Malaria

Question 1

Explain the lifecycle of malaria

Answer 1

Malaria is a blood parasite with an entirely intracellular existence

• Vector is the female Anopheles mosquito.Takes blood meal with parasite in her salvia.
  
  • P. vivax/ovale remain dormant in the liver. Exo-erythrocytic phase (hepatic phase) explains relapses
  • Mulitply in RBC’s leading to anemia
• Treat both liver and blood forms.
• can cause hypoglycemia = malaria consumes sugar in blood

Question 2

How many species of malaria are there?

Answer 2

> 100 species of malaria

Question 3

Which species of malaria is the bad one?

Answer 3

P. falciparum is the BAD ONE

Question 4

What is THE MOST IMPORTANT parasitic disease?

Answer 4

malaria

Question 5

What are the usual clinical manifestations of malaria?

Answer 5

Fever (most commonly), anemia, splenomegaly – all non-specific

*take travel hx!

Question 6

What are the UNusual clinical manifestations of malaria?

Answer 6

• CNS manifestation in P. falciparum – seizures, coma, renal failure, and death.
• Nephrotic syndrome with P. malariae

Question 7

What are the special clinical considerations of P. falciparum?

Answer 7

• Medical emergency
• causes sticky blood cells = poor profusion
• Can die w/in 24 hrs, despite good care
  
  • seizures, renal failure, ARDS, disseminated intravascular coagulation (DIC), severe anemia, hypoglycemia, hypotensive shock
• Increased fetal/maternal mortality

Question 8

Approximately how many are infected with malaria annually?

Answer 8

300-500 million to 1 billion infected annually
*most important of parasitic disease.
Huge economic effect b/c adults & children can develop chronic anemia (cannot learn or work well).

Question 9

Approximately how many people die from malaria each year?

Answer 9

1-3 million / year, mostly children

Question 10

What countries are most affected by malaria?

Answer 10

Sub-Saharan Africa

Question 11

How many cases of malaria occur in the US each year?

Answer 11

1200-1400 cases per year in US

Question 12

How do you diagnose malaria?

Answer 12

• TAKE TRAVEL HISTORY in acute febrile illness of unknown et
• Always r/o malaria febrile patient with international travel to risk area
• thick and thin malaria blood smears - is malaria present (thick) what species (thin, %)
  
  • % of parasites high = bad news
• ask for head of lab to run tests (need expertise)
• Sometimes PCR
• Serum not practical - mostly retrospective dx for CDC’s purposes

Question 13

How might anti-malarial meds affect incubation?

Answer 13

Antimalarial meds can prolong incubation periods. Time frame(s) for incubation should not rule this out as a diagnosis.

Question 14

What is the standard incubation period for

P. falciparum?

Answer 14

7-14 days, but can take longer

Question 15

What is the standard incubation period for

P. vivax?

Answer 15

2-3 weeks or longer

Question 16

What is the standard incubation period for

P. malariae?

Answer 16

More than 3 weeks.

Question 17

Explain how to treat malaria

Answer 17

• Seek consultation from ID, who will consult CDC (24/7 hotline)
• Generally treated with quinine sulfate

Question 18

How do you prevent malaria?

Answer 18

• acquired immunity incomplete
• Natural immunity with sickle cell and thalassemia. Lower mortality rates.
• Poor complacence with anti-malarial meds = chemopophylaxis
• repellant with DEET, long pants, long sorts, tuck pants into socks, etc.