Chapter 25: ID IV - Opportunistic Infections Flashcards
(34 cards)
What are opportunistic infections (OIs)?
Infections that occur when the immune system is weak and unable to respond normally to invading pathogens
OIs can be caused by bacteria, fungi, viruses, and protozoa.
What is a key characteristic of immunocompromised patients?
They are predisposed to opportunistic infections
This predisposition can result from diseases or drug treatments that suppress the immune system.
What is a defining criteria for AIDS?
CD4 T lymphocyte count < 200 cells/mm³
This indicates a severely weakened immune response.
What systemic steroid treatment duration and dosage can lead to immunocompromised status?
Use of systemic steroids for 14 days or longer at a dose of ≥ 20 mg/day or ≥ 2 mg/kg/day
Prolonged steroid use suppresses the immune system.
What condition is characterized by asplenia?
Lack of a functioning spleen
This can be due to sickle cell disease or splenectomy.
Which medications can lead to immunocompromised states?
Immunosuppressants for autoimmune conditions or post-transplant
Examples include TNF-alpha inhibitors.
What is a significant side effect of cancer chemotherapy agents?
Destruction of white blood cells, particularly severe neutropenia (ANC < 500 cells/mm³)
This increases the risk of infections.
What is chemoprophylaxis?
Prevention of infections with antimicrobials such as antibiotics and antivirals
This is a key component in managing patients with HIV.
What is the purpose of primary prophylaxis for OIs?
To prevent many opportunistic infections in immunocompromised patients
Criteria for starting and stopping prophylaxis is crucial for effective management.
Are prophylactic treatments recommended for oral/esophageal Candida infections in immunocompromised states?
No, prophylaxis is not usually recommended
Although these infections are more likely in immunocompromised individuals.
What type of viral infections are transplant recipients especially at risk for?
Cytomegalovirus (CMV)
What medications are used for CMV ppx in transplant patients?
CMV prophylaxis is common with letermovir or valganciclovir.
Which pneumonia can be prevented in transplant recipients?
Pneumocystis jirovecii pneumonia (PJP or PCP)
Similar prophylaxis options as those used for patients with HIV.
What is the criteria for starting primary ppx for PCP?
CD4 count is < 200 cells/mm3
What is the preferred primary prophylaxis regimen for Pneumocystis jirovecii pneumonia (PJP)?
SMX/TMP DS or SS daily
Alt: Dapsone/ Atovaquone/ Dapsone+pyrimethamine+leucovorin
When should primary prophylaxis for Pneumocystis jirovecii pneumonia be discontinued?
CD4 count > 200 cells/mm3 for > 3 months and remains on ART
ART refers to antiretroviral therapy.
What is the criteria for starting primary ppx for Toxoplasma gondii encephalitis?
CD4 count is < 100 cells/mm3
What is the preferred regimen for Toxoplasma gondii encephalitis?
What are the Alt?
SMX/TMP DS daily
Alternatives include dapsone + pyrimethamine + leucovorin OR atovaquone
What are the criteria for starting prophylaxis for Mycobacterium avium complex (MAC)?
CD4 count < 50 cells/mm3 and no active MAC infection and not taking ART
Not recommended if ART is started immediately.
What is the preferred regimen for prophylaxis against Mycobacterium avium complex?
Azithromycin 1,200 mg weekly
Alternatives include azithromycin 600 mg twice weekly.
Fill in the blank: Leucovorin is added to all pyrimethamine-containing regimens as _______.
rescue therapy
This helps reduce the risk of pyrimethamine-induced myelosuppression.
What is a second-line regimen for PCP in the setting of a sulfa allergy?
Atovaquone, dapsone, pentamidine
Patient-specific factors determine the selection of alternate regimens.
What are the criteria to discontinue MAC primary ppx?
Taking fully suppressive ART
