Presentation for in-house capacity-building session at Abuja Clinics, 2003. The material is out-dated but uploaded for the record.

1. MALARIA: New Trends
in Treatment/Vaccination
Presenter – Dr Victor Ordu

2. Malaria (it. “bad air”) is a disease caused by
infection with parasites of the genus
Plasmodium.
First described by Hippocrates
P. falciparum, P. malariae, P. ovale and P. vivax
cause disease in humans.
Falciparum malaria accounts for majority of
complications and deaths.
It is transmitted from person-to-person by female
anopheline mosquitoes during blood meals

3. Distribution
A disease of the
tropics
500 million
cases annually
1 million deaths
every year –
90% of these in
Sub-Saharan
Africa (SSA)
Most deaths are
among children
aged 1 – 59
months

4. Transmission
occurs in 2
forms –
endemic and
epidemic

Endemic –
young children
and pregnant
women are
worst hit
 Epidemic –
population
usually non-
immune & all
age groups
affected

5. Malaria Control
First successful efforts by the ancient
Romans – drainage of marshlands
Cinchona bark used by Peruvians in the
1600s
Discovery of malaria agent by Alphonse
Laveran in 1879
Malaria transmission elucidated by
Ronald Ross (1897)
DDT discovered by Paul Muller in 1942;
first used in Italy in 1944

6. Failure of malaria eradication efforts of the
1950s-60s gave way to an era of maintenance of
malaria-free zone
Control in N. Africa largely successful b/c of
predominance of P.vivax infections. Surveillance
efforts continue in these countries
In SSA resilience of main vector (A. gambiae),
dearth of resources & complacency led to
failure.
In SSA, data shows rise in malaria related
deaths in the 1990s due to drug resistance,
breakdown of control programmes, climate &
environmental change, exposure of non-immune
popns and HIV/AIDS

7. Rolling Malaria Back
WHO initiated Roll Back Malaria campaign
in 1998 to coordinate a global effort at
reducing malaria-related morbidity and
mortality.
African Heads-of-State pledge to fight
malaria at Abuja Summit in 2000.
Private sector involvement
Global Fund to Fight AIDS, Tuberculosis &
Malaria

8. New Strategies and
Technologies
Insecticide-Treated Nets (ITNs)
Intermittent Preventive Treatment (IPT)
Artemisinin-based Combination Therapy (ACTs)
Home-based management of fever (HBMF)
Malaria Early Warning Systems (MEWS)
Vaccine development
Malaria Genomics

9. Insecticide-Treated Nets (ITNs)
Introduced in the mid 1980s
Pyrethroids in use – deltamethrin, labda-cyalothrin
Probably the most effective preventive measure in
use
15% U5s slept under nets; 2% under ITNs
(AMR, 2003)

10. Evidence of some studies show:
 Reduced U5 mortality by 20%
 Reduced Clinical falciparum dx by 50%

Reduced maternal morbidity
Problems of cost; need for relaxation of taxes
and tariffs
Progress – Long Lasting Insecticide treated Nets
(LLINS) can last for 4 – 5 years & resist washing
reduce exposure and environmental
contamination

11. Intermittent Preventive
Treatment (IPT)
2 single-dose administrations of antimalarials at
therapeutic doses during the routine antenatal
visits
Sulfadoxine-pyrimethamine (SP) is drug of
choice (in areas where there is no resistance)
Studies so far indicate a decreased proportion of
women with anaemia and placental infection at
delivery
Complemented by ITNs & effective case
management

12. Artemisinin-based Combination
Therapy (ACTs)
Monotherapies are failing!
Many countries have changed drug policies in
favour of combination therapies especially where
CQ resistance ehas been documented
ACTs are currently recommended (WHO 2004)
due to:
 Documented efficacy
 Likely delay in devt of resistant strains
Costly and hence require donor inputs
 CQ – USD 0.13

SP – USD 0.14

ACTs – USD 1-3
(for adult outpatient treatments)

14. Favoured combinations

Atrmether-lumefantrine (Coartem)

Artesunate-amodiaquine

Artesunate-SP
Non artemisinin based combination are also
acceptable e.g. amodiaquine- SP,

15. Malaria Early Warning Systems
(MEWS)
Used to predict and improve response to
malaria epidemics
Largely employed in the SADC bloc and the
northern fringe of the malaria zone
Involves monitoring vulnerability and
transmission risk factors such as:
 Seasonal climate forecasts
 Rainfall estimates
 Population movements

Entomological indices

16. MEWS often require high degree of
technical expertise and inter-sectoral
collaboration
Very helpful in the event of complex
emergencies such as natural distasters or
civil strife which account for 30% of
malaria deaths (malaria is No.1 killer in
complex emergencies in SSA)

17. Malaria Genomics
Recent advances
 Human genome elucidated
 Genomes of A. gambiae and P. falciparum
(Oct 2002)

P. yoelli – rodent malaria. Provides a model
for studies

18. Possible uses
 Study of mechanisms of drug/insecticide
resistance
 Development of vaccines

Elucidation of mechanisms of immune
evasion
 Genetic engineering of vectors
 Discovery of drug targets

19. Malaria Vaccine Research
Ideal vaccine – multispecies, multistrain
4 general vaccine candidates undergoing
R&D

Pre-erythrocytic (Sporozoite & liver stage) –
e.g. CS, LSAs

Asexual blood stage – e.g. MSPs, AMA-1

Transmission-blocking – Pfs 25 & 28, Pvs 25

Anti-disease – Anti-GPI
Still undergoing clinical trials

20. Thank you