California’s plan to follow the traveler when the virus gets stuck when overwhelmed, research results

In the early days of coronavirus outbreaks, like many countries, the United States had a very short opportunity to limit the spread of disease at the border. Identifying travelers from high-risk countries and tracking their contact with others has been an important step, if done early enough.

In California, the largest state and the gateway for thousands of travelers from Asia, a program has been established to do just that. However, the tracking system was overwhelmed by many passengers, often inaccurate contact information, and in some cases lack of personnel deactivated the program. Study published Monday by Centers for Disease Control and Prevention, It was looking only at California.

“Despite the intensive efforts, the traveler screening system did not effectively prevent the introduction of Covid-19 in California,” the report said.

In early February, more than 11,000 Chinese travelers (and later Iran) landed in California were identified for contact tracking. Hope is that people traveling from high-risk countries will be tracked, public health authorities will identify possible cases of coronavirus, quarantine them, and contact infected people to limit the spread of the infection. Was to be possible.

But when the program started on February 5, weeks had already passed since the disease was first identified in Wuhan, China. On March 17, the program was abandoned, allowing healthcare professionals to shift their focus to reducing the spread of the disease in the state. By mid-March, the coronavirus had already had a foothold in California. Preventing further introductions from abroad was considered less important than fighting in the field.

“This report is a good example of an attempt to control and prevent pandemic infections using travel screening,” said Dr. Timothy Brewer, a professor of medicine and epidemiology at the University of California, Los Angeles.

This report is C.D.C. Created by the California Department of Public Health, other states provided similar passenger information.

A spokesman for the California Department of Health said the report said about itself. When asked if traveler surveillance was a useful tool in the fight against a pandemic, a spokesman could refer to the text of the report to help start early enough, but breathe like a coronavirus. Infections can occur before the symptoms that have been described as particularly difficult for organ disorders.

It also states that passenger monitoring is most effective when there is accurate information about passengers and the number of passengers does not overwhelm the system. In this case, these conditions did not exist.

Dr. Brewer said strict measures in smaller countries such as New Zealand and Taiwan are believed to have contained the outbreak there. New Zealand instructed everyone coming into the country after the outbreak to spend two weeks in quarantine, and Taiwan took similar steps.

But they are much less populated island nations, and Dr. Brewer said Taiwan has begun to put restrictions “within a day or two after realizing the existence of Covid-19.”

When a passenger flies from China to California during the investigation period, the information is recorded by Customs and Border Protection personnel, then forwarded to C.D.C. and C.D.C. Has sent contact information to the California Health Authority. These names were then given to the health departments of state-wide jurisdictions for contact tracking and follow-up.

Beginning March 5, travelers from Iran have been included in a program called Return Traveler Monitoring. The study later found that three passengers, including two from Iran, were reported to the California Department of Health as Covid-19 patients.

Theoretically, after arrival, travelers will be contacted to see if they have any symptoms and will find the person they met directly. If any of the passengers develop symptoms or are tested positive for the coronavirus, they can be quarantined to prevent further infections, and those contacted can also be quarantined.

In C.D.C. California, the report states that incomplete information made it difficult to fully enact the plan. Sometimes names, addresses, phone numbers were incorrect, or passengers could not be found for follow-up.

Also, the number of people chasing was overwhelming. The study found that during the seven weeks of the program, a median of 1,431 people from Asia arrived in California in one week. By comparison, California identified effective passenger identification during the 2014-15 Ebola outbreak. This is because there were only 21 people a week from countries affected by Africa.

The study also cited the problem of asymptomatic patients. They can spread the disease before they show signs of disease.

Still, C.D.C. It reports approved traveler surveillance programs, which are “more likely to be effective during the initial containment phase” of the outbreak.

The current outbreak in California is under control, the study said, in the event of another wave of illness, public health officials should try to introduce a follow-up program. However, it is advisable to do so in a more efficient and comprehensive way, especially when collecting accurate information about passengers.

The C.D.C. airline has requested that the airline passenger list be provided to federal authorities and that the health department communicate using text messages after the passenger leaves the airport. All said it might help to “maintain a low incidence”.

“The key word is” low incidence, “said Dr. Brewer. “They say, this might work if you got on it before your system was overwhelmed. That’s what Taiwan did.”

“To do it right, you’ll need far more resources than is normally available in the public health sector,” he added.