The chest radiograph is an invaluable tool in the diagnosis of pulmonary tuberculosis. Pulmonary tuberculosis typically demonstrates number of abnormalities on chest radiographs. Primary pulmonary tuberculosis most commonly reveals hilar lymphadenopathy, which may cause right middle lobe compression and atelectasis. Pulmonary infiltrates may be seen in primary tuberculosis, typically in the middle or lower lobes, [...]
The Rickettsiae are minute infectious agents, smaller than most germs and larger than most viruses. Most classifications put them midway between the bacteria and the viruses. Rickettsia are too large to pass through a bacterial filter and are visible with an ordinary microscope. Like the viruses, they multiply only in the presence of living cells [...]
The flu spreads much more readily than a cold, primarily moving directly from person to person via virus-contaminated airborne droplets released by coughs and sneezes and even normal conversation. The illness also can be spread through hands and inanimate objects. Like cold viruses, flu viruses can live for a brief time— about one to three [...]