Malaria is a major public health problem, especially in developing countries. It is caused by Plasmodium parasites and transmitted via the bites of infected Anopheles mosquitoes. The most severe form is caused by P. falciparum, which can lead to complications like cerebral malaria, respiratory distress, and circulatory collapse. Diagnosis involves blood smears to identify the parasite species. Treatment depends on the severity of the case and type of malaria parasite. Children under 5 are most at risk.
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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
3. Geographical Distribution of
Malaria
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.
Although previously
widespread, today
malaria is confined
mainly to Africa, Asia
and Latin America.
About 40% of the
world’s population is at
risk of malaria. It is
endemic in 91
countries, with small
pockets of transmission
occurring in a further 8
countries.
4. Female Anopheles mosquito taking a blood
meal
Source:http://phil.cdc.gov/phil/quicksearch.as
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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.
5. etiology
• P. falciparem
• P. vivax
• P. ovale
• P. malariae
• P. knowlesi
P. falciparem can infect all stage of RBC so it causes
high level of parasitemia and it’s the most common
cause of sever malaria
P. knowlesi is known to infect only monkey.
P. vivax & ovale infect immature RBc while P malariae
infect older RBC
6. Clinical Manifestations
• Febrile paroxysms are characterized by high
fever, sweats, and headache, as well as
• myalgia, back pain, abdominal pain, nausea,
vomiting, diarrhea, pallor, and jaundice.
7. • Periodicity is less apparent with
1. P. falciparum and mixed infections and
2. may not be apparent early on in infection
3. when parasite broods have not yet
synchronized.
,
8. Diagnosis
P. falciparum malaria include symptoms
occurring
• less than 1 mo after return from an endemic
area,
• more than 2% parasitemia,
• ring forms with double chromatin dots, and
• erythrocytes infected with more than 1
parasite
9. diagnosis
• Giemsa-stained smears of peripheral blood or
by rapid immunochromatographic assay
• thick smear, is used to quickly scan large
numbers of erythrocytes
• thin smear ,malaria species and
determination of the percentage of infected
erythrocytes and is useful in following the
response to therapy
10. non-severe malaraia
Diagnosis
The child has:
• fever (temperature ≥37.5 °C or ≥99.5 °F) or
history of fever, and
• a positive blood smear or positive rapid
diagnostic test for malaria.
11. Sever malaria
• P. falciparum is the most severe form of
malaria and is associated with higher density
parasitemia and a number of complications.
• common serious complication is severe
anemia(but not unique)
12. WHO CRITERIA FOR SEVERE MALARIA
• Impaired consciousness(coma)
• Prostration
• Respiratory distress .deep, laboured breathing while
the chest is clear,sometimes accompanied by lower
chest wall indrawing
• Multiple seizures
• Jaundice
• Hemoglobinuria(blackwater fever)
• Abnormal bleeding
• Severe anemia-all children with a haematocrit of
≤15% or Hb of ≤5 g/dl
• Circulatory collapse
• Pulmonary edema
13. Sever malaria on px
• fever
• lethargic or unconscious
• generalized convulsions
• acidosis (presenting with deep, laboured
breathing)
• generalized weakness (prostration), so that the
child can no longer walk in the abscence of
impaired consiousness
• cant sit up without assistance
14. Sever malaria on px
• jaundice
• respiratory distress, pulmonary oedema
• shock
• bleeding tendency
• severe pallor.
15. Sever malaria Laboratory
investigations.
• severe anaemia (haematocrit <15%; haemoglobin <5 g/dl)
• hypoglycaemia (blood glucose <2.5 mmol/litre or <45
mg/dl).
In children with altered consciousness and/or convulsions,
check:
• blood glucose.
In addition, in all children suspected of severe malaria,
check:
• thick blood smears (and thin blood smear if species
identification required)
• haematocrit.
16. • P. ovale malaria is the least common type of
malaria.
• P. malariae is the mildest and most chronic of
all malaria infections .
• Nephrotic syndrome is a unique complication
to P. malariae
17. • Recrudescence after a primary attack may
occur from the survival of erythrocyte forms
in the bloodstream
• Long-term relapse is caused by release of
merozoites from an exoerythrocytic source in
the liver, which occurs with P. vivax and P.
ovale, or from persistence within the
erythrocyte, which occurs with P. malariae
18. Complications
• unique to P. falciparum include
1. cerebral malaria,
2. acute renal failure,
3. respiratory distress from metabolic acidosis,
algid malaria
4. and bleeding conditions
19. Cerebral malaria
• defined as the presence of coma in a child
with P. falciparum parasitemia and an
absence of other reasons for coma
• It is associated with a fatality rate of 20-40%
and is associated with long-term cognitive
impairment in children
20. px
• Normal or
• High fever, seizures, muscular twitching,
rhythmic movement of the head or
extremities
• Hemiplegia
• positive Babinski sign
21. Respiratory distress
• is a poor prognostic indicator in severe
malaria and appears to be due to metabolic
acidosis rather than intrinsic pulmonary
disease
22. Circulatory collapse (algid malaria)
complication that manifests as
• hypotension,
• hypothermia,
• Rapid weak pulse,
• shallow breathing,
• pallor, and
• vascular collapse.
23. Tropical splenomegaly syndrome
• a chronic complication of P. falciparum
malaria in which
• massive splenomegaly persists after
treatment of acute infection
• syndrome is characterized by
1. marked splenomegaly,
2. hepatomegaly,
3. anemia, and an elevated IgM level