Malaria prevention Flashcards

1
Q

list the different organisms causing malaria malaria

A

there are 100s of plasmodium species but only 5 causes malarial disease in humans :
- P.falciparum
-P.vivax
-P.malaria
-P.ovale
-P.knowlesi

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2
Q

why does sickle-cell anemia protects against malaria ?

A

P vivax attaches to the red blood cells by Duffy antigen and the people with sicle-cell anemia do not have this receptor in their red blood cells

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3
Q

explain the life cycle of the malaria parasite

A

-plasmodium -infected female anopheles mosquito hunts for blood meal in the evening and through the night
- bites a person
the Plasmodium is in a stage of development called the sporozoite waiting patiently in the mosquitos salivary gland .
-through the bite ,sporozoites spill out of the mosquito saliva and make it into the bloodstream .
- the sporozoites reach the liver and mount an attack on the hepatic parenchymal cells= where they start asexual reproduction
-at this point the Plasmodium species vary a bit over the next one to two weeks Plasmodium falciparum plasmodium, malariae and Plasmodium Knwolese->sexual reproduction
- it’s generally asymptomatic
->released into the blood and they infect RED (undergoe other 3transformational changes and asexual reproduction inside the cell)->early trophozoite(ring)->late tropozoite->schizont
- mitosis ->defferentiation into merozoites -> get released to blood ->some merozoites undergo gametogony
- another mosquito takes a bite o the infected person

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4
Q

which places are high risk of malaria or hae high prevence

A
  • SubSaharan countries ->very high risk
    -mostly countries at are at the equator
    Malaria risk in South Africa :
  • low risk - eastern Mpumalanga (Northern KZN)
  • moderate risk - North eastrern Limpopo (among other things that side we are close to other countries that are very high risk such as Mozambique and Zim the boarder is a bit leaky 😅)
  • KZN really tried to eliminate malaria and they seem to be effectie in thier measures
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5
Q

which are people are at risk ?

A

-Travelers( 80% took no prophylaxis and
Of those that took prophylaxis, only 25% took it appropriately)
Most common travel destination – Mozambique
- People living in endemic areas
In South Africa, mainly north-eastern Limpopo and eastern Mpumalanga (northern KZN)
High risk groups :
- people located in endemic areas
-pregnant women
-children under 5
- people with other comobidities e.g HI+

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6
Q

In South Africa when does the risk of Malaria increases andd what is recommanded during this time ?

A
  • June to August ->low risk places ->Only non-drug measures recommended ->places such Mpumalanga ,KZN
  • September to May->MODERATE RISK ->Where malaria chemoprophylaxis is indicated. mefloquine, OR atovaquone-proguanil, OR doxycycline should be used in addition to non-drug measures from .-> (Limpopo)
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7
Q

Which non drug measures can one take against malaria?

A
  1. Remain indoors between dusk and dawn
  2. Wear long, light coloured clothing
    3.Screen doorways and windows
    4.Apply a DEET-containing repellent (repeat every 4-6h if outdoors) the recommanded strength is 20%-50%-> stick ,cream ,lotion and aerisol from brands like Tabard, Peaceful Sleep and Mylol.
    - most effective spray is from Tabard.30%
    -both peaceful sleep and tabard’s stick is 35%
    lotion and cream are useless<20%
  3. Use mosquito mats & coils,
  4. Use (long-lasting) insecticide-treated bed nets & IRS sprayed accommodation.
    7.Spray aerosol insecticide .
  5. Use ceiling fans /air conditioner
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8
Q

name the 3 chemoprophylaxis for malaria

A

1.Atoaquone-proguanil(S2)
2.DOXYCYCLINE (S2)
3. Mefloquine(S4)
( these are effective if the person is adharent , and ALWAYS use non-drug measures to avoid mosquito bites )

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9
Q

How long does someone have to take the malaria chemoprophylaxis and how frequent ?

A

they vary ,
ATOVAQUONE-PROGUANIL (S2):
-frequency -> daily
-start -> 1-2 days before travel.
-continue until-> 7 days after leaving malaria area

DOXYCYCLINE S2:
-frequency ->daily
-start ->1-2 days before travel
-continue until->4 weeks after leaving malaria area

MEFLOQUINE S4:
-frequency -> Weekly
-start -> 1-2 weeks before travel
-continue until-> 4 weeks after leaving malaria area .

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10
Q

what are the most common ADR to Mefloquine ? and special precautions ?

A

ADR:
-nausea
-strange dreams
-dizziness
-mood changes
-insomnia
-headache
-diarrhoea

SPECIAL PRECAUTION :
-Avoid if requires fine motor coordination

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11
Q

what are the most common ADR to Doxycycline ? and special precautions ?

A

-Photosensitivity
-Oesophageal ulceration
-GIT symptoms
-Candida super-infections (GIT/ vaginal)

SPECIAL PRECAUTIONS:
-Sunscreen
-Take with a full glass of water
-Don’t lie down for 1 hr after dose
( for the GIT sx, the drug will be better when taken with food or water ->increase absorption ->fewer side effects )

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12
Q

what are the most common ADR to Atovaquone proguanil ? and special precautions ?

A

ADR :
(Well tolerated)
-Headache
-Mouth ulcers
-Stomatitis
-Abdominal pain

SPECIAL PRECAUTIONS:
Take with water / food for better absorption

for the GIT sx, the drug will be better when taken with food or water ->increase absorption ->fewer side effects )

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13
Q

from people in vulnerable groups where can Mefloquine be used and where not to use it ?

A
  1. pregnacy : use
    2.breastfeeding : use
    3.children : use >5 years
    4.HIV+: potential drug interaction
    5.Epilepsy : contraindicated
    6.psychiatric conditions : contraindicated (even if only as a medical history )
    7.renal /hepatic impairment : contraindicated in severe hepatic impairment .
    8.Diabetics ( monitor glucose levels): use
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14
Q

from people in vulnerable groups where can Atovaquone-proquanil be used and where not to use it ?

A
  1. pregnancy: drug interaction
  2. breastfeeding: USE? (CDC if >5kg baby)
  3. children : >11kg
    4.HIV+:potential drug interactions
  4. Epilepsy: USE
  5. psychiatric conditions: USE
  6. renal /hepatic impairment: contraindicated (GFR<30ml/min)
  7. Diabetics ( monitor glucose levels): USE
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14
Q

from people in vulnerable groups where can Doxycycline be used and where not to use it ?

A
  1. pregnancy: contraindicated
  2. breastfeeding: use?(is it allowed if the trip is short )
  3. children :> 8 years
    4.HIV+:USE
  4. Epilepsy: USE (but there are drug interactions)
  5. psychiatric conditions: USE
  6. renal /hepatic impairment: USE
    8.Diabetics ( monitor glucose levels): high insulin-related hypoglycaemia
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15
Q

From the 3 drugs for malaria chemoprophylaxis rank accounding to the most expensive to least

A
  1. Atovaquone -proguanil (no available in SA public sector )
  2. Mefloquine
  3. Doxycycline

BUT …
(Chemoprophylaxis selection based on efficacy (all recommended options equally effective), safety / tolerability, suitability, then cost)

16
Q

if you were to counsell a patient about malaria preention and prophylaxis ,what could you advise them about ?

A
  1. Take measures to prevent being bitten by mosquitoes.
  2. Take dose at same time every day / same day every week
  3. If you miss a dose, take it as soon as possible and carry on as before.
  4. If vomiting occurs within one hour of taking the dose, repeat it.
  5. Report any adverse effects that occur.
  6. Get a malaria test within 24 hours if you develop fever / flu-like symptoms
17
Q

why is there a need to indiidualise prophylaxis choice for each traveler ?

A
  • Age and weight
  • Pregnant / breastfeeding (contraception; infants)
  • Activities - scuba diving, flying
  • Concomitant medication e.g. ARVs, rifampicin, chloroquine, doxycycline (e.g. for acne), anticoagulants, antimalarial allergy
  • Other medical conditions e.g. epilepsy, mental health problems, diabetes, cardiac patients, renal / hepatic impairment, etc
18
Q

which malaria
chemoprophylaxis are not recommended ?

A
  1. Citronella oil
    - Citronella oil is the most effective of alternative insect repellents – but less effective than DEET and need to be re-applied every 40 – 90min; it has been withdrawn as insect repellent in EU
  2. Artemisinin deriatives ->ONLY use as comination treatment