Leptospiroses

LEPTOSPIROSES Shakera Sadiq Gill

Definition Weils disease Acute systemic infections of humans and

animals caused by various serovars of Leptospira interogans

Etiology Leptospires are

Motile Gram negative Spiral shaped Terminal hooks

Fletcher medium is used for culture Culturing at 28-30o C

The organisms are detected by dark field microscopy

Important human leptospiral serovars

L interrogans serovars Reservoirs Icterohaemmorrhagiae Rat

Gripotyphosa Mouse

Australis Mouse Pomona Cattle

Canicola Dog

Hardio cattle

Occurrence Worldwide distribution Prevalent in the tropics Carried by >100 animal species Wild animals can also be infected Excrete large number of leptospires in

their urine

Population at risk In human population peak incidence is

during summer and fall Agricultural workers Veterinarians Breeders Abattoir workers Butchers

People handling meat Cooks Dog owners Hunters Animal trappers Sewage workers

Transmission Skin lesions from professional exposure Swimming or walking with bare feet Bites of rats, mice, hamsters Animal urine voided at the time of bite is

most likely source of infection Lesions in the nose, mouth and mucosa

are also the portal of entry

Divers Swimmers Canal workers Leptospiroses also observed after

flooding Adventure tourists

Clinical manifestations Leptospires are able to invade any organ They damage epithelial cells by means of

cytotoxic glycoprotein and induce bleeding and ischemic lesions

90% of the infections are self limited nonspecific febrile illnesses

Incubation period is 5-14 days (range 2-26 days)

Leptospires follow a diphasic course Bacteremic phase Immune phase

Bacteremic phase Phase of 4-7 days Sudden bout of fever up to 40oC Chills Malaise Headache Meningeal irritation Non productive cough

Hepatospleenomegaly Mild jaundice Abdominal pain Loss of appetite Nausea Vomiting

Detection of leptospires in bacteremic phsase

In blood In CSF Kidneys Urine More than 50% of the cases the disease

goes into second immune phase

Immune phase 1-30 days period Meningitis Iridocyclitis Jaundice Renal failure Anemia

Leptospires can also cause miscarriage Mortality rate ranges from 5-40 %which is

due to hepatic or renal failure

Disease in animals Acute febrile illness Jaundice Anemia Haematuria Abortion Mostly asymptomatic

Diagnosis History including occupational and

recreational activities During first week organism is detected

from CSF or urine by culturing on fletcher medium

Guinea pigs and hamsters are used to propagate organism

Microagglutination-lysis is the test of choice for detecting antibodies against leptospires

ELISA Diagnosis in animals

Agglutination lysis test

Differential diagnosis In first week

Influenza Salmonellosis Brucellosis Malaria dengue

In second week Hepatitis Meningitis Glomerulonephritis

Therapy In severe cases

Pencillin G Ampicilin

In less severe cases Amoxicilin should be administered orally for 7

days

Animals should be treated with tetracycline and streptomycin

Prophylaxis Rat and mouse control Protective clothing Water tight boots ,gloves and goggles

should be used for high risk population Walking bare footed and swimming in

stagnant should be discouraged Chemoprophylaxis with doxycyclin is >95

efficacious

End