Zoonoses Honor

Science & Health

Requirements

1. What are zoonoses?

   Answer: Zoonoses are diseases and infections that can be naturally transmitted between animals and human beings (and vice versa), caused by viruses, bacteria, fungi, parasites, or other agents. Examples: rabies, toxoplasmosis, leptospirosis, and spotted fever. — Understanding what zoonoses are is the basis for preventing diseases transmitted by animals.

2. What is a Zoonosis Control Center? What are its responsibilities?

   Answer: The Zoonosis Control Center (CCZ) is a public health agency responsible for monitoring, preventing, and controlling zoonoses. Among its responsibilities: controlling animal populations (dogs, cats, rodents, bats), vaccinating animals (e.g., rabies vaccine), collecting stray animals, investigating cases, controlling vectors (mosquitoes, ticks), and guiding the public on responsible pet ownership and disease prevention. — The CCZ protects public health by controlling diseases that pass from animals to people.

3. What is the difference between zoonoses and arboviruses? Give examples of each type.

   Answer: Zoonoses are diseases transmitted between vertebrate animals and human beings (e.g.: rabies, leptospirosis, toxoplasmosis). Arboviruses are diseases caused by viruses transmitted by arthropods, mainly mosquitoes (the name comes from 'arthropod-borne virus'); e.g.: dengue, zika, chikungunya, and yellow fever. The difference is the vector/mode of transmission: a zoonosis comes from a vertebrate animal; an arbovirus comes from the bite of an arthropod. — Distinguishing a zoonosis from an arbovirus helps to understand how each disease reaches people and how to prevent it.

4. Name two zoonoses that can be transmitted by rats and name preventive measures.

   Answer: Two zoonoses transmitted by rats: leptospirosis (transmitted through rat urine, mainly in floodwaters) and hantavirus/plague (associated with rodents). Preventive measures: keep the environment clean and free of clutter, store garbage and food properly, seal cracks and holes, avoid contact with floodwater, and control the rodent population. — Rat control and environmental hygiene are the main ways to avoid diseases transmitted by rodents.

5. Which animals can transmit rabies? What should be done when bitten by an animal?

   Answer: 1) Transmitting animals: rabies can be transmitted by mammals, mainly unvaccinated dogs and cats, bats, and wild animals (monkeys, foxes, raccoons). 2) What to do when bitten: wash the area well with soap and water for several minutes, immediately seek a health service for evaluation and, if indicated, begin the rabies vaccination; whenever possible, identify/observe the animal. — Rabies is almost always fatal when not treated in time — that is why vaccinating animals and getting prompt help are vital.

6. What is toxoplasmosis and what are the main risk groups for this zoonosis? How is it transmitted?

   Answer: 1) What it is: toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii. 2) Main risk groups: pregnant women (it can cause malformation in the baby) and people with low immunity. 3) How it is transmitted: by ingesting raw or undercooked meat with cysts, food or water contaminated with the feces of infected cats, or by contact with contaminated soil/sand. Prevention: cook meat thoroughly, wash food and hands well, and take care with the hygiene of the cats' litter box. — Knowing how toxoplasmosis is transmitted protects pregnant women and people with low immunity in particular.

7. Explain how the following zoonoses are transmitted and how we can avoid them:
   • Tuberculosis;
   • Brucellosis;
   • Leishmaniasis;
   • Cryptococcosis.

   Answer: 1) Tuberculosis (zoonotic): transmitted through unpasteurized milk from infected cattle and via the respiratory route (droplets); avoided by consuming only pasteurized or boiled milk, keeping environments well ventilated, and testing/treating the herd. 2) Brucellosis: transmitted through contact with infected animals (cattle, goats, sheep) and through consumption of raw milk or cheese; avoided through pasteurization of dairy products, vaccination of the herd, and the use of gloves and care in handling animals. 3) Leishmaniasis: transmitted through the bite of the sand fly (phlebotomine), with the dog as the main reservoir; avoided with repellent, fine screens on windows, insecticide collars on dogs, insect control, and elimination of breeding sites (accumulated organic matter). 4) Cryptococcosis: caused by a fungus (Cryptococcus) present in the dried droppings of birds, especially pigeons, and in the soil; infection occurs through inhalation of the spores. It is avoided by preventing the accumulation of pigeon droppings, dampening the area before cleaning, and using a mask and gloves when sanitizing these environments. — Each zoonosis has its own route of transmission — knowing it is what allows for the right prevention.

8. Make a diagram showing the cycle of taeniasis/cysticercosis, demonstrating the forms of contamination, the hosts, and forms of prevention.

   Answer: In the cycle: the human with taeniasis (adult worm in the intestine) eliminates tapeworm eggs in the feces; the pig (Taenia solium) or the ox (Taenia saginata) ingests these eggs and develops cysticerci in the muscles; the human acquires TAENIASIS by eating raw or undercooked meat with cysticerci. Human CYSTICERCOSIS, on the other hand, occurs when a person ingests the tapeworm EGGS (water/food contaminated with human feces), forming cysts in the body, including in the brain. Prevention: cook meat thoroughly, basic sanitation, hand and food hygiene, and treatment of the sick. — Understanding the cycle shows why cooking meat thoroughly and having hygiene and sanitation breaks the chain of contamination.

9. What is spotted fever and how is it transmitted? How can it be prevented?

   Answer: 1) What it is and how it is transmitted: spotted fever is a serious zoonosis caused by bacteria of the genus Rickettsia, transmitted by the bite of an infected tick (the star tick, common on capybaras and horses). 2) How it can be prevented: avoid infested areas; wear light-colored, closed clothing and repellent; inspect the body after passing through brush/pasture and remove ticks correctly; and seek prompt care in case of fever after exposure. — Spotted fever can be fatal if not treated early — protecting yourself from ticks is essential in high-risk areas.

10. What care do we need to take with our pets so that they have a healthy life and to prevent them from getting sick?

    Answer: Care: keep vaccinations (rabies and others) and deworming up to date; take them to the vet regularly; provide clean food and water; maintain the hygiene of the animal and its environment (pick up feces); control fleas and ticks; and practice responsible ownership (do not abandon them and neuter them to control reproduction). — Well-cared-for and vaccinated animals get sick less and do not transmit diseases to the family.