Medical Testing may Become Stricter

As early as next January, immigrants applying to Canada will undergo stricter medical tests for infectious diseases, and the tests will be tailored to their country of origin.

Health Canada and Immigration Canada are planning an overhaul of their antiquated testing system, and will apply the two medical clauses in the Immigration Act more aggressively.

The first clause denies entry to any individual "who is, or is likely to be, a danger to public health or to public safety." The second clause denies immigrant status to anyone who "would cause, or might reasonably be expected to cause, excessive demands on health or social services."

The act applies to immigrants, refugees, temporary workers and visitors staying longer than six months. Under the present system, they have to pass a medical exam, a blood test for syphilis and a chest X-ray for tuberculosis.

Health Canada is using a new computer model to assess the risk posed by 47 infectious diseases, a process that could take a year.

However, if in the interim the computer study identifies a pressing need to test for a certain disease, "we won't wait until we have 15 diseases as a package" to impose testing requirements, said Dr. Ron St. John of the Laboratory Centre for Disease Control in Ottawa. "No, we'll do it right away."

The new system will be more agile. Screening immigration applicants for a particular disease can literally begin overnight, around the world or in one country or region.

Dr. St. John isn't yet sure which diseases will be universally tested for, because the new computer model that Health Canada is developing may produce some surprises. The computer model will first assess the need to screen for tuberculosis, hepatitis B, HIV, syphilis and influenza.

Dr. St. John speculated that the computer model will show a need for mandatory, universal tests for tuberculosis and hepatitis B and C.

However, the issue of cost will probably decide whether all immigrants will have to pass an HIV test. Despite the infectious nature of HIV, Dr. St. John says he doesn't see it as a public-health issue.

"HIV is totally preventable and there's plenty of HIV already in Canada," he said. "Given that 98 per cent of the population is quite knowledgeable, if you just met a man or a woman from Ghana, are you going to rush into a sexual relationship?" A person should know the HIV status of any new sexual partner, he added, regardless of their
birthplace.

A person with HIV, however, costs between $110,000 and $178,000 in direct medical care, according to Greg Williams, research associate with the Canadian Policy Research Networks in Ottawa. A recent University of British Columbia study adds an additional $600,000 per person as an indirect cost to society in lost productivity.

The Health Canada computer model will study the need to screen for HIV, but Dr. St. John said it is now being "debated and discussed" in a variety of government departments as a possible exclusionary disease because of the medical costs.

Tuberculosis, not HIV, is right at the top of the list of dangerous infectious diseases because 30 per cent of the world's population has been infected with it.

Of the roughly 225,000 immigrants who came here in 1996, some 60,000 people with inactive, non-contagious tuberculosis. Of the 2,000 reported cases of active tuberculosis in Canada each year, 57 per cent occur in immigrants, and the number is growing each year. With the disease surging world-wide, experts predict that Canada will have 6,000 new cases of contagious tuberculosis each year in the future.

The mandatory chest X-ray catches perhaps 70 per cent of active cases. These people can be admitted to Canada once they've received antibiotic treatment that makes them non-contagious.

However, one in 10 such cases becomes active again when the tuberculosis bacteria overwhelm the weakened immune systems of elderly or people with HIV. In fact, a person with a combination of HIV and inactive tuberculosis has a one-in-12 chance of developing active tuberculosis every year. "Not over a lifetime," Dr. St. John stressed, "but every year."

Nevertheless, Health Canada's computer analysis may show that universal tuberculosis testing isn't needed. For example, people applying from Norway and from Southeast Asia get chest X-rays, even though Norway has an even lower tuberculosis rate than Canada. (Canada's overall rate reflects the health of its native population, whose incidence of tuberculosis matches that in some developing nations.)

The disease is endemic in Southeast Asia, which provided roughly 40 per cent of all immigrants last year. And in some parts of Somalia, Ethiopia and Zimbabwe, as many as 90 per cent of the people have tuberculosis. "In some countries, maybe we should do even more than chest X-rays," said Dr. St. John. Skin tests and sputum tests give more accurate diagnoses.

As the scientists, headed by Dr. Trong Nguyen, plow through the disease list, they will also assess Chagas' disease, a blood parasite that lives unnoticed for years, only to suddenly attack the heart, sometimes fatally. It might be a prime target for regional testing since it is prevalent in Central and South America. In some countries such as El Salvador, two per cent of blood donors have Chagas.

Chagas' disease has made its way into the Canadian blood supply: A Manitoba woman died in 1986 after receiving blood contaminated with the parasite. Although there is no known treatment, an immigrant who tests positive and is admitted to Canada could be advised against donating blood or sharing needles.

The medical screening project is the brainchild of Dr. Brian Gushulak, Canada's former director of quarantine health services. Dr. Gushulak is serving a term as medical director for the International Organization on Migration in Geneva, Switzerland.

The Canadian scientists are working parallel to a team of U.S. scientists from the American Centres for Disease Control. Each team is testing a different computer model. They'll meet in Atlanta in December and compare notes.

Apparently the scientists compare more than computer models. The U.S. Centres for Disease Control "would much rather have our law than theirs," said Dr. St. John. To add or subtract a disease for screening in the U.S. -- the Americans still test for leprosy, along with tuberculosis, sexually transmitted diseases and HIV -- is a cumbersome legislative process.

Three federal departments -- Health, Citizenship and Immigration and Foreign Affairs -- will apply the computer model's results in pilot studies overseas. If they're successful, "probably a year from now we may have all the changes world-wide."

If the computer model holds up, Canada will share it internationally. It could add crucial speed and flexibility to the arsenal against the onslaught of infectious diseases.

Health Canada is also proposing changes to its Quarantine Act to allow health officials to hold a potentially infectious person as long as necessary.

A sensational case involving a would-be refugee who stepped off a plane in Toronto's Pearson International Airport during the l995 Ebola outbreak in Zaire prompted the amendment.

The man, arriving from Britain, was "one of those persons who ate their papers and claimed to be a refugee," said Dr. St. John. "He decided it would help his case, since he was from Zaire originally, to say he had just come from the site of the Ebola outbreak there, where he had helped to bury his dead mother."

That story sent Health Canada into a scramble for its long-buried quarantine form, last used 40 years earlier. When health officials realized that the law allowed only 14 days of detention, they rushed to the courts to beg for extra time. Ebola has an incubation period of three weeks. "Fortunately, we had a sympathetic judge."

Meanwhile, back at the airport, the man was being held in the VIP lounge. Police eventually discovered that he actually lived in London, not Zaire.

With the man's identify unmasked and his Ebola story discredited, the officials decided to change the law and are now planning formal procedures for detaining and isolating potentially contagious individuals. That includes finding an alternative to using VIP lounges in public health crises.