Let's talk about sex
By Katie Cumby

OTTAWA — Ann Jolly likes to talk about sex, but not in the way you might think.

Jolly outlining sexual networks in her laboratory.

Jolly is a senior research epidemiologist for the Centre for Infectious Disease Prevention and Control at the Public Health Agency of Canada.

Jolly studies the transmission of sexually transmitted infections and other infectious diseases.

Research focus

The area she’s most interested in is sexual networks of infected people. In 2004, Health Canada awarded Jolly the Most Promising Scientist Award to recognize her work in this field.

Studying sexual networks helps show who is having sex with whom, says Jolly. This data can then be used to examine disease and infection transmission.

"In these networks, people can be attached in a kind of web-like thing, like a spider web," says Jolly, who completed her PhD in community health sciences at the University of Manitoba in 1998.

"But we also have to remember that sometimes someone in a network isn’t linked to everybody else," she says.

All the people who have STIs are in a network, but only some are linked to each other in what is called a component.

Sexual networks can show us how people are indirectly sexually connected to each other.

For example, if Jane has sex with John and John has sex with Mary, Jane and Mary are indirectly linked in the sexual network.

Talking about sex . . . in Manitoba

Jolly has lived in Ottawa for seven years. She says the springboard for her career was a 5-year research project, funded by the Manitoba Health Research Council, that looked at chlamydia sexual networks in Manitoba. The results were peer reviewed and published in The Journal of Infectious Diseases.

Jolly worked with John Wylie, a scientist with Manitoba Health. They combined sexual network data and genotype data of people with chlamydia.

They compared these two data types to see if the chlamydia strain passed along in certain sexual networks matched the infected people said they had sex with.

"When people say they had sex with each other, we learned that it’s often supported by the fact that they all have the same strain," says Jolly.

The purpose of genotyping data, says Jolly, is to look for different strains of a disease or infection.

"When we genotype data, we’re just taking the bug, taking the DNA, looking at the proteins and we see if it’s identical to another type," says Jolly.

How they did it

Using a test called Chlamydiazyme, they analyzed samples from people who were infected in 1997 and 1998.

Public health nurses then asked them for personal information, like their gender, race, birth date and address. They also asked them for the names of their sexual contacts.

Using a network analysis program called PAJEK, Jolly and Wylie constructed sexual networks that made links between infected people. They genotyped chlamydia specimens from 359 people.

Of these 359 people, they looked at specimens of 297 to see whether or not there was a relationship between the sexual network and the genotype data.

Inspiring results

"We found that about 60 per cent of networks had one strain, which supports the patients’ responses about who they said they had sex with," says Jolly. "You can see that the genotype data correlates quite well with the person with whom they said they’ve had sex."

According to Jolly, about 30 per cent of the networks they studied contained more than one chlamydia strain, suggesting, among other findings, that some of the sexual partner links were missing.

These results inspired Jolly to continue looking into sexual networks and genotyping. Jolly and Wylie have looked at these two concepts in relation to geographical, spatial and temporal clustering of strains of chlamydia and other diseases and infections.

"These studies made us want to start looking at other organisms. So for example, if this works with this STI, will it work with others?"

Talking about sex — now and in the future

Jolly and Wylie are currently studying sexual networks and different strain types of gonorrhea in Shanghai, China. Jolly says the ultimate goal of this and all of her studies is to help minimize how many people contract sexually transmitted infections and other infectious diseases.

"We know there’s people out there who are having sex together and they form a sexual network which somehow we need to break into," she says. "We need to get into that and look at what we can do to help these folks."