Transcript 10. - University of Alberta

THE NEED OF PREVENTION
PROGRAMMES
IN AFRICA
SARALA NAICKER
Division of Nephrology
University of Witwatersrand
Johannesburg, South Africa
MAJOR PROBLEMS IN AFRICA






Poverty
Rapid urbanization
Overcrowding
Lack of clean water
Inadequate sanitation
Wars, crime, violence
HEALTH PROBLEMS IN AFRICA
•Infectious diseases
43% in Africa
1.2% in developed world
•
•
•
•
•
tuberculosis
malaria
acute respiratory infections
diarrhoeal diseases
HIV/AIDS
•Trauma/ violence
•Increase in non-communicable/ chronic disease
Major causes of death
Causes of death
1. Infections & parasitic
diseases
Developing World (%) Developed world (%)
43
1.2
2. Disease of the
circulatory system
24.5
45.6
3. Cancers
9.5
21
4. Respiratory diseases
4.8
8.1
5. Perinatal & Neonatal
causes
9.1
1
6. Maternal causes
1.5
0
7. Other/unknown
7.7
23.1
WHO,1997
THE GLOBAL BURDEN OF CARDIOVASCULAR
DISEASE MORTALITY (1990-2020)
5.7
3.9
4.1
2.0
2.1
37%
157%
0.6
0.6
3.6
0.8
1.3
130%
1.4
96%
1.6
119%
2.0
0.8
139%
144%
1990
2020
* In million subjects
1990
2020
World
Developed
Developing
10.6 m
20.2 m
4.1 m
5.6 m
6.5 m
14.5 m
CHRONIC RENAL FAILURE
High incidence in Afro-Americans
(Easterling 1977; Mausner et al, 1978;
Rostand et al, 1982)
Impression : 3 - 4 x more prevalent
in Africa (Barsoum et al, 1974;
Abdulla, 1979; Abdullah 1981).
Birth weight and Renal disease
• 2000 Lackland et al. USA:
– Black 30% of population but 69% of ESRD
population
– 70% of ESRD attributed to HT
– Low birth weight associated with ESRD of
all causes
• 1998 Hoy et al. Australia: Aborigines
– 21 x renal disease
– High rate of low BW, HT, T2 DM, CVD,
obesity
People of African Origin
• 1996 Forrester et al. Jamaica: 1610 kids
6-16y
– SBP inversely related to BW
– ↑ HbA1c in children shorter at birth
• 1999 Levitt et al. Soweto: 849 5y olds
– SBP ↓ by 3.4 mmHg for every 1Kg ↑ BW
• 1999 Longo-Mbenza et al. DRC: 2648
school children
– Odds ratio of 2 for ↑ BP with low birth weight
People of African Origin
• 1998 Woelk et al. Zimbabwe: 756 6-7y.o.
– SBP ↑ by 1.73 mmHg for every 1Kg ↓ BW
• 2000 Olatunbosun et al. Nigeria: 988 adults
– Negative correlation with height and IGT but not BP
• 2000 Steyn et al. Soweto (BTT): 964 5y.o.
– SBP and DBP significantly higher in black children
POVERTY, MATERNAL MALNUTRITION, MATERNAL HT
OTHER “HITS”
DM, HT, Pyelonephritis,
obesity, environmental
factors, diet, stress
LOW BIRTH WEIGHT AND
IMPAIRED RENAL
DEVELOPMENT
ACQUIRED
GLOMERULOSCLEROSIS
GLOMERULAR/SYSTEMIC
HYPERTENSION
REDUCED
FILTRATION
SURFACE AREA
GN IN CHILDREN
• 20 year review- 636 children with NS
Indian: Total 286
minimal change 46.8%
FSGS 20.6% (prev. 1.8%)
Black: Total 306
minimal change 14.4%
FSGS 28.4% (prev. 5%)
Bhimma et al, Ped Nephrol,1997
CRF IN NIGERIA
10 year study
368 patients / 10% of medical admissions
Aetiology : Undetermined 62%
Rest- Hypertension 61%
DM 11%
Chronic GN 5.9%
(Mabayoje et al,1992)
CRF IN TROPICAL AND
EAST AFRICA
Aetiology
 Chronic GN
 Hypertension
(Nseka and Tshiani, 1989
McLigeyo and Kaying,1993)
PRIMARY RENAL DISEASE CAUSING
ESRD IN S AFRICA
Hereditary
Other
Cystic disease
Drugs
CIN
Multisystem
Unknown
HPT
GN
0
500
1000
1500
Number of Patients
2000
SADTR 1994
SADTR DATA
• Causes of ESRD in 8576 patients
– GN
– Hypertension
23%
21%
• 25% of adult population
• Malignant hypertension: 16% of hospital
admissions
SADTR, 2000
THE FACTS
40 % of diabetics are at risk of overt
nephropathy
Diabetic patients with renal disease
have a 5-6 fold increased mortality rate
as compared to diabetic patients with
no signs of renal disease or healthy
subjects
THE GLOBAL BURDEN OF
DIABETES (2000-2025)
30.7
38.4
37.5
18.6
24.5
57.2
16.7
25%
102%
22.8
47%
21.8
150%
9.1
39.3
140%
18.2
0.4 0.7
64%
2000
116%
2025
* In million subjects
2000
2025
World
Developed
Developing
154 m
300 m
55 m
72 m
99 m
228 m
DIABETIC NEPHROPATHY
•
•
•
•
•
South Africa 14-16%
Zambia
23.8%
Egypt
12.4%
Sudan
9%
Ethiopia
6.1%
Amos et al (1997). Diabetic Medicine
Type 2 Diabetes Mellitus
90.00%
Blacks
Indians
Total (n=172)
80.00%
70.00%
60.00%
50.00%
40.00%
30.00%
20.00%
10.00%
0.00%
Retinal
Prot.-uria
HPT
Type 2 DM prevalence: 13.7% I
6.7% B
GFR
Creat.
Amod, SEMDSA abstracts 1996
60%
MICROVASCULAR
COMPLICATIONS of DIABETES
MELLITUS
Blacks
Indians
Total (n=47)
50%
40%
30%
20%
10%
0%
Retinal
Prot.-uria
HPT
Type 1 DM
GFR
Creat.
NEPHROTIC SYNDROME
 greater frequency, compared to temperate
regions
 hospital admissions
Zimbabwe 0.5%
Kwazulu Natal , S Africa 0.2%
Uganda 2%
Nigeria 2.4%
Seedat,1996
RENAL DISEASE IN EAST AFRICA
 2-3% of medical admissions
 poor response to treatment
 progression to renal failure
Presentation: commonly – nephrotic
syndrome; age of onset 5-8 years
Infectious aetiology : p malariae,
schistosomiosis, HBV, streptococcal
infections, syphilis, leprosy, filariasis,
hydatid disease
Mc Ligeyo, 1990
GN
•
•
•
•
Sudan
Cote d’Ivoire
Egypt
Saudi Arabia
36.6%
49.1%
11%
28%
Barsoum, 2002
RENAL DISEASE IN NORTH
AFRICA
•
•
•
•
GN
Interstitial nephritis
Diabetic nephropathy
Nephrosclerosis
18-24%
14-32%
5-20%
5-18%
Barsoum, 1998
PREVALENCE OF HbsAg in
CHILDREN
• Urban
• Rural
• Institutionalised
6.3%
18.5%
35.4%
MEMBRANOUS GN
• 306 Black children with NS
• 43% with membranous GN
• 86.2% HBV antigens
HIV AND RENAL DISEASE
• Asymptomatic patients screened: 76
–
–
–
–
Proteinuria > 1gm: 17
Proteinuria < 1gm: 6
Microalbuminuria: 27
Haematuria: 9
• Histology
– HIVAN 48%
Han et al, 2004
RRT IN SUB-SAHARAN AFRICA
HD
Namibia
7
Zimbabwe
59
Botswana
CAPD
IPD
TP
20
38
4
4
3
Sudan
200
150
Congo
2
30
Kenya
80
20
300
6
Variable
± 2/week
Table 2. Renal replacement therapy in Africa
(1993 – 1996)
Country
Population
(millions
28.0
GNP per capita
(US dollars)
2170
Dialysis
(pmp)
78.5
Egypt
60.0
1000
129.3
Libya
5.1
1800
30.0
Morocco
27.0
1010
55.6
Tunisia
8.7
1260
186.5
S Africa
34.4
2560
99.0
Algeria
Frequency of HD
100
1 session/wk
2 sessions/wk
3 sessions/wk
90
80
Percent of patients
70
60
50
40
30
20
10
0
Thailand
Egypt
Tunisia
S. Africa
India
Pakistan Argentina
Mexico
Venzuala
Barsoum, 2002
DIALYSIS PATIENTS WORLD-WIDE
(1996)
Europe: 317,000
China: 30,000
USA: 283,000
India: 20,000
Japan: 167,000
10,000
Latin Am: 82,000
AU/NZL: 11,000
World-ESRD (1996)
Prevalence
Incidence
1,000,000
220,000
South Africa
2560 (25%)
Schena, Kidney Int (Suppl 74), 2000
United States
700
30
Dialysis
25
$ ( billions)
Patients ( x 1,000)
600
Costs
500
20
400
15
300
10
2000
2005
2010
2000
2005
2010
Growth to year 2010 projected on the basis of historical data (19821997) by stepwise autoregression and exponential smoothing models
Xue et al., J Am Soc Nephrol, 2001
Renal replacement therapy is
so costly that there is minimal
probability for the vast
majority of the world’s
population to take advantage
from it
Prevention: Tackling the problems
Diabetes
Hypertension
Glomerular Disease
LIFESTYLE MEASURES
Public education and commitment to health
Smoking 
hypertension
hastens progression to kidney failure
Dietary salt
Obesity
Prudent diet
Exercise
HIGH RISK GROUPS
• Identified at early stage
• Effective management at all levels
Kidney Disease Renoprotection
Programmes
Chronic Kidney Disease
Tx
Dialysis
ESRD
Preparing people
Prevent Progression
KDRP Programmes
Initiator / Injury
Protein leakage, Proteinuria
Locate People at risk
Diabetes, Hypertension, Elderly, HIV
Study before PPP was started
Blood Pressure was poorly controlled
18.4%
81.6%
Controlled
Uncontrolled
Percentage of controlled patients if 80% of the readings are
= or < 140/90
Gauteng Health Department Report 2000
Kidney disease detection and renoprotection
programme in Johannesburg
• 11 intervention clinics
• 4 “usual” care clinics
795 pts evaluated:
35% proteinuria
25% albuminuria
10% micro-albuminuria
HBV VACCINE
• Vaccine coverage rates
– 1st dose
– 2nd dose
– 3rd dose
85.4%
78.2%
62%
Impact of HBV vaccination
on NS in children
• 1984 – 2001
 1984 – 1994
 2000 – 2001
119 children with HBV MN
aRR 0.25/ 105
0.22
0.03
pre-vaccine
 0 – 4 years
 5 – 10 years
0.16
0.46
post-vaccine
0.00
0.19
Bhimma et al, 2003
WHAT IS THE GLOBAL STRATEGY
NEEDED IN LESS-DEVELOPED
WORLD?
Identify apparently healthy subjects at risk of
developing renal and cardiovascular diseases
later in life
Build regional or national prevention strategies
by
developing
therapeutic
intervention
programs
PREVENTION STRATEGIES
• Public education
• Free antenatal care for pregnant women
and children
• Ban on smoking
• Screening for hypertension and diabetes
• Eradication of Schistosomiasis
• HBV vaccine in EPI since 1995
• Effective intervention programmes
A WORLD-WIDE STRATEGY
REQUIRING INTERNATIONAL
PARTNERSHIPS
• Government ministries of health
(and education)
• International Agencies
• Academic centers
• Foundations