AIDS-associated cytomegalovirus infection mimicking central nervous system tumors: a diagnostic challenge

Cytomegalovirus (CMV)-Driven Transformation: An Uncommon Cause of a Central Nervous System Pseudotumor

Cytomegalovirus (CMV) is an opportunistic virus that can cause life-threatening neurological diseases in immunocompromised individuals, particularly those with HIV/AIDS. In this case report, a patient presenting with left gait lateralization was found to have a ring-enhancing cerebral mass lesion that was attributed to CMV. To date, only eight similar cases have been documented. When evaluating patients with HIV/AIDS who have cerebral mass lesions, clinicians should keep CMV as a possible cause because prompt antiviral therapy may improve clinical outcomes.

Encephalitis Due to Co-Infection with Cytomegalovirus and Herpes Simplex Virus Type 2 in a Patient with Acquired Immunodeficiency Syndrome

BACKGROUND Opportunistic infections are commonly seen in immunocompromised patients. Here, we present an interesting case of a patient with poorly controlled human immunodeficiency virus (HIV) infection who presented with multiple opportunistic infections. CASE REPORT A 44-year-old woman with medical history of HIV infection (CD4 <20 cells/µl, viral load 172 996 copies/ml), presented with symptoms of headache for 2 days and changes in mentation. She was recently treated for pulmonary mycobacterium avium complex infection. Her physical examination revealed normal breath sounds and her abdominal examination was unremarkable. She did not have any focal neurological deficits, nuchal rigidity, or papilledema on examination. Computed tomography (CT) head was negative for any acute lesions. She was empirically started on vancomycin and piperacillin-tazobactam. Due to persistent symptoms, a lumbar puncture was performed, which revealed elevated total proteins in CSF, and a viral polymerase chain reaction test was positive for herpes simplex virus type 2 (HSV-2) and cytomegalovirus (CMV). Magnetic resonance imaging of the brain showed mild enhancement of the ventricular lining. She was treated with acyclovir, which was later changed to ganciclovir, with resulting clinical improvement. The patient had clinical improvement and was discharged home. CONCLUSIONS Multiple opportunistic co-infections should be considered in patients with poorly controlled HIV infection.

Neuroimaging of CNS infection in haematological malignancy: important signs and common diagnostic pitfalls

Patients with haematological malignancy are at increased risk of developing central nervous system (CNS) infections, which are associated with significant morbidity and mortality. Neuroimaging plays a pivotal role in the diagnostic pathway of these patients; however, layers of complexity are added to image interpretation by the heterogeneity in imaging manifestations of haematological malignancies in the CNS, overlapping imaging features of CNS infection, treatment-related parenchymal changes and the presence of intracranial comorbidity. In this article, we review important intracranial findings of CNS infection cases accrued in 1,855 studies over more than a decade at a specialist tertiary centre. We offer schema to identify common and important neuroimaging features, discuss key differential diagnoses and frequent diagnostic pitfalls.

Disseminated cytomegalovirus infection with bilateral adrenal pseudotumors masquerading as recurrent hematologic malignancy

BACKGROUND

Mass-like lesions are an uncommon presentation of cytomegalovirus (CMV) disease.

CASE

We report on a case of disseminated CMV disease with bilateral adrenal pseudotumors in a patient with a history of acute leukemia in remission.

CONCLUSION

In the settings of advanced cancer therapy and organ transplantation, a high index of suspicion for CMV should be maintained for mass-like disease.

Nocardia amikacinitolerans and cytomegalovirus: distinctive clinical and radiological characterization of the rare etiologies of brain abscesses: report of 2 cases

Central nervous system infections in immunosuppressed patients are rare but potentially lethal complications that require swift diagnoses and intervention. While the differential diagnosis for new lesions on neuroradiological imaging of immunosuppressed patients typically includes infections and neoplasms, image-based heuristics to differentiate the two has been shown to have variable reliability.The authors describe 2 rare CNS infections in immunocompromised patients with atypical physical and radiological presentations. In the first case, a 59-year-old man, who had recently undergone a renal transplantation, was found to have multifocal Nocardia amikacinitolerans abscesses masquerading as neoplasms on diffusion-weighted imaging (DWI); in the second case, a 33-year-old man with suspected recurrent Hodgkin's lymphoma was found to have a nonpyogenic abscess with cytomegalovirus (CMV) encephalitis.As per review of the literature, this appears to be the first case of brain abscess caused by N. amikacinitolerans, a recently isolated superbug. Despite confirmation through brain biopsy later on in case 1, the initial radiological appearance was atypical, showing subtle diffusion restriction on DWI. Similarly, the authors present a case of CMV encephalitis that presented as a ring-enhancing lesion, which is extremely rare. Both cases draw attention to the reliability of neuroimaging in differentiating an abscess from a neoplasm.

Other central nervous system infections: cytomegalovirus, Mycobacterium tuberculosis, and Treponema pallidum

Human immunodeficiency virus (HIV)-infected individuals are particularly susceptible to several central nervous system infections: human cytomegalovirus, which may cause encephalitis, ventriculitis, polyradiculitis, or polyradiculomyelitis; Mycobacterium tuberculosis, which can cause meningitis or space-occupying lesions; and Treponema pallidum subspecies pallidum (T. pallidum), which affects the meninges, cerebrospinal fluid, cranial nerves, and vasculature in early neurosyphilis, and additionally the brain and spinal cord parenchyma in late neurosyphilis. Central nervous system cytomegalovirus infection is seen in HIV-infected individuals with very advanced immunosuppression. Its prognosis is poor and optimal therapy has not been determined. Tuberculous meningitis has a high mortality in those also infected with HIV, especially in the developing world, and better therapies are urgently needed. As the rates of syphilis increase in the developed world, neurosyphilis and in particular ocular syphilis are increasingly reported. The likelihood of all three of these central nervous system infections is decreased in individuals who receive potent antiretroviral therapy.

Viral and Prion Infections of the Central Nervous System: Radiologic-Pathologic Correlation: From the Radiologic Pathology Archives

Viral infections of the central nervous system (CNS) range in clinical severity, with the most severe proving fatal within a matter of days. Some of the more than 100 different viruses known to affect the brain and spinal cord are neurotropic with a predilection for producing CNS infection. The host response to viral infection of the CNS is responsible for the pathophysiology and imaging findings seen in affected patients. Viral CNS infections can take the form of meningitis, encephalitis, encephalomyelitis, or, when involving the spinal cord and nerve roots, encephalomyeloradiculitis. In 1982, an infectious particle termed a prion that lacked nucleic acid and therefore was not a virus was reported to produce the fatal neurodegenerative disease Creutzfeldt-Jakob disease and related disorders. These prion diseases produce characteristic neuroimaging findings that are distinct from those seen in most viral infections. The clinical and imaging findings associated with viral CNS infection are often nonspecific, with microbiologic analysis of cerebrospinal fluid the most useful single test allowing for diagnosis of a specific viral infection. This review details the spectrum of viral CNS infections and uses case material from the archives of the American Institute for Radiologic Pathology, with a focus on the specific clinical characteristics and magnetic resonance imaging features seen in these infections. Where possible, the imaging features that allow distinction of these infections from other CNS inflammatory conditions are highlighted.

Causes of Death Among Patients Infected with HIV at a Tertiary Care Hospital in China: An Observational Cohort Study

The objective of this study was to elucidate the causes of death and mortality in a cohort of inpatients infected with HIV. The causes of death and mortality were evaluated by using the clinical data of 1,076 patients admitted to the Center for Infectious Diseases, Beijing Ditan Hospital, between January 1, 2009, and November 30, 2012, and who were followed for 6 months after discharge. During the 4-year study period, 216 patients had died by the 6-month follow-up (mortality rate, 20.1%). Opportunistic infections were the most common causes of death (42.0%), followed by malignancies (23.1%), unexplained central nervous system infections and occupying lesions (18.1%), infectious shock (10.2%), severe hepatitis and decompensated cirrhosis (3.2%), sudden death (1.4%), lactic acidosis (0.9%), and uremia (0.9%). The strong risk factors for mortality were cost constraints and unaffordable further diagnosis and treatment (adjusted hazard ratio [AHR] = 134.394, 95% confidence interval [CI] = 25.748-701.481, p < .001), unexplained etiologies (AHR = 12.551, 95% CI = 6.642-23.716, p < .001), and multiple complications (AHR = 5.798, 95% CI = 2.973-11.308, p < .001). Mortality was not associated with CD4 levels or combined antiretroviral therapy (cART) in a cohort of inpatients at a special hospital for HIV/AIDS patients in China. AIDS-related infections and malignancies were the most common causes of death in patients infected with HIV, and improvement of the etiological diagnosis would help physicians provide appropriate treatment and reduce mortality rates.

Frequent occurrence of therapeutically reversible CMV-associated encephalopathy during radiotherapy of the brain

BACKGROUND

Neurological decline during radio(chemo)therapy of the brain is often attributed to disease progression or side effects of radiotherapy. Diagnosis of opportunistic neurotropic infections such as cytomegalovirus (CMV) infections is uncommon, even though high-grade gliomas and some brain metastases are known to contain CMV particles. We prospectively examined the frequency of CMV encephalopathy during radiotherapy of the brain.

METHODS

Fifty patients requiring whole-brain radiotherapy for brain metastases (n = 27) or local radio(chemo)therapy of the brain for high-grade gliomas (n = 23) were observed in the prospective observational GLIO-CMV-01 study. MRIs and blood samples were obtained before, halfway through, and at the end of radiotherapy. MRIs were screened for disease progression or increased intracranial pressure. Blood was tested for anti-CMV immunoglobulin (Ig)M, anti-CMV IgG, and CMV DNA.

RESULTS

Thirty-two of 50 (64%) patients were positive for anti-CMV IgG before radio(chemo)therapy. Fifteen of those 32 (48%) developed viremia during or up to 28 days after treatment. Thirteen of those 15 (87%) required treatment for CMV-associated encephalopathy. MRIs were negative for disease progression, edema, or bleeding. None of the patients negative for anti-CMV IgG developed viremia, suggesting a reactivation rather than a primary infection.In the group at risk consisting of anti-CMV IgG+ patients, age >65 (P = .004) and the amount of dexamethasone taken during radio(chemo)therapy (P = .004) were associated with an increased risk for CMV-associated encephalopathy. One hundred and fifty days after the start of radio(chemo)therapy, survival was 74% (14/19) (no encephalopathy) versus 54% (7/13) (encephalopathy) (odds ratio, 0.42; 95% CI, 0.03-1.86; P = .25).

CONCLUSION

CMV reactivation frequently causes encephalopathy during radio(chemo)therapy of the brain. The unexpected high incidence of this infection makes it highly clinically relevant for every treating physician.

Epilepsia Partialis Continua as Presenting Manifestation of AIDS: A Rarity

Seizures, most commonly generalized tonic-clonic, are common in known human immune deficiency virus (HIV) sero-positive patients, and they usually have a focal lesion on brain imaging. However, it is very unusual to see a patient with no premorbid illness presenting with epilepsia partialis continua (EPC) and then being detected HIV seropositive with an Acquired Immune Deficiency Syndrome (AIDS)-defining illness. We report the case of a teenaged boy with no past significant history or known high-risk behavior who presented with recurrent focal seizures of 5 days' duration, EPC, and encephalopathy. His electroencephalogram showed periodic lateralized epileptiform discharges (PLEDS), and magnetic resonance imaging (MRI) of the brain showed abnormal signal changes in the right parieto-occipital cortex and thalamus, both as yet unreported in cytomegalovirus (CMV) encephalitis, which was diagnosed by the cerebrospinal fluid (CSF) analysis.

Central nervous system infections of herpesvirus family

Herpesviruses are one of the most common groups of pathogens causing central nervous system infections in humans. They mostly cause encephalitis, meningitis, or myelitis in immunocompetent and immunocompromised patients. Children, adults, and the elderly can all be affected. Although contrast-enhanced CT is more widely used for diagnosis, contrast-enhanced MR imaging combined with diffusion-weighted imaging is superior to CT in the detection of early changes and the real extent of the disease, and in assessing prognosis and monitoring response to antiviral treatment. More sophisticated techniques, such as MR spectroscopy and perfusion imaging, can aid in the differential diagnosis of herpesvirus infections from other tumoral, demyelinating, and ischemic processes.

Neuroimaging of herpesvirus infections in children

Six members of the herpesvirus family cause well-described neurologic disease in children: herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella-zoster (VZV), Epstein-Barr (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6). When herpesviruses infect the central nervous system (CNS), the clinical presentation is non-specific and often confounding. The clinical urgency is often underscored by progressive neurologic deficits, seizures, or even death, and prompt diagnosis and treatment rely heavily on neuroimaging. This review focuses on the spectrum of cerebral manifestations caused by these viruses, particularly on non-congenital presentations. Recent advances in our understanding of these viruses are discussed, including new polymerase chain reaction techniques that allow parallel detection, which has improved our recognition that the herpesviruses are neurotropic and involve the CNS more often than previously thought. Evolving knowledge has also better elucidated viral neuropathology, particularly the role of VZV vasculitis in the brain, HHV-6 in febrile seizures, and herpesvirus reactivation in immunosuppressed patients. The virology, clinical course, and CNS manifestations of each virus are reviewed, followed by descriptions of neuroimaging findings when these agents infect the brain. Characteristic but often subtle imaging findings are discussed, as well as technical pearls covering appropriate use of MRI and MRI adjuncts to help differentiate viral infection from mimics.

The expanding spectrum of herpesvirus infections of the nervous system

Herpesviruses cause various acute, subacute, and chronic disorders of the central (CNS) and peripheral (PNS) nervous systems in adults and children. Both immunocompetent and immunocompromised individuals may be affected. Zoster (shingles), a result of reactivation of varicella zoster virus (VZV), is the most frequent neurologic complication. Other neurological complications include encephalitis produced by type I herpes simplex virus (HSV-1), and less frequently HSV-2, as well as by VZV and cytomegalovirus (CMV). Acute meningitis is seen with VZV and HSV-2, and benign recurrent meningitis with HSV-2. Combinations of meningitis/ encephalitis and myelitis/radiculitis are associated with Epstein Barr Virus (EBV); myelitis with VZV, CMV, EBV, and HSV-2; and ventriculitis/encephalitis with VZV and CMV. Brainstem encephalitis due to HSV and VZV, and polymyeloradiculitis due to CMV are well documented. HHV-6 produces childhood exanthem subitum (roseola) and febrile convulsions. Immunocompetent and immunocompromised hosts manifest different incidences and patterns of herpesvirus infections. For example, stroke due to VZV-mediated large vessel disease (herpes zoster ophthalmicus) occurs predominantly in immunocompetent hosts, while small vessel disease (leukoencephalitis) and ventriculitis develop almost exclusively in immunocompromised patients. EBV-associated primary CNS lymphomas also are restricted to immunosuppressed individuals. Recent large CSF PCR studies have shown that VZV, EBV, and CMV more frequently produce meningitis, encephalitis, or encephalopathy in immunocompetent hosts than was formerly realized. We review herpesvirus infections of the nervous system and illustrate the expanding spectrum of disease by including examples of a 75-year-old male on steroid treatment for chronic lung disease with fatal HSV-2 meningitis and an 81-year-old male with myasthenia gravis, long-term azathioprine use, and an EBV-associated primary CNS lymphoma.

Atteintes du système nerveux central et infection par le VIH-1

Central nervous system complications are common in HIV-1 infected patients and occur either as a result of concomitant immunosuppression (opportunistic infections, lymphoma and tumors), as a primary manifestation of HIV infection, or as an adverse effect of therapy (immune restoration and toxicity). These complications contribute largely to patient morbidity and mortality. In the era of highly active antiretroviral therapy (HAART) these disease states have changed in presentation, outcome and incidence. We review in detail the epidemiology, pathogenesis, clinical features, diagnosis, and management of these disorders.

New Times for an Old Disease: Intracranial Mass Lesions Caused by Mycobacterium tuberculosis in 5 HIV-Negative African Immigrants

BACKGROUND

The tuberculosis epidemic is still a global emergency, and its spread in the past 20 years has been fueled by the acquired immune deficiency syndrome pandemic and increasing drug resistance. International travel and migration may increase the incidence of tuberculosis in industrialized countries.

METHODS

We reviewed the clinical charts of patients admitted to the infectious diseases unit of Ospedali Riuniti (Bergamo, Italy) to identify patients with intracranial mass lesions caused by Mycobacterium tuberculosis.

RESULTS

During the past 6.5 years, 5 of 30 patients with a mass of infectious origin in the brain had tuberculous brain lesions diagnosed. All 5 were human immunodeficiency virus (HIV)-negative adults and African immigrants. No patient had concomitant meningitis, 1 had a concomitant pulmonary disease, and 3 subjects reported a past history of tuberculosis. At presentation, no patient had fever and 3 had seizures. Examination of cerebrospinal fluid revealed normal findings for 4 of 4 subjects, and neuroimaging showed multiple intracranial mass lesions in 4 of 5 patients. The diagnosis was definite for 2 subjects (based on analysis of brain specimens) and presumptive for 3 subjects (1 had concomitant pulmonary tuberculosis, and 2 had clinical response to therapy). Results of susceptibility tests for M. tuberculosis were available for 2 patients: both isolates were resistant to isoniazid, and 1 was also resistant to streptomycin. Duration of medical treatment ranged from 11 to 23 months, and 2 subjects underwent surgical procedures at the time of diagnosis. All 5 patients recovered.

CONCLUSIONS

Clinicians in western countries should consider the possible role of tuberculosis in causing mass lesions in the brain, particularly in immigrants from regions where tuberculosis is endemic.

Cerebral mass lesion due to cytomegalovirus in a patient with AIDS: case report and literature review

Cytomegalovirus (CMV) disease in acquired immunodeficiency syndrome (AIDS) patients most commonly presents as chorioretinitis and gastro-intestinal infection. Neurological involvement due to CMV may cause several clinical presentations: polyradiculitis, myelitis, encephalitis, ventriculo-encephalitis, and mononeuritis multiplex. Rarely, cerebral mass lesion is described. We report a 39 year-old woman with AIDS and previous cerebral toxoplasmosis. She presented with fever, seizures, and vulval ulcers. Her chest X-ray showed multiple lung nodules, and a large frontal lobe lesion was seen in a brain computed tomography scan. She underwent a brain biopsy through a frontal craniotomy, but her condition deteriorated and she died in the first postoperative day. Histopathological studies and immunohistochemistry disclosed CMV disease, and there was no evidence of cerebral toxoplasmosis, bacterial, mycobacterial or fungal infection. CMV disease should be considered in the differential diagnosis of cerebral mass lesion in AIDS patients. High suspicion index, timely diagnostic procedures (surgical or minimally invasive), and proper utilization of prophylactic and therapeutic medication could improve outcome of these patients.

Spinal cord biopsy: a review of 38 cases

OBJECTIVE

Neurosurgeons are frequently asked to evaluate patients for spinal cord biopsies when preoperative magnetic resonance imaging studies demonstrate nonspecific features. These lesions often appear unresectable, but surgeons must decide whether a biopsy is warranted. To determine the best approach to these cases, we evaluated the clinicopathological findings for patients with unknown spinal cord lesions who underwent spinal cord biopsies.

METHODS

Thirty-eight consecutive patients who underwent spinal cord biopsies at the Mayo Clinic (Rochester, MN) between August 1988 and July 1998 were studied. A detailed review of the case histories, radiological results, surgical notes, histological findings, and outcomes was performed.

RESULTS

Spinal cord biopsies were performed for 21 male and 17 female patients (mean age, 42.1 yr) with progressive neurological deficits related to spinal cord lesions. All patients underwent preoperative magnetic resonance imaging evaluations. High T2-weighted signal intensity and spinal cord expansion were identified in 92 and 87% of cases, respectively. After gadolinium infusion, the majority (94%) of the inflammatory lesions demonstrated patchy and often peripherally situated enhancement. This neuroradiological pattern was less common for neoplasms (50%) and benign lesions (40%). The most common pathological findings were inflammatory changes of demyelination or sarcoidosis, which together accounted for 13 cases (34%). Nonspecific changes or benign lesions were observed in 10 cases (26%). Neoplasms were identified in eight cases (21%). One case of tuberculosis and one of schistosomiasis were found. Overall, 47% of the preoperative diagnoses made by the attending surgeon were correct. For 26% of the patients, specific treatment was based on the biopsy results. The average follow-up period was 12 months (standard deviation, 14 mo; range, 0-50 mo).

CONCLUSION

Preoperative laboratory and imaging studies are often diagnostically inconclusive in cases of spinal cord lesions with nonspecific features. Biopsies should be considered for patients with progressive symptomatic lesions.

CNS manifestations of cytomegalovirus infections: diagnosis and treatment

Cytomegalovirus (CMV) infection of the CNS occurs most commonly in patients with severe immunosuppression such as those with advanced HIV infection (i.e. AIDS) or those who have undergone bone marrow or solid organ transplantation. Immunocompetent patients are affected very rarely. The infection of the CNS may affect the brain (diffuse encephalitis, ventriculoencephalitis, cerebral mass lesions) or the spinal cord (transverse myelitis, polyradiculomyelitis). Diagnosis is very difficult and should be based on clinical presentation, results of imaging and virological markers. The most specific diagnostic tool is the detection of CMV DNA by polymerase chain reaction in the CSF. Treatment should be initiated promptly if CMV infection is suspected. Antiviral therapy consists of intravenous ganciclovir, intravenous foscarnet or a combination of both. Cidofovir is the treatment of second choice. Patients who experience clinical improvement or stabilisation during induction therapy should be given maintenance therapy. After immune reconstitution (in HIV-positive patients) or discontinuation of immunosuppressive therapy (in transplant recipients), maintenance therapy may be stopped. Despite therapy, the prognosis for long-term survival is very poor, especially in patients with AIDS.

Non-neoplastic intramedullary pathology. Diagnostic dilemma: to Bx or not to Bx

There are several non-neoplastic lesions which may mimic intramedullary spinal cord neoplasm in their radiographic and clinical presentation. These can be classified as either infectious (TB, fungal, bacterial, parasitic, syphilis, CMV, HSV) and non-infectious (sarcoid, MS, myelitis, ADEM, SLE) inflammatory lesions, idiopathic necrotizing myelopathy, unusual vascular lesions (amyloid, infarct, isolated intramedullary vascular lesions) and radiation myelopathy. Although biopsy may be indicated in many cases, the mistaken diagnosis of intramedullary neoplasm can often be eliminated pre-operatively.

Diagnostic imaging of the brain in acquired immunodeficiency syndrome (AIDS)

The central nervous system is commonly involved in acquired immunodeficiency syndrome (AIDS), resulting in a variety of lesions and diseases. They can be divided into the primary effects of human immunodeficiency virus (HIV), opportunistic infections, tumors, and vascular disease. This article is a review of the major imaging findings observed in each disease, with clinical and pathological correlations relevant to the goal of differential diagnosis.

Cytomegalovirus encephalitis in an HIV positive patient presenting with a cerebral mass lesion

Cytomegalovirus (CMV) encephalitis typically occurs as a diffuse cerebral infection in patients with advanced AIDS. This is a case report of a patient who presented with right-sided weakness and subsequently was found to have a cerebral mass lesion due to CMV. Only four similar cases are described in the literature. Though uncommon, CMV encephalitis must be considered in the differential diagnosis of cerebral mass lesions in patients with advanced AIDS.

Cytomegalovirus disease presenting as a focal brain mass: report of two cases

OBJECTIVE AND IMPORTANCE

Although the differential diagnosis of intracranial lesions in patients who have tested positive for human immunodeficiency virus is extensive, toxoplasmosis, lymphoma, and progressive multifocal leukoencephalopathy comprise approximately 90% of such cases. Cytomegalovirus infection of the central nervous system may be difficult to diagnose and rarely presents as mass lesions revealed by radiographic studies.

CLINICAL PRESENTATION

Two patients who had tested positive for human immunodeficiency virus presented with progressive focal neurological deficits. Radiographic studies revealed solitary contrast-enhancing lesions in the right basal ganglia and right cerebellar hemisphere, respectively.

INTERVENTION

The first patient underwent a stereotactic biopsy but died despite appropriate therapy. The second patient died without tissue having been obtained for diagnosis. Postmortem examinations revealed necrotizing lesions with diffuse areas of infiltrating histiocytes containing eosinophilic cytomegalovirus inclusion bodies.

CONCLUSION

Although rare, cytomegalovirus infection should be considered in patients who have tested positive for human immunodeficiency virus and who present with enhancing intracranial lesions.

Summary of the International Consensus Symposium on Advances in the Diagnosis, Treatment and Prophylaxis and Cytomegalovirus Infection

CMV infection and CMV disease can be difficult to differentiate and the diagnosis is usually based on a compatible clinical picture and the results of a diagnostic test for CMV. The only exception to this rule is in HIV-infected patients where fundoscopy is sufficient to diagnose CMV retinitis. Of the current diagnostic tests, qualitative and quantitative PCR, branched DNA and Hybrid Capture, are the most promising. The pp65 antigenemia assay has the disadvantage of being more labor-intensive than the DNA based tests. Preliminary data show that a positive qualitative PCR in a HIV-infected patient has a predictive value for the development of CMV retinitis. However, of the patients positive by qualitative PCR, those with high viral loads in quantitative PCR were at the greatest risk of CMV disease. This might make it possible to identify with great certainty the patients who will go on to develop CMV retinitis, thereby decreasing the number of patients eligible for preemptive or prophylactic therapy and increasing the cost-benefit of this therapeutic measure. Quantitative test might also be useful in monitoring response to therapy, but randomized trials comparing the test are needed. Prophylactic antiviral agents should not be used in seronegative transplant recipients receiving organs from seronegative donors. In high-risk transplant recipients, ganciclovir should be used. CMV vaccines are useful for the protection of babies from CMV seronegative mothers against congenital CMV disease. It also may be useful in seronegative transplant recipients receiving a seropositive donor organ, although the benefit of chemo prophylaxis may surpass that of vaccine. HIV-infected patients with CMV retinitis who relapse under either ganciclovir or foscarnet benefit from subsequent combination therapy, rather than switching to the other drug. However, the cost is high in terms of quality of life. Intravitreal therapy for CMV retinitis is very efficacious, suggesting that drug delivery is a problem in systemic therapy. However, intravitreal therapy does not protect against the development of CMV retinitis in the contralateral eye or from CMV disease elsewhere. Therefore, systemic therapy should be added. CMV disease of the CNS should be diagnosed early and treated agressively, possible with combination therapy. A diagnosis of CMV disease should be based on a compatible clinical picture and the demonstration of CMV in CSF by DNA or antigen assays which are more sensitive than culture.