Monograph

Fri, 01/21/2011 - 15:22 — Anonyme

definition:

Leptospirosis is an infectious, contagious, virulent, inoculable disease of bacterial origin that affects numerous animal species and humans.

It appears on the OIE list.

Situation in America:

All continents are affected by leptospirosis regardless of climate, although tropical regions are particularly affected. However, there are factors specific to various regions of the globe regarding the spread of serogroups of the spirochete.

In Guadeloupe, as in most tropical regions, it is endemic and serological studies conducted in 2002 show a globally high pressure of infection.

Susceptible species:

The species acting as reservoirs for leptospires are primarily rodents, which carry and excrete the disease.

The majority of mammals, both wild and domestic, are sensitive species. Youth and pregnant females have, however, generally forms of the disease more severe.

Etiological agent:

Leptospirosis is caused by Gram-negative, strict aerobic bacteria belonging to the order Spirochaetales, the Leptospiraceae family and the genus Leptospira. Only the Leptospira interrogans species is pathogenic for humans and animals.

photo of leptospira

Leptospira interrogans (Source Science photo library)

Methods of transmission

Transmission:

Leptospires enter an organism through skin wounds or abrasions. They can also cross the ocular, oropharyngeal, nasal, or respiratory and genital mucous.

Symptoms:

Incubation time: 4 to 10 days

General symptoms:

- Transient hyperthermia

- Loss of appetite, weight loss

- dehydration

- Depression, lethargy

- anemia

- Jaundice, haematuria

- Gastrointestinal symptoms (diarrhea, vomiting, sometimes with blood)

- Congested mucous

- Drop in milk

Peracute to chronic

- Pneumonia and / or abortion with retained placenta notament frequent in ruminants, horses and pigs

- Renal and / or liver failure in carnivores

- Recurrent uveitis in horses

Lesions

Microscopic lesions:

thrombocytopenia in 74% of cases

hemolytic anemia in 21% of cases

Diagnostics

Differential diagnosis:

Distemper in dogs

Laboratory diagnosis:

- Detection of the pathogenic agent through dark field microscopy or PCR

- Detection of antibodies using an ELISA test[/list]

Treatment:

- Symptomatic treatment

- Special treatment: Good sensitivity to antibiotics (no resistance yet)

Prophylaxis:

Sanitary:

Rodent control, inspecting bathing water, provision of information to at-risk personnel in an infected area, isolation of the affected subject, cleaning and disinfecting of infected premises and equipment

Vaccines:

Inactivated-bacteria vaccine containing the main serotypes likely to infect the animal species concerned

Links:

CDC website

FAO - Leptospirosis in cattle