Leptospirosis is an infectious disease that is caused by a microorganism called Leptospira. It affects both humans and animals and rodents, dogs, cattle, and pigs are considered reservoirs for this organism. As humans rarely are chronic carriers, they are considered accidental hosts. The organism survives in the kidney system of these animals and is excreted in the urine into standing water or soil. Infection can be either direct via contact with the body fluids or organs of an acutely infected animal or indirect by exposure to soil or water contaminated with the urine of an animal that is a chronic carrier. It is believed that bacteria enter the body through - abrasions in healthy skin, sodden and waterlogged skin, directly through intact mucus membranes or conjunctiva or lungs by inhalation of aerosolized body fluid.
The disease is characterized by acute fever followed by mild self-limiting after-effects or an even more severe, and often fatal, illness involving many organs including kidneys and liver. The incubation period is about 5 days to 2 weeks but has been reported to range from 3 days to a month. During the acute phase there is high fever (38-40°C), rigors, sudden headache, nausea and vomiting, anorexia, diarrhoea, cough, pharyngitis, skin rash, and muscle pain (usually in the calf and back). This may last for about a week following which the patient begins to recover or it may progress to a more severe illness called Weil’s disease.
Laboratory investigations are used to confirm the diagnosis and ancillary tests done to determine the extent of organ involvement and severity of complications. Confirmation can be done by either isolation of the organism by culture from urine, as the microbe is present in the urine at the start of clinical symptoms and persists into the third week of infection. It can be identified in tissue biopsy (liver, muscle, kidney, skin, eyes) or by positive result on the microscopic agglutination test done on blood showing anti-leptospiral antibodies. It is advised that 2 specimens, one at the beginning of the illness and the other during convalescence be used to confirm the diagnosis. A 4-fold rise in titers is considered a positive result. A presumed diagnosis is made by observing an antibody titer of greater than or equal to 1:100 in conjunction with symptoms consistent with the disease.
It is difficult to comment on your symptoms as the acute phase usually involves three organ systems - the brain, kidneys, and liver (jaundice). The typical rash in leptospirosis is reddish, hemorrhagic, and itchy and the external genitalia are not the usual site for it. You should discuss with an infectious disease expert who can examine you and then comment.