HTLV-1 virus detected in Nunavut

Nunavut health officials report at least one death related to human T-cell lymphotropic virus type 1 (HTLV-1) and “fewer than 20” infected persons.

Nunavut's Medical Officer of Health, Dr. Issac Sobol, says residents need to take this very seriously, but adds, “It's not what we consider an outbreak. In fact, it's been here a number of years.” It can take up to 20 years before symptoms appear. There is no effective treatment to reduce the viral load.

In response to the death and reported cases, the Nunavut Department of Health and Social Services began offering testing for HTLV-1 to pregnant women and the population in general in October, “We worried about our capacity to handle demand [from the general population],” says Sobol. As of Dec. 7, only 300 people had been tested.

Figure. Custom condom wrappers, community events, posters and other strategies help prevent the spread of STDs, including HTLV-1, in Nunavut. Photo by: Pauktuutit

Sobol would not disclose the precise number of people infected or the number of HTLV-1–related deaths. He stated that such caution is common in sparsely populated areas where anonymity is difficult. It is important to “ensure that Nunavummiut feel absolutely confident that no information will ever be revealed that could in any way be traced back to either communities or to individuals.” Even one death in a small community could raise suspicions.

HTLV-1 is rare in Canada (see Box 1), but the number of cases is not known because it's not a reportable disease in most jurisdictions. Canadian Blood Services has been screening donated blood for HTLV-1 since 1990 and reports an average of 10–12 positive tests per 800 000 donations annually (prevalence of 0.0014%). If even 15 people in Nunavut are infected, among a population of 29 000, the prevalence is 0.05%.

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Box 1.

HTLV-1 can be transmitted sexually, which is cause for concern. “We know that there are still high levels of unprotected sex occurring because of our static chlamydia rates,” says Dr. Geraldine Osborne, Nunavut's associate chief medical officer of health. Chlamydia rates have remained fairly stable since 1991 at 2500 per 100 000 population, compared to 188 per 100 000 in Canada generally. Gonorrhea rates have declined from 900 per 100 000 in 1991 to 250 today, largely due to “effective treatment and contact tracing,” says Osborne. Rates for other STIs including syphylis and HIV are very low; less than 20 reported cases each.

HTLV-1 will top the agenda at a sexual health symposium at the end of February, says Aideen Reynolds, manager of Sexual Health Policy and Program for Pauktuutit, an Ottawa-based NGO that has offered STI prevention programs for the North since 1999.

Reynolds says the problems are myriad: “How do you mobilize communities to take it on and believe that they are at risk?”

Part of the solution involves proving risk. The Nunavut department of health and the Public Health Agency of Canada (PHAC) are developing a seroprevalence study that includes anonymous testing of all blood samples taken in the territory. Preliminary results are expected by June; statistically significant results will take 2 years.

Dr. Frank Plummer, director general of PHAC's Centre for Infectious Disease Prevention and Control says HTLV-1 is ”not a huge public health threat.” The important thing is to ensure there is antenatal screening in areas where there is an appreciable prevalence, he adds.