RSV and The Ulu:The Cutting Edge of Research into the

Causes of Severe Recurrent Lower Respiratory Tract Infections in Inuit

Infants

Tom Kovesi MDPediatric RespirologistAssociate Professor of PediatricsChildren’s Hospital of Eastern OntarioUniversity of OttawaOttawa, Canada

Bronchiolitis

Bronchiolitis isan infection, causedby a virus, of thevery tiny airwaysin a baby’s lungs

0

100

200

300

400

500

Hospitalization Rate per 1000 infants

All United States

Yukon-KuskowkwimDelta (Alaska)

Baffin Region,Nunavut

Northern Communities Have the Highest

Incidence of Severe RSV Bronchiolitis in the World

Karron, J Infect Dis 1999; Banerji, CMAJ 2001

Nunavut has the highest rate of Tuberculosis infection in Canada

0

20

40

60

80

100

120

140

160

TB rates per 100,000 persons

Canada (general)

CanadianAboriginals

Inuit

What the Houses? Indoor Air?

Do they play a role?

What About Ventilation?

Cape Dorset Pilot Project: Kovesi, Indoor Air 2006Multi-Community Study: Kovesi, CMAJ 2007

Occupancy Distribution

Number of People Per House

12.010.08.06.04.02.0

12

10

8

6

4

2

0

Number of Houses

Median number occupants: 6, mean 5.9, range 2-12

Cape Dorset, 20 houses of Inuit Infants

(Kovesi, Indoor Air 2006)

Environmental Tobacco Smoke Exposure

5%90%

5%

Smoking Reported

Likely Smoking

No Smokers

Smokers present 90% (probably 95%) of households

Ventilation

• 96 Inuit children in 4 communities: • Mean ventilation 5.6 L/s/person• Mean CO2 1358 ppm (Kovesi, CMAJ 2007)

Recommended

BelowRecommended

20.1%

79.9%

Ventilation within recommendedCanadian standards (7.5 L/s/person)

Mean CO2 > 1000

< 1000

> 1000

33.3%

66.7%

ppm

1321N =

Pneumonia

PresentAbsent

Mea

n CO

2 (p

pm)

3000

2000

1000

0

Risk of Lower Respiratory Tract Infection

1525N =

Pneumonia

PresentAbsentO

ccup

ancy

12

10

8

6

4

2

• Ventilation also known to be important risk factor for TB (Menzies, Ann Int Med 2000)• *too few non-smoking households to test the effect of smoking

Heat Recovery Ventilators• Heat Recovery Ventilators bring fresh outside air

into furnace, transfer heat from stale air to fresh air to maintain energy efficiency, and move stale air out of house

• Trial of HRV’s installed in homes of Inuit children 5 years & less in 4 communities

• HRV’s were installed in fall-winter 2006-2007:– Clyde River– Igloolik– Pangnirtung– Pond Inlet

Study HRV’s• Venmar Constructo 1.0 HRV,

– (Venmar Ventilation Inc.) • Determined that additional 25-30

L/second ventilation needed to provide 7.5 L/s/person

• Active HRV’s provided this ventilation

• Placebo units circulated air in the house, but not increase the house’s outside (fresh) air

• Placebo units were reprogrammed as functional devices at end of study (reprogram internal circuit board)

Conducting Research in Nunavut

– Community Support• Town Hall Meetings: Pilot & Multi-community

Studies; mainly assumed for HRV study• Qikiqtani Inuit Association, Nunavut

Tunngavik Inc.• Approval from Nunavut Research Institute,

Ministry of Health and Social Services

– Need for community research coordinators with good organizational and computer skills (“too few and in too much demand”

– Capacity-building: enlisted high school students to help with collecting data

Heat Recovery Ventilator

Venmar HRV, Pond Inlet, Nunavut

HRV Study Findings - Engineering

• Installations– 68 HRV’s installed– 51 available for analysis

• Units (6) in Clyde River couldn’t be powered• 3 families dismantled units• Children in 4 families moved

• HRV’s significantly reduced indoor CO2 (33%)– Mean CO2 1385 ppb placebo units– Mean CO2 924 ppb active units

Effect of HRV’s on Reported Wheezing

• Significant reduction in risk of reported rhinitis (not associated with cold air exposure) (p = 0.0044)

Challenges• HRV’s significantly reduced relative humidity

(25.6 vs 30.9%) & tended to reduce indoor temperature

• Occupant complaints (house colder, drier…) • 21% active houses, • 27% placebo houses

• Units unplugged > 50% of study period in ~20% houses (counter data, questionnaires)

Research Questions

• Are Heat Recovery Ventilators the answer?– Maintenance and installation issues– Dry air– Small but real electricity cost– Retrofits

• Can Heat Recovery Ventilators be engineered better for very cold weather performance?– Issue of drafts

• Role of overcrowding/need for new homes versus ventilation (e.g. heat recovery ventilators)

• Role of surface v.s. airborne transmission virus

Future Research (2)• How to deal with environmental

tobacco smoke• Human architecture of Inuit housing• Capacity-building – research in

Nunavut

Acknowledgements• Program of Energy Research and

Development, NRCan• Nassivik Centre, CIHR• Canada Mortgage and Housing

Corporation• Natural Resources Canada• Qikiqtani Inuit Association• Venmar Ventilation Inc. • Nunavut Housing Corporation• Health Canada• Children’s Hospital of Eastern

Ontario Research Institute• Department of Health and Social

Services, Government of Nunavut