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Introduction 1

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Title: Introduction 1


1
Introduction 1
Malaria
  • Welcome to the malaria module!
  • Malaria is a major public health problem in warm
    climates especially in developing countries.
  • It is a leading cause of disease and death among
    children under five years, pregnant women and
    non-immune travellers/immigrants.

Children under 5 are the major at risk group in
malarious regions. Inset An Anopheles mosquito
taking a blood meal Sources http//www.ifnc.org/p
ictures.html http//phil.cdc.gov/phil/quicksearch
.asp
For more information about the authors and
reviewers of this module, click here
2
How to use this module
  • This self-directed learning (SDL) module has been
    designed for medical and other health care
    students
  • We suggest that start with the learning
    objectives and try to keep these in mind as you
    go through the module slide by slide, in order
    and at your own pace.
  • Print-out the malaria SDL answer sheet. Write
    your answers to the questions on the mark sheet
    as best you can before looking at the answers.
  • Repeat the module until you have achieved a mark
    of 22/27 (80).
  • You should research any issues that you are
    unsure about. Look in your textbooks, access the
    on-line resources indicated at the end of the
    module and discuss with your peers and teachers.
  • Finally, enjoy your learning! We hope that this
    module will be enjoyable to study and complement
    your learning about malaria from other sources.

3
Introduction 2
Learning Outcomes
  • By the end of the module, you would be expected
    to be able to describe
  • How P. falciparum malaria is a major killer of
    people in warm climates and that children years, pregnant women and non-immune
    visitors/immigrants are at greatest risk
  • The 4 species of malaria, their geographical
    distribution and the major stages of the life
    cycle
  • How malaria is transmitted by the female
    anopheles mosquito and how levels of endemicity
    vary according to climate and mosquito ecology
  • How parasite and host factors determine disease
    severity
  • The clinical features of simple, uncomplicated
    disease and 8 important severe manifestations of
    malaria
  • How malaria is diagnosed by blood film
    examination, antigen detection and molecular
    methods
  • The role of chloroquine, quinine, artemesin and
    other drugs in treatment
  • How malaria can be prevented by reducing
    man-mosquito contact, chemoprophylaxis and
    intermittent presumptive treatment

4
What is malaria ?
Malaria is a disease caused by the protozoan
parasites of the genus Plasmodium. The 4 species
that commonly infect man are
5
The burden of malaria
  • The direct burden of malaria
  • morbidity and mortality
  • Every year, there are about 500 million clinical
    attacks of malaria. Of these, 2-3 million are
    severe and about 1 million people die (about 3000
    deaths every day).
  • Malaria in pregnancy accounts for about 25 of
    cases of severe maternal anaemia and 10-20 of
    low birthweight. Low birthweight due to malaria
    accounts for about 5-10 of neonatal and infants
    deaths.
  • 80 of all malaria cases occur in tropical Africa
    where the disease
  • accounts for 10-30 of all hospital admissions
  • is responsible for 15-25 of deaths in children
    aged
    year.
  • kills an African child every 30 seconds
  • The indirect burden of malaria
  • Human development Impaired intellectual
    development, developmental abnormalities
    (especially following cerebral malaria), lost
    school attendance and productivity at work
  • Economics Malaria retards economic development
    in the developing world. The cost of a single
    bout of malaria is equivalent to over 10 working
    days in Africa. The cost of treatment is between
    US0.08 and US5.30, depending on the type of
    drugs prescribed as required by the local pattern
    of drug resistance.
  • The total cost of malaria in Africa in terms
    of healthcare, treatment and lost productivity,
    is currently estimated to be US12 billion
    every year.

6
Geographical Distribution of Malaria
Although previously widespread, today malaria is
confined mainly to Africa, Asia and Latin
America. About 40 of the worlds population is
at risk of malaria. It is endemic in 91
countries, with small pockets of transmission
occurring in a further 8 countries.
Malaria is transmitted by the female anopheles
mosquito. Factors which affect mosquito ecology,
such as temperature and rainfall, are key
determinants of malaria transmission. Mosquitoes
breed in hot, humid areas and below altitudes of
2000 meters. Development of the malaria parasite
occurs optimally between 25-30oC and stops below
16oC. Indigenous malaria has been recorded as far
as 64oN and 32oS. Malaria has actually increased
in sub-Saharan Africa in recent years. The major
factor has been the spread of drug-resistant
parasites. Other important factors include the
persistence of poverty, HIV/AIDS, mosquito
resistance to insecticides, weak health services,
conflict and population migration.
7
Endemicity and immunity to malaria
  • Endemicity refers to the amount or severity of
    malaria in an area or community. Malaria is said
    to be endemic when there is a constant incidence
    of cases over a period of many successive years.
  • Endemic malaria may be present in various
    degrees. Recognised categories of endemicity
    include
  • A. Hypoendemicity - little transmission and
    the disease has little effect on the population.
  • B. Mesoendemicity - varying intensity of
    transmission typically found in the small, rural
    communities of the sub-tropics.
  • C. Hyperendemicity - intense but seasonal
    transmission immunity is insufficient to prevent
    the effects of malaria on all age groups.
  • D. Holoendemicity - intense transmission
    occurs throughout the year. As people are
    continuously exposed to malaria parasites, they
    gradually develop immunity to the disease. In
    these areas, severe malaria is mainly a disease
    of children from the first few months of life to
    age 5 years. Pregnant women are also highly
    susceptible because the natural immune defence
    mechanisms are impaired during pregnancy.
  • Depending on the intensity of transmission,
    malaria can be stable or unstable, reflecting
    different epidemic scenarios.
  • Stable malaria Sustained incidence over
    several years. Seasonal fluctuations in
    transmission may occur but epidemics are
    unlikely.
  • Unstable malaria- Marked variations in the
    incidence of malaria over time. Population does
    not develop immunity and people of all ages are
    susceptible to severe disease when transmission
    increases.

8
End of Section 1
  • Well done!
  • You have come to the end of the first section.

,
  • We suggest that you answer Question 1 to assess
    your learning so far. Please remember to write
    your answers on the mark sheet before looking at
    the correct answers!

Click to Reveal Answers
9
Question 1Write T or F on the answer sheet.
When you have completed all 5 questions, click on
the box and mark your answers.
Click for the correct answer
  • P. ovale occurs mainly in West Africa
  • P. falciparum is the most important species of
    malaria
  • The largest burden of malaria occurs in South
    East Asia
  • Malaria epidemics are likely to occur in a
    holoendemic area
  • e) Environmental factors which affect mosquito
    breeding are closely related to the intensity of
    malaria transmission

a
b
c
d
e
10
How is malaria transmitted?
  • Malaria parasites are transmitted from one person
    to another by the bite of a female anopheles
    mosquito.
  • The female mosquito bites during dusk and dawn
    and needs a blood meal to feed her eggs.
  • Male mosquitoes do not transmit malaria as they
    feed on plant juices and not blood.
  • There are about 380 species of anopheles mosquito
    but only about 60 are able to transmit malaria.
  • Like all mosquitoes, anopheles breed in water -
    hence accumulation of water favours the spread of
    the disease.

Female Anopheles mosquito taking a blood
meal Sourcehttp//phil.cdc.gov/phil/quicksearch.
asp
11
How does infection develop ?
  • Plasmodium infects the human and insect host
    alternatively and several phases of the parasite
    life cycle are described.
  • During feeding, saliva from the mosquito is
    injected into the human blood stream. If the
    mosquito is carrying malaria, the saliva contains
    primitive stages of malaria parasites called
    sporozoites.
  • Hepatic, tissue or pre-erythrocytic phase
    Sporozoites invade and develop in liver cells.
    The infected hepatocyte ruptures to release
    merozoites.
  • Erythrocytic phase Merozoites then invade red
    blood cells. The red cells lyse and this causes
    bouts of fever and the other symptoms of the
    disease. This cycle repeats as merozoites invade
    other red cells.
  • Sexual phase Sexual forms of the parasites
    develop and are ingested when another female
    anopheles mosquito feeds. These develop into
    sporozoites in the gut of the insect host and
    travel to its salivary glands. Then the cycle
    starts again
  • The life cycle of the malaria parasite is shown
    on the next slide

12
The Malaria Parasite Life Cycle
Click on the diagram to explore different areas
of the life cycle
Show Me
13
The Malaria Parasite Life Cycle
Back
14
The Malaria Parasite Life Cycle
1. Transmission Female anopheles mosquito bites
and releases sporozoites into the blood stream.
These circulate for about 30 mins and then invade
the liver.
15
The Malaria Parasite Life Cycle
2. Pre-erythrocytic phase Also called the
tissue or hepatic phase Takes place in
hepatocytes. The sporozoites mature into
schizonts which rupture to release merozoites.
Duration of this phase depends on the species.
In P. vivax and P. ovale, the schizont may also
differentiate into hypnozoites. These are dormant
forms of the parasite which may remain in the
liver for several months or years and cause
relapse in the human host.
16
The Malaria Parasite Life Cycle
3a. Asexual phase (Erythrocytic
schizogony) Merozoites invade red blood cells.
Here they grow and mature into trophozoites which
appear as ring forms. The trophozoites develop
into schizonts. The infected red blood cells then
rupture to release numerous merozoites from the
schizont to infect other red cells. Merozoite
release results in fever, chills, rigours and
other symptoms of malaria infection.
17
The Malaria Parasite Life Cycle
3b. Sexual phase Some merozoites differentiate
into male and female gametocytes, the forms of
Plasmodia infective to mosquitoes. These are
taken up by a mosquito during another blood meal.
These fuse to form an ookinette in the gut lumen
of the mosquito. The ookinette invades the
stomach wall to form the oocyst. This in turn
develops and releases sporozoites which migrate
to the salivary gland of the mosquito. This
mosquito then goes on to infect another human
host.
18
Severity of disease and host factors
  • In addition to parasite factors, several host
    factors determine the outcome of exposure to
    malaria
  • Naturally-acquired immunity. People who are
    constantly exposed to malaria gradually acquire
    immunity, firstly against clinical disease and
    later against parasite infection. Clinical
    manifestations of malaria are most severe in the
    non-immune. In holoendemic areas, these are
    children aged (especially primagravidae). People of any age
    from areas that are free from malaria, or have
    limited malaria transmission, are at risk when
    they are exposed to malaria.
  • Red cell and haemoglobin variants. Well known
    examples of inherited factors that protect
    against malaria are Haemoglobin S carrier state,
    the thalassaemias and Glucose-6-phosphate
    dehydrogenase (G6PD) deficiency. Malaria provides
    the best known example whereby an environmental
    factor (malaria) has selected human genes because
    of their survival advantage.
  • Foetal haemoglobin (HbF) High levels of HbF
    occur in neonates, and in some people with
    inherited haemoglobin variants, protect against
    severe forms of P. falciparum malaria.
  • Duffy blood group P. vivax requires the Duffy
    blood receptor to enter red blood cells.
    Therefore, people who do not carry the Duffy
    blood group are resistant to this malaria
    species. This explains the rarity of P. vivax in
    Africa, as most Africans are Duffy blood group
    negative.

19
End of Section 2
  • Well done!
  • This is the end of the second section.
  • We suggest that you proceed to answer questions 2
    and 3 to assess your learning further. Do
    remember to write your answers on the mark sheet
    before looking at the right answer!

20
Question 2 Parasite factors and disease
severity. Study the table below. Write down on
your answer sheet 2 features of the biology of P.
falciparum which contribute to it being
responsible for nearly all severe malaria. Then
click on the box and mark your answers.
Click here for the answers
Incubation period is the number of days from
exposure (injection of sporozoites) to the onset
of clinical symptoms.
21
Question 3 The following people are at risk of
severe malariaWrite T or F on the answer
sheet. When you have completed all 7 questions,
click on the box and mark your answers.
Click for the correct answer
a
  • Pregnant women
  • Neonates
  • Immigrants from Europe
  • A 20 year old man who has lived all of his life
    in Nigeria
  • A 3 year old girl resident in an area holoendemic
    for malaria
  • A 10 year old child with sickle cell disease
  • A 3 year old boy with Duffy negative blood group

b
c
d
e
f
g
22
The clinical course of P. falciparum
  • Following a bite by an infected mosquito, many
    people do not develop any signs of infection. If
    infection does progress, the outcome is one of
    three depending on the host and parasite factors
    enumerated in the previous slides
  • Asymptomatic parasitaemia (clinical immunity)
  • Acute, uncomplicated malaria
  • Severe malaria

23
A. Asymptomatic parasitaemia
This is usually seen in older children and
adults who have acquired natural immunity to
clinical disease as a consequence of living in
areas with high malaria endemicity. There are
malaria parasites in the peripheral blood but no
symptoms. These individuals may be important
reservoirs for disease transmission. Some
individuals may even develop anti-parasite
immunity so that they do not develop parasitaemia
following infection.
24
B. Simple, uncomplicated malaria
This can occur at any age but it is more likely
to be seen in individuals with some degree of
immunity to malaria. The affected person, though
ill, does not manifest life-threatening disease.
Fever is the most constant symptom of malaria.
It may occur in paroxysms when lysis of red cells
releases merozoites resulting in fever, chills
and rigors (uncontrollable shivering).
Children with malaria waiting to be seen at a
malaria clinic in the south western part of
Nigeria. Identifying children with severe
malaria, and giving them prompt treatment, is a
major challenge when large numbers attend clinics.
25
The periodicity of malaria fever
  • Erythrocytic schizogony is the time taken for
    trophozoites to mature into merozoites before
    release when the cell ruptures.
  • It is shortest in P. falciparum (36 hours),
    intermediate in P. vivax and P. ovale (48 hours)
    and longest in P. malariae (76 hours).
  • Typical paroxysms thus occur every
  • 2nd day or more frequently in P. falciparum
    (sub-tertian malaria)
  • 3rd day in P. vivax and P. ovale (tertian
    malaria)
  • 4th day in P. malariae infections, (quartan
    malaria)

Note how the frequency of spikes of fever differ
according to the Plasmodium species. In practice,
spikes of fever in P. falciparum, occur
irregularly - probably because of the presence of
parasites at various stages of development.
26
Other features of simple, uncomplicated malaria
include
  • Vomiting
  • Diarrhoea more commonly seen in young children
    and, when vomiting also occurs, may be
    misdiagnosed as viral gastroenteritis
  • Convulsions commonly seen in young children.
    Malaria is the leading cause of convulsions with
    fever in African children.
  • Pallor resulting mainly from the lysis of red
    blood cells. Malaria also reduces the synthesis
    of red blood cells in the bone marrow.
  • Jaundice mainly due to haemolysis.
  • Malaria is a multisystem disease. Other common
    clinical features are
  • Anorexia
  • Cough
  • Headache
  • Malaise
  • Muscle aches
  • Splenomegaly
  • Tender hepatomegaly
  • These clinical features occur in mild malaria.
    However, the infection requires urgent diagnosis
    and management to prevent progression to severe
    disease.

27
C. Severe and complicated malaria
Nearly all severe disease and the estimated 1
million deaths from malaria are due to P.
falciparum. Although severe malaria is both
preventable and treatable, it is frequently a
fatal disease. The following are 8 important
severe manifestations of malaria Click on each
severe manifestation for details
  • Acute renal failure
  • Pulmonary oedema
  • Circulatory collapse, shock or algid malaria
  • Blackwater fever
  • Cerebral malaria
  • Severe malaria anaemia
  • Hypoglycaemia
  • Metabolic acidosis

Note It is common for an individual patient to
have more than one severe manifestation of
malaria!
28
Summary of differences in the clinical features
of severe malaria in adults and children
Frequency of occurrence
29
End of Section 3
  • You have made tremendous progress!
  • This is the end of the third section.
  • You should now be able to answer Question 4 to
    assess what you have learnt. You are to remember
    to write your answers on the mark sheet before
    looking at the right answer!

30
Question 4 Clinical malariaWrite T or F on
the answer sheet. When you have completed all 7
questions, click on the box and mark your
answers.
Click for the correct answer
  • Asymptomatic parasitaemia signifies acquired
    immunity to malaria
  • Symptoms typically occur during the hepatic phase
    of infection
  • Young children with mild malaria require urgent
    assessment and treatment
  • A single convulsion signifies severe disease
  • The clinical signs of acidosis are rapid
    respirations with deep breathing
  • Acute renal failure occurs in older children and
    adults
  • A patient with malaria and dark urine is unlikely
    to be anaemic

a
b
c
d
e
f
g
31
Diagnosis
  • Malaria is a multisystem disease. It presents
    with a wide variety of non-specific clinical
    features there are no pathognomonic symptoms or
    signs. Many patients have fever, general aches
    and pains and malaise and are initially
    misdiagnosed as having flu.
  • P. falciparum malaria can be rapidly progressive
    and fatal. Prompt diagnosis saves lives and
    relies on astute clinical assessment
  • A good history
  • Residence or a recent visit (in the preceding 3
    months) to a malaria endemic area
  • History of fever (may be paroxysmal in nature)
  • Recognise significance of non-specific clinical
    features such as vomiting, diarrhoea, headache,
    malaise
  • Physical examination
  • Identify signs consistent with malaria fever,
    pallor, jaundice, splenomegaly
  • Exclude other possible causes of fever (e.g.
    signs of viral and bacterial infections)
  • The diagnosis of malaria should be considered in
    any unwell person who has been in a malarious
    area recently


32
Investigations
Blood Film Examination Thick and thin blood
films (or smears) have remained the gold
standard for the diagnosis of malaria. The films
are stained and examined by microscopy. Thick
blood film - Used for detecting malaria a
larger volume of blood is examined allowing
detection of even low levels of parasitaemia.
Also used for determining parasite density and
monitoring the response to treatment. Thin blood
film Gives more information about the parasite
morphology and, therefore, is used to identify
the particular infecting species of Plasmodium.
Show Me
Source- SOM 208 Microbiology Syllabus
Show Me
33
Thick blood film
  • A drop of blood is spread over a small area.
    When dry, the slide is stained with Fields or
    Giemsa stains. The red cells lyse leaving behind
    the parasites.
  • Used to detect parasites, even if parasitaemia is
    low
  • Less useful for speciation

Back
34
  • A small drop of blood is spread across a
    microscope slide, fixed in methanol and stained
    with Giemsa stain.
  • The microscopist finds the area of the film where
    red cells are lying next to each other. The fine
    details of the parasites can be examined to
    determine the species.
  • Used for speciation
  • Does not detect low parasitaemia

Thin blood film
Back
35
Appearance of P. falciparum in thin blood films
Ring forms or trophozoites many red cells
infected some with more than one parasite
Gametocytes (sexual stages) After a blood meal,
these forms will develop in the mosquito gut
http//phil.cdc.gov/phil/quicksearch.asp
36
Other methods of diagnosis of malaria
  • These are not routinely used in clinical
    practice. They include
  • Antigen capture kits. Uses a dipstick and a
    finger prick blood sample. Rapid test - results
    are available in 10-15 minutes. Expensive and
    sensitivity drops with decreasing parasitaemia.
  • PCR based techniques. Detects DNA or mRNA
    sequences specific to Plasmodium. Sensitivity and
    specificity high but test is expensive, takes
    several hours and requires technical expertise.
  • Fluorescent techniques. Relatively low
    specificity and sensitivity. Cannot identify the
    parasite species. Expensive and requires skilled
    personnel.
  • Serologic tests. Based on immunofluorescence
    detection of antibodies against Plasmodium
    species. Useful for epidemiologic and not
    diagnostic purposes.

37
Treatment
  • The treatment of malaria depends on a number of
    factors which include
  • severity of the infection whether simple,
    uncomplicated or severe, complicated malaria.
  • parasite factors species, drug sensitivity
    (usually inferred from the known sensitivity
    pattern in the geographical location where the
    infection was acquired)
  • patient factors age, pregnancy, prior
    chemoprophylaxis, known allergies, likelihood of
    drug compliance.
  • In the absence of reliable diagnosis, clinical
    assessment alone can not differentiate malaria
    from other common febrile illnesses. Therefore,
    in this situation, anti-malarial treatment should
    be given routinely for people with fever.

38
Treatment of simple, uncomplicated malaria
single agents
  • 4-aminoquinolines Chloroquine, Amodiaquine.
  • Chloroquine is cheap and widely available and has
    been the most widely used antimalarial drug. It
    is a blood schizonticide - it kills the
    erythrocyte stages but has no effect on the
    exo-erythrocytic (liver) stages or gametocytes.
    Use is now severely limited because of widespread
    resistance of P. falciparum to chloroquine in
    South East Asia, East Africa and other parts of
    Africa. Most cases of P. vivax are still
    sensitive to chloroquine, although resistance is
    emerging.
  • Amodiaquine is an alternative for
    chloroquine-resistant falciparum malaria.
  • Sulphadoxine/pyrimethamine Fansidar has
    replaced choloroquine as first line treatment for
    P. falciparum malaria in many countries, although
    resistance to this drug has also developed
    rapidly
  • Mefloquine useful in areas of chloroquine
    resistance. Blood schizonticide. Use limited by
    adverse effects, especially neuropsychiatric
    disturbances.
  • Artemisinins artemether, artesunate, artheether
    based on the Chinese herb quinhaosu. Rapidly
    acting and effective against gametocytes as well
    as erythrocytic stages (therefore, may reduce
    transmission).
  • Halofantrine Useful in cases of multi-drug
    resistant malaria. Blood schizonticide. May cause
    cardiac arrhythmias and sudden death.
  • 8- aminoquinolines Primaquine is active against
    the exo-erythrocytic forms of P. vivax and P.
    ovale. Primaquine is usually added to the
    treatment to prevent relapses.

39
Treatment of simple, uncomplicated malaria drug
combinations
  • The rapid emergence of resistance to drugs when
    used as single agents has led to the development
    of drug combinations for first-line treatment.
  • Because of rapid action and current low levels of
    resistance, many drug combinations include an
    artemisinin derivative. Examples include
  • Artemether lumefantrine
  • Artesunate mefloquine
  • Non-artemisinin combinations include
  • Chlorproguanil dapsone (Lapdap)
  • Atovaquone Proguanil (Malarone)
  • The choice of which combination to use depends on
    many factors, including the existing pattern of
    resistance and cost.

40
Treatment of severe, complicated malaria
  • Quinine is the most widely used drug. It is
    administered by rate-controlled intravenous
    infusion. Where this is not possible, it can be
    administered by deep intramuscular injection.
    This is less desirable because of slow and
    uncertain absorption and risks such as injection
    abscess and muscle necrosis.
  • Artemisinin derivatives are also used to treat
    severe malaria.
  • Supportive therapy is a vital adjunct to clinical
    management. It includes the general care of the
    unconscious patient, careful fluid balance,
    control of seizures, nasogastric tube feeding,
    correction of metabolic derrangements (e.g.
    hypoglycaemia, metabolic acidosis) and blood
    transfusion for severe anaemia. Bacterial
    infection can also co-exist with severe malaria
    and require antibiotic treatment.

41
Malaria prevention and control- 1
Reducing man-mosquito contact Insecticide-treated
nets (ITNs) are relatively cheap and, if used
correctly, an effective means of preventing
malaria. The development of longlasting nets may
help to overcome the requirement to re-treat nets
with insecticide regularly. The major difficulty
remains achieving high coverage rates of ITNs in
the most at-risk populations. Historically,
indoor house-spraying with residual insecticides
(e.g. DDT) achieved many successes but was not
sustainable. However, some countries still use
this approach as part of their public health
measures against malaria. Other means to reduce
contact for individuals are wearing of protective
clothing and insect repellents at dawn and dusk.
Families are advised to prioritise the use of bed
nets for children under 5 years and pregnant
women the family members at most risk of
developing severe malaria.
42
Malaria prevention and control- 2
  • Chemoprophylaxis - the administration of drugs to
    individuals likely to be exposed to malaria.
  • Indicated in travellers and also pregnant women
    and people with sickle cell disease living in
    malaria endemic areas
  • Effective malaria prophylaxis is challenging
    because of cost, drug resistance and adverse
    effects.
  • The recommendations vary according to likely
    parasite resistance and patient characteristics
    (e.g. age, breastfeeding, pregnancy).
  • Commonly-used drugs include chloroquine and
    proguanil, mefloquine and malarone.

43
Malaria prevention and control- 3
  • Vaccines against P. falciparum
  • Research is progressing rapidly with some recent
    successes. Vaccine development has targeted
    different stages of the parasite life cycle
  • Pre-erythrocytic aimed to either prevent
    sporozoite invasion of hepatocytes or to kill
    infected hepatocytes
  • Blood-stage mainly focussed on antigens involved
    in parasite invasion of red cells
  • Transmission-blocking aimed at preventing
    mosquito infection during blood feeding
  • Other approaches include inducing T-cell immunity
    by using different preparations of an antigen in
    a prime-boost strategy and whole-organism
    vaccines.
  • The most advanced vaccine to date combines a
    circumsporozoite protein with hepatitis-B surface
    antigen (RTS,S/AS02A pre-erthrocytic) and has
    been shown to provide some degree of protection
    in recent trails of both adults and children.

44
Malaria in pregnancy
  • More than 45 million women (30 million inAfrica)
    become pregnant in malaria endemic areas each
    year.
  • Common adverse effects of malaria in pregnancy
    include
  • Maternal anaemia
  • Stillbirths
  • Premature delivery and intrauterine growth
    retardation result in the delivery of low birth
    weight infants
  • The WHO now recommends intermittent preventive
    treatment (IPT) the administration of
    anti-malarial drugs (e.g. sulphadoxine-pyrimethami
    ne) during antenatal care whether or not women
    show symptoms. IPT has been shown to
    substantially reduce the risk of maternal anaemia
    in the mother and low birth weight in the
    newborn.
  • Previously, chemoprophylaxis (e.g. with
    chloroquine) was recommended for all women living
    in malaria endemic areas.

Source http//phil.cdc.gov/phil/quicksearch.asp
45
International initiatives
  • Many international organisations are involved in
    the fight against malaria.
  • The WHO in partnership with UNICEF, UNDP and the
    World Bank initiated Roll Back Malaria (RBM) in
    1998 to promote an effective control strategy to
    combat the disease. The goal of RBM is to halve
    the worlds burden of malaria by 2010. RBM was
    later joined by a broader group of partners
    including governments of countries affected by
    the disease, multi and bilateral agencies, NGOs,
    international private sector representative and
    research groups.
  • RBM focuses on
  • Rapid clinical case detection and provision of
    prompt access to effective malaria treatment,
    especially in the home.
  • Preventing and controlling malaria during
    pregnancy.
  • Promoting the use of insecticide treated bed
    nets (ITN) as a means of prevention, especially
    in young children and pregnant women.
  • Dealing effectively with malaria in emergency
    and epidemic situations.

Prompt effective malaria treatment saves lives
46
End of Section 4
  • You have come a long way!
  • This is the last of the sections.
  • For the section just ended, you should be able to
    answer Question 5 to assess what you have learnt.
    It is still required that you put down your
    answers on the mark sheet before looking at the
    right answer!

47
Question 5 Malaria diagnosis, prevention and
treatmentWrite T or F on the answer sheet.
When you have completed all 6 questions, click on
the box and mark your answers.
7. Quiz 1
Click for the correct answer
  • A well-prepared and stained thick blood film is
    usually the most practical way to diagnose
    malaria
  • Chloroquine prophylaxis is recommended during
    pregnancy in East Africa
  • More than one anti-malarial drug should be used
    for first-line treatment
  • Quinine is the drug of choice for severe malaria
  • Poor compliance with antimalarial therapy favours
    the development of resistance
  • Insecticide-impregnated bednets are used to
    prevent malaria mainly in travellers

a
b
c
d
e
f
48
Sources of information
  • Malaria. Greenwood BM, Bojang K, Whitty CJ,
    Targett GA. Review Lancet 2005 3651487-98.
  • http//mosquito.who.int/cmc_upload/0/000/015/372/R
    BMInfosheet_1.htm
  • These WHO fact sheets developed by the Roll Back
    Malaria Partnership cover many different aspects
    of malaria including prevention with
    insecticide-treated bed nets and treatment with
    atemesinin-based combination therapies
  • http//www.cdc.gov/malaria/
  • The US Centre for Disease Control and Prevention
    site for malaria
  • http//www.malaria.org/
  • Follow the Learn about malaria link on the
    Malaria Foundations website. This contains
    numerous useful and accessible resources.
  • http//www.rph.wa.gov.au/labs/haem/malaria/
  • An interactive resource from the Royal Perth
    Hospital, Western Australia. Contains useful
    self-assessment exercises in malaria diagnosis by
    microscopy that are set in the context of
    clinical cases.

49
End of Module
  • Well done!
  • Now that you have completed the malaria module
    and attempted sectional questions, you may wish
    to take on the full quiz to assess your learning
    for the whole module. Please print out the
    questions
  • The questions may differ slightly from those you
    have come across in the sectional assessment but
    are based on the material covered in this module.
  • END OF MODULE QUIZ
  • You will also find a link to the answers at the
    end of the quiz to measure your performance
  • Please attempt this as many times as you wish.
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