1. Malaria incidence in
Limpopo
province, South
Africa, 1998-2007
A.A.M. Gerritsen (Epi Result),
P. Kruger, M.F. Schim van der Loeff, M.P. Grobusch

2. “Malaria - now Limpopo and Mpumalanga suffer.”
(Bateman C. SAMJ. 2008;98:17-18.)
Limpopo province had the highest number of cases (6,369) and
deaths (57) in 2006.
• Malaria endemic in Limpopo, Mpumalanga and KwaZuluNatal
• 2006: 12,098 cases, 87 deaths in South Africa
• Data Malaria Control Programme Limpopo used for
National Health Statistics
Dr. A.A.M. Gerritsen

3. Intermezzo: Basic epidemiology (1)
Descriptive epidemiology analyses the occurrence of health events in the
population by time, place and person.
•
Time: seasons (1998/1999 – 2006/2007, months of
the year)
•
Place: districts (Vhembe, Mopani, Bohlabela,
Waterberg, Sekhukhune, Capricorn)
•
Dr. A.A.M. Gerritsen
Person: sex, age (5-year categories)

4. Intermezzo: Basic epidemiology (2)
Incidence rate gives an indication of the number of new cases in a population.
Incidence rate
Number of people who develop
disease during a specified period
(x 10n)
I=
Sum of the length of time during which
each person in the population is at risk
(or: average number of people in the
population)
61
Dr. A.A.M. Gerritsen

5. Intermezzo: Basic epidemiology (3)
The case-fatality rate gives an indication of the severity of a disease.
Case-fatality rate
Number of people who dying from
disease during a specified period
(x 10n)
I=
Total number of people with disease
in the population
62
Dr. A.A.M. Gerritsen

6. Burden of malaria in Limpopo
The aim of this descriptive study is to give an overview of the malaria incidence
and mortality in this province for the seasons 1998-1999 to 2006-2007.
•
Reported malaria cases: numbers and incidence
rates (using population estimates from Statistics
South Africa)
•
Deaths: numbers and case-fatality rates (CFR)
•
For the whole province, and by sex, age and
district council
•
Chi-square test (for trend) used to test statistically
significant differences
Dr. A.A.M. Gerritsen

7. Higher incidence, equal CFR for men
The mean incidence rate in men was higher than in women. However, the
CFR was similar for both sexes.
•
Total: 58,768 cases, 628 deaths
Per season:
– 6,530 cases (55% men)
– incidence rate 124.5 per 100,000 p-y (145.8 for men,
105.6 for women)
– 70 deaths (54% men)
– CFR 1.1% (both men and women)
Dr. A.A.M. Gerritsen

8. Incidence decreases over seasons
The incidence rates of malaria in Limpopo province show a decreasing trend from
the 1998 – 1999 (173/100,000 p-y) to 2006 – 2007 (51/100,000 p-y) season. The
CFR was fairly stable over the whole period.
Dr. A.A.M. Gerritsen

9. Peak in January
Numbers are very low in June-August. From September onwards
numbers are increasing, peaking in January, and decreasing towards
May.
Dr. A.A.M. Gerritsen

10. 30-39 year olds most affected
Incidence is lowest in the 0 – 4 year olds and then gradually increases and peaks
at the ages of 30 – 39 years, after which it gradually decreases again. The CFR
however, increased with increasing age (to 3.8% for those 60 years and older).
Dr. A.A.M. Gerritsen

11. Vhembe largest burden
Of the six districts of Limpopo, Vhembe has by far the highest incidence rate,
followed by Mopani and Bohlabela. However, the CFR in Capricorn (3.4%) was
high compared to that of the other districts.
Dr. A.A.M. Gerritsen

12. Way forward
The information of this study may serve as baseline data:
to determine the course and distribution of the disease in
Limpopo province over time for research to refine targeted
intervention strategies (prevention, diagnosis, treatment),
and to evaluate those
This information can further guide towards the
development of a malaria elimination strategy for Limpopo
and other epidemic prone malaria areas.
Dr. A.A.M. Gerritsen

13. Questions? Additional information?
Gerritsen AA, Kruger P, Schim van der Loeff MF,
Grobusch MP.
Malaria incidence in Limpopo Province, South Africa,
1998-2007.
Malaria Journal 2008, 7:162.
annette.gerritsen@epiresult.com
Dr. A.A.M. Gerritsen