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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,
mucocutaneousCandida 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.

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.



رفعت المحاضرة من قبل: Mubark Wilkins
المشاهدات: لقد قام عضوان و 60 زائراً بقراءة هذه المحاضرة








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