Malaria and Tick borne Illness: Schoenwald (exam 4) Flashcards
Malaria:
- Vector?
- how many forms are there?
- **Mosquito borne-Anopholes (female)
- **5 forms of protozoa-Plasmodium falciparum, vivax, ovale, or malariae-recently human infection with knowlesi
Malaria:
- how many infections/year worldwide?
- MC regions in the world?
- 350-500 million infections/year worldwide, approx. 1 million deaths
- Central and South America, India and Africa high incidence
Malaria:
- risk to travelers?
- epidemiology? (2018 cases)
- Dependent on area of travel and activity
- About 2000 cases annually in US–>Mostly in returning travelers
2018 cases:
- -228 million cases worldwide-transmission in Africa, Asia, Central and South America
- -93% from sub-Saharan Africa
- -Southeast Asia next at 3%
- -85% of all cases from Africa and India
- *405,000 deaths
malaria zones:
-Chloroquine-resisitant?
- subsaharan africa
- -areas of resistance to chloroquine have risen in the last few decades (dark regions on the map are chloroquine-resistant)
-central america, mexico, and parts of south america are the few places left that are chloroquine-sensitive**
Malaria transmission:
-MC mech. of transmission?
- Mosquito=MC*
- transfusion
- Organ transplantation
- Needle sharing
- Mother to fetus
Types of Malaria:
-5 recognized types of Plasmodium:
- Plasmodium falciparum–>most common in Africa 99.7% of cases
- Plasmodium vivax
- India and South America- Plasmodium ovale
- Plasmodium malariae
- Plasmodium knowlesi
- newly recognized in humans in 2014
- primarily in Southeast Asia-Malaysia
Malaria Life cycle
It takes the mosquito vector and the parasite, it makes it to the RBC’s in the end, but it’s housed in the liver first. Once it breaks out of the liver cell, it infects the blood stream (erythrocytes)
-there are different maturation phases
- immature= ring phase
- gametocytes (look like bananas in the RBC’s)= the mature form
- if the mosquito comes along and bites an infected person, the uninfected mosquito gets the gameocytes, and the cycle starts inside the mosquito
Take home message:
- Mosquito is the vector
- liver phases
- RBC phases (more mature infection)
Schoenwald’s take home message regarding malaria life cycle:
Take home message:
- Mosquito is the vector
- liver phases
- RBC phases (more mature infection)
Malaria–> prevention?
- Insect Repellent
- Anopheles mosquito nocturnal feeders
- Mosquito netting
- Permethrin containing clothes, tents, and other equipment (clothing lines that manufacture w/ permethrin– kind of a sticky material)
- Malaria chemoprophylaxis
(notes: anopheles come out at night but DON’T rely on that– so sleeping in mosquito nets may help and insect repelent)
Medications for Malaria Chemoprophylaxis (prevention side):
-**Chloroquine is standard! resistance issues? (where is it primarily used?)
- Used primarily for Central America (it’s not used as much anymore due to resistance)
- Generally well tolerated
- Weekly dosing through 4 weeks after return (start them 1 week prior to their travel leave)
-Note: chloroquine and Atovaquone are the MC used preventative meds
Medications for Malaria Chemoprophylaxis. (*Prevention side): list example medication
- *Atovaquone/Proguanil (Malarone)
- -**NO resistance to date
- -Very well tolerated
- -Daily dosing to continue through 7 days after return
Other Medications that can be used for Malaria Chemoprophylaxis: list 4
- doxycycline
- mefloquine (Lariam)
- Primaquine
- Tafenoquine(Arakoda, Krintafel)
Medications used for Malaria Chemoprophylaxis: doxycycline: --resistance? -tolerated? -dosing?
- Very little reported resistance
- Generally well tolerated-caution **sun sensitivity!
- Daily dosing to continue 30 days after return
(isn’t always the best med since it’s generally sunny areas)
Medications used for Malaria Chemoprophylaxis: Mefloquine (Lariam): -resistance? -S/E? -Dosing?
- Some resistance- primarily in Cambodia, Laos and Burma
- **Higher rate of side effects!! ie depression, confusion, night terrors, hallucinations
- Weekly dosing to continue through 4 weeks after return
- the only FDA med approved in pregnancy for tx of malaria
Medications used for Malaria Chemoprophylaxis: Primaquine: -used for? -Dosing? -what should you check for in the Pt?
Primaquine:
-Used for prophylaxis and antirelapse therapy (P vivax)
- Daily dosing to continue for 7 days after return
- **Check for G6PD-deficiency prior to administration-fatal hemolysis
(use this med in addition to another agent like Larium, but used for Pts who are traveling in areas with high incidence of P vivax)
Medications used for Malaria Chemoprophylaxis: Tafenoquine(Arakoda, Krintafel) -describe this agent -DO NOT give in pts with \_\_\_\_\_\_ -Dosing?
- Newest agent
- **Do not give in G6PD deficiency
- Start daily for 3 days prior to travel then weekly thru 1 week after return
(note: this one has different dosing)
Malaria: Signs and Symptoms
Usually cyclical:
- Fever
- Chills
- Headache
- Myalgias
Severe Cases:
- Seizures
- Confusion
- Renal failure
- Acute respiratory distress syndrome
- Coma
- Death
Diagnostic tools/Lab testing: Malaria
- what part of the hx is the most important?
- what is the *Gold standard test for Malaria?
-*Travel hx is very important part of diagnosing
Laboratory testing:
- -*Blood smears= Gold standard test!
- -It’s the MOST sensitive
- -It Determines species of malaria
- -Able to estimate percent parasitemia
- -*Best if done during episode of fever
Other diagnostic tools/labs for Malaria:
-rapid diagnostic tests?
Rapid diagnostic tests:
- Immunochromatographic methodology
- Detect malaria antigens
Limitations:
- -Cannot speciate
- -Less sensitive
- -Need to be confirmed by microscopy
- -Can stay positive for weeks beyond treatment
-*PCR–> More sensitive. And Referenced lab based
Malaria: tx?
-In the US what is gold standard?
In US:
**Atovaquone/Proquanil standard–>4 tablets po q day x 3 days
(preventative dosing is different than tx dosing!!)
Malaria and Pregnancy:
- infection potentially more ______ in pregnancy
- high rate of _____
severe
- -High rate of premature births, spontaneous abortions and stillbirth
- -Pregnant women should avoid travel to malaria zones
What are the 2 meds that are approved for malaria prophylaxis in pregnancy?
Chloroquine or Mefloquine
Which med is CONTRAINDICATED in pregnant Pts for malaria prophylaxis?
doxycycline**
Dengue Fever:
-is a _____ borne virus
mosquito
Dengue Fever:
- how many strains of this virus?
- Present in which areas?
4
-Present in Asia, Central and South America, Africa