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EPIDEMIOLOGY OF INFECTIOUS DISEASES
Pamela M. Aducal, RPh, MSc
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Types of Microorganisms
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COMMON DISEASES IN
HUMAN BEINGS
Viral Diseases
• Pneumotropic diseases (Respiratory tract infected by Influenza)
• Dermotropic diseases (skin and subcutaneous tissues affected by
chicken pox and measles)
• Viscerotropic diseases (blood and visceral organs affected by yellow
fever and dengue fever)
• Neutrotropic diseases (CNS affected by rabies and polio)
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Protozoan diseases
Protozoan diseases
1. Amoebiasis
- Entamoeba hystolitica
- House flies (Musca domestica) acts as a carrier for transmitting
the parasite from contaminated faeces and water.
- Symptoms of amoebiasis can range from diarrhoea to dysentery with
blood and mucus in the stool.
2. African sleeping sickness
- Trypanosoma spp.
- blood sucking Tsetse flies.
Vector
Disease
1. T. gambiense
Organism
Glossina palpalis (Tsetse
fly)
Gambian or Central
Africal sleeping sickness
2. T. rhodesiense
Glossina morsitans
Rhodesian or East
African sleeping sickness
3. T. cruzi
Triatoma megista
Chagas disease or
American
trypanosomiasis
Protozoan diseases
Protozoan diseases
3. Kala-azar
- Leishmania donovani
- Transmitted by Phlebotomus (sand fly)
- Symptoms of Kala azar are weight loss, anaemia, fever, enlargement
of spleen and liver.
3. Malaria
- transmited from one person to another by the bite of the infected
female Anopheles mosquito.
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Fungal diseases
Helminthic diseases
• The two most prevalent helminthic
diseases are Ascariasis and Filariasis.
1. Ascariasis
- Ascaris lumbricoides commonly called
the round worms
- transmitted through ingestion
of embryonated eggs through
contaminated food and water
Helminthic diseases
2. Filariasis
- Wuchereria bancrofti , commonly
called filarial worm.
- The life cycle is completed in two hosts,
man and the female Culex mosquito
- The female filarial worm gives rise
to juveniles called microfilariae larvae.
- The accumulation of the worms block the
lymphatic system resulting in
inflammation of the lymph nodes.
Assessment schedule:
- May 3, 2023 (Wednesday) 12:00NN-1:00PM
- Coverage: Lecture + Hand outs provided
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