Leptospira species or spirochetes that are considered saprophytic aquatic organisms, and those phathogenic for man and animals do not appear to multiply outside the host.
Infection occurs by penetration of the organism through the mocous membrane of conjunctiva, diegestive tract, reproductive tract, skin wounds or moisture damaged skin.
Hematogenous spread of the organism can result in seeding of multiple organs, including uterus and establishment of renal infection.
Leptospirosis is a contagious disease of humans and animals with a spirochete- leptospira. There are 198 distinct leptospiral serovars recognized and these are grouped into 23 sero groups. Pathogenic leptospira were classified as members of the L interrogans group while non-pathogenic ones as L biflexa group.
Infected animals may suffer from clinical disease or remain as asymptomatic carriers excreting the leptospirosis in their urine, and constitute a source of infection for man and animals. L andamana, l Pomona, l grippotyphosa, l hebdomadis, l semoranga and L inctero haemmorrhagia are found to be predominant. Certain species have host preferences L.canicola in dogs.
Pathologic involvement of different systems and organs of the body express the symptoms of leptospirosis.
Leptospirosis in man manifests as fever, headache, chill, severe malaise, vomiting, muscular aches and conjunctivitis. Occasionally meningitis and rash may occur. Jaundice, renal insufficiency, haemolytic anemia and hemorrhage in skin and mucous membranes are of infrequent occurrence. Clinical illness may last upto three weeks and relapses may occur. In some cases infection may be asymptomatic or mild and mimic influenza or some common bacterial or viral disease. Clinical diagnosis by symptoms only is rather difficult.
Rats and pigs are very susceptible to the infection and develop nephritis or develop asymptomatic infection and shed leptospira in the urine. Abortion is one of the most important manifestations in cattle, sheep and pigs. In dogs kidney and liver are involved resulting in heavy shed of leptospira in urine. Gingival ulcers, fever, loss of appetite, haemoglobinuria and depression are some of the clinical features of leptospirosis.
Laboratory diagnosis is perforPre in three modalities serological tests, microscopic examination and isolation of leptospires.
Slide agglutination test with pooled antigens is useful for field application. Macroscopic plate and capillary tube agglutination test using formal fixed antigens are also a useful diagnostic aid. However, microscopic agglutination test using live antigens in fluid culture is very sensitive and specific test for the detection of acute infection. The test can be perforPre only in specialized laboratories where a number of prevalent and important serotypes of leptospira are maintained. Complement fixation test and ELISA are also practiced.
Microscopic demonstration of leptospira in the urine and tissue impression smears is possible by fluorescent microscopy or silver impregnation staining tests.
Blood, Cerebrospinal fluid collected during acute illness or urine after one week of sickness are used for the isolation of leptospires.
There is no specific treatment for the persons affected with Jap. Encephalitis. However symptomatic treatment with antibiotics to ctrvent complications, food supplements etc are given to the affected persons. Early Prevention and prompt treatment are essential for saving the person.
All suspected cases should be examined by specialist doctors and treated symptomatically, duly supported by laboratory Prevention. Pigs should be kept away from human habitations and vaccinated with pig JE vaccine. Anti mosquito measures like using mosquito nets, application of mosquito repellents to the screens of the doors and windows where people sleep. Use of fumigants and spraying insecticides like BHC, Malathion or Pyrethrum alkaloids. An integrated approach like, pig control, mosquito control and child vaccination are essential for the proper control of Japanese encephalitis.
What is leptospirosis?
Leptospirosis is a bacterial disease that affects humans and animals. It is caused by bacteria of the genus Leptospira. In humans it causes a wide range of symptoms, and some infected persons may have no symptoms at all. Symptoms of leptospirosis include high fever, severe headache, chills, muscle aches, and vomiting, and may include jaundice (yellow skin and eyes), red eyes, abdominal pain, diarrhea, or a rash. If the disease is not treated, the patient could develop kidney damage, meningitis (inflammation of the membrane around the brain and spinal cord), liver failure, and respiratory distress. In rare cases death occurs.
Many of these symptoms can be mistaken for other diseases. Leptospirosis is confirmed by laboratory testing of a blood or urine sample.How do people get leptospirosis?
Outbreaks of leptospirosis are usually caused by exposure to water contaminated with the urine of infected animals. Many different kinds of animals carry the bacterium; they may become sick but sometimes have no symptoms. Leptospira organisms have been found in cattle, pigs, horses, dogs, rodents, and wild animals. Humans become infected through contact with water, food, or soil containing urine from these infected animals. This may happen by swallowing contaminated food or water or through skin contact, especially with mucosal surfaces, such as the eyes or nose, or with broken skin. The disease is not known to be spread from person to person.How long is it between the time of exposure and when people become sick?
The time between a person's exposure to a contaminated source and becoming sick is 2 days to 4 weeks. Illness usually begins abruptly with fever and other symptoms. Leptospirosis may occur in two phases; after the first phase, with fever, chills, headache, muscle aches, vomiting, or diarrhea, the patient may recover for a time but become ill again. If a second phase occurs, it is more severe; the person may have kidney or liver failure or meningitis. This phase is also called Weil's disease.
The illness lasts from a few days to 3 weeks or longer. Without treatment, recovery may take several months.Where is leptospirosis found?
Leptospirosis occurs worldwide but is most common in temperate or tropical climates. It is an occupational hazard for many people who work outdoors or with animals, for example, farmers, sewer workers, veterinarians, fish workers, dairy farmers, or military personnel. It is a recreational hazard for campers or those who participate in outdoor sports in contaminated areas and has been associated with swimming, wading, and whitewater rafting in contaminated lakes and rivers. The incidence is also increasing among urban children.How is leptospirosis treated?
Leptospirosis is treated with antibiotics, such as doxycycline or penicillin, which should be given early in the course of the disease. Intravenous antibiotics may be required for persons with more severe symptoms. Persons with symptoms suggestive of leptospirosis should contact a health care provider.Can leptospirosis be prevented?
The risk of acquiring leptospirosis can be greatly reduced by not swimming or wading in water that might be contaminated with animal urine.
Protective clothing or footwear should be worn by those exposed to contaminated water or soil because of their job or recreational activities.
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