Infectious Diseases

Why has there been an increase in the number of reported STI’s in recent years? 

Increasing: antibiotic resistance, new pathogens, change in sexual mores/attitudes 

Which organism causes Gonorrhea?

Neisseria gonorrhoeae, a gram-negative diplococcus.

What is a common co-infection associated with Gonorrhea?

Chlamydia trachomatis.

What symptoms do men often experience with Gonorrhea?

Painful urination and discharge.

What complications can Gonorrhea cause in women?

Can lead to systemic infections.

What is Opthalmia neonatorum?

Severe eye infection in newborns caused by exposure to pathogens during birth.

Why did the incidence of STIs increase in the 1960s/70s?

Due to the sexual revolution and changes in social norms, leading to less protection.

Why did STI incidence decrease in the 1980s?

Thanks to public health campaigns and increased protection due to AIDS awareness.

What does polymicrobic mean in Chlamydia?

Refers to infections involving multiple microorganisms.

Which pathogen causes Chlamydia?

Chlamydia trachomatis.

What makes Chlamydia trachomatis virulent?

Its ability to invade host cells.

What is an obligate intracellular parasite?

A pathogen that can only replicate and survive within host cells.

What is Trachoma and is it an STI?

An eye infection caused by Chlamydia, NOT an STI, typically spread by contaminated objects.

Which organism causes Syphilis?

Treponema pallidum, a spiral-shaped bacterium.

What are the sign/symptoms at each stage of Syphilis: primary, secondary, latent, tertiary 

Primary- chancre at site of infection, Secondary-skin and mucosal rashes
Latent- none
Tertiary stage- Gummas on organs 

What is a chancre? What is a gumma?

Chancre- ulcer at infection site at prim stage and usually heals
Gumma- soft growth caused by inflammation (tumor like lesions) 

What are the effects of congenital syphilis?

Passed from mother to fetus during pregnancy, stillbirth, abnormalities, blindness, deafness, and systemic infections. 

What are the leading 3 infectious disease causes of death globally? 

Tuberculosis, HIV/AIDS, and Malaria.

What animal was the original host for HIV?

Chimpanzees.

What are the steps in HIV replication?

Attachment, Entry, Reverse Transcription, Integration, Replication, Assembly, Budding.

Which cells are targeted by HIV?

CD4+ T cells.

What do reverse transcriptase, integrase, and protease do?

Reverse Transcriptase- converts viral RNA to DNA, Integrase- incorporates viral DNA into host genome, Protease- processes viral proteins for assembly of new viruses

What happens to CD4 levels, antibody levels, and viral levels as the disease progresses?

CD4 levels decrease, antibody levels rise but becomes ineffective, viral levels spike early then stabilize and rise again when CD4 cells are depleted. 

What is required for an AIDS diagnosis?

A CD4 count of less than 200 cells or the presence of specific AIDS illnesses.

Which bodily fluids can transmit HIV, and which one can't?

Blood, semen, vaginal fluids, rectal fluids, and breast milk can transmit HIV;
saliva, sweat, tears, and urine cannot.

What is meant by Universal Precautions?

Measures such as hand washing and PrEP medication for those at risk.

What mosquito species carries malaria?

Anopheles mosquitoes, specifically females.

How is malaria prevented?

Insect repellents, antimalarial drugs, environmental control, and vaccines like RTS.

Where in the US has malaria been a problem?

Usually in the Southeastern US.

What percentage of the world’s population is infected with Mycobacterium tuberculosis?

33%.

What is the origin of the name “tuberculosis”?

From the Latin word 'tuberculum' meaning small swelling.

What pathogen causes Rabies?

Rabies virus, belonging to the Lyssavirus genus.

What is furious rabies? Paralytic rabies?

Furious Rabies- restless then highly excitable. Paralytic Rabies -seems unaware of surroundings 

What is the pathology of rabies?

Virus enters tissue from saliva of biting animal; Virus replicates in muscle near bite; Virus moves up peripheral nervous system to CNS; Virus ascends spinal cord
Virus reaches brain and causes fatal encephalitis
Virus enters salivary gland and other organs of victim. 

What is hydrophobia?

Fear of water, often due to painful throat spasms observed in furious rabies.

What is the most common rabies reservoir in the US?

Wildlife, especially bats, foxes, skunks, and raccoons.

What is the treatment for someone bitten by a rabid animal?

A vaccine plus rabies immune globulin (RIG).

What is the mortality rate of rabies?

It is nearly 100% fatal without treatment.

How is the US population kept protected from rabies?

Active domestic animal vaccination (HDCV).