VULNERABILITY TO DENGUE FEVER IN JAMAICA

Charmaine Heslop-Thomas, Wilma Bailey, Dharmaratne Amarakoon, Anthony Chen, Samuel Rawlins, David Chadee, Rainaldo Crossbourne, Albert Owino, Karen Polson, Cassandra Rhoden, Roxanne Stennett, Michael Taylor.

HISTORY

Virological evidence of the presence of dengue in the Caribbean in the 1950s.

The disease has been appearing with increasing frequency.

All four viruses are circulating.

The appearance of dengue 1 in Jamaica in 1977 resulted in 60,000 cases.

The last large epidemic appeared about 10 years ago. Increase in temperature will shorten the incubation period of the virus.

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RISK

Increase in temperature will shorten the incubation period of the virus.

The vector may become more infective more quickly.

Reproduce more rapidly.

Bite more frequently.

There may also be the increased risk of DHF.

EVIDENCE

A.aegypti is already appearing at higher elevations.

Simulations suggest a potential to spread into higher latitudes.

A link between El Nino and the incidence in some Pacific islands.

OBJECTIVES

To assess the vulnerability of the population of Jamaica to dengue.

To identify specific factors that put communities at risk.

BACKGROUND

An upward (but not significant) trend in rainfall indices.

An increase in the incidence of dengue in the corresponding period.

The increase particularly marked in El Nino and El Nino +1 years.

A seasonal peak in occurrence in the latter part of the year, after a few months of warming and when the rainfall is receding.

A lag between climatic parameters, especially temperatures and the epidemics.

In the Caribbean the association of the disease with temperature is stronger and the lag with temperature is greater than that with rainfall

DISTRIBUTION OF EPIDEMICS PEAKS AMONG ENSO PHASES 1981-2001

REGION TOTAL El Nino & +1

La Nina Neutral

Caribbean 8 7 -

1

T & T 8 6 - 2

Barbados 6 5 - 1

Jamaica 5 4 - 1

Belize 4 3 1

Time series graph of reported cases of dengue with rainfall and temperature for Jamaica

0

100

200

300

400

500

600

700

800

900

0 10 20 30 40 50 60 70

Ra

infa

ll In

cid

en

ce

of

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ue

20

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32

Te

mp

era

ture

(o

c)

rainfall dengue temp

1995 1996 1997 1998 1999 2000

PROJECTIONS

Projections for Jamaica for the years 2020, 2050, 2080 using statistical downscaling methods and two scenarios (SRES A2 AND B2) indicate the possibility of increased warming in the next century.

TO SUMMARISE

Changing climatic conditions may enhance dengue transmission.

Immunity is low.

But individual and contextual circumstances could modify vulnerability.

TWO LEVELS OF ANALYSIS

Generic and Specific Adaptive Capacity

Macro level – current social and economic trends.

Expert interviews in public sector organisations and NGOs. How do they interpret their roles? How prepared are they?

Local level study in communities that had experienced an outbreak. How vulnerable are they to an outbreak?

The Survey

Johns Hall

Irwin

Retirement

Tucker

GranvillePitfour

Dengue Cases 1998 - St James

500 0 1/4 1/2 3/4 1

10500

1000

1000METRES

YARDS

4 KILOMETRES

MILE32

32

URBAN BOUNDARY 2001

DENGUE OCCURANCE

N

river

gully

MONTEGO BAY

URBAN

RURAL

THE MACRO LEVEL

The ending of the bauxite/alumina inspired boom in the 1970s.

IMF and its conditionalities. Their effect felt most keenly by the poor:-Job loss.-Devaluation and price increases.-Removal of subsidies on basic food items.

No real economic growth in more than 30 years.

THE INTERVIEWS

A – THE MINISTRY OF HEALTH

Most saw the possibility of increasing transmission.

No long term strategies are in place.

A resource constraint necessitates prioritising: HIV/AIDS is the priority.

The cost of surveillance, and control, public education is too high.

Environmental sanitation is the responsibility of communities.

The positives:

a well organised system of primary health care built on interlocking system of clinics.

a long tradition of involvement in policy oriented research eg. their involvement in the current climate change project.

A decentralised system of health care.

THE INTERVIEWS

B. OTHER ORGANISATIONS Office of Disaster Preparedness and Emergency

Management; National Environment and Planning Agency; Water Resources Authority; National Meteorological Service.

-Health was not a part of their mandate-Sea level rise posed a greater threat.

The NGOs Long term considerations such as climate change were not on

their agenda.

Vulnerability of Communities

Based on indicators identified in the literature: Immunity, knowledge of symptoms and vectors of disease. Use of

protective measures. Measures of resilience and stress – education, employment, income, female

household headship, room densities, coping strategies, integration into the community.

Source of water, water storage. Distance from the nearest health facility

Community Ranking

Most Vulnerable: Johns Hall - 44 Least Vulnerable: Granville/Pitfour - 26

Vulnerable Groups

Characteristics Group 5

(%)

Group 1

(%)

1.Female Household headship 94 40

2.Unskilled 88 13

3.Primary education or none. 77 7

4.Minimum wage or less 57 0

5.Not Coping 88 0

6.Water storage in drum 88 20

7. Clinic distance 64 13

8. No protection 88 53

9.No knowledge of dengue transmission

94 7

10. No social integration 53 47

11. No knowledge of dengue symptoms

88 13

12. No personal acceptance for dengue control

77 7

Community with highest proportion

Phi coefficient

H/headship-0.6 p<.000

Water storage in drums 0.6 p<.000

Knowledge of dengue transmission 0.9 p<000

Johns Hall -53% Granville/Pitfour – 73%

CONCLUSIONS

Substantial number of people living in informal settlements is vulnerable.

Between 55,000 and 60,000 persons in Montego Bay (over 25 %) live in such settlements.

The poor are vulnerable and many of the poor work.

If communities must take responsibility for environmental sanitation they must be given the tools – education.

Access to water must be tackled on two fronts - the provision of low-cost, secure drums.

-the granting of security of tenure to those who, because of their status, are denied access to running water.

Public sector organisations must be persuaded that:

-The threat of an outbreak of disease is not incompatible with a mandate to mitigate disaster or sustain development.

-Healthy lifestyle is an outcome of sustainable development

-They can incorporate disease control into their education programme.

THANK YOU