004 Malaria pathology pathophysiology medicine

Internal medicine slide discussing the etiology, and management of malaria

1. MALARIA BY DR. Y B JIBRIN

2. MALARIA Malaria is caused by a protozoa called plasmodium Four species of the plasmodium are recognized ( P. falciparum, p. Vivax , P.ovale and P. malariae ) It is transmitted by the bite of female anophelus mosquito It occurs throughout the tropics and sub-tropics Globally, there are approximately 515 million cases of malaria annually 75% of cases occur in sub-Saharan Africa

3. Malaria is still a major cause of morbidity and mortality in Nigeria Nigeria alone contributes to 23% (almost a quarter) of the global malaria cases 90% of Nigerian population is at risk 60% of the case burden in health facilities 30% of hospitalizations among children under five years of age in Nigeria The economic burden of malaria is N 7,340 per head

4. Pathogenesis of malaria

5. Pathophysiology Red cells infected with malaria are prone to haemolysis leading to anamia which is more severe with P. falciparum In P. falciparum , red cells containing trophozoites adhere to vascular endothelium of kidney, liver, brain, lungs and gut; they also form rouleaux with uninfected red cells These results in widespread organ damage Rupture of schizonts releases toxic and antigenic substances leading to the clinical features seen in patients with malaria infection

6. Clinical features The clinical features are nonspecific Clinical diagnosis of malaria must be suspected in anyone living in or travel to endemic area P. falciparum infection This is the most dangerous of the malarias and patients are either “killed or cure” The symptoms are usually insidious with: Malaise, Headache, Vomiting, Cough, diarrhoea Fever with no particular parttern Mild tender hepertomegaly and splenomegaly, Palor

7. Symptoms of complication like, cerebral malaria especially in children and immunocompromised, complication of pregnancy

8. P. vivax and P ovale infection symptoms starts with several days of continued fever before the development of classical alternate day fever with rigor The patient feels cold and the temperature may rise up to 40 oc After 30 min to 1 hour, the hot or flush phase begins and last several hours then give way to profuse sweating and a gradual fall in temperature The cycle is repeat 48 hours later

9. p. malariae It is usually associated with mild symptoms and fever occur every third day Chronic P. malariae infection causes glomerulonephritis and nephrotic syndrome in children 

10. Investigation Giemsa stained thick and thin blood films for malaria parasite or by malaria rapid diagnostic tests (RDTs) is recommended in all patients suspected of malaria before treatment is started Malaria antigen detection using immunochromatography DNA detection is used mainly in research

11. Treatment of malaria Mild P falciparum It is resistant to chloroquine and sulfodoxin-pyrimethamin ( Fansidar ) Artemisinin -based combination therapy (ACT)treatment is recommended worldwide Commonly used combination is artemether and lumefantrin ( Coatem ) It is given 4 tablets at 0, 8, 24 36, 48 and 60 hours. Other combinations are artesunate amodiaquine and artisunate mefloquine

12. Alternative treatments are: Quinine 600mg 3 times daily for 7 days Clindamycin (450mg 3 times daily for 7 days) Artovaquine-proguanil 4 tablets once daily for 3 days Avoid atemether in early pregnancy

13. Management of complicated P. falciparum Severe malaria should be considered in any non-immune patient Severe malaria is a medical emergency Immediate commencement of antimalarial therapy Active treatment of complication

14. Correction of fluid and electrolytes and acid base balance Treatment of choice is intravenouse artisunate , however as soon as the patient recovers it should be changed to oral tablets Intravenous Quinine can also be used

15. Management of non-falciparum malaria Other non-falciparum malaria should be treated with oral Chloroquine 600mg stat followed by 300mg after 6 hours then 150mg twice daily for 2 days

16. Prevention Chemoprophylaxis using chloroquine , proguanil or Fansidar in high risk group Use of perimethrin -impregnated mosquito nets and long lasting insecticide treated nets (ITNs) Malaria vaccine (being evaluated) Vector (mosquito) control

17. The end