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L3
HIV/AIDS
D. Haider
HIV
OPPORTUNISTIC INFECTIONS
In patients with untreated HIV infection, decreasing CD4 cell counts predispose them to
infections that do not usually occur in persons with an intact immune system. These
opportunistic infections usually develop when the CD4 cell count is less than 200/μL and
become even more likely when the count is lower. However, mucocutaneous Candida infection
can develop with CD4 cell counts greater than 200/μL. Oral candidiasis
(Thrush) most often can be treated with topical agents such as clotrimazole troches. Dysphagia
or other swallowing symptoms indicate esophageal involvement, and treatment of esophageal
candidiasis requires a systemic agent such as fluconazole.
Cryptoccocal meningitis
Cryptococcus may be isolated to the lung but usually has disseminated before diagnosis and
manifests as subacute or chronic meningitis, cryptoccocal meningitis is usually diagnosed by
CSF culture or by cryptoccocal antigen test in serum or CSF fluid.
Treatment includes antifungal agents and control of increased ICP by serial LP and shunting.
Pneumocystis jirovicii pneumonia
Pneumocystis jirovecii pneumonia is a common complication in patients with HIV infection who
have not received prophylaxis. Patients present with subacute onset of fever, dyspnea, and dry
cough, and chest radiographs most commonly show diffuse interstitial or alveolar infiltrates
.Although the microorganisms may be found in induced sputum, diagnosis usually requires
stains of bronchoalveolar lavage fluid.
High-dose trimethoprim-sulfamethoxazole is the treatment of choice. During treatment, an
immune response to dying microorganisms may actually worsen disease in the first few days.
Adjunctive glucocorticoids are beneficial and should be used in patients with an arterial partial
pressure of oxygen (breathing ambient air) of less than 70 mm Hg (9.31 kPa) or an alveolar-
arterial gradient of greater than 35 mm Hg (4.66 kPa).
Toxoplasma gondii
Toxoplasma gondii can cause encephalitis in patients with CD4 cell counts less than 100/μL.
Diagnosis is typically based on signs and symptoms and imaging findings. Patients present with
headache, fever, focal neurologic deficits, and possibly seizures. Multiple ring-enhancing lesions
are seen on imaging studies. MRI is preferred to CT because of higher sensitivity.
Toxoplasmosis in patients with AIDS is almost always a reactivation disease; therefore, results
of serologic testing for anti-Toxoplasma IgG antibodies are usually positive. After presumptive
treatment (with pyrimethamine plus either sulfadiazine or clindamycin), patients should be
assessed for response within 1 or 2 weeks of starting therapy.
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Mycobacterial infections
Tuberculosis and MAC infection are the most common mycobacterial infections in patients with
AIDS.
Tuberculosis may present at any CD4 cell count, is more likely to be extra pulmonary at
presentation, and may not have the classic chest radiographic findings. Treatment of tuberculosis
and HIV confection must take into account drug interactions between the rifamycins and many
antiretroviral agents. MAC infection in patients with AIDS is usually disseminated at
presentation and develops at CD4 cell counts less than 50/μL.
Clinical features
include fever, sweats, weight loss, lymphadenopathy, hepatosplenomegaly,
and cytopenias. Treatment involves a multidrug regimen with clarithromycin or azithromycin as
the cornerstone of therapy.
CMV infections:
Cytomegalovirus (CMV) infection in patients with AIDS usually presents with specific end-
organ dysfunction rather than a nonspecific systemic illness. The most common manifestations
are retinitis, esophagitis or colitis, and polyradiculitis or encephalitis.
The diagnosis may be made clinically or by demonstrating CMV by histopathology studies or
NAAT. Initial treatment of CMV infection is oral valganciclovir or intravenous ganciclovir.
Skin opportunistic infections:
Molluscum contagiosum is a poxvirus infection that most commonly causes multiple small
papules on the face and trunk; it usually responds to immune reconstitution after treatment of
the HIV infection. Bartonella infection causes bacillary angiomatosis and is characterized by
skin lesions that resemble Kaposi sarcoma (KS).
KS is caused by a herpes family virus (human herpes virus 8) and presents with lesions that may
vary in color from red to purple to brown and may be macules, papules, plaques, or nodules. KS
is most often found on the skin but may also occur on mucous membranes of the respiratory and
gastrointestinal tracts.
Management guidelines:
1. The treatment by HAART(highly active antiretroviral therapy).
2. The treatment should be initiated in any adult with symptoms ascribed to HIV
infection regardless of CD4 count.
3. The treatment should be initiated in any asymptomatic patients with CD4 cell count
less than 350 cells per microliter.
4. Treatment is recommended for 3 conditions regardless of CD4 count or whether the
patient symptomatic or not. (pregnancy,HIV nephropathy, hepatitis B virus
confection).
5. Antiretroviral treatment should be offered to all patients who are ready to take
treatment.
Mubark A. Wilkins