Orthomyxoviridae (Influenza) The family Orthomyxoviridae, which includes enclosed viruses with segmented negative-sense, single-strand RNA genomes, includes influenza viruses. Types A and B are the most clinically significant of the four genera in this family (A, B, C, and D) because they cause influenza pneumonia with potentially serious side effects like encephalitis, myocarditis, and mortality. Both […]