LEPTOSPIROSIS

Leptospirosis is an infection caused by corkscrew-shaped bacteria called Leptospira. Symptoms can range from none to mild such as headaches, muscle pains, and fevers; to severe with bleeding from the lungs or meningitis.If the infection causes the person to turn yellow, have kidney failure and bleeding it is then known as Weil's disease.If it causes lots of bleeding from the lungs it is known as severe pulmonary haemorrhage syndrome.

SIGNS AND SYMPTOMS

 Leptospirosis is a biphasic disease that begins suddenly with fever accompanied by chills, intense headache, severe myalgia muscle ache, abdominal pain, conjunctival suffusion red eye, and occasionally a skin rash.The symptoms appear after an incubation period of 7–12 days. The first phase acute or septicemic phase ends after 3–7 days of illness.The disappearance of symptoms coincides with the appearance of antibodies against Leptospira and the disappearance of the bacteria from the bloodstream. The patient is asymptomatic for 3–4 days until the second phase begins with another episode of fever.The hallmark of the second phase is meningitis inflammation of the membranes covering the brain.

CAUSE

Leptospirosis is caused by spirochaete bacteria belonging to the genus Leptospira. 21 species of Leptospira have been identified.13 species cause disease or have been detected in human cases.

Leptospira are also classified based on their serovar. About 250 pathogenic serovars of Leptospira are recognized. The diverse sugar composition of the lipopolysaccharide on the surface of the spirochete is responsible for the antigenic difference between serovars. Antigenically related serovars are grouped into 24 serogroups, which are identified using the microscopic agglutination test MAT. A given serogroup is often found in more than one species, suggesting that the LPS genes that determine the serovar are exchanged between species

Leptospirosis is transmitted by the urine of an infected animal and is contagious as long as the urine is still moist. Although Leptospira has been detected in reptiles and birds, only mammals are able to transmit the bacteria to humans and other animals.Rats, mice, and moles are important primary hosts but a wide range of other mammals including dogs, deer, rabbits, hedgehogs, cows, sheep, raccoons, opossums, skunks, and certain marine mammals carry and transmit the disease as secondary hosts.

PREVENTION/ TREATMENT

Effective rat control and avoidance of urine contaminated water sources are essential preventive measures. Human vaccines are available in a few countries, including Cuba and China.Currently, no human vaccine is available in the US. Animal vaccines only cover a few strains of the bacteria. Dog vaccines are effective for at least one year.

Effective antibiotics include penicillin G, ampicillin, amoxicillin and Doxycycline. In more severe cases cefotaxime or ceftriaxone should be preferred.

Glucose and salt solution infusions may be administered; dialysis is used in serious cases. Elevations of serum potassium are common and if the potassium level gets too high special measures must be taken. Serum phosphorus levels may likewise increase to unacceptable levels due to renal failure.