en.energymedresearch.com
infectious diseases

Leptospirosis in brief: summary of leptospirosis

Scroll down the page to read the summary table on leptospirosis

Leptospirosis General term including a series of systemic infectious zoonoses with acute course, caused by bacteria belonging to the genus Leptospira
Leptospirosis: synonyms
  • Autumn fever
  • Seven-day fever
  • Swamp fever
  • Mud fever
  • Dog cutter fever
  • Icterememorrhagic fever
  • Icteric leptospirosis
  • Pork fever
Leptospirosis: first descriptions Late eighteenth century: first description of leptospirosis by a well-known surgeon, but diagnosed as a plague

1870: first correct diagnosis

1917: identification of the responsible beat

Leptospirosis: epidemiology
  • Leptospirosis is one of the most prevalent infectious syndromes
  • The disease is heavily underestimated due to poorly defined symptoms
  • Italy: 100 people affected per year
  • Disease spread: especially in tropical and sub-tropical areas
  • Globally: estimated annual incidence around 0.1-1 cases per 100, 000 (per inhabitant in temperate climate zones)
  • 10-100 cases per 100, 000 healthy subjects in tropical areas
  • In Europe: leptospirosis is not widespread at all
Leptospirosis: ideal target Leptospirosis affects mainly domestic animals, birds and reptiles but, following an occasional contact with these infected animals, the infection can also affect humans
Leptospirosis: causative agent Leptospirosis is caused by serological varieties of small parasites (spirochetes) belonging to the genus Leptospira (Fam. Leptospiraceae )
Leptospire: description of the beat
  • Gram-negative bacteria without flagella
  • Filamentous body
  • Typically spiral shape
  • Widespread in water and in damp environments
  • Responsible for many zoonoses
  • Immersed in the environment through the urine of infected animals (the bacteria reservoir), they pollute the soil and water
Leptospire: temperature and pH Temperatures above 22 ° C

Water at pH 5.5 or slightly basic

Leptospirosis: mode of infection
  • The leptospires nest at the level of the renal apparatus of rodents, domestic and wild animals, thus infecting the urine
  • The man is infected by the contact, intake or inhalation of water infected by the urine of the carrier animals
  • The contagion between man and man is almost impossible
Leptospirosis: severity of the disease Severity of the disease proportional to the infectious / inhaled charge
Leptospirosis: risk categories The categories most at risk include all those people who, for various reasons (eg working), are forced to stay in frequent contact with water or wet lands
Leptospires potentially pathogenic to humans Serovar icterohaemorrhagiae : more dangerous and virulent leptospira

Pomone, Canicola, Batavie, Grippotyphosa, Hyos, Sejroe and Australis are among the pathogenic human serotypes.

Leptospirosis: biphasic course
  1. Septicemic phase: either leptospirotic phase or acute phase
  2. Immune phase of leptospirosis: or leptospirulica
Both phases occur in each of the three clinical forms of the disease:
  1. Sub-clinical leptospirosis
  2. Anitteric leptospirosis
  3. Weil Syndrome or Icteric Leptospirosis
Septicemic phase of leptospirosis: either leptospirotic phase or acute phase
  • Duration varies from 4 to 8 days
  • Unexpected and sharp increase in basal temperature
  • Bad headache
  • Chills, general malaise, nausea, vomiting and anorexia
  • Rarely: jaundice
  • Faringodinia and morbilliform exanthema (less frequent)
Immune phase of leptospirosis: or leptospirulica
  • Duration: generally 5 days
  • Formation of specific antibodies against bacteria
  • Disappearance of leptospires in the blood
  • Appearance of histological lesions affecting kidney, meninges and liver
  • Marked lesions at the level of the distal nephron
  • Interstitial edema
  • Lymphocyte infiltration
  • Destruction of the epithelium of the basement membrane
  • Meninges: lymphocytic infiltration
  • Liver: necrosis of liver cells and choleresis
Sub clinical leptospirosis
  1. Acute phase: fever, lower abdominal pain, headache, vomiting, often accompanied by typical flu symptoms. Marked presence of circulating leptospires
  2. Immune phase: the patient becomes ill, leptospires are not found in the blood, specific antibodies appear. Symptoms: uveitis, rash, kidney and / or hepatic lesions
Anitteric leptospirosis
  1. Acute phase: general malaise, marked alteration of basal temperature, respiratory pulmonary disorders, headaches, chills, vomiting, pain in the lower abdomen and decrease in blood pressure
  2. Immune phase: headache, low-grade fever, aseptic meningitis (less frequent), eye disorders. The pathogens are not observable in the liquor (which presents itself normal, with hyperproteinorrachia and with normal values ​​of glycorrachia)
Weil Syndrome (Icteric Leptospirosis) The most alarming and most dangerous clinical form among leptospirosis
  1. Acute phase: hepatic and renal damage, often accompanied by bleeding, high fever, obvious jaundice, renal involvement. Possible cases of myocarditis
  2. Immune phase: worsening of liver and kidney conditions, associated with hyperazotemia and hypercreatininemia. Rare, though possible, tubular necrosis
Leptospirosis: diagnosis Essential elements for diagnosis:
  1. Isolation of the bacterium (pathogen)
  2. Specific antibody serological analysis
Diagnostic tests:
  • Clinical and symptom analysis → attention is focused on the presence of fever, myalgia, hemorrhage, jaundice and conjunctival hyperemia
  • Anamnestic story → survey on the patient's work, trips made in recent periods, sanitary conditions and contact with potentially infected animals
  • Isolation of the bacteria → conducted on specific media and biological liquids (liquor, blood, urine) and / or tissues damaged by leptospirosis (liver or kidney)
  • Serological diagnostic investigations (specific antibody type): repeated several times
  • Biohumoral tests → leukocyte analysis, CSF test, transaminase test, search for possible hyperazotemia, hypercreatininemia, thrombocytopenia and hyperbilirubinemia
  • Microscopic agglutination test (MAT):
  • ELISA
  • Test Lepto Tek Flow and Test Lepto Tek Dri Dot
Leptospirosis: therapies
  • Oral administration of antibiotics (eg Doxycycline)
  • Penicillin, ampicillin, macrolides, clindamycin, quinolones and third-generation cephalosporins → for the forms of leptospirosis requiring patient hospitalization
  • Maintenance of the electrolyte balance of the leptospirotic patient
  • Dialysis (in case of renal impairment associated with leptospirosis)
  • Transfusions (in the case of leptospirosis associated with bleeding phenomena)
  • Targeted cardiological care (in case of concomitant cardiovascular insufficiency)

Interesting Articles