Leptospirosis

Leptospirosis
DEFINITION
• Leptospirosis is a bacterial disease that affects humans and animals. It is caused by bacteria of the genus Leptospira. In humans, it can cause a wide range of symptoms, some of which may be mistaken for other diseases. Some infected persons, however, may have no symptoms at all.

• Leptospirosis is caused by infection with pathogenic spirochetes of the genus Leptospira.

EPIDEMIOLOGY
• Leptospirosis is a zoonosis of global distribution. It happened in mostly in raining seasons.
• It causes approximately 1.03 million cases per year. In 2015, South-East Asia is the highest incidence of leptospirosis about  55.54 cases per 100,00 population. In Thailand, the incidence rate is 39.04 % and 37.48 in the South and the Northeast, respectively.

• Leptospirosis is maintained in nature by chronic renal infection of carrier animals, especially rodents.
• Infections typically occur following occupational or recreational exposure to water or soil contaminated with rodent urine.
• In developing countries with poor housing standards, leptospirosis outbreaks occur regularly in urban settings a er heavy rainfall and flooding.
 
MICROBIOLOGY

• Twenty-one named leptospiral species have been described, of which 11 are known to be pathogenic.
• Genus Leptospira, order Spirochetales, family leptospiraceae
• There are about 250 servars from 20 species causes diseases and animals.

 
Leptospirosis that looked in the Dark field Microscopic

Leptospirosis Transmission Cycle and Risk factors

DIAGNOSIS
• Clinical diagnosis requires a high index of suspicion based on epidemiological exposure.
• Serologic tests are helpful when positive but may have poor sensitivity during the first week of illness.
• The signs and symptoms of early leptospirosis are nonspecific such as muscle pain, fever, headache....etc.

THERAPY
• Antibiotic therapy should be initiated as early in the course of the disease as suspicion allows.
For mild disease, doxycycline, amoxicillin, or oral ampicillin is recommended. For more severe disease, intravenous cetriaxone, ampicillin, or penicillin is used.
• Patients with early renal disease with high-output renal dysfunction and hypokalemia should receive aggressive volume repletion and potassium supplementation.
• Patients who progress to oliguric renal failure should undergo rapid initiation of hemodialy- sis or peritoneal dialysis, which is typically required on only a short-term basis.


PREVENTION
• most effective preventive strategy is to reduce direct contact with potentially infected animals and indirect contact with urine-contaminated soil and water.
• Chemoprophylaxis with doxycycline 200 mg once a week is recommended for individuals who will be unavoidably exposed to endemic environments.