Leptospirosis: diagnosis and therapies

Introduction

The diagnosis of leptospirosis, an infectious syndrome caused by bacteria of the genus Leptospira, is particularly artificial and complex, above all due to the marked clinical polymorphism. Strictly speaking, even therapies aimed at healing from leptospirosis often represent a limitation, since the diagnostic tests currently available are not always clear and irrefutable.
In this final article we will try to examine all possible diagnostic strategies and possible exploitable therapies.

Leptospirosis: diagnosis

Clearly, being an infectious disease, the diagnosis of leptospirosis is based in particular on two fundamental elements:

Isolation of the bacterium (pathogen)
Specific antibody serological analysis

Starting from these considerations, it is clear that the diagnosis is based both on the "symptomatological - clinical analysis, and on the anamnestic story which, unfortunately, often remains an" unknown. As regards the study of symptoms, in most cases attention is focused on the presence of fever, myalgia, hemorrhages, jaundice and conjunctival hyperemia; as regards the anamnesis, however, the patient's work activity is investigated, on trips made in recent periods, on health and hygiene conditions and, lastly, on contact with potentially infected animals.
The isolation of the bacteria, leptospires, is carried out on specific media and biological liquids (CSF, blood, urine - above all) and / or tissues damaged by leptospirosis (liver or kidney). artificial are effective and reliable, since leptospires tend to develop very slowly. The microbiological inspection performed directly on blood, CSF, urine or injured tissues is instead more reliable [taken from Zoonoses and public health, by E. Matassa].
Serological diagnostic investigations (specific antibody type) are undoubtedly more advantageous and safer, since the probability of false positives is rarer (a very common occurrence in bacterial culture isolation).
Serological tests are usually done during the initial symptoms of leptospirosis (when symptomatic); for this investigation, we use the most common serotypes in the area. Serological tests should be repeated several times in order to confirm the diagnosis.
In the case of hypothesized and not fully demonstrated leptospirosis, it is possible to carry out biohumoral tests, which are essentially based on the leukocyte analysis (whose values are almost standard), CSF test, transaminase tests (generally not too high) , search for possible azotemia, hypercreatininemia, thrombocytopenia and hyperbilirubinemia.
Other diagnostic tests include:

Microscopic Agglutination test (MAT): very specific but particularly complex and laborious test. Confirmation of leptospirosis or not is obtained in a relatively long time.
ELISA: immuno-enzymatic diagnostic test, simpler than the previous one.
Lepto Tek Flow and TestLepto Tek Dri Dot tests: rapid agglutination tests, but unfortunately not very reliable.

Therapies

For further information: Medicines for the treatment of Leptospirosis

There are two treatment options for leptospirosis, although they are somewhat controversial.
The first therapy is based on the oral administration of antibiotics (eg doxycycline 100mg / day), particularly indicated in all phases of the disease; the forms of leptospirosis requiring hospitalization of the patient are treated with penicillin, ampicillin, macrolides or clindamycin. Quinolones and third generation cephalosporins (eg ceftriaxone) are also effective.
If leptospirosis is not diagnosed immediately, the therapeutic treatment is clearly not promptly carried out: in such situations, the probability of ineffectiveness of antibiotics increases.
The maintenance of the electrolyte balance of the leptospirotic patient is essential.
In case of severity, supportive therapy is absolutely essential:

when leptospirosis compromises the renal structure, dialysis is useful
transfusions are useful in case the disease is characterized by haemorrhagic phenomena
in case of cardiovascular insufficiency associated with leptospire infections, a targeted cardiological treatment is preferable

In conclusion, the timeliness of specific therapies, following diagnostic tests, is essential both to avoid complications and aggravations of the disease and to shorten the natural course of leptospirosis.