HIV & Retroviruses
This type of virus contains two copies of single-stranded, positive-sense RNA and uses reverse transcriptase to convert its genome into DNA, which integrates into the host genome.
What is a retrovirus?
During the primary immune response to a vaccine antigen, this isotype is produced first and has low affinity, but its presence is essential for initiating class switching and memory formation.
What is IgM?
This blood parasite is transmitted by the female Anopheles mosquito and causes cyclic fevers due to erythrocyte lysis
What is Plasmodium?
This flavivirus is transmitted by Aedes mosquitoes and can cause a febrile illness that progresses to hemorrhagic fever and shock. It’s a leading cause of mosquito-borne viral disease in tropical and subtropical regions.
What is Dengue virus (DENV)?
This infection control method must be performed before and after every patient contact and is the most important way to prevent healthcare-associated infections.
What is hand hygiene?
This opportunistic infection is most commonly seen when CD4+ counts fall below 200 cells/µL and is characterized by shortness of breath, fever, and diffuse interstitial infiltrates on chest imaging.
What is Pneumocystis jirovecii pneumonia?
This live attenuated vaccine is no longer used in the United States due to a risk of vaccine-derived poliovirus, but is still employed in many parts of the world because of its ability to confer mucosal immunity.
What is the oral polio vaccine (OPV or Sabin vaccine)?
The intracellular, non-flagellated form of Leishmania found in human macrophages is called this.
What is the amastigote?
This virus is primarily transmitted through aerosolized rodent excreta, and is endemic to Western Sub-Saharan Africa. It can progress to hemorrhagic fever with multiorgan involvement.
What is Lassa fever virus (LFV)?
This term describes an infection that arises 48 hours or more after hospital admission or less than 48 hours after discharge.
What is a nosocomial infection?
This chemokine receptor is necessary for entry of R5-tropic HIV into host cells and is blocked by the drug maraviroc.
What is CCR5?
This form of passive immunization contains high titers of pathogen-specific antibodies and is used in post-exposure prophylaxis when immediate immunity is required, such as in hepatitis B exposure in a newborn.
What is hyperimmune globulin?
This nematode is transmitted by the Simulium blackfly and causes dermal nodules, intense pruritus, and river blindness.
What is Onchocerca volvulus?
This alphavirus, known for causing arthralgia and rash, has no approved vaccine and is transmitted by Aedes mosquitoes, sharing overlap with Dengue and Zika endemic regions.
What is Chikungunya virus (CHIKV)?
This type of precaution is required when caring for a patient with suspected Clostridioides difficile infection and involves hand hygiene with soap and water rather than alcohol-based hand rubs.
What are contact precautions?
Unlike HIV, which causes immunodeficiency, this retrovirus induces T-cell proliferation and can lead to adult T-cell leukemia/lymphoma (ATL) via its Tax protein.
What is HTLV-1?
This class of vaccine additive enhances immune responses by activating pattern recognition receptors (e.g., TLRs), prolonging antigen presentation, and boosting cytokine production, but may also increase local reactogenicity.
What are adjuvants?
This drug used to treat Babesia microti infections inhibits electron transport in parasite mitochondria, thereby blocking nucleic acid and ATP synthesis.
What is atovaquone?
This New World hantavirus, including the Sin Nombre virus, causes hemorrhagic fever with ________ syndrome?
What is Hantavirus pulmonary syndrome (HPS)?
This level of disinfectant kills most organisms but may not be effective against spores. Examples include alcohols, iodophors, and phenolics.
What is intermediate-level disinfection?
This mechanism is the primary cause of CD4+ and CD8+ T-cell depletion in the end-stage of HIV infection, leading to immune collapse and susceptibility to opportunistic infections—even in uninfected lymphocytes.
What is T-cell exhaustion?
A 24-year-old pregnant woman in her third trimester presents to the clinic for routine prenatal care. She is healthy and up to date on most of her childhood vaccinations. Her provider recommends a TDaP booster despite her history of prior tetanus vaccination.
The patient is confused and expresses concern, saying, “I’ve already had this shot before. Why do I need it again during pregnancy?”
What is the most appropriate immunological rationale for administering the TDaP vaccine during every pregnancy, even in previously vaccinated individuals?
What is: To provide passive immunity to the newborn by boosting maternal antibody production, particularly against pertussis, which can then be transferred transplacentally to the infant before birth.
A 36-year-old man returns from a mission trip to Uganda with 2 weeks of intermittent fever, malaise, and lymphadenopathy. On exam, he has a chancre at the site of a previous insect bite and posterior cervical lymphadenopathy.
A peripheral blood smear shows flagellated organisms with an undulating membrane.
You learn the region is endemic for Glossina palpalis, and the infection appears to be progressing slowly. What is the most likely parasite causing this infection, what disease is this, and what is the recommended first-line treatment in the early stage?
What is Trypanosoma brucei gambiense, causing West African sleeping sickness (African trypanosomiasis), and the first-line treatment in the early stage is pentamidine or fexinidazole?
A 25-year-old man returns from a 3-week research trip in Bolivia with a 5-day history of fever, malaise, conjunctival injection, petechiae, and bleeding gums. Labs reveal thrombocytopenia and elevated liver enzymes. There is no recent travel to Africa or exposure to known infected patients. He lives near a rodent-infested field station. What is the most likely causative virus, and what is the most appropriate next step in management?
The most likely causative virus is Machupo virus (Bolivian hemorrhagic fever), an Arenavirus transmitted through aerosolized rodent excreta.
The next step is supportive care and notify public health authorities.
Name the five most common types of nosocomial infections, which account for approximately 85% of healthcare-associated infections.
What are:
Urinary tract infections
Surgical site infections
Pneumonia,
Bloodstream infections
Gastrointestinal infections