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Malaria clinical features
 

Malaria clinical features

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    Malaria clinical features Malaria clinical features Presentation Transcript

    • Malaria
      Clinical features and diagnosis
    • EPIDEMIOLOGY
      Malaria is a major public health problem
      Malaria is the fifth most common infectious cause of mortality
      3.3 billion ( half of world’s population ) are at risk of malaria in 109 countries
      In 2009
      • Cases-225 million
      • deaths -7.81 million
      www.searo.who.int
    • Disease Burden in South East Asia Region
      Out of 11 countries of the Region 10 countries are malaria endemic
      15% of the global reported confirmed cases and 2.7% of the global mortality.
      In southeast Asia region India accounts for 80% of cases
      www.searo.who.int
    • India
      80.5% of the population lives in malaria risk areas
      In 2010
      • 15.9 million cases were reported
      • No of deaths- 1023
      nvbdcp.gov.in
    • KSCH data(2010-2011)
      Total no of slides examined -7092
      Total no of positives- 336
      P vivax-291
      P falciparum-45
      Deaths- 10
    • Clinical features
      Children are asymptomatic during the initial phase– the incubation period
      • P falciparum ---- 9-14 days
      • P vivax---- 12-17 days
      • P ovale---- 16-18 days
      • P malariae--- 18-40 days
      • Prolonged in p vivax, partial immunity and incomplete chemoprophylaxis.
    • Prodromal symptoms
      Headache
      Fatigue
      Anorexia
      Myalgia
      Pain in joints
      Chest and abdominal pain
    • Clinical features (cont..)
      The classic presentation is paroxysms of fever alternating with periods of fatigue but otherwise relative wellness
    • Clinical features (cont…)
      Fever is the cardinal symptom of malaria
      Febrile paroxysms associated with rigors , headache, myalgia , back pain, abdominal pain, nausea and vomiting.
      Paroxysms coincide with rupture of schizonts
      P vivax: every 48 hours( benign tertian malaria)
      P falciparum and mixed infections: no periodicity or less appparent.
    • Presentation
      Fever 96%
      Chills 96%
      Headache 79%
      Muscle Pain 60%
      Palpable liver 33%
      Palpable Spleen 28%
      Nausea or vomiting 23%
      Abdominal pain/diarrhea 6%
      (According to the working group of WHO,2001)
    • On the basis of severity malaria can be classified as
      uncomplicated complicated
    • Uncomplicated malaria
      Uncomplicated malaria is defined as symptomatic malaria without signs of severity or evidence (clinical or laboratory) of vital organ dysfunction.
      The signs and symptoms of uncomplicated malaria are nonspecific.
      Malaria isusually suspected clinically on the basis of fever or a history of fever.
      Guidelines for the treatment of malaria – 2nd edition World Health Organization, 2010
    • Complicated or severe malaria
      In a patient with P. falciparumparasitaemia presence of certain clinical features or laboratory parameters classify the patient as severe or complicated malaria
    • Complicated malaria (cont..)
      Clinical features
      Impaired consciousness or unrousable coma
      prostration
      Failure to feed
      Multiple convulsions (more than 2 episodes in 24 h)
      Deep breathing, respiratory distress
    • Complicated malaria (cont..)
      Clinical features (cont..)
      Circulatory collapse or shock, systolic blood pressure < 70 mm Hg in adults and < 50 mm Hg in children
      Clinical jaundice ( serum bil > 3 mg/dl) plus evidence of other vital organ dysfunction
      Haemoglobinuria
      Abnormal spontaneous bleeding
      Pulmonary oedema (radiological)
    • Complicated malaria (cont…)
      Laboratory parameters
      Hypoglycemia (blood glucose < 2.2 mmol/l or < 40 mg/dl)
      Metabolic acidosis (plasma bicarbonate < 15 mmol/l)
      Severe normocytic anaemia (Hb < 5 g/dl)
      Haemoglobinuria
      Hyperparasitaemia(> 2%in low intensity transmission areas or > 5% in areas of high stable malaria transmission intensity)
      Hyperlactataemia (lactate > 5 mmol/l)
      Renal impairment (serum creatinine 3 mg/dl)
    • Clinical profile of Severe malaria in India
      Indian Pediatrics 2003; 40:939-945 
    • Cerebral malaria
      Cerebral malaria is the most severe neurological complication of Plasmodium falciparum
      It is a major cause of acute non-traumatic encephalopathy in tropical countries
    • cerebral malaria (cont..)
      Clinical syndrome characterised by
      Coma (inability to localise a painful stimulus) at least 1 h after termination of a seizure or correction of hypoglycaemia
      Detection of asexual forms of P falciparum malaria parasites on peripheral blood smears, and exclusion of other causes
      WHO. Severe falciparum malaria. Trans R Soc Trop Med Hyg 2000
    • cerebral malaria (cont...)
      Seizures
      Seizures are commonly reported and occur in over 60% of children
      causes of seizures
      • In children not associated with fever at the time of the seizure or electrolyte disturbances.
      • Sequestration of infected erythrocytes
      • Parasite-derived toxins
      • Immune mechanisms
    • Cerebral malaria (cont..)
      Coma
      • Cerebral malaria is a diffuse encephalopathy characterised by coma and bilateral slowing on Electroencephalography
      • coma is potentially reversible.
      Brainstem signs
      • Changes in pupillary size and reaction
      • Disorders of conjugate gaze and eye movements.
      • Abnormal respiratory patterns (such as hyperventilatory, ataxic, and periodic breathing)
      • posture (decerebrate, decorticate, or opisthotonic posturing), and motor abnormalities of tone and reflexes
    • Cerebral malaria (cont..)
      Cerebral malaria should be considered in the differential diagnosis of any patient who has a febrile illness with impaired consciousness who lives in or has recently travelled to malaria endemic areas
      The mortality rate in children is about 20%, and most deaths happen within 24 h of admission.
    • Cerebral Malaria
      Lancet Neurol2005; 4: 827–40
    • Neurological sequelae
      Hemiplegia
      Cortical blindness
      Aphasia
      Ataxia
      Cognitive impairment
      Richard Idro ,Lancet Neurol 2005; 4: 827–40
    • Malarial Retinopathy
      Common in children with cerebral malaria(60%) and may be related to pathological changes
      Malarial retinopathy consists of four main components: retinal whitening, vessel changes(whitening of retinal vessels), retinal hemorrhages, and papilledema
      Bad prognostic indicator
      Lancet Neurol2005; 4: 827–40
    • Anemia of Malaria
      • Hemoglobin less than 8 g/dl, which is equivalent to a hematocrit of less than 24% in a parasitemic individual
      Abdalla S, Weatherall D, Wickramasinghe SN and Hughes M (1980). The anaemia of P. falciparum malaria. Br. J. Haematol. 46: 171
      • World Health Organization has defined severe malarial anemia (SMA) as a hemoglobin less than 5 g/dL or a hematocrit less than 15% seen in the context of malaria but without specifying parasitemia .
      WHO (2000). Severe falciparum malaria. Trans. R. Soc. Trop. Med. Hyg. 94: Suppl. 1.
    • Pancytopenia
      Pancytopenia can occur in both falciparum and vivax infections.
      Can be due to microangiopathic hemolytic anemia, hypersplenism
      Few cases due to bone marrow suppression have and hemophagocytosis have been reported
      J Fam Community Med. 2009;16:71-73
    • Hepatic dysfunction
      In patients with severe malarial infestation, the incidence of jaundice is reported to be around 2.5%
      Transient abnormalities of liver enzymes are most commonly seen
      If serum bil > 3 mg/dl---- severe malaria
      Hepatic encephalopathy is almost never seen.
      Bhalla A J Postgrad Med 2006 Oct-Dec;52(4):315-20.
    • Renal failure
      • In P. falciparum malaria, acute renal failure may develop in 0.1-0.6% of the patients
      Defined as Urine output <400 ml/24 hours in adults (<12 ml/kg/24 hours in children) and a serum creatinine >265 µmol/l (> 3.0 mg/dl) despite adequate volume repletion
      Renal failure is rare in children
      • High mortality (upto 45%)
      Indian Academy of Clinical Medicine Vol. 3, No. 2 April-June 2002
    • Renal failure contd..
      The vulnerable group of patients are:
      with high parasitaemia
      with deep jaundice
      with prolonged dehydration
      patients receiving NSAIDs
      Manifests as ATN ,renal cortical necrosis never develops
    • Metabolic acidosis
      Venous lactate concentration at 4 hours after admission to hospital is the BEST PROGNOSTIC INDICATOR in severe malaria. (>5mmol/l has bad prognosis)
      • This may result form renal failure, but more commonly there is a primary lactic acidosis
      Trans R Soc Trop Med Hyg. 1994 Jan-Feb;88(1):67-73.
    • Hypoglycemia
      Hypoglycemia occurs in 30% of children
      Hypoglycemia is a sign of poor prognosis with a mortality rate as high as 40%.
    • Pulmonary edema/adult respiratorydistress syndrome (ARDS)
      May develop even after several days of antimalarial therapy
      Mortality >80%
    • P vivax…. neglected and not benign
      In recent years, complicated and even fatal cases of malaria due to P. vivax have been increasingly reported
    • Complications of p vivaxcontd..
      Severe anemia
      Acute respiratory distress syndrome (ARDS)
      • Incidence is less in children compared adults
      Coma
      Malnutrition
      Splenic rupture
      Thrombocytopenia
      Acute renal failure and shock
      mortality rate - 1.6% among hospitalized patients
      Trends in Parasitology Vol.25 No.5
    • Diagnosis
      Symptom-based (clinical) diagnosis
      Not possible to accurately diagnose malaria using any one set of clinical criteria
      Microscopy
      Microscopy of stained thick and thin blood smears remains the gold standard for confirmation of diagnosis of malaria.
    • Diagnosis(cont..)
      In profound anemia ---parasite --often absent
      malaria pigment in polymorphonuclear leukocytes and monocytes-- malaria
      If more than 5% of PNM contains visible pigment it denotes poor prognosis.
      Recommendations and IAP plan of action indianpediatrics volume 42 november 2005
    • EXAMINATION OF BLOOD FILM
      A minimum of 100 fields should be examined before concluding the slide to be negative.
      Samples may be examined for at least three consecutive days where clinical suspicion of malaria persists.
    • ADVANTAGE OF MICROSCOPY
      Advantages of microscopy are:
      The sensitivity is high. It is possible to detect malaria parasites at low densities.
      It also helps to quantify the parasite load.
      It is possible to distinguish the various species of malaria parasite and their different stages
      WHO Expert Committee on Malaria. Twentieth report. Geneva, World Health Organization, 2000
    • Diagnosis (cont..)
      Rapid diagnostic tests are immunochromatographic tests that detect parasite-specific antigens in a finger-prick blood sample
      WHO recommends that such tests should have a sensitivity of > 95% in detecting plasmodia at densities of more than 100 parasites per μl of blood
    • Diagnosis RDT..
      Current tests are based on the detection of histidine-rich protein 2 (HRP2), (specific for P. Falciparum)
      pan-specific or species-specific Plasmodium lactatedehydrogenase (pLDH)
      pan-specific aldolase
      Commercially available kit can detect falciparum, vivax and other malaria but cannot differentiate ovale and malarie malaria.
    • Diagnosis RDT..
      HRP-II tests can remain positive for 7-14 days following malaria treatment even when blood doesn't show parasitemia by microscopy
      p LDH is produced by only viable parasite so the tests detecting this antigen becomes negative within 3-5 days of treatment
    • ADVANTAGES OF RDTS IN COMPARISON TOMICROSCOPY
      simple, straight forward ,less time consuming, requiring no special equipment or skill/training
      They can detect P. falciparum infection even when the parasite is sequestered
      This test can exclude mixed falciparum and vivax malaria where the former may not be evident microscopically
    • DISADVANTAGE OF RDTS IN COMPARISONTO MICROSCOPY
      RDTs that target HRP-II of P. Falciparumis unsuitable for assessment of treatment failure and monitoring of drug resistance.
      They do not quantify the parasite load so they do not have prognostic value
    • Disadvantages RDT cont...
      Under optimal conditions an expert microscopist can detect even 5-10 parasite per μl of blood, detection threshold of RDTs are 40- 60 parasite per μl of blood
      Currently, available RDT kits are required to be stored up to or under 30ºC