Biology of Measles Virus: Epidemiology and Clinical Manifestations

Measles virus is a highly infectious RNA virus belonging to the genus Morbillivirus in the family Paramyxoviridae. It causes measles, a respiratory disease that is one of the leading causes of childhood mortality worldwide. The virus has a pleomorphic structure and a genome consisting of a single strand of negative-sense RNA. The genome encodes six structural proteins, including the nucleocapsid (N), phosphoprotein (P), matrix (M), fusion (F), hemagglutinin (H), and the large polymerase (L) proteins. Measles virus enters host cells through the interaction of the viral H protein with cellular receptors, followed by fusion of the viral envelope with the host cell membrane. The virus then undergoes replication and assembly, leading to the release of new virus particles. The viral life cycle is complex and involves numerous host factors. Diagnosis of measles virus is typically made by detecting the virus in clinical specimens using laboratory tests such as RT-PCR or serological assays. Clinical symptoms such as fever, cough, runny nose, and rash can also aid in the diagnosis. Complications of measles virus infection include pneumonia, encephalitis, and death. Prevention of measles virus involves vaccination, maintaining high population immunity, and early identification and isolation of infected individuals. Measles virus remains a significant public health threat, particularly in areas with low vaccination coverage. The virus is highly contagious and can cause severe disease and mortality. The global incidence of measles has increased in recent years due to outbreaks in various regions. Treatment for measles virus infection is primarily supportive, with no specific antiviral therapies currently available.