Lecture 33: Acquired Immune Deficiency Syndrome and Headache Flashcards
What does AIDS stand for?
Acquired Immune Deficiency Syndrome
What are some AIDs defining illnesses?
HIV does not kill the person, but it dampens the immune system, making them susceptable for the following illnesses
Infection with human immunodeficiency virus (HIV) leads to acquired immune deficiency syndrome (AIDS). AIDS defining illnesses include:
- Pneumocystis jiroveci (pneumonia)
- Toxoplasma gondii (brain abscesses)
-
Candida albicans (oesophagitis, oral candidiasis)
- Oral candidiasis was often a common first sign
- Cryptococcus neoformans (meningitis)
- Mycobacterium tuberculosis (tuberculosis disease)
- _Kaposi’s sarcoma (_cancer caused by human herpesvirus 8 (HHV-8), including lesions on skin, lymph nodes, mucous membranes, nose and throat)
- Almost never occur in people without HIV
- CNS lymphoma
- Cytomegalovirus retinitis (viral eye infection of retina)
Describe the Time Course of Untreated HIV infection
- Infection with HIV
- Level of HIV in tissues and blood rises
- Cytotoxic T lymphocytes kill many HIV producing cells
- Number of T helper lymphocytes in blood falls
- Level of HIV in blood falls
- Killing of infected lymphocytes causes a brief “glandular fever-like” illness
- B lymphocytes start producing antibodies to HIV
- Level of HIV remains stable for many years
- T helper lymphocyte number continues to fall
- T helper lymphocyte depletion is severe AIDS illnesses
- Level of HIV in blood rises further
Draw the time course of treated HIV infection
If the virus is kept under control, their gential excretions has no HIV in it, so they cannot infect others.
What are the approximate risk of transmission of HIV per unprotected epsiode (if not on treatment)
Approximate Risk Of Transmission Of HIV Per Unprotected Episode
- Man to man is 1%
- Man to woman is 0.1%
- Woman to man is 0.1%
- Mother to infant is 25% at delivery, 12% with breastfeedingf
At what approx CD4 countds do AIDs definining illnesses manifest?
What are some fungal diseases in AIDS?
Fungal infections can be common, minor, skin and mucosal infections; and rare, serious, deep tissue infections.
Fungal diseases in AIDS include:
- Oral and oesophageal mucosal disease due to Candida albicans
- Meningitis due to Cryptococcus neoformans
Describe a simple way of classifying Fungi
Yeasts are round or oval, reproduce by budding
- Candida albicans and other Candida sp. *
- Cryptococcus neoformans
Moulds are tubular hyphae, reproduce by g_eneration spore_s on conidia extending from tubular hyphae (kind of like a flower)
- Dermatophytes *
- Aspergillus species
- Zygomycetes
Describe Candida albicans
- Where they’re found
- Can cause
Candida Albicans
Candida albicans are commensal of mouth, gut, vagina (one organism benefits from the other without affecting it)
- Overgrowth related to antibacterial therapy, immune suppression, h_ormonal effects_, f_oreign bodies_
- It can cause:
- Oral or vaginal “thrush” (pharyngitis, vaginitis, vulvovaginitis (nappy rash))
- Cutaneous or n_ail candidiasis_
- Intertrigo (dermatitis that affects skin folds)
- e.g. In baby’s thigh, if the nappies haven’t been changed frequently enough.
- Candida paronychia (infection of nail bed)
- Intertrigo (dermatitis that affects skin folds)
- Urinary catheter-related bladder infection
-
Rare systemic infection
- __Due to cather infection (very very rare)
How do you Diagnose Candid Albicans?
Diagnosis of Candid Albicans
- Candid albicans is seen as black yeasts with pseudo-hyphae (incomplete budding where the cells elongate but remain attached after division) on Gram-stain.
- It also grows well on blood agar.
Describet he treatment of Candidiasis
Usually topical, sometimes oral, including:
- Nystatin suspension or pastilles
- Amphotericin B pastilles
- Azole pessaries or cream
Has been an area of ‘alternative medicine’ fantasy, overgrowth in gut, etc.
Describe the Diseases of Cryptococcus Neoformans
Crytococcus neoformans is the ‘other” yeast (very much rarer!)
- Pulmonary infections are due to inhalation of aerosolised fungus from environment, totally controlled in people with normal immune system (usually asymptomatic)
- Spread via blood to CSF is ONLY in people with severe immunodeficiency
- Meningitis in immunodeficient people, e.g. AIDS, high dose prolonged corticosteroid therapy, etc.
- Chronic lymphocytic meningitis is slow deterioration in mental state with headache and fever
How do you diagnosie Crytococcal Meningitis?
Lumbar puncture for CSF include:
- Usually 10-100 (not 1000s) WBCs in CSF
- Lymphocytes are not PMN predominance
- Protein raised, glucose low
Microscopy and culture include:
- Encapsulated yeasts seen with India ink stain
- C. neoformans grown on agar
- Cryptococcal antigen positive in CSF and serum
How do you treat Cryptococcal Meningitis?
Approximately 6 weeks total therapy for crytococcal meningitis treatment, which includes amphotericin B (IV), (anti-fungal drug that cannot be absorbed via the gut) and fluconazole (IV or oral).
What symptoms can dermatophytes cause?
-V. v. common mould
Tinea = “ringworm”
Dermatophytes cause
- tinea faciei (face),
- capitis (scalp),
- corporis (trunks),
- cruris (inguinal groin),
- pedis (athletes foot),
- onychomycosis (nail), etc.
What is tinea?
Tinea is a condition caused by a fungi that infect the skin.
