Exemplar Problems
Question:
How does the transmission of each of the following diseases take place?
(a) Amoebiasis
(b) Malaria
(c) Ascariasis
(d) Pneumonia
Answer:
(a) Amoebiasis:
Transmission of Amoebiasis primarily occurs through the ingestion of contaminated food or water.
The disease is caused by the amoeba parasite Entamoeba histolytica.
Individuals become infected when they consume food or water that contains cysts of the parasite. These cysts can survive in the environment and are shed in the feces of infected individuals.
Poor sanitation and hygiene practices contribute to the spread of Amoebiasis.
(b) Malaria:
Malaria is primarily transmitted through the bite of infected female Anopheles mosquitoes.
The disease is caused by various species of the Plasmodium parasite, such as Plasmodium falciparum and Plasmodium vivax.
When an infected mosquito bites a person, it injects the parasite into the bloodstream.
The parasite then multiplies in the liver and infects red blood cells, causing the characteristic symptoms of malaria.
(c) Ascariasis:
Ascariasis is transmitted through the ingestion of soil, food, or water contaminated with the eggs of the roundworm Ascaris lumbricoides.
The eggs are shed in the feces of infected individuals and can contaminate the environment.
When people consume contaminated food or water without proper hygiene, they can become infected.
The eggs hatch in the intestine, and the larvae migrate to the lungs and back to the intestine, causing symptoms.
(d) Pneumonia:
Pneumonia can be caused by various pathogens, including bacteria, viruses, and fungi.
Pnemonia is usually caused by Streptococcus pneumoniae Transmission of pneumonia depends on the causative agent:
Bacterial Pneumonia: Often spreads through respiratory droplets when an infected person coughs or sneezes. It can also occur through contact with contaminated surfaces or objects.
Viral Pneumonia: Typically spreads through respiratory droplets and close contact with an infected person.
Fungal Pneumonia: May result from inhaling airborne fungal spores, often found in the environment.
Proper respiratory hygiene, vaccination (for some types), and infection control measures are essential for prevention.
BETA
