What is the pathophysiology of the calf pain in patients with leptospirosis?

im working on the signs and symptoms of leptospirosis in humans for a report however, i can't figure out why a patient with such disease would manifest with calf pain.
Best answer:
Transmission, Development, and Pain

Leptospires are ubiquitous and abundant due to their abilities to infect a variety of animals and to persist outside the host. Transmission occurs through contact with contaminated water or contaminated food, during coitus, or through transplacental transmission. The leptospire bacteria have a predilection for the kidneys and the urinary tract where they may produce a persistent infection. The leptospire organisms may be excreted with the urine resulting in transmission of the bacteria. Infective urine constitutes the major sources of infection for humans, domestic animals and wild animals. Transmission usually occurs when there is direct contact between urine droplets or urine contaminated water and the mucous membranes of the eye, nose and mouth or through abraded skin. Transmission of the leptospire organisms may also occur through the food chain by the ingestion of leptospiral-infected carcasses by carnivorous species. This is the most significant mode of spread of leptospires among carnivores.

Humans usually are exposed by swimming in urine-contaminated water, or occupationally through exposure to an infected animal's urine.

The leptospire organisms can survive outside the body if environmental conditions are favorable. The bacteria prefer moist, slightly alkaline soil, stagnant ponds, and low-flow, slow-moving, slightly alkaline streams. In these conditions the organism can survive for several weeks.

Once infection has occurred, the leptospires multiply in the kidneys, lungs, reproductive organs and brain. Uterine penetration of pregnant animals results in infection of the fetuses.

The pain is intense and requires pain killers. The fact of 20% of humans who would die from the disease; the pain killer is thought to be an abrupt move. Caution is the best way to attack this disease, with the death toll remaining quite high. Although most patients have the calf pain, there will also be some with bisep. The disease settles in the large leg and arm muscles. If it goes to the heart muscle; that is automatic death.