06. Malaria

OTHER NAMES
Quartan malaria; falciparum malaria; biduoterian fever; black water fever; tertian malaria; plasmodium
DEFINITION
Malaria is a vector-borne infectious disease caused by protozoan parasites.A parasitic disease characterized by fever, chills, and anemia.
CAUSES

Malaria parasites

Malaria is caused by protozoan parasites of the genus Plasmodium (phylum Apicomplexa). In humans malaria is caused by P. falciparum, P. malariae, P. ovale, and P. vivax. However, P. falciparum is the most important cause of disease and responsible for about 80% of infections and 90% of deaths. Parasitic Plasmodium species also infect birds, reptiles, monkeys, chimpanzees and rodents. There have been documented human infections with several simian species of malaria, namely P. knowlesi, P. inui, P. cynomolgi, P. simiovale, P. brazilianum, P. schwetzi and P. simium; however these are mostly of limited public health importance. Although avian malaria can kill chickens and turkeys, this disease does not cause serious economic losses to poultry farmers. However, since being accidentally introduced by humans it has decimated the endemic birds of Hawaii, which evolved in its absence and lack any resistance to it.

SYMPTOMS
- sequential chills, fever, and sweating
- headache
- nausea and vomiting
- muscle pain
- anemia
- stools, bloody
- jaundice

- convulsion
- coma
SIGNS AND TESTS
Physical examination may show an enlarged liver (hepatomegaly) and an enlarged spleen (splenomegaly).
Tests:
Malaria blood smears given at 6- to 12-hour intervals confirm the diagnosis.
TREATMENT
Drugs Used in Chemoprophylaxis & Treatment

Drug Classification

By chemical groups, some of the major antimalarial drugs are as follows: 4-aminoquinolines—chloroquine, hydroxychloroquine, amodiaquine;* diaminopyrimidines—pyrimethamine, trimethoprim; biguanides—proguanil (chlorguanide,* chlorproguanil*); 8-aminoquinolines—primaquine; cinchona alkaloids—quinine, quinidine; sulfonamides—sulfadoxine, sulfadiazine, sulfamethoxazole; sulfones—dapsone; 4-quinoline-carbinolamines—mefloquine; and antibiotics—tetracycline, doxycycline, clindamycin; and others—halofantrine,* artemisinin (qinghaosu)* and its derivatives, and atovaquone Pyrimethamine and proguanil are known as antifolates, since they inhibit dihydrofolate reductase of plasmodia. Drug combinations used to treat chloroquine-resistant P falciparum malaria include Fansidar (pyrimethamine plus sulfadoxine), Maloprim (pyrimethamine plus dapsone), Lapdap (proguanil plus dapsone), and Malarone (atovaquone plus proguanil). Chloroquine combined with proguanil has been used in prophylaxis in sub-Saharan Africa but is no longer recommended by the Centers for Disease Control and Prevention. Artemisinin and its derivatives are being used in treatment and continue under evaluation in fixed-dose combinations with other drugs: eg, artemether-lumefantrine (co-artemether), artesunate-Fansidar, artesunate-mefloquine, and artesunate-proguanil-dapsone.

Prevention of malaria in nonimmune adult travelers.

TO PREVENT ATTACKS OF ALL FORMS OF MALARIA AND TO ERADICATE P falciparum AND P malariae INFECTIONS   REGIONS WITH CHLOROQUINE-SENSITIVE P falciparum MALARIA: Central America west of the Panama Canal, the Caribbean, Mexico, and parts of the Middle East and China.      Chloroquine        Dose: Chloroquine phosphate, 500 mg salt (300 mg base) orally weekly. Give a single dose of chloroquine weekly starting 1–2 weeks before entering the endemic area, while there, and for 4 weeks after leaving.   REGIONS WITH CHLOROQUINE-RESISTANT P falciparum malaria: All other regions of the world; the frequency and intensity of resistance vary by region.       Malarone (atovaquone [250 mg] combined with proguanil [100 mg] [preferred method])        Dose: One tablet orally daily at the same time each day. Give one tablet the day before entering the endemic area, daily while there, and daily for 1 week after leaving.     Mefloquine (alternative method)        Dose: One 250-mg tablet salt (228 mg base) orally weekly. Give a single dose of mefloquine weekly starting 2–3 weeks before entering the endemic area, while there, and for 4 weeks after leaving.     Doxycycline (alternative method)        Dose: 100 mg orally daily. Give the daily dose for 2 days before entering the endemic area, while there, and for 4 weeks after leaving. TO ERADICATE P vivax AND P ovale INFECTIONS   Primaquine     Start primaquine only after returning home, during the last 2 weeks of chemoprophylaxis. Dose: 52.6 mg salt (30 mg base) daily for 14 days. An alternative regimen in regions where chloroquine is effective in prophylaxis is chloroquine phosphate, 500 mg (salt), plus primaquine phosphate, 78.9 mg (salt), weekly for 8 weeks.

Treatment of malaria in nonimmune adult populations.

Treatment of Infection With All Species (Except Chloroquine-Resistant P falciparum or P vivax)   Treatment of Infection With Chloroquine-Resistant P falciparum or P vivax Strains   Oral treatment of uncomplicated P falciparum or P malariae infection Chloroquine phosphate, 1 g (salt) as initial dose, then 0.5 g at 6, 24, and 48 hours. Oral treatment of P vivax, P ovale infection, or species not identified Chloroquine3,4 as above followed by 0.5 g on days 10 and 17 plus primaquine phosphate, 52.6 mg (salt) daily for 14 days starting about day 4. Treatment of severe attacks Parenteral quinine dihydrochloride or quinidine gluconate. Start oral chloroquine therapy as soon as possible; follow with primaquine if needed. or Parenteral artesunate, artemether, or chloroquine until the patient can take oral chloroquine. Follow with primaquine if needed. Oral treatment of uncomplicated P falciparum resistant to chloroquine Malarone two tablets twice daily with food for 3 days (each tablet contains atovaquone [250 mg] and proguanil [100 mg]). or Quinine sulfate, 10 mg/kg 3 times daily for 3–7 days, plus one of the following: (1) doxycycline, 100 mg twice daily for 7 days; (2) clindamycin, 7 mg/kg 3 times daily for 7 days; (3) tetracycline, 250–500 mg 4 times daily for 7 days. or Artesunate, 4 mg/kg/d orally for 3 days plus mefloquine (750 mg followed by 500 mg 12 hours later). or Mefloquine, 750 mg (salt) followed after 6–12 hours by 500 mg. or Atovaquone/doxycycline, 500 mg/100 mg, twice daily for 3 days. Oral treatment of P vivax resistant to chloroquine Malarone or mefloquine (dosages above). or Quinine plus doxycycline, or tetracycline plus primaquine (dosages above). Parenteral treatment of severe attacks Artemether, or artesunate; followed by oral mefloquine (750 mg followed by 500 mg 12 hours later) or Quinine dihydrochloride or quinidine gluconate plus intravenous doxycycline, tetracycline, or clindamycin. Start oral therapy with quinine sulfate plus the second drug as soon as possible to complete the course of treatment.

EXPECTATIONS (PROGNOSIS)
The outcome is expected to be good in most cases of malaria with treatment, but poor in Falcipamm infection with complications.
COMPLICATIONS
- liver failure and kidney failure
- destruction of blood cells (hemolytic anemia)
- meningitis
- rupture of the spleen and subsequent massive hemorrhage 

Courtesy:

Compiled and Shared By: Habib Anwar 

habib.anwar@hotmail.com