Opportunistic Infections

Infections caused by pathogens that don't usually affect the immunocompetent are

OI (opportunistic infections)

(T/F) OI is the number 1 cause of death in immunocompromised patients


A healthy person has an intact defense system (provides protection working with surfaces, cells, soluble factors...), when do infections set in?

Once it's breached

How many CD4 T cells does a healthy uninfected person usually have?

800 to 1200

Which disease is most associated with gradual decrease in CD4 cells?


(HIV) as a person's CD4 decreases, they become more

Prone to OI

What is the CD4 count of a person showing symptoms and starts being prone to infection?

Below 500

When we diagnose a person with aids, what must their CD4 count be?

Below 200

(T/F) ALL countries have access and can/MUST conduct a CD4 count to officially report HIV/AIDS status

False (developing countries rely on symptoms - hard to conduct CD4 count)

If a person has 500+ CD4, what type of pathogens are found in their body?

Usual pathogens

(T/F) If a person has CD4 count 500-200, they have USUAL PATHOGENS

True (disease more frequent and severe tho)

What must the CD4 count be for the pathogen to be considered an OPPORTUNISTIC PATHOGEN


When CD4 count less than 50, what do we consider these pathogens to be?

Severe opportunistic pathogens

What is the MOST COMMON cause of death in HIV patients?


Tb is caused by the intracellular pathogen ����� �����-

Mycobacterium tuberculosis

When the CD4 count in below 500, there is an (increase/decrease) of the incidence of diseases that could also affect a normal host


The common infections when CD4<500:
1) recurrent ���- �����-
2) pulmonary ����-
3) ������� pneumonia
4) Cervical ����-

1)vaginal candidiasis

Pneumococcal pneumonia is a type of (virus/bacteria) that's caused by ��� �����

Bacteria, strep pneumoniae

Candidiasis is caused by the fungus ����- ����

Candida albicans

Candida albicans is/isn't part of the normal flora


Where is Candida albicans found?

GIT, genitourinary, respiratory tract

In a person infected with HIV, candidiasis occurs in 3 forms: �����-, ����, and ������- diseases

Oropharyngeal, esopharyngeal, vulvovaginal

Candida albicans causes �����- candidiasis


In AIDS patients, the most common candidiasis related infections include:
1) ����
2) Angular ���� (red/swollen patches in mouth corners)
3) ����� candidiasis
4) ���� candidiasis

Thrush, chelitis, vaginal, esophageal

(T/F) common candidiasis related infections present in AIDS patients is also common in HIV patients (w/o AIDS)

False (rare)

White patches causes by candidiasis infections (thrush) removal causes


(Vaginal/esophageal) candidiasis is EXTREMELY difficult to treat


How many types of herpes viruses can cause human infections?


Give me the 4 herpes viruses causing human infections (mentioned on slide)

Herpes simplex, Herpes zoster, EBV, HHV8

HSV-1 and 2 are considered which number HHV?

HHV 1, HHV 2

Herpes zoster considered which number HHV?


EBV is considered which number HHV?


How many types of HSV (herpes simplex virus) are there?

2 (HSV 1, HSV 2)

Which of the HSV infections is most common?


What is the CD4 count for patients with HSV?


Herpes zoster/Varicella zoster virus (VZV) is also knows as


EBV is associated with

Oral hairy leukoplakia

Kaposi's sarcoma (KS) is typical of AIDS patient with ���- (type of HHV)


HIV patient with CD4 count les than 200: common infections:
1) ������- ���� pneumonia (PCP)
2) ������- (toxic)
3) ������� (cryptic)

Pneumocystis Carinii, toxoplasmosis, cryptococcus

PCP is a (bacterial/fungal) infection caused by pneumocystis ����

Fungal, jiroveci

Where is pneumocystis jiroveci commonly found in?


Pneumocystis jiroveci is an OI common among

HIV patients

Common symptoms of PCP include:
Progressive �����- dyspnea (95%), ��� (>80%), nonproductive ���- (95%), Chet discomfort, weight loss, chills, and rarely causes ������ (coughing blood).

Exertional, fever, cough, hemoptysis

What stain is used to diagnose PCP?

Methanamine silver stain

2 treatment method for PCP:
2) ����- (penthouse)


2 treatment method for PCP:
1) _����-
2) pentamidine (penthouse)


Toxoplasmosis is a (parasitic/fungal) infection caused by ����- ���-

Parasitic, Toxoplasma Gondii

What is the leading cause of focal CNS disease in AIDS?


Toxoplasma Gondii is an (intra/extra-cellular) parasite


Transmission of toxoplasmosa gondii is usually from ��� to humans


Causes of toxoplasmosis in order of most common to least common:
1) reactivating of old ���- ���-
2) ������- spread of previously acquired infection
3) (primary/secondary) infection

CNS lesions, hematogenous, primary

In healthy ppl who get toxoplasma gondii, it isn't completely cleared, but it hides inside ���� ���- or ��- cells

Tiny structures, muscle

Cryptococosis is a (fungal/parasitic) infection that could causes ����- ���- in ICPs and is causes by ������ ����

Fungal, Chronic meningitis, crytococcus neoformans

Crytococosis can causes ���� ��� that affect structures like lungs & bones

Disseminated lesions

Cryptococcus neoformans is ubiquitous (found everywhere), it's even found in ����- droppings (poop)


how is cryptococcus neoformans transmitted


What's the virulence factor of cryptococcus neoformans?

Polysaccharide capsule

Cryptococcus neoformans can produce which enzyme?


Cryptococcus neoformans produces ���-, which is why is is ��� oxidase test positive

Melanin, Phenol

Cryptococcosis is rapidly diagnosed by:
1) ���� Ink stain (country) - if infection suspected or yeast cells found in CSF
2) ���� - polysaccharide AG in CSF

India, EIA

India ink test is dark colored stain that's forms ��� color showing the ����� ����-

White, cryptococcus neoformans

Where does crytococcus neoformans usually grow in animals and why?

Intestines, needs high temp (42)

During severe decline of CD4 (less than 50) all previous infections could occur and these 4 infections could be experienced as well:
1) ���� ����-
2) �������� ����- ����- (MAC)
4) Progressive Multifocal ��������-

CMV retinitis, mycobacterium Adium complex, cryptosporidiosis, leukencephalopathy

CMV is short for


CMV family


CMV is commonly a (primary/secondary) infection and happens through reactivation


CMV treatment


MAC is an OI caused by 2 species of mycobacterium:

Mycobacterium avium, mycobacterium intercellulare

MAC causes severe illnesses in AIDS patient, does it also do that in other people

No (rarely)

In what form does MAC occur in ppl with CD4 less than 50?


Disseminated MAC causes �����- infection


Where do the 2 mycobacterium species causing MAC enter body? (2)

Respiratory tract, GIT

Which infection ONLY affects the lungs

Pulmonary Tb

Cryptosporidiosis and �����- are BOTH causes by protozoan (fungi/parasites)

Isosporiasis, parasites

Cryptosporidiosis/Isosporiasis tramsittted through ����- and ���- contact

Food/water, direct

What do cryptosporidiosis/isosporaisis cause: (4) (TIP: remember transmission)

Vomiting, diarrhea, nausea, stomach cramps

In immunocompetent Inds affected by cryptosporidiosis/isospordiasis, smyptoms don't last more than ���-

14 days

(T/F) For infections in immunocompromised ppl, etiology CAN be anything


(T/F) It is NOT possible for the immunocompromised infections to be caused by more than 1 pathogen


The 3 aggressive approach to diagnosis are: �- ���, BAL (bronchoalveolar lavage), biopsy

Ct scan

The 3 aggressive approach to diagnosis are: Ct scan, ���, biopsy


The 3 aggressive approach to diagnosis are: Ct scan, BAL (bronchoalveolar lavage), ����-


Due to ����-, most OIs have decline 80-90%


OIs seen most commonly in ppl that are ������- ��� and those not adhering to

Undiagnosed HIV+, therapy