Malaria and Tick Borne Illnesses Flashcards
What are 5 ways that malaria can be transmitted? MC?
MC - mosquito
Transfusion
Organ transplantation
Needle sharing
Mother to fetus.
What are the 5 recognized types of Plasmodium/malaria? MC?
Plasmodium flaciparum - MC 99.7% cases in Africa
Plasmodium vivax -India & South America
Plasmodium ovale
Plasmodium malariae
Plasmodium knowlesi - new recognized in 2014 - SE Asia-Malaysia.
What is the life-cycle of malaria?
- Mosquito takes a blood meal, injecting sporozoites)
- Sporozoites go to the liver cells, infects the liver cells.
- Liver cells turn into Schizont.
- Schizont rupture and go into the blood.
- Schizont infect RBCs and turn into immature trophozoites
- Trophozoites mature and rupture.
- Ruptured trophozoites turn into schizont again which infect RBCs
- Infected RBC’s can go from immature trophozoites into gametocytes.
- Mosquito bites again and takes ingests the infected gametocytes.
- Macrogametocytes and exflagellated microgametocytes, and microgametocytes turning into macro converted into OOKINETE.
- Ookinete turns into oocyst.
- Oocyst ruptures and releases sporozoites. - Injected into another human to begin the process again.
What are 5 methods of prevention of malaria?
Insect repellent
Anopheles mosquito - nocturnal feeders
Mosquito netting
Permethrin containing clothes, tents, other equipment
Malaria chemoprophylaxis.
Chloroquine is used primarily where? Problem with it? Dosage recommendation?
Chloroquine is used primarily for central america, and is generally well tolerated.
This is weekly dosed through 4 weeks after return
Problem: resistance issues.
Atovaquone/Proguanil (malarone) is dosed how? Any problems?
This is daily dosing to continue through 7 days after return. Want to make sure infection clears.
VERY well tolerated. No resistance to date.
Doxycycline dosing for malaria? Common s/e?
Daily dosing to continue for 30 days after return
Very little resistance reported, and generally well-tolerated - but sun sensitivity is a common s/e
Mefloquine (Lariam) dosing regimen? Areas of resistance? Can be used in what?
Dosed weekly to continue through 4 weeks after return. Can be used in pregnancy.
Areas of resistance in cambodia, laos, and Burma.
Caution: higher rate of side effects - depression, confusion, night terrors, hallucinations, anxiety.
Primaquine dosing regimen? What should you check for before using?
Primaquine is used for both prophylaxis AND antirelaspse therapy (P vivax) - often used in addition to other medications.
Daily dosing to continue for 7 days after return.
Check for G6PD deficiency prior to adminstration - fatal hemolysis.
Tafenoquine (arkoda, Krintafel) dosing regimen? What should you check for before starting?
This is the newest agent, start daily for 3 days prior to travel then weekly through 1 week after return.
DO NOT GIVE IN G6PD deficiency
What are the s/s of malaria? Severe? What pattern do they follow?
Usually a cyclic pattern of Fever, Chills, Headache, Myalgias
Severe cases: seizures, confusion, renal failure, ARDS, coma, death.
How do you diagnose Malaria?
Travel history is important part of diagnosing. B
Laboratory testing - blood smears are the gold standard, best done during episode of fever.
Most sensitive, determines species of malaria, and able to estimate percent parasitemia
What are rapid diagnostic tests to diagnose malaria?
-
Immunochromatogrpahic methodology - Detect malaria antigens
- Limitations - cannot specitate, less sensitivity, need to be confirmed by microscopy, can stay positive for weeeks beyond treatment.
-
PCR
- More sensitive, - referenced lab based.
What is the standard treatment for malaria in the US?
Atovaquone/Proquanil is standard - 4 tablets q day x 3 days.
What effect does malaria have on pregnancy?
Infection potentially more severe in pregancy - higher rate of premature deaths, spontatneous abortions and still birth
Avoid travel if pregnant
What medications are approved for malaria in pregnancy?
Chloroquine and Mefloquine - only approved meds for malaria prophylaxis in pregnancy
Doxy - contraindicated.
What is a mosquito borne virus called “bone break fever”?
Dengue fever.
What is the treatment for Dengue fever?
Treatment is supportive, - avoid NSAIDS - can cause hemorrhagic fever
S/s of Dengue fever?
“Bone break fever” - fatigue, fever, extreme muscle and body aches.
Found in Asia, Central and South America, Africa.
What disease is from the Culex Mosquito?
West Nile Virus
How long does West Nile Virus incubate?
3-14 days
What are the S/s of west nile virus? How do you treat them?
s/s - headache, mental status change, fever, body aches, sometimes rash
1 in 150 develop serious illness like meningitis or flaccid paralysis.
Treatment is supportive.
How do you diagnose West Nile?
Diagnose with serologies IgG and IgM in blood or spinal fluid.
What are the 3 tick borne illnesses?
Lyme disease
Rickettsial diseases
Babesia
Lyme disease is caused by?
Spirochete Borrelia burgdoferi
Where is lyme disease located?
Found in deer ticks,
Found in northeastern, north central, and pacific coastal regions of the US. - All ages are at risk.
S/s of Lyme disease? How long does it Incubate?
Can cause dermatologic rheumatologic, neurologic, or cardiac abnormalities. - Incubates for 3-32 days
What is the characteristic rash of lyme disease?
Erythema migrans - within 30 days of exposure.
Infection can spread to other parts of the body
What are the stages of lyme disease?
- Stage 1 - early infection
- erythema migrans present (75%)
- Fever, myalgias, fatigue
- Stage 2
- conduction abnormalities (5% some sort of AV block)
- Stage 3
- Persistent infection, arthtritis type symptoms, usually not previously treated.
How do you diagnose lyme disease?
History of exposure to ticks is paramount
Serologic testing often negative in 1st week of infection. ELISA followed by Western Blot.
How do you treat Lyme disease?
Doxycycline 100 mg po bid x 21 days.
Children younger than 8 - Amoxicillin 50 mg/kg/day - q8hrs - 14-21 days.
What disease is carried by ixodes scapularis?
Babesia
What tick borne illness is characterized by hemolytic anemia with fatigue, body aches, fever, +/- splenomegaly and hepatomegaly
Babesia
What is the treatment for Babesia?
Atovaquone 750 mg po bid and Azithromycin 500-1000 mg daily x 7-10 days.
What disease is from Rickettsia?
Spotted fever
Where does Spotted fever/Rickettsia come from?
Tick or flea borne
Worldwide occurence
Rocky mountain spotted fever in the southeastern US.
What illness is characterized by fever, headache, abdominal pain, maculopapular rash progressing to petechiae.
Spotted fever/Rickettsia - rash on hands and feet and then spreads to the body.
How do you diagnose Spotted fever/rickettsia?
PCR - acute and covalescent sera.
What is the treatment for Spotted fever/Rickettsia?
Doxycycline 100 mg po bid x 14 days
Doxycycline for kids and preganant women (chloramphenicol also consideration in pregnancy)
You notice Morulae, inclusions in WBCs, what illness is this from?
Anaplasma and Ehrlichia
How do you diagnose and treat Anaplasma and Ehrlichia?
Diagnose by serology - MORULAE (INCLUSIONS IN WBC)
Patient will also have fever and myalgias
Treat with doxycycline
Your friend travels between CO and ID. He presents with fever, rash, headache, pain behind his eyes, and low platelet count. What does he have?
Colorado Tick Fever. - Viral illness
What is Colorado Tick fever, and how do you treat it?
This is a viral tick borne illness that is primarily is Colorado and Idaho. People present with fever, rash, headache, and pain behind their eyes, also thrombocytopenia.
Self limiting - supportive care.
What is the current recommendation for abstience after travel in Zika zone?
Was 6 months - is now 3 months.
What is the main risk of zika virus during pregnancy?
Congenital birth defects - microcephaly
What is caused by the flavivirus? And transmitted by the Aedes aegypti mosquito?
Yellow fever.
Where does yellow fever occur?
Occurs in Saharan Africa and South America.
Flavivirus- transmitted by the Aedes Aegypti mosquito.
What are the symptoms of yellow fever? What can happen initially? What happens if it progresses?
Incubation of 3-6 days with acute onset of fever, myalgias, headache, backache, n/v.
Initially improvement, and then 15% go on to relapse and worsening symptoms.
Progression: - Jaundice, hemorrhagic symptoms, shock, multiorgan failure - death in up to 50% of these cases.
How do you diagnose Yellow Fever?
Based on area of travel
Clinical presentation
History of immunization
Serology and nucleic acid testing available - but problematic
Contact CDC for testing guidence
How do you treat yellow fever?
No treatment - symptomatic care only - avoid NSAIDS as increase risk of hemorrhage.
Can you prevent yellow fever?
YES - vaccine available - live virus
Careful in age > 60 and pregnancy.
