Background

1
Assessing the Risk of Self-diagnosed Malaria in
Urban Informal Settlements
Background
Objective
Methods
Results
Yazoumé Yé Elizabeth Kimani John Kebaso Frederick
Mugisha
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
2
Malaria Endemicity in Kenya

• In Kenya, malaria is the leading cause of
  outpatient attendance in 6/8 provinces
• Level of malaria transmission varies across the
  country
• Different malaria epidemiological zones namely
• endemic zone,
• epidemic prone zone
• low risk zone.

Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
3
Malaria in Nairobi

• Nairobi, is classified as a low risk area
• High altitude (1700m) gt cold temperatures limit
  transmission
• Urban habitat is less suitable for An. gambiae
  s.s. and An. Funestus

Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
4
History of Malaria Cases in Nairobi
Background

• 1926 Presence in Nairobi of An. gambiae and An.
  Funestus
• 1929 A school survey showed 2.5
• parasites prevalence

Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
5
Low Prevalence of Malaria in Nairobi
Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
Pf prevalence
Pf prevalence at sites across the city in 1982
(Rapuoda Achola, 1984)
6
Malaria Diagnosis in Nairobi
Background

• Malaria is a common diagnosis among out-patients
  in the city
• Overuse of anti-malaria drug
• With introduction of ACT accurate diagnosis is
  needed

Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
7
Questions
Background

• What is the level of self-diagnosed malaria in
  the community?
• Does the population from informal settlements
  perceive malaria as one of their key morbidities?

Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
8

• To explore the risk of perceived malaria and
  associated factors in two Nairobi informal
  settlements

Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
9
Study Population
Background

• Household survey May-August 2004
• 7288 individuals from DSS database
• Population of interest 1394 individuals
  (reported at least one illness )

Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
10
Morbidity Survey
Background

• Self report of maximum of three illnesses and
  associated symptoms
• Recall period Past 15 days
• Proxy respondents for participants lt14 years

Objectives
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
11
Statistical Analysis
Background

• Outcome Reported malaria (Y/N)
• Explanatory variables
• Slum of residence, sex, age, ethnicity, symptom
  score
• Multivariate Logistic regression mode

Objectives
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
12
Computation of Symptom Scores
Background
Selected symptoms malaria
Objective
Methods

• Tiredness
• Loss of appetite
• Abdominal pain
• Diarrhoea

Fever Convulsions Headache Vomiting Joint pain
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
13
Computation of Symptom Scores, cont

• Score Fever other symptoms
• Score0, none of these symptoms
• Score1, only fever was reported
• Score2, fever 1 symptom
• Etc

Background
Objectives
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
14
Study Population Characteristics
Factors Factors n
Ethnicity Ethnicity Ethnicity
Kikuyu 367 26.3
Kamba 311 22.3
Luha 199 14.3
Luo 305 21.9
Other 212 15.2
Symptoms Symptoms
Score 0 413 29.6
Score 1 139 10.0
Score 2 291 20.9
Score 3 290 20.8
Score 4 168 12.1
Score 5 93 6.7
Factors Factors n
N N 1394 100
Slums Slums
Korogocho 818 58.7
Viwandani 576 41.3
Sex Sex
Female 654 46.9
Male 739 53.0
Age group (years) Age group (years) Age group (years)
lt5 343 24.6
5-14 235 16.9
15-24 214 15.4
25-39 367 26.3
gt40 235 16.9
Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
15
Top Five Illnesses
Background
416
450
392
Objective
400
320
Methods
350
300
Results
Number of Cases
250
Discussion
165
200
Conclusion
150
100
36
35
30
50
0
Other (160
Malaria
Common cold
Don't know
Typhoid
Pneumonia
Asthma
illnesses)
Illnesses
INDEPTH Network AGM 2007, September 3rd-7th, 2007
16
Distribution of Self-diagnosed Malaria
Factors Factors cases
Ethnicity, x2, plt0.001 Ethnicity, x2, plt0.001 Ethnicity, x2, plt0.001 Ethnicity, x2, plt0.001
Kikuyu 83 22.6
Kamba 101 32.5
Luha 63 31.7
Luo 108 35.4
Other 37 17.5
Symptoms, x2, plt0.001 Symptoms, x2, plt0.001 Symptoms, x2, plt0.001 Symptoms, x2, plt0.001
Score 0 24 5.8
Score 1 15 10.8
Score 2 101 34.7
Score 3 125 43.1
Score 4 76 45.2
Score 5 51 54.8
Factors Factors cases
N N 392 28.1
Slums, x2, p0.008 Slums, x2, p0.008 Slums, x2, p0.008
Korogocho 208 34.1
Viwandani 184 46.9
Sex, x2, p0.250 Sex, x2, p0.250 Sex, x2, p0.250
Female 174 26.6
Male 218 29.5
Age group (yrs), x2, plt0.001 Age group (yrs), x2, plt0.001 Age group (yrs), x2, plt0.001 Age group (yrs), x2, plt0.001
lt5 81 23.6
5-14 50 21.3
15-24 60 28.0
25-39 136 37.1
gt40 65 27.7
Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
17
Risk associated with Self-diagnosed Malaria
Factors Factors OR 95 CI
Ethnicity Ethnicity Ethnicity
Kikuyu 1
Kamba 1.5 1.1 - 2.2
Luha 2.2 1.4 - 3.4
Luo 2.1 1.5 - 3.1
Symptoms Symptoms
Score 0 1
Score 1 2.1 1.1 - 4.3
Score 2 9.4 5.8 - 15.5
Score 3 13.6 8.4 - 22.1
Score 4 14.9 8.8 - 25.3
Score 5 23.7 13.0 - 43.2
Factors Factors OR 95 CI
Slums Slums
Korogocho 1
Viwandani 1.6 1.1 - 2.3
Sex Sex
Female 1
Male 1.1 0.9 - 1.5
Age group (yrs) Age group (yrs) Age group (yrs)
lt5 1
5-14 1.0 0.7 - 1.6
15-24 1.3 0.9 - 2.0
25-39 2.1 1.4 3.0
gt40 1.3 0.9 - 2.0
Background
Objectives
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
18
Discussion
Background

• High level of self-diagnosed-malaria
• Expected high use of anti-malarial drugs
• Risk of development of drug resistance
• Wastage of scarce resources

Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
19
Imported Malaria?

• Risk factors suggest imported malaria
• High risk among age group 25-40 yrs
• High risk among Luos and Luyha from high risk
  areas
• High risk in Viwandani where there is high
  mobility

Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
20
Locally Acquired Infection?
Background

• Locally acquired malaria cannot be ruled out
• Significant proportion of the so-called stable
  population had reported malaria
• Nairobi is not a malaria free zone though the
  transmission may be low

Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
21
Reliability of Self-diagnosed

• Self reported approach for assessing malaria?
• However, very few (5.8) reported malaria without
  fever
• ? number of symptoms was associated with ? risk
  of perceived malaria
• Fever was the basis of reporting malaria

Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
22
Key Messages

• Malaria is perceived as a problem by the
  community of the informal settlements
• Whether misdiagnosis or imported, there is a
  cause for concern for National control programs
• Need for a more comprehensive assessment of
  malaria epidemiology

Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
23
How can DSS help?

• Parasite prevalence surveys
• Data on fever could be routinely collected
• History of travelling should be collected

Background
Objective
Methods
Results
Discussion
Conclusion
INDEPTH Network AGM 2007, September 3rd-7th, 2007
24
Further reading
Yazoumé Yé, Elizabeth Kimani-Murage, John Kebaso
and Frederick Mugisha. Assessing the risk of
self-diagnosed malaria in urban informal
settlements of Nairobi using self-reported
morbidity survey. Malaria Journal 2007, 671

• Thank you for your attention!!!