WEEK 1: EPIDEMIOLOGY OF OPPRTUNISTIC INFECTIONS IN BOTSWANA Flashcards
What is an opportunistic infection?
Infections that result in disease formation in immune suppressed individuals.
Opportunistic infections (OIs) are illnesses that occur more frequently and are more severe in people with HIV. This is because they have damaged immune systems.
At what stage of chronic HIV infection do opportunistic infection occur?
AIDS stage
What are the common sources of opportunistic infection?
*From the environment
*Re-activation of latent infections
Among the pathogens that can cause opportunistic infections, name at least 2 classes/group of pathogens that dominate as opportunistic infections.
*Viruses
*Bacteria
Draw a table titled “Opportunistic infections according to CD4 level among People Living with HIV.”
Opportunistic Infection CD4 Count Cut-Off
Pneumocystis pneumonia (PCP) <200 cells/mm3
Toxoplasmosis <100 cells/mm3
Cryptococcal meningitis <100 cells/mm3
Cytomegalovirus (CMV) retinitis <50 cells/mm3
Mycobacterium avium complex (MAC) <50 cells/mm3
CD4 Level | Opportunistic Infections |
|————-|——————————————–|
| >500 cells/mm³ | Generally no increased risk of OIs |
| 350-500 cells/mm³ | Slight risk of mild OIs (e.g., oral candidiasis) |
| 200-350 cells/mm³ | Moderate risk of OIs (e.g., TB, Pneumocystis pneumonia) |
| <200 cells/mm³ | High risk of severe OIs (e.g., Cryptococcal meningitis, CMV retinitis) |
| <50 cells/mm³ | Very high risk of life-threatening OIs (e.g., Mycobacterium avium complex, toxoplasmosis) |
Mycobacteria tuberculosis complex disease is the leading opportunistic infection in Botswana. Tru/False
True
Kaelo comes to the clinic with extremly pain rash that wraps around mid abdomen. The rash starts at the back (just lateral to the spine) and extends to just by the umbilicus. What is this opportunistic infection? What pathogen is responsible?
Shingles
Varicella zoster virus
Margaret has history of HIV with a CD4 count of 23 cells/ul. She comes to the clinic because she has had headache for 2 weeks, associated with neck stiffness and low grade fever. You plan to do an LP. Use “Pocket Medicine” authored by Sabatine MD to study different cerebrospinal fluid (CSF) tests and findings you expect in evaluating her for opportunistic infection.
some of the CSF tests that can be useful are:
*CSF cell count and differential: to detect pleocytosis, which may indicate infection or inflammation.
*CSF protein and glucose: to assess the integrity of the blood-brain barrier and the presence of bacterial or fungal infection.
*CSF Gram stain and culture: to identify the causative organism of bacterial meningitis.
*CSF cryptococcal antigen: to diagnose cryptococcal meningitis, which is common in HIV patients with low CD4 counts.
*CSF India ink stain: to visualize cryptococcal organisms in CSF.
*CSF VDRL: to rule out neurosyphilis, which can occur in HIV patients.
*CSF PCR: to detect viral DNA or RNA of herpes simplex virus, varicella-zoster virus, cytomegalovirus, or HIV.
Some of the CSF findings that you may expect in Margaret’s case are:
*Elevated CSF HIV RNA: This indicates active viral replication in the central nervous system and may be associated with cognitive impairment.
*Low CSF glucose: This suggests bacterial or fungal infection, such as tuberculosis or cryptococcosis.
*Positive CSF cryptococcal antigen: This confirms the diagnosis of cryptococcal meningitis, which is a common opportunistic infection in HIV patients with CD4 counts below 50 cells/ul1.
*Positive CSF India ink stain: This shows the presence of cryptococcal organisms in CSF1.
You are asked to evaluate a patient with HIV, CD4 35 cells/ul who presented with a headache. On inspection you note soft, yellowish, painless multiple umbilicated rash (<2-4mm). What is the most likely opportunistic infection in her?
The most likely opportunistic infection in this patient is molluscum contagiosum, a viral skin disease caused by a poxvirus.
It presents as clusters of pink, dome-shaped, smooth, waxy, or pearly and umbilicated papules 2 to 5 mm in diameter.
Other differential diagnoses of umbilicated rash include acne vulgaris, common warts, chicken pox, folliculitis, and condyloma acuminatum. However, these are less likely in a patient with HIV and low CD4 count.
You are asked to evaluate a patient with HIV, CD4 35 cells/ul who presented for initiation of treatment. On inspection you note soft, mobile, painless masses in the axilla, groin and neck. Name three opportunistic infections that can present this way?
some of the opportunistic infections that can cause lymphadenopathy in people with HIV are:
Tuberculous and nontuberculous mycobacterial infections
Lymphoma
Kaposi sarcoma
You are asked to evaluate a patient with HIV, CD4 35 cells/ul who presented with a decrease in ability to taste. On examination you note while plaques that you are able to scrap off. What is the most likely opportunistic infection in her?
Oral hairy leukoplakia
Caused by EBV
You are asked to evaluate a patient with HIV, unknown CD4 count, who presented with tonic clinic seizures and weakness of the right arm. He has oral thrush. CT of the brain reveals a ring enhancing lesion. What is the most likely opportunistic infection in her? What is his predicted CD4 count?
The most likely opportunistic infection in this patient is toxoplasmosis, which is caused by the parasite Toxoplasma gondii.
This infection is common in patients with advanced HIV, especially when the CD4 count is less than 100 cells/mm3.
Toxoplasmosis can cause multiple ring-enhancing lesions in the brain, typically located at the corticomedullary junctions of the frontal and parietal lobes, centrum semi-ovale and basal ganglia.
These lesions can cause seizures, focal neurological deficits, headache, confusion and other symptoms.
You see a 23-year patient with history of HIV and dry cough for 3 weeks, easy fatiguability, low grade fever. His CD4 count is 165 cells/ul. Name 2 opportunistic infection that can present this way.
Pneumocystis pneumonia (PCP): a fungal infection that affects the lungs and can cause difficulty breathing, high fever and dry cough.
Tuberculosis (TB): a bacterial infection that affects the lungs and other organs and can cause persistent dry cough, weight loss, night sweats and fever.
You are asked to evaluate a patient with HIV, unknown CD4 count, who presented with severe odynophagia and dysphagia. Name at least 2 opportunistic infections that can present this way.
*Candida esophagitis: a fungal infection of the esophagus that may also cause oral thrush.
*Cytomegalovirus (CMV) esophagitis: a viral infection of the esophagus that may cause ulcers and bleeding.
*Esophageal lymphoma: a rare type of cancer that affects the lymphatic system in the esophagus.
Other possible causes include herpes simplex virus (HSV) esophagitis, tuberculosis (TB) esophagitis, Kaposi sarcoma (KS) and aphthous ulcers.
You see a 23 years patient with history of HIV and gradual loss of vision. His CD4 count is 15 cells/ul. Name 2 opportunistic infection that can present this way.
*Cytomegalovirus retinitis
*Toxoplasmosis
