Infection with HIV results in lifelong persistence of the virus in the body of infected persons, independent of antiretroviral treatment. Therefore, efficient and meaningful therapy monitoring has been developed since its introduction in the 1980s. Whereas, primarily, the measurement of the CD4 cell count was the most important clinical marker of disease progression, nowadays the estimation of plasma viral load with molecular methods plays a major role as a marker of therapy success. To optimize therapy changes in patients failing on antiretroviral therapy regimen, HIV-1 genotyping has been introduced and is now widely accepted as an additional diagnostic tool. Due to this increase in diagnostic parameters, clinicians and virologists have to cope with many different methods. This review should give a brief overview of the current commercially available assays for detection and quantification of HIV, as well as for HIV-1 genotypic resistance testing. Quantitative reverse transcriptase PCR, real-time PCR, nucleic acid sequence-based amplification and the branched DNA system are described in detail, and the advantages and disadvantages are discussed. In addition, two commercially available HIV-1 genotyping assays are compared. However, a general recommendation to favor one system over the other cannot be given, because the final decision of which system to use should be decided on the individual requirements.

The seroprevalence of parvovirus B19 in patients admitted to the University Hospital in Frankfurt a.M. was, on average, lower than that among the general population in Germany. Infection among patients in specific risk groups did not spread more than that in age-matched non-selected patients, with the exception of the group of immunocompromised patients.

Varicella-zoster virus (VZV), known as one of the eight human herpesviridae, shows a ubiquitous distribution and is the cause for acute exanthema in childhood (chickenpox). VZV is highly infectious, spread by respiratory droplets and direct contact with fluid in vesicles. As a characteristic of the alpha-herpesviridae, VZV establishes latency in the nucleus of the paraspinal cells. Reactivation of VZV (zoster) is possible in all infected persons, but becomes more common with increasing age and a decline of VZV-specific cell-mediated immunity. Immunocompromised patients and older people (> 50 years) have an increased risk for a severe course of disease. The postherpetic neuralgia (PHN), as one of the most common and feared complications, is defined as a neuropathic pain (burning character), which persists for > 6 weeks after onset of disease and needs adequate antiviral and pain treatment.

In Germany, five antiviral agents are approved for antiviral therapy in zoster patients (acyclovir, valacyclovir, famciclovir, brivudine, and foscarnet). They should be administered within 72 h after rash onset and can significantly shorten viral replication and reduce the complications. In 2004, the German Standing Committee on Vaccination (STIKO) at the Robert Koch Institute suggested the active immunization against varicella with a live attenuated varicella vaccine (Oka strain) for all children and young persons. The first dose is given between the ages of 11 and 14 months, the second at the earliest 4 weeks later. Passive immunization is indicated as postexposure prophylaxis in high-risk individuals within 72-96 h after exposure. High-risk individuals are pregnant women, immunocompromised patients, or newborns, whose mothers had a primary varicella infection 5 days before or 2 days after birth. The Shingles Prevention Study demonstrated that vaccination is the most effective strategy for prevention of herpes zoster and postherpetic neuralgia.