Leptospirosis
Fig. 1 — Visual Archive: Leptospirosis
Leptospirosis is a blood infection caused by bacteria of the genus Leptospira that can infect humans, dogs, rodents, and many other wild and domesticated animals. Signs and symptoms can range from none to mild (headaches, muscle pains, and fevers) to severe (bleeding in the lungs or meningitis). Weil's disease ( VILES), the acute, severe form of leptospirosis, causes the infected individual to become jaundiced (skin and eyes become yellow), develop kidney failure, and bleed. Bleeding from the lungs associated with leptospirosis is known as severe pulmonary haemorrhage syndrome. More than 10 genetic types of Leptospira cause disease in humans. Both wild and domestic animals can spread the disease, most commonly rodents. The bacteria are spread to humans through animal urine or feces, or water or soil contaminated with animal urine and feces, coming into contact with the eyes, mouth, or nose, or breaks in the skin. In developing countries, the disease occurs most commonly in pest control, farmers, and low-income people who live in areas with poor sanitation. In developed countries, it occurs during heavy downpours and is a risk to pest controllers, sewage workers, and those involved in outdoor activities in warm and wet areas. Diagnosis is typically by testing for antibodies against the bacteria or finding bacterial DNA in the blood. Efforts to prevent the disease include protective equipment to block contact when working with potentially infected animals, washing after contact, and reducing rodents in areas where people live and work. The antibiotic doxycycline is effective in preventing leptospirosis infection. Human vaccines are of limited usefulness; vaccines for other animals are more widely available. Treatment when infected is with antibiotics such as doxycycline, penicillin, or ceftriaxone. The overall risk of death is 5–10%, but when the lungs are involved, the risk of death increases to the range of 50–70%.