Science and Technology for Canadians

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Summary

Dr. Rosanna Peeling, a scientist at Health Canada, is aiming to make long-term complications due to Chlamydia a thing of the past. In 1991 a test called the "Heat Shock Assay" was developed. It is a method to predict the amount of risk a woman has for developing complications due to Chlamydia. This bug is responsible for over 50% of Sexually Transmitted Diseases in Canada (40,000 new cases per year in Canada, 2-3 million in USA). Chlamydia is the cause of a large number of women becoming infertile and a cause of preventable blindness (5 million world-wide). The publishing of the test created a slew of further investigations into the field including the collaboration between Health Canada and the London School of Hygiene and Tropical Medicine as a part of a WHO initiative to eliminate preventable blindness by the year 2020.

Transcript of Video

Narrator
It takes just one of these bacteria to infect someone. The symptoms are usually quite subtle, and often go unnoticed. But left untreated, sexually transmitted chlamydia can have devastating consequences.

Dr. Rosanna Peeling
Genital chlamydial infection is the most frequent infectious cause of infertility in women. We found in this cohort of infertile women that 70-90 percent of them actually had evidence of a previous chlamydial infection which they did not know about.

Narrator
With chlamydia, what you don't know, can hurt you.

Dr. Rosanna Peeling
We don't really know how long it takes from cervical infection to infertility in humans, but we do have some data in mice... in mouse models where if the mice were not treated within four days of infection they will then go on to develop infertility.

Narrator
There are still things we don't know about chlamydia. But great strides have been made since a 1984 study of infertile women with the infection. For the first time, scientists uncovered clues as to how chlamydia might cause infertility.

Eighty-five percent of the subjects in the study had an antibody response to a particular chlamydial protein, one of the so-called heat shock proteins, or HSPs. They're present in all living cells, and the HSPs in microbes bear a striking resemblance to those in human cells. Dr. Peeling suggests that when a woman's immune system mounts an attack against chlamydial HSP it sometimes targets the identical human protein instead. If that happens, it starts attacking its own cells. This auto-immune response may result in scarring of the fallopian tubes and infertility.

In 1991 Dr. Peeling and her collaborators developed an assay, or test, that detects and measures antibody response to HSPs. It can be used to assess who's at risk of infertility from chlamydial infection.

Dr. Rosanna Peeling
We were able to develop this assay in a format that is easy to use and that would allow us to test a large number of individuals at the same time.

Narrator
It's estimated that about 35,000 new cases of genital chlamydia are reported in Canada every year. The test can identify women at risk... before they become infertile.

Dr. Rosanna Peeling
Now that we could identify women who are at risk, what we want to do is to see whether more aggressive therapy would allow us to eradicate the chlamydia from the infected individuals and therefore prevent any long-term complications. And then the other side is that we want to do some more basic science research to find out the mechanism of how this heat shock protein is involved in the long-term complications, and therefore, perhaps, once we elucidated the mechanism, we'd be able to find a way to intervene in this progression.

Narrator
Dr. Peeling and her colleagues' ongoing research is geared toward making the infertility caused by chlamydia a thing of the past.

Earth Tones is produced in co-operation with Health Canada.