The human herpes family viruses (HHV) consist of eight separate viruses, all with potential of causing human disease. The prevalence of HSV-1 (HHV-1) and HSV-2 (HHV-2) in the general population is 65 % and 29 %, respectively. HSV-1 is mostly transmitted through nonsexual contact and is most frequently associated with oral mucosal lesions, while HSV-2 is mostly transmitted through sexual contact and commonly infects urogenital mucosa. Shortly after primary infection, the virus can be found in a dormant state in sensory neurons. Reactivation may occur at a later time. Immunocompromised patients are at increased risk for reactivation with subsequent disseminated disease. HSV reactivation in posttransplant patients can cause pneumonia, hepatitis, encephalitis, and disseminated disease. Oral acyclovir has been shown to be an effective prophylactic and treatment agent for HSV-1 and HSV-2.

Respiratory syncytial virus (RSV) and parainfluenza are part of the paramyxovirus family that is a frequent cause of both upper and lower respiratory tract infections in children. Peak seasonal appearance occurs in the winter, similar to influenza. Immunocompromised patients, such as posttransplant and lymphopenic patients, are more likely to have progression of the infection into the lower respiratory tract with significantly higher mortality rates. The paramyxoviruses have been associated with posttransplant complications, including post-viral obliterative bronchiolitis, a cause of chronic rejection. While vaccination is not available, RSV prophylaxis can be effectively managed with immunoglobulin and monoclonal antibodies. Treatment centers on the use of ribavirin, RSV antibodies, and supportive measures. In comparison, there are no proven preventative or treatment measures for parainfluenza.

Perhaps the one virus that has gained global notoriety in history for global epidemics has been the influenza virus. Despite widespread vaccination, the potential for antigenic shift and drift exists, a situation that could contribute to worldwide pandemics. Influenza A and B are RNA viruses that cause upper and lower respiratory tract disease. Like RSV, the progression to lower respiratory tract disease is more prevalent in immunocompromised patients and disease peaks in the winter. Neuraminidase inhibitors, such as oseltamivir and zanamivir, are effective treatments, especially when begun early in the viral course. These treatments are augmented by amantadine and rimantadine. Vaccination is available, but it may not cover all strains of the virus.

Blood-borne viruses are a major concern in the hospital for both the patient and healthcare providers. Virus transmission from an infected host during percutaneous or mucosal penetration is reported to be 0.3 % for human immunodeficiency virus (HIV), 3 % for hepatitis C, and 30 % for hepatitis B. In order to calculate risk of transmission from percutaneous or mucous membrane injury, several factors must be considered, including method of transmission (needle penetration versus blood splash to mucous membrane), needle type (hollow-bore needle such as an IV needle versus solid-bore needle such as suture needle), needle gauge, penetration of needle into patient and healthcare worker, presence of blood on needle, access of the needle to the patient’s bloodstream, or whether the needle has passed through gloves or other barriers prior to entering the skin. Personal protective equipment and situational awareness remain the mainstays of prevention. Effective protection methods to minimize risk of transmission of blood-borne diseases include gloves, double gloving if needed, face shields or other eye protection, sleeve reinforcements, knee-high trauma boots, plastic aprons under surgical gowns, and avoidance of blind suturing techniques.