WEEK 10 - Tropical Diseases and Chemoprophylaxis Flashcards

1
Q

Explain how factors like: Geography, Urbanisation, Social inequalities and Conflict influence tropical disease spread and contribute to NTD

NTD - Neglected tropical disease

A

Geography / Climate:
- Tropical disease thrive in high humidity, temp., and warmth
- esp. vector-borne disease

Acsess to Healthcare:
- Tropical disease are common in low-income countries
- Have limited access to healthcare, water and proper sanitation

Urbaninisation:
- Overcrowded living conditions

Poor sanitation:
- ↑ spread of tropical disease
- Inadequate sewage systems
- Contaminated water sources

Tropical disease affects tropical and subtropical areas

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2
Q

What are the 4 causes of tropical disease

A
  1. Vector-borne disease
    • diseases transmitted by insects e.g. mosquitos, flies, ticks
  2. Protozal Infections
    • disease caused by protoza
  3. Bacterial Disease
  4. Helminthic Infections
    • caused by parasitic worm
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3
Q

List 5 examples of tropical diseases

ALL disease is included in PFP exam but NOT integrated

A
  1. Dengue
  2. Yellow fever
  3. Cholera
  4. Typhoid fever
  5. Malaria

NOTE:
- Hard to diagnose as they present like many other conditions = delayed treatment
= ↑ complication risk = ↑ mortality risk

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4
Q

How do we control + prevent the spread of tropical disease

A
  1. Vector control
    - ↓ populations of disease-carrying insects
    - use insecticides
  2. Vaccinations
  3. Improved sanitation
    - access to clean water, imrpoved hygiene
  4. Surveillance and early detectiion
    - monitor disease outbreak, notify GOV
    - provide quick treatment to prevent spread
  5. Health education
    - health campaigns for prevention + seeking help
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5
Q

What is the cause of Malaria

INTEGRATED focues ONLY on Malaria

A

Plasmodium (a protazoan parasite)

5 Plasmodium Species:
1. Plasmodium falciparum – most deadliest
- most commonly seen
- causes many complications
2. Plasmodium vivax – recurring malaria, Asia and Latin America
3. Plasmodium ovale – milder, recurring malaria
4. Plasmodium malariae –chronic often asymptomatic malaria
5. Plasmodium knowlesi –primarily Southeast Asia, can cause severe illness

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6
Q

Describe the transmission of Malaria

A

Plasmodium infects liver cells and RBC
ROUTE: Vector to Human
- also be transmitted via shared needles, blood transfusion or vertically

  1. Plasmodium parasite targets mosquitos
    - virus is transmitted to humans as mosquitos feed on human blood
  2. Infected mosquito bites human + injects sporozites into bloodstream
  3. Sporozites travel to liver where they mature + multiply
  4. Mature sporozites leave liver, enter bloodstream + invade RBC
  5. Invasion causes RBC to burst
    - causes symtpoms e.g. fever
  6. Infection cycle continues:
    • An un-infected mosquito bites an infected human and uptakes the parasite (gamate) from blood
      - Parasite develops in mosquito
      - Mosquito becomes infected + bits another human
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7
Q

What are the symptoms of Malaria and how is it diagnosed

A

SYMPTOMS:
- Fever, chills
- Headache
- Fatigue
- Anaemia
- due to liver being affected
- Muscle aches
- Abdominal discomfort
- GI issues e.g. diarrhoea, constipation
- N&V
- Seizures, coma
- Jaundice
- Respiratory distress
- Pulmonary oedema

DIAGNOSIS:
- Blood tests
- hypoglycaemia, acidsosis, severe anaemia

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8
Q

What is the treatment for Malaria

inc. Severe infection in pregnancy

A

UncomplicatedP. falciparum:
(asymptomatic, not a child / pregnant, have impairment)
1. Artemether with lumefantrine
- if unavailable oral quinine or atovaquone with proguanil
2. Quinine
- highly effective but poorly tolerated (bad SE)
- in combination with one other drug [oral doxycycline or clindamycin]

Severe or complicated P. falciparum:
(child, pregnant, symptoms)
1. HDU or ICU management
2. Immediate treatment
- IV Artesunate (min 24 hours) and step down to oral combination artemisinin when improved
- Alternative: oral quinine + doxy
3. Anti-emetics (for N&V)

Infection by P.falciparum in pregnancy:
- A MEDICAL EMERGENCY + requires HOSPITAL ADMISSION

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9
Q

List the 3 chemoprophylaxis / prevention options for malaria

A
  1. Atovaquone-proguanil (Malarone)
    - Start 1-2 days before travel
    - Taken once daily, before travel, during stay and for 7 days after leaving
    - ADRs: GU upset, headache
    - Most commonly used, has least SE
  2. Doxycycline
    - Start 1-2 days before travel
    - Taken once daily, before travel, during and for 4 wees after leaving
    - NOT SUITABLE: child and pregnancy
    - ADRs: GI upset, sun sensitivity
  3. Mefloquine (Larim)
    - Start 1-2 weeks before travel
    - Taken once weekly, before travel and 4 weeks after leavinf
    - NOT SUITABLE: pregancy
    - ADRs: anxiety, depression, vivid dreams, nightmares

NOTE:
- Not 100% effective = BITE PREVENTION is KEY

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10
Q

Malaria: Special Patient Groups

What risks are associated with malaria in children + pregnancy

A

Children:
- Severe anaemia
- Enlarged liver and spleen
- Hypoglycaemia (low sugar levels)
- Recurrent infections

Pregnant Women:
(have an ↑ risk of being bit as their blood is more attractive to mosquitos)
- Premature labour
- Still birth / infant mortality
- Low birth weight (malaria causes restrictions to growth)
- Congenital malaria, foetal distress
- Maternal anaemia, haemorrhage
- Hypoglycaemia
- Acute pulmonary oedema
- ↑ risk of severe infection
- ↑ risk of recurrence (P.falciparum can remain in placenta)

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11
Q

What advice is given to individuals going to high-risk areas

A
  1. Take chemoprophylaxis
  2. Bite prevention
    • as chemoprophylaxis is not 100% effecive
    • use min. 50% deet repellent
    • use mosquito nets covered in insecticides
    • wear longer clothing
    • know the times of day to avoid
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12
Q

Malaria Vaccine INFO

A

Has been developed + trialled

  • Only given to children (given in 4 doses)
  • R21 = most effective vaccine
  • Vaccine ↓ malaria cases + prevents seasonal malaria
  • HOWEVER vaccine does NOT give life-long immunity
    - may need boosters or annual vaccines
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13
Q

Describe the cause, transmission, signs and symptoms of Dengue

A

CAUSE: Viral

TRANSMISSION: Mosquito bite

SYMPTOMS:
Majority cases are asymptomatic or mild
- Fever
- Severe headache
- Severe abdominal pain
- Eye pain, swollen glands, muscle and joint pain, weakness
- Nausea and vomitting (N&V)
- Rash
- Breathing problems
- Cold skin
- Blood in vomit / stool
- Bleeding gums / nose
Appear 4-10 days after infection
Last 2-7 days

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14
Q

What is the treatment for Dengue

A

Non-specific symtomatic releif
- e.g. paracetamol
- treatment manages symptoms as its a viral disease

  • AVOID NSAIDs (they ↑ bleeding risk)
    - e.g. aspirin, iibuprofen
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15
Q

What is the prevention and control for Dengue

A
  1. Bite prevention (e.g. mosquito nets)
  2. Vector control (e.g. control mosquio breeding)
  3. Odenga Vaccine (not availble for all, specific critieria)
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16
Q

Describe the cause, transmission, signs and symptoms and diagnosis of Yellow fever

A

CAUSE: Arbovirus

TRANSMISSION: Day-biting mosquitos

SYMPTOMS:
- Fever
- Headache
- Loss of apetitie
- N&V
- Rash
- Muscle pain
Last 3-4 days
- Low % develop toxic phase inc: liver & kidney effects, dark urine, abdominal pain with vomitting, high fever, bleeding from mouth, nose, eyes
- leads to death

DIAGNOSIS: PCR test, ELISA test

17
Q

What is the treatment for Yellow fever

A
  1. Non-specific symptomatic relief
    • inc. paracetamol
    • NO NSAIDs
  2. Hydration
18
Q

What is the prevention and control for Yellow fever

A
  1. Bite prevention
  2. Vector (mosquito) control
  3. Vaccination
    • have 80-100% immunity 10 days after recieving
19
Q

Describe the cause, transmission, signs and symptoms of Cholera

A

CAUSE: Bacterium (vibrio cholerae)

TRANSMISSION: Ingestion of contaminated food / water

SYMPTOMS:
Many cases are asymptomatic
- Acute watery diarrhoea (rice water stool)
- Severe dehydration

20
Q

What is the treatment of Cholera

A
  1. Antibiotics
  2. IV Fluids
    - replaces electrolytes + fluids
  3. Oral rehydration solution (ORS)
  4. Zinc (reduces watery diarrhoea)
    - useful in child <5
    - can also ↓ duration of diarrhoea

NOTE:
- Cholera is easily treatable

21
Q

What is the prevention and control of Cholera

A
  1. Vaccination (oral vaccine)
  2. Surveillance of cases
  3. Disease control
    • good hygiene practices, clean water, good sanitation
22
Q

Describe the cause, transmission, signs and symptoms and diagnosis of Typhoid fever

A

CAUSE: Bacterium (salmonella typhi)

TRANSMISSION: Ingestion of contaminated food / water

SYMPTOMS:
- Prolonged fever
- Fatugue
- Headace
- N&V
- Constipation or diarrhoea
If severe: rash, liver / kidney failure, death

DIAGNOSIS: Blood tests

23
Q

What is the treatment for Typhoid fever

A
  1. Antibiotics
24
Q

What is the prevention and control for Typhoid fever

A
  1. Vaccination
    • typhoid conjugate vaccine
    • given to those age 2 and over
    • a live, attenuated oral vaccine
    • does NOT provide LONG lasting immunity
  2. Disease control
    • surveilance of cases
    • clean water access
    • good sanitation and hygiene