1 Blood clots can also obstruct veins, causing pain. 2  Veins return blood from the legs to the heart. 3  There are two systems of veins in the leg: superficial and deep. 4  If a blood clot occurs in a deep vein (deep venous thrombosis), it causes a damming effect, and blood is trapped behind the blockage.
Typhoid fever, also known simply as typhoid, is a symptomatic bacterial infection due to Salmonella typhi. Symptoms may vary from mild to severe and usually begin six to thirty days after exposure.
INFECTIOUS AGENT. Typhoid fever is a potentially severe and occasionally life-threatening febrile illness caused by the bacterium Salmonella enterica serotype Typhi. Paratyphoid fever is a similar illness caused by S. enterica serotype Paratyphi A, B (tartrate negative), or C.he incubation period of typhoid and paratyphoid infections is 6â30 days. The onset of illness is insidious, with gradually increasing fatigue and a fever that increases daily from low-grade to as high as 102Â°Fâ104Â°F (38Â°Câ40Â°C) by the third to fourth day of illness.