AIDS is a incurable condition produced by HIV1 or HIV2
It is estimated that 10 Billion HIV particles are produce and Destroyed every day.
CD4 Lymphocytes which plays Major role in Immunity are destroyed.
Makes Every AIDS patients venerable to infections, and uncommon malignant conditions.
What went wrong in AIDS
Immune system is a complex and complicated organ - it sometimes fails to work to protect
HIV infection causes
Secondary Immunodeficiency disorder.
Initiated with destruction of CD4 type of T Lymphocytes, Monocytes.
Lead to onset of AIDS ( Acquired Immuno deficiency syndrome )
Manifest with various opportunistic infections.
In some cases present with various forms of cancer.
AIDS causes overall Defect
Overt failures of Immune system manifests with reduced ability to resist Infections
HIV virus infects CD4 lymphocytes and destroys
When you says it is AIDS
Infected with HIV1 or HIV 2
When the CD4 cells drop to < 200/mm 3
Present with one of the 26 different opportunistic infections.
Relation of AIDS to Infections
Relevant or chronic infections
Inability to clear Infections after standard regimes of Antibiotic therapy
Defining AIDS in relation to Infections
Many indicator diseases vary from one Geographic region to another.
Majority are only Endogenous infections which were acquired in the past and only reactivated in the present scenario.
Some are exogenous infections particular to geographic location where the patient lives.
Eg Toxoplasmosis, Cryptococcosis ( common in Africa )
Common AIDS defining Illnesses in the past and continues
Pneumocystis jiroveci pneumonia
HIV wasting syndrome
AIDS defining illness at present
1. Recurrent bacterial infections.
2. Invasive cervical carcinoma.
3 Pulmonary tuberculosis.
PRROTOZAL INFECTIONS IN AIDS
Toxoplasmosis ( Toxoplasmosis gondii )
Domestic cats spread the disease to humans in vicinity
Avoiding cats, and cat feces makes a difference to HIV infected.
Most important / common space occupying lesion of brain in HIV infections
Clinicians track the Diagnosis
Usually diagnosed by C T scans
MRI is highly sensitive than C T
Produces space occupying lesions Cats spread the disease
Toxoplasmosis ( Diagnosis )
Serological tests may not confirm diagnosis in HIV ? AIDS patients.
Look for alternative, more specific methods like Brain Biopsy
Sabin – Feldman dye test.
ELISA may be guiding in complex presentations in resource poor settings.
A common cause of Diarrhea in AIDS patients
Microscopic examination may confirm Diagnosis
Detection of Oocysts in fresh stool
Staining the stool samples with modified acid fast stains
Fluorescent Microscopy with Monoclonal tagged antibodies may confirm the specific Diagnosis
Cryptosporium oocysts in stool specimen
Several species of Microsporidia infect humans.
AIDS patients have higher predisposition
Microsporidal infections occurs along with Cryptosporial infections
Different species cause opportunistic infection in Immunosuppresed and AIDS patients
1 Encephalitozoon helium
2 Virraforma cornae
In intestine - Enterocytozoon beeneusi
Present with gastrointestinal Manifestations clinically
Found in Intestinal tract
Fresh specimens of stool specimens examined for Oocysts
Caused by Giardia intestinalis
May produce Infections in Immunosupressed
Manifest with diarrhea and malabsorption syndrome
Examination of stool will reveal Cysts and Trophozoites.
Life cycle of Giardiasis Infection
Strongyloidosis - AIDS
Caused by Strongyloides stercoralis
In AIDS / Immunosuppresed Filariform larva may penetrate gut directly in large numbers and produce overwhelming infection with fatal outcome
Life cycle of Strongyloidosis
Amoebiasis is common in many geographic locations
Rarely attributed in the developing world as AIDS defining illness
Microscopic examination for Trophozoites will confrim the active infection
Life cycle of Entamoeba Histolyticum
Endemic in many developing countries,
Poor hygiene and in sanitary conditions predispose to infection
Examination of fresh specimens are highly essential
Differentiate E.histolytica from Entamoeba coli.
Infections are prevalent in Tropical Africa, South America, Mediterranean
Produce Non specific manifestations
Demonstration of Amastigotes in Bone marrow biopsy and splenic aspirates confirms diagnosis.
Life cycle of Lesihmania donovani
Viral Infections in AIDS
Viruses infecting AIDS Patients
Human papilloma virus
Papovavirus / Papilloma virus.
Hepatitis B and C may be associated.
CMV Retinitis most common cause of Retinal infections in AIDS
Isolation of CMV viruses
grown on Human fibroblasts
shows Cytomegalic changes and
Most useful investigation in resource poor settings
Ig G estimation will inform only past infections
Ig M estimation will reveal current predisposition with CMV infection
Serological assays are not reliable in highly Immunosuppresed patients.
May need PCR methods from various samples
Molecular methods helps in Specific Diagnosis
Establishes the viral Load in actively suffering patients.
AIDS patients suffer more often and most severe Infections
Herpes simplex 2 are identified as most prominent sexually transmitted infection world wide.
Produce simple lesions to disabling Disease
Isolation of viruses
from throat washings
Serology - Not very specific in establishing Diagnosis
Polymerase chain reaction – Sensitive/Specific
Most useful establishing the Diagnosis of CNS infections.
Varicella Zoster Virus
Varicella zoster virus causes chicken pox in children and young
Latent infection persists in ganglion
Reactivation of latent infection causes Varicela Zoster
AIDS are prone for Zoster manifestations.
Produces most severe morbidity
Disease starts with pain on skin or mucous membrane with eruptions supplied by one or more groups of sensory nerve routes
Usually diagnosed clinically
On many occasions Herpes zoster leads to suspicion of AIDS
Diagnosis of Herpes zoster
A clinically diagnosed condition.
Laboratory testing confirms
Virus can be isolated from vesicle fluid cultured on human cells
Complement fixation tests
Helps in atypical cases
Epstein Barr virus - AIDS
Appear with intermittent manifestations
Manifest with lesions on the lateral border of tongue or mucous membrane
Histological examination Under Electron Microscopy
Human Papilloma virus - AIDS
There are >100 strains of Papilloma viruses
About 30 strains are transmitted sexually
Can produce cervical cancer in women
Growing Importance in AIDS patients.
Abnormal pap smear suggestive
DNA technologies are emerging.
Papova virus - AIDS
JC virus a member of the group
Produce multifocal leucoencephalopathy
Produce neurological and intellectual impairment
Can produce hemiparesis
Definitive diagnosis with Histological examination for virus with Biopsy specimens
Other viruses - AIDS
AIDS patients can be co infected with Hepatitis B and C
They share same route of transmission as in drug abuse, Blood transfusion even sexual transmission
Hepatitis B infection - AIDS
Needs further evaluation on the progress of Infection
Infected patients become chronic carriers
Hepatitis C - AIDS
Hepatitis C is much more dangerous in producing chronic complications than Hepatitis B infection
Lesion have propensity for spreading widely over the patients body
Usually sexually transmitted
AIDS patients are highly prediposed..
Bacterial Infections in AIDS
Bacteria - AIDS
Mycobacterium avium intracellulare
High prevalence of Tuberculosis in AIDS
High prevalence of AIDS associated with Tuberculosis.
An early disease in AIDS patients
Can occur even at minimal Immuno Suppression
TB in HIV may be reactivation of latent TB - common in Developing world.
Present with similar picture as in HIV negative patients, as long as CD4 counts are high
TB in Advanced AIDS
Present with atypical manifestations, as
Absence of cavitations
Without hilar Lymphadenopathy
But may effect Lymphnodes – present with Lymphadenopathy
Involvement of Bone marrow, Liver
Bacteremia a leading clue to diagnosis
Diagnosis of Tuberculosis
X ray chest - the minimal investigation.
Sputum microscopy most important Investigation
In advanced disease Smear positivity decreases, need culturing for Mycobacterium
Use of Florescent Microscopy is gaining importance for detection of AFB in HIV patients.
X – ray Chest remains the Most important Investigation in Tuberculosis
Sputum Microscopy the most important simple investigation
Acid fast bacilli detection by Florescent Methods are more sensitive
Atypical mycobacterium - AIDS
Mycobacterium intracellulare occurs in the late stage of disease ( with gross Immuno Supression )
Needs newer methods of diagnosis, as
Direct examination and blood culture for AFB
Examination of Lymphnodes, Bone Marrow, and liver give better diagnostic options.
Mycobacterium avium intracellulare identified as the most important Atypical mycobacterium infecting AIDS patients
Other Methods of Diagnosis to Tuberculosis
Tuberculin test is less helpful in diagnosis of Tuberculosis associated with AIDS
Even indurations of
> 5 mm to 10 mm are taken to consideration as positivity.
Other Bacterial Infections
The abnormalities of the B cell function associated with HIV lead to infections with encapsulated bacteria, as reduced production of Ig G 2 , ,, cannot protect against the polysaccharide coat of such organisms.
HIV patients are predisposed with
1 Streptococcus pneumonia
2 Haemophilus influenzae
3 Moraxella catarrhalis.
Diagnosis ( Common Bacterial Infections )
Routine culture methods are adequate diagnosis.
Many respond to routine antibiotic treatment
But may need long term treatment to control to prevent relapses
Salmonella ( non Typhoidal )
Can be isolated from Blood and stool cultures
A frequent pathogen in HIV infection
Acquired orally produce disseminated infections.
Any organ can be involved
Staphylococcal infections can produce, Abscess, Cellulitis,and Folliculitis, and Furuncles
Routine culture methods are adequate to isolate the Bacteria
But Antibiotic resistance is concern in treating the patients.
Produce raised, reddish
highly vascular skin lesions
Mimic Kaposi's Sarcoma
May manifest as fever without clues
Bartonella henselae manifest as zoonotic infection spread by young cats
High level of suscipicion necessary for diagnosis.
Fungi and Yeasts
Fungi and Yeasts - AIDS
1 Pneumocystis jiroveci ( formerly carnii )
2 Cryptococcus neoformans
3 Candia spp
5 Histoplasma capsulatum
6 Coccidioides imitis
Most common cause of Pneumonia in AIDS patients
Difficult to Diagnose
If the CD4 counts are > 250, Pneumocystis is unlikely.