Opportunistic Infections (OI)

DEEPA BABINASST PROF MICROBIOLOGY

TMC

India had an estimated 3.5million HIV positives in 2009(NACO)

22

Patients are susceptible to bacterial, fungal, parasitic and viral infections

HIV, Cancer chemotherapy, bone marrow transplantation, immune deficiency disorder or blood disorders .

Background

Definition

• An infection by a microorganism when the body's immune system is impaired and unable to fight off infection, as in AIDS, Infants, neutropenia, and congenital

AIDS (Aquired Immune Deficiency Syndrome)

• AIDS (Aquired Immune Deficiency Syndrome) is the final stage and natural progression of HIV (Human Immunodeficiency Virus.)

• These infections usually occur when the CD4 cells drop below 200 cells/ul, i.e. immunocompromised state.

• It is estimated that as many as 40 million people worldwide suffer from AIDS

Opportunistic Infections

OI (CDC GUIDELINE 2011)• Fungal• Candidiasis of bronchi,

trachea, esophagus, or lungs oral thrush, vaginitis

• Coccidioidomycosis• Cryptococcosis(Meningitis)• Histoplasmosis• Pneumocystis carinii

pneumonia• Aspergillosis• Penicilliosis(P. marneffi)

• VIRUS• Cytomegalovirus disease

(particularly CMV retinitis)• Herpes simplex 1,2 : chronic

ulcer(s) (greater than 1 month's duration); or bronchitis, pneumonitis, or esophagitis

• Herpes zoster• Human papilloma virus• Hepatitis B• HHV-6 and HHV-7 Disease• Varicella-Zoster Virus Disease• Human Herpesvirus-8 Disease• Molluscum contagiosum

OI (CDC GUIDELINE 2011)

• PARASITES• Isosporiasis, chronic

intestinal (greater than 1 month's duration)

• Toxoplasmosis of brain• Cryptosporidiosis, chronic

intestinal (greater than 1 month's duration)

• Leishmaniasis• Chagas Disease • Malaria• Isosporiasis

• BACTERIA• Mycobacterium avium complex• Tuberculosis• Pneumonia -recurrent• Progressive multifocal

leukoencephalopathy• Salmonella septicemia- recurrent• Neurosyphilis Syphilis• Bartonellosis

• OTHERS• Wasting syndrome due to HIV• Invasive cervical cancer• Kaposi's sarcoma• Lymphoma, multiple forms• Encephalopathy, HIV-related

Respiratory Infections

• Bacterial pneumonias (LRTI) can be very serious & recurrent

• As Cell Mediated Immunity depletes, opportunistic infections such as Pneumocystis , severe fungal and viral pneumonias may occur.

Respiratory InfectionsBacterial:

Pneumococcal, Klebsiella, E.coli,

Heamophilus, Staphylococcal

pneumonias, Tuberculosis, MAC.

Fungal: Cryptococcosis, Histoplasmosis,

Pneumocystis jiroveci Aspergillosis,

Viral: Cytomegalovirus

Herpes simplex virusLymphocytic interstitial

pneumonitis

Other: Kaposi’s sarcoma,

Pneumocystis jiroveci Most common one with Lung infection, other organs like liver, spleen,bonemarrow can also infect.

Chest radiograph Classically bilateral, diffuse interstitial shadowingCan be relatively normal even with severe respiratory distress

Induced sputum and Bronchoalveolar lavage

Can give definitive diagnosis

Mycobacterium tuberculosis• 85,000 new cases of tuberculosis in

United States in 2009 (6% among children <15 years of age)

• Number of these that were HIV infected is uncertain

• Incidence of TB in HIV-infected 100 times higher than in uninfected

• Extrapulmonary and miliary TB more common

• Congenital TB has been reported• Drug-resistant TB can be

transmitted

Diagnosis of Pulmonary TB

• Sputum examination– Negative Sputum does not

exclude TB!– Sputum negative PTB more

common in HIV+– Only 50% sensitive

• Chest radiograph– No “typical” TB X-ray– TB can create almost any

abnormality, or even none

Diagnosis of Extrapulmonary TB

• Often very difficult – CXR often normal and sputum if available is

negative• If lymph nodes enlarged - aspirate• If meningism present - lumbar puncture• If septic arthritis or abscess - aspirate– Always request ZN Stains on samples

A Patient with HIV Wasting Syndrome

This can be clinically indistinguishable from advanced TB

Mycobacterium avium Complex

• Appear as isolated lymphadinitis• Recurrent fever, weight loss, failure to thrive,

neutropenia, night sweats, chronic diarrhea, malabsorption, abdominal pain

• Lymphadenopathy, hepatomegaly, splenomegaly• Respiratory symptoms• Diagnosis-Biopsy,AFB stain,Blood culture,PCR

Gastrointestinal InfectionsCauses:

Direct HIV infection Bacterial/viral/protozoal/parasitic infection

Presentations• Watery/loose Diarrhoea,+/-

malabsorption due to villous atrophy

• loss of appetite, nausea & vomiting, progressive weight loss

N.B. bloody stool indicates shigellosis/amoebic dysentry

- Bacterial• Salmonella• Shigella• Campylobacter• Clostridium difficile- Enteric viruses• adenovirus• astrovirus

- CMV- Mycobacterium avium

complex- Parasites• Microsporidia• Cryptosporidia• Cyclospora cayetanensis• Giardia lamblia• Isospora belli

Acute ChronicDiarrhoea

Neurological Infections

• Most frequent systemic fungal infection in HIV infected persons

• Symptoms: headache, neck stiffness, cranial nerve palsies,+/- coma; fever is rare

• Prognosis is poor with no treatment.

Cryptococcal Meningitis

                                                                                                                                                                              

: Raised skin lesions resulting from dissemination of the yeast in an imunocompromised patient.

.B.

Syphilis• Treponema pallidum • Neurosyphilis• Rate of congenital syphilis 50

times greater among infants born to HIV-infected mothers

• All infants born to mothers with reactive nontreponemal and treponemal test should be evaluated with a quantitative nontreponemal test, e.g., slide test, rapid plasma reagin (RPR)

Toxoplasmal meningitis

CNS infection of T gondii is an AIDS indicator

CD4 cells >50 cells/mlMeningitisDiagnosisSerology-Ab detectionPCR

CandidiasisCausative organism: Candida speciesSites of colonisation– Gastrointestinal tract – Genital tract womenTypical presentations :

Oral/vulvovaginal thrushBalanitis+/- oesophageal candidiasis

Oral Hairy leukoplakia

• Common in HIV immunosuppressed• Characterised by fine linear, warty growths

on edge of tongue.• Can be mistaken for candidiasis• Caused by Epstein Barr virus/?HPV• No specific treatment; good oral hygeine

Oral Herpes

Causative organism: Herpes simplex virus

Infection: superficial painful ulcers;

Site:mouth , around lips and nose

Treatment: 5 days acyclovir 200mg

Skin Conditions

• Herpes Zoster• Reactivation of previous

varicella (chicken pox) • Very common• Can occur early in HIV disease• Multi-dermatomal, recurrent

Causes acute, severe pain• Risk of debilitating post herpetic

neuralgia (PHN more common in older aptient)

• Disfiguring keloid formation• Diagnosis clinical

HIV and Genital Herpes• More extensive disease • Frequent recurrences • Chronicity • Associated high genital viral

load • Important cofactor for

transmission of HIV• Treatment of fist episode as

standard however higher doses may be required for longer periods especially in chronic cases

Infective Dermatoses

• Scabies• Seborrheic dermatitis

Giant granulomatous leishmanial ulceration

Visceral leishmaniasisHas become more

PrevalentUnusual presentations

Often occure.g.

Leishmania species Normally causing only

Cutaneous disease, Can present with

Visceral Leishmaniasis

HIV Related Malignancies

• Kaposi’s sarcoma• Primary CNS lymphoma• Carcinoma of the cervix• Other lymphomas

This is the person living

with HIV/AIDS

The Role of ARVs in Opportunistic Infections

• Antiretroviral therapy(ARV)• ARVs improve the immune status, and therefore, enhance

how the host fights disease – keeping it free from infections that might otherwise have taken the opportunity to occur.

• Widespread use of Highly Active Anti Retroviral Therapy (HAART) has been associated with considerable

– Reduction in mortality– Reduction in morbidity– Reduction in social isolation

HIV/AIDS is one of the greatest worldwide public health challenges of the modern age, and as future health care workers, it is of the utmost importance that we maintain awareness and continuing knowledge of this heartbreaking and deadly scourge.

THANK YOU ALL MY DEAR STUDENTS