Virology Cases

Viral infections in humans are ubiquitous. Individuals can be infected with different viruses on multiple occasions over a lifetime; sometimes the same type of virus can infect a person repeatedly, such as influenza virus. Some viral infections are subclinical, meaning they do not elicit overt signs and symptoms of infection. Other times with certain types of viral infections, the clinical manifestations can be significant and sometimes deadly. The diagnostic virology laboratory plays a large role in identifying patients with both types of viral infections. Accurate and timely identification of viruses is important not only for the diagnosis of infections but also to help direct therapy as antiviral therapeutics become increasingly available. This chapter reviews the conventional and advanced methods used in the diagnostic virology laboratory and provides a number of detailed patient cases in which the laboratory was critical in determining the etiology of infection. Each case includes the clinical presentation, differential diagnosis, relevant laboratory findings, and a discussion pertinent to the pathogen identified and a brief review of other potential etiologies for the clinical syndrome described.