introduction epidemiology and global situation policies and targets for malaria control strategies...

AN UPDATE ON EPIDEMIOLOGY AND CONTROL OF MALARIA

Introduction Epidemiology and global situationPolicies and targets for malaria controlStrategies for control

Antimalarial drugs Vector control

Progress in malaria control and interventionsSurveillance Summary References

OUTLINE

The WHO has acknowledged that malaria is the most important parasitic disease in the world today.

It is responsible for death and untold suffering among millions of the world population.

INTRODUCTION

EPIDEMIOLOGY

In 1950’s the epidemiological classification for malaria was established by the WHO into:

i. Holoendemic ii. Hyperendemic iii. Mesoendemic iv. Hypoendemic

EPIDEMIOLOGY CONT’D

Malaria kills at least one million persons /year90% of deaths occur in Sub-Saharan AfricaMalaria & poverty are closely interlinked with

one feeding the other in a two way linked causal relationship.

GLOBAL SITUATION

It is estimated that African countries spend up to 40% of their healthcare budgets on efforts to prevent, control & treat malaria.

Effective and efficient health interventions are available.

GLOBAL SITUATION CONT’D

GLOBAL SITUATION: AFRICA

Population displacement Increased vulnerability Exposure to malarial vectors Collapse of health services and supply lines Environmental deterioration

RISK FACTORS OF MALARIA BURDEN

Ensure rapid cure of the infection Reduce morbidity and mortality, including

malaria related anaemiaPrevent the progression of uncomplicated

malaria into severe and potentially fatal disease Reduce the impact of malaria infection on the

fetus during pregnancy Reduce the reservoir of infection Prevent the emergency and spread of drug

resistance Prevent malaria in travellers.

POLICIES AND TARGETS OF MALARIA CONTROL

Vector control Intermittent preventive treatmentChemoprophylaxis Vaccines

PROGRESS IN PREVENTION


Main objective is to reduce significantly the incidence and prevalence of both parasite infection and control malaria.

VECTOR CONTROL

PREVENTION

Progress in vector control: 2 main approaches complemented by other methods

1. Indoor residual spraying (IRS)

2. ITN3. Source reduction (larval

control)1. Formulations containing Bt

4. Environmental management


IRS Recommended during epidemics and other emergency situations

Generally recommended for better sustainability

According to NMCP data, >100million pple were protected by IRS in 2006, including 70million in India and 22 million in the African region.


ITN’s Key strategy for cost-effective malaria prevention

Can reduce malaria related morbidity and mortality by up to 30-50%

2% of children in Africa currently sleep under a bed net treated with insecticide

LLINs

Supplies of ITN to NMCPs were sufficient to protect an estimated 26% of people in 37 African countries.



Chemoprophylaxis Short-term visitors Specific epidemic

emergency situations WHO does not

recommend long term prophylaxis for residents of endemic areas


IPT Pregnant women as part of their antenatal care package.

Infants during contacts with the routine childhood vaccination services such as EPI (IPTi)

Cyclical basis in high endemic areas with high and strictly seasonal transmission patterns.

PROGRESS IN MALARIA CONTROL

Diagnosis: WHO recommendation

Treatment should be based on a laboratory-confirmed diagnosis, with the exception of children under 5years of age in areas of high transmission in whom treatment may be provided on the basis of a clinical diagnosis.


Diagnosis: what’s new?

RDT have been developed, validated & introduced in control programmes.

RDT still need further development and evaluation.

RAPID DIAGNOSTIC TESTS


Treatment: What’s

new?

Resistance is widespread against “old” drugs such as chloroquine and Fansidar.

Fansidar is still in use in some countries but is gradually being replaced in Africa by ACTS.


Treatment: WHO recommendations

Uncomplicated P. falciparum infections should be treated with an ACT

P. vivax with chloroquine and primaquine except where P.vivax is resistant to chloroquine; should be treated with ACT and primaquine.

Ban of artemisinin monotherapies which are still widely used in Africa.

Resolution 19.1.2006

PROGRESS IN CONTROL

Treatment: WHO

Only three co-formulated ACTs prequalify for the list:

1. Artemethar-lumefantrine (Coartem®) from Norvatis Pharma AG

2. Artesunate-amodiaquine from Sanofi-Synthelabo/Guilin

3. Pyronaridine-Artesunate PYRAMAX™ from Shin Poong (S-Korea)


Treatment

42 malaria-endemic countries (23 of them in Africa) have adopted ACTs: 38 as first line treatment and 14 as second-line treatment.

Distribution of ACTs has failed to reach scale envisaged

In areas of high malaria transmission where access to facility-based healthcare is poor Home Management of Malaria (HMM) is recommended.

Strategy to achieve high coverage of prompt and effective antimalarial treatment in in the highly vulnerable group.



HMM 1. Informing and educating mothers 2. Training community-level

providers 3. Supplying pre-packaged quality-

assured medicines.

Household surveys and data from national malaria control programmes (NMCPs) show coverage of all interventions in 2006 was far lower in most African countries than the 80% target set by World Health Assembly.

Surveys in 18 African countries found that 34% of households owned an ITN, 23% of children & 27% of pregnant women

SURVEILLANCE

It accounts for a quarter of all cases in the WHO African region.

Transmission in the south occurs all-year round & is more seasonal in the north.

Almost all cases are caused by P. falciparum but most are unconfirmed.

No evidence of a systematic decline in malaria burden.

IRS is not a national policy. ITN & ACT delivered by NMCP is far below

total requirements.

MALARIA : NIGERIA

In 2006, 3.3 billion people were at risk and nearly 1 million deaths mostly of under 5’s. 109 countries were endemic for malaria in 2008, 45 within African countries.

LLIN, ACT, IRS and IPTi are tools to combat malaria

At least 7 of 45 African countries with relatively small populations, good surveillance and high intervention coverage reduced malaria cases and deaths by 50% or more btw 2000-2007.

SUMMARY

ACT Artemisinin-based combination therapy BMGF Bill & Melinda Gates Foundation Bt Bacillus thuringiensis DDT Dichloro-diphenyl-trichloroethane GSK Glaxo Smith Kline IPT Intermittent preventive treatment IPTi Intermittent Preventive Treatment in infants IPTp Intermittent Preventive Treatment in pregnant women IPTc Seasonal Intermittent Preventive Treatment IRS Indoor Residual Spraying ITN Insecticide-treated net MDG Millennium Development Goals RBM Roll Back Malaria RDT Rapid diagnostic tests UNICEF United Nations Children’s Fund WB World Bank WHO World Health Organization

ABBREVIATIONS

introduction epidemiology and global situation policies and targets for malaria control strategies...

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