Dengue and malaria Flashcards
dengue mosquitoes
Aedes aegypti
Aedes albopictus
who is prone to dengue shock syndrome
- Infants less than 1 year with primary dengue infection
- Children 1 year older while experiencing a second dengue infection (majority) `
diagnosis of dengue
Serological tests:
PCR and NS1 antigen: during viraemia
Dengue IgM ELISA: more than 1 week after acute infection
Blood tests:
Thrombocytopenia (low platelet count)
- Haematocrit increased by 20% or more
symptoms of dengue fever
- 85% are asymptomatic, rest appear w influenza like symptoms
- Abrupt onset of high fever lasting 2-7 days
- Severe headache with retro-orbital pain
- Muscle & joint pain
- Generalized rash
2 complications of dengue
Dengue Hemorrhagic Fever (DHF)
Dengue Shock Syndrome (DSS)
symptoms of dengue hemorrhagic fever
- acute onset of continuous high fever lasting 2-7 days
- Haemorrhagic manifestations, including at least positive tourniquet test
- Petechiae
dengue shock syndrome clinical features
- Acute abdominal pain
- Cold extremities
- Oliguria
- Lethargy
Duration of shock is short; patient may die within 12-24 hours
dengue vaccine
Live-attenuated
Tetravalent
treatment of dengue
Dengue without warning signs:
Non-severe and usually self limiting
Dengue with warning signs:
- Need strict observation and intervention: intravenous rehydration
- Paracetamol to relieve symptoms
2 other viruses similiar to dengue
chikungunya fever and zika fever
differential symptoms and method of diagnosis for chikungunya fever
Differential symptoms:
Fever that lasts for 2 days then ends abruptly
Arthritis
Photophobia
Diagnosis:
Detect viral RNA with RT-PCR
4 serotypes of malaria virus
Plasmodium falciparum
Plasmodium vivax
Plasmodium malariae
Plasmodium ovale
malaria mosquitoes
Anopheles mosquitoes
- A. sundaicus
- coastal , brackish waters
- A. maculatus
- Clear water, streams, hilly areas
what is the gold standard for malaria lab diagnosis
Giemsa stain microscopy
Gold standard
BUT
Time-consuming, laborious, requires trained personnel
difference between thick smear and thin smear
Thick smear - presence of parasite
Thin smear - Malaria species
thick smear findings
Broken or irregular rings: ‘comma’, ‘exclamation marks’ if malaria parasite is present
thin smear findings of Pf
- Multiple infections in single RBC (infected RBC same size as uninfected cell)
- Crescentic (sausage-shaped) gametocytes
Usually trophozoites and gametocytes seen on film
thin smear findings of Pv
- Enlarged RBCs
- Schüffner’s dots
Usually trophozoites, gametocytes and schizonts seen on film
symptoms of malaria
Prodromal symptoms: Flu-like symptoms, tiredness
Onset symptoms: High fever, headache, chills, vomiting
If untreated within 24 hours, plasmodium falciparum malaria can progress to severe illness, often leading to death
severe malaria symptoms
Pf is main culprit
Symptoms:
Coma
Acidosis
Jaundice
Death
what is rosetting and what is it associated with
binding of infected RBC with uninfected RBC
- parasite inside the RBC produces the PfEMP1 protein which is then expressed on the surface of the cell
Associated with coma and death
Treatment of uncomplicated Pf malaria
Artemisinin-based combination therapies (ACTs)
Artemether + Lumefantrine
Artesunate + Mefloquine
Treatment of Pv malaria
First Choice: Chloroquine + Primaquine in combination
Choice 2: ACTs + Primaquine
For chloroquine-resistant P. vivax
what is primaquine used for and its contraindication
Primaquine:
Added to prevent relapses
Dose and frequency of the administration should be guided by the patient’s G6PD enzyme activity
Severe G6PD or Pregnant woman: contraindicated and should NOT be used
