Epstein - Barr Virus (EBV) is a common human herpesvirus that infects most people during their lifetime.While often asymptomatic, it can cause infectious mononucleosis, a self - limiting illness characterized by fever, fatigue, and swollen lymph nodes.EBV can also be associated with various cancers, including Burkitt lymphoma and nasopharyngeal carcinoma. Qualitative PCR is a highly sensitive and specific molecular diagnostic test used to detect EBV DNA in biological samples. By amplifying specific DNA sequences unique to EBV, this technique can provide a rapid and accurate diagnosis of active EBV infection, even in individuals with no symptoms.

VARICELLA-ZOSTER VIRUS (VZV) CAUSES BOTH VARICELLA (CHICKENPOX) AND HERPES ZOSTER (SHINGLES). VZV PRODUCES A GENERALIZED VESICULAR RASH ON THE DERMIS (CHICKENPOX) IN NORMAL CHILDREN, USUALLY BEFORE 10 YEARS OF AGE. AFTER PRIMARY INFECTION WITH VZV, THE VIRUS PERSISTS IN LATENT FORM AND MAY EMERGE, USUALLY IN ADULTS 50 YEARS OF AGE AND OLDER CLINICALLY TO CAUSE A UNILATERAL VESICULAR ERUPTION, GENERALLY IN A DERMATOMAL DISTRIBUTION (SHINGLES). VZV DNA IS DETECTED IN CEREBROSPINAL FLUID FROM PATIENTS WITH CENTRAL NERVOUS SYSTEM DISEASE CAUSED BY THIS VIRUS.

THIS TEST IS ESSENTIAL FOR DIAGNOSING AND MONITORING CMV INFECTION, PARTICULARLY IN IMMUNOCOMPROMISED PATIENTS (E.G., ORGAN TRANSPLANT RECIPIENTS, HIV/AIDS PATIENTS) AND NEWBORNS. IT IS USED TO CONFIRM ACTIVE INFECTION, MONITOR THE EFFECTIVENESS OF ANTIVIRAL TREATMENT, AND ASSESS THE RISK OF CMV-RELATED DISEASE.

THE PRESENCE OF IGG ANTIBODIES INDICATES A PAST INFECTION OR CHRONIC EXPOSURE TO HSV-1. IT IS USEFUL FOR SCREENING INDIVIDUALS TO DETERMINE IF THEY HAVE BEEN PREVIOUSLY INFECTED.

PARVOVIRUS B19 IS THE ONLY MEMBER OF THE FAMILY PARVOVIRIDAE KNOWN TO BE PATHOGENIC IN HUMANS. THE VIRUS IS WIDESPREAD, AND MANIFESTATIONS OF INFECTION VARY WITH THE IMMUNOLOGIC AND HEMATOLOGIC STATUS OF THE HOST. INFECTION WITH B19 OCCURS EARLY IN LIFE AND VIRUS IS TRANSMITTED BY RESPIRATORY SECRETIONS AND OCCASIONALLY BY BLOOD PRODUCTS. INFECTION IN ADULTS IS SOMETIMES ASSOCIATED WITH AN ACUTE SYMMETRIC POLYARTHROPATHY THAT MAY MIMIC RHEUMATOID ARTHRITIS.

HUMAN PARECHOVIRUSES (HPEV) BELONG TO THE PICORNAVIRIDAE, A HIGHLY DIVERSE FAMILY OF SMALL, NON-ENVELOPED RNA VIRUSES, MANY OF WHICH ARE ASSOCIATED WITH HUMAN DISEASE. SINCE THEIR FIRST IDENTIFICATION IN 1956, PARECHOVIRUSES HAVE BEEN ASSOCIATED WITH MILD RESPIRATORY AND GASTROINTESTINAL DISEASE IN YOUNG CHILDREN. THEY HAVE BEEN ASSOCIATED WITH RESPIRATORY DISEASE, INCLUDING UPPER AND LOWER RESPIRATORY TRACT DISEASE. IT HAS ALSO BEEN CLAIMED THAT THEY COMMONLY CAUSE MILD GASTROENTERITIS AND LESS FREQUENTLY, MENINGITIS AND NEONATAL SEPSIS.

ENTEROVIRUSES ARE POSITIVE-SENSE RNA VIRUSES IN THE PICORNAVIRIDAE FAMILY. THE NORMAL SITE OF ENTEROVIRUS REPLICATION IS THE GASTROINTESTINAL TRACT WHERE THE INFECTION IS TYPICALLY SUBCLINICAL. HOWEVER, IN A PROPORTION OF CASES, THE VIRUS SPREADS TO OTHER ORGANS, CAUSING SYSTEMIC MANIFESTATIONS, INCLUDING MILD RESPIRATORY DISEASE (EG, THE COMMON COLD); CONJUNCTIVITIS; HAND, FOOT, AND MOUTH DISEASE; ASEPTIC MENINGITIS; MYOCARDITIS; AND ACUTE FLACCID PARALYSIS. COLLECTIVELY, ENTEROVIRUSES ARE THE MOST COMMON CAUSE OF UPPER RESPIRATORY TRACT DISEASE IN CHILDREN. IN ADDITION, THE ENTEROVIRUSES ARE THE MOST COMMON CAUSE OF CENTRAL NERVOUS SYSTEM (CNS) DISEASE; THEY ACCOUNT FOR ALMOST ALL VIRUSES RECOVERED IN CULTURE FROM SPINAL FLUID.

ADENOVIRUSES (HADV) CONSIST OF NON-ENVELOPED DSDNA AND ARE A COMMON CAUSE OF RESPIRATORY ILLNESS. THE SYMPTOMS CAN RANGE FROM THE COMMON COLD TO PNEUMONIA, CROUP AND BRONCHITIS. DEPENDING ON THE TYPE, ADENOVIRUSES CAN CAUSE OTHER ILLNESSES SUCH AS GASTROENTERITIS, CONJUNCTIVITIS, CYSTITIS, AND LESS COMMONLY NEUROLOGICAL DISEASES. ADENOVIRAL INFECTIONS AFFECT INFANTS AND YOUNG CHILDREN MUCH MORE FREQUENTLY THAN ADULTS. SEVERE DISSEMINATED INFECTION CAN OCCUR IN IMMUNOCOMPROMISED SUBJECTS.