little access to treated water or proper sanitation.

“We’ve been telling the country that we don’t think there will be a lot of cholera in the United States,” said Dr. David L. Swerdlow, a medical epidemiologist with the Centers for Disease Control who came to San Diego several months ago to work with the health department. But “there are pockets in the U. S. where there could be cholera. I don’t think there’s any doubt about that.”

Fifteen cases of the epidemic-related strain of cholera have cropped up in the United States, according to the CDC. These cases involved Americans who traveled to Latin America or ate tainted crab that had been cooked in Ecuador and smuggled into the United States. So far, there have been no cases on the West Coast.

The epidemic reached Peru in January, moving next to Ecuador and Colombia, and surging through the Americas. Mexico has reported 1,226 cases since June, with 18 deaths, the government news agency Notimex said this weekend.

Swerdlow has tracked the disease to the small islands of Micronesia in the Pacific and Malawi in Africa as well as Peru, where the disease has stricken 256,343, infected 52% of the population, and killed 2,453.

In San Diego, he is working with health officials, bolstering the county’s defense against cholera and setting up early warning systems.

The county has sent out notices to physicians and contacted major laboratories and hospitals, making sure they know the procedures for conducting tests for cholera. County workers also are visiting migrant camps, informing the inhabitants about the disease and its symptoms.

Advocates for migrant workers say they fear that the specter of cholera will only increase tensions between North County homeowners and workers who live in makeshift shacks just yards away.

“It’ll be a pretext for getting rid of the camps,” said Claudia Smith, regional counsel for the California Rural Legal Assistance. “I’m worried that this will create some type of hysteria. People are really inclined already to believe that the men in the camps are disease-ridden. And that is just not true.”

But Swerdlow says his intent is to set up a system to monitor and treat the county’s most vulnerable population.

Swerdlow and his colleagues are trying to win the trust of the migrant workers, some of whom have immigrated illegally and distrust outsiders. Last month, health workers made special arrangements with men chosen from five camps. Each man reports to a visiting health worker each week, informing the worker of any illnesses that strikes the camp. With this system, which health workers hope to expand, Swerdlow believes that the county can better monitor conditions in the camps.

Earlier this month, health officials began a weekly ritual of testing sewage from Point Loma and Tijuana for cholera bacteria. The sewage test, they say, will serve as a tripwire signaling the arrival of the disease.

Officials are looking for Vibrio cholerae ( Vibrio is Greek for “comma”), a strain that got its name because of the comma shape of the bacterium. This strain of cholera has struck 23 countries in 2 1/2 years, said Dr. Allen Reis, a CDC epidemiologist who specializes in intestinal diseases.

Last month, Reis headed a team that started in San Diego and traveled along the border through Texas to identify areas most vulnerable to the disease.

The CDC does not recommend the cholera vaccine it has because it is ineffective and has side effects. Reis and others emphasize that cholera can easily be treated with rehydration therapy, which replaces lost water and minerals, and sometimes with antibiotics. Untreated, cholera kills half of those it strikes.

Not all individuals infected with cholera get sick. In fact, about 75% of those infected will have no symptoms and can remain infected for seven to 10 days.

Because the cholera bacteria can live independently of human beings, experts do not believe that the disease will be eradicated.