Biological Hazards and Human Health

Comprehensive practice flashcards covering biological hazards, types of pathogens, immunity, transmission routes, and detailed sections on bacterial, viral, and protozoan infectious diseases.

What is the definition of Zoonosis?

An infectious disease that is transmissible to humans from other animals.

What are the four main types of pathogens described in the lecture?

Worms (multicellular, parasitic), Protozoa (unicellular, parasitic), Bacteria (unicellular, most not parasitic), and Viruses (strands of DNA or RNA, parasitic).

How does active immunity differ from passive immunity?

Active immunity occurs when the body produces antibodies upon first exposure to an antigen (often via vaccination), while passive immunity involves the preparation and administration of antibodies directly.

What is 'herd immunity'?

Practical protection that occurs if enough members of a group are immune, making it difficult to maintain the chain of infection.

What is the distinction between isolation and quarantine?

Isolation is the separation of persons who have an infectious illness, whereas quarantine is the separation of persons who have been exposed to an infectious agent.

According to global patterns, what are the three leading infectious causes of death?

Respiratory infections ($29\%$), diarrheal disease ($20\%$), and HIV/AIDS ($14\%$).

Which infectious agents are known to cause Liver, Cervix, and Stomach cancer respectively?

Liver: Hepatitis B and C viruses or liver fluke; Cervix: Human papilloma virus; Stomach: Helicobacter pylori bacterium.

What are the primary symptoms of Tuberculosis (TB)?

Chest pain, coughing up blood, a productive cough for more than three weeks, fever, chills, night sweats, appetite/weight loss, paleness, and easy fatigue.

What bacterium causes Anthrax and what are its three major clinical forms?

Bacillus anthracis; the three forms are Cutaneous (skin), Inhalation, and Gastrointestinal.

Which form of Anthrax is considered the most lethal, and what is its death rate even with supportive care?

Inhalation anthrax, which results in death in $75\%$ of cases.

Name the bacterium that causes the Plague and list its three types.

Yersinia pestis; the three types are Bubonic Plague, Pneumonic Plague, and Septicemic Plague.

Which type of plague is a lung infection that can spread from person to person through the air?

Pneumonic Plague.

What is the mosquito vector for Yellow Fever?

Aedes aegypti.

Describe the 'toxic phase' of Yellow Fever.

A secondary phase occurring in some victims characterized by jaundice, internal bleeding, and kidney failure; $50\%$ of those who reach this phase die within $10$ to $14$ days if untreated.

When was HIV first recognized, and what fluids can transfer the infection?

Dec. $1^{st}$, $1981$; it is transferred through blood, semen, vaginal fluid, or breast milk.

What is the estimated survival time for an HIV-infected person without treatment?

The average survival time is $11$ years.

What is the H5N1 strain commonly known as, and how does it reach humans?

Bird Flu; it spreads from waterfowl to chickens, and then to humans who are in close contact with infected birds.

What are the three possible clinical effects of West Nile Virus on humans?

1. Asymptomatic infection, 2. West Nile Fever, and 3. West Nile Meningitis or Encephalitis.

What protozoan genus causes Malaria and how is it spread?

Plasmodium; it is spread by several species of female mosquitoes and reproduces in the human liver and bloodstream.

What are the common symptoms of Malaria?

Fever, chills, sweating, headache, fatigue, muscular pain, dry cough, nausea, vomiting, and spleen enlargement.