Session 6 Flashcards
(24 cards)
What organism causes malaria?
Plasmodium species (falciparum, vivas, ovale and malarie) protozoa.
How is malaria spread?
Via the female Anopheles mosquito. No case-to-case spread.
What is the incubation period of malaria?
6 or more days. May be over a year in some cases.
What symptoms do malaria patients typically present with?
Fever, chills and sweats in cycles. May also have splenomegaly.
What is the mechanism of infection of malaria?
Sporozites from mosquito are injected into the human; sporozites travel to hepstocytes where they replicate to form merozoites; merozoites infect new RBCs in the liver and replicate to form new merozoites; RBC bursts and the merozoites go on to infect more RBCs. Dormant hypnozoites may remain in the liver and cause a secondary infection.
How is malaria treated?
Malignant using artesunate or quinine and doxycycline.
Benign using chloroquine and primaquine.
How is malaria prevented?
Prevent bites using nets, clothing and repellant; specific chemoprophylaxis before, during and after travel.
How is enteric fever transmitted?
Via fecal-oral transmission due to poor sanitation.
What causes enteric fever?
Salmonella enterica.
How does Salmonella enterica appear histologically?
Gram negative rods.
How does enteric fever spread through the body?
Via the lymph system.
What features of Salmonella enterica make it more effective?
Produces invasion to allow intracellular growth; has fimbrae on the surface to aid in adherence to epithelium over ideal lymphoid tissue.
What are the common symotoms of enteric fever?
Systemic disease due to bactaraemia, fever, headache, abdominal discomfort, constipation, dry cough, relative bradycardia.
What may a patient with enteric fever show on examination?
Anaemia, lymphopenia, raised LFTs.
How is enteric fever treated?
Ciprofloxacin, ceftriaxone used if resistant to ciprofloxacin.
How is enteric fever prevented?
Good food and water hygiene, typhoid vaccine administered to travellers and lab workers.
How is Dengue fever transmitted?
By mosquitos.
What distinguishes the transmission of Dengue fever from malaria?
Dengue fever is spread by mosquitos which will bite during the day, malaria mosquitoes only bite at night.
What symptoms usually result from a first infection with Dengue fever?
Fever, headache, joint and muscle pain, vomiting, widespread flat rash. May be asymptomatic or very severe.
What is the treatment for a first infection of Dengue fever?
Only supportive treatment. Self limiting and lasts 1-5 days.
What can result from reinfection with Dengue fever?
Reinfection with a different stereotype can cause Dengue haemmoragic syndrome or Dengue shock syndrome.
How is influenza spread?
Via droplets or aerosol.
How is ebola spread?
Via direct contact with body fluids.
How is Zika virus spread?
Via the Andes mosquito or by sexual transmission.
