What is Leptospirosis in Children?
Leptospirosis is a zoonotic infectious disease that has an acute onset, manifested by symptoms of intoxication, fever, damage to the liver, kidneys and nervous system, various manifestations of hemorrhagic syndrome.
Leptospirosis is of the following types:
- leptospirosis icteric-hemorrhagic;
- other forms of leptospirosis;
- unspecified leptospirosis.
Epidemiology
Leptospira is stored in the body and carried by wild rodents. The causative agent is excreted in their urine, which leads to environmental contamination, since urine enters the food and water, as well as the soil. Thus, cattle, pigs, horses, dogs and humans are susceptible to infection.
Infected animals most often become carriers and sources of infection, sometimes they die.
Infection pathways
The most common route of infection is swimming in water bodies infected with leptospira. There is also a high risk when eating infected food and in contact with infected objects. A person cannot catch an infection from an infected person.
Foci of leptospirosis were recorded in the Crimea, the North Caucasus, in the foothills of Altai, Northern Kazakhstan, the Far East, Siberia, and in the central regions of the European part of Russia. The foci include, first of all, forest zones, floodplains of rivers, moist wetlands.
The highest incidence rate is among the villagers in summer and autumn, which coincides with the periods of agricultural work. In the warm season, epidemics of leptospirosis among people are possible. Individual, unrelated cases are recorded not only in autumn and summer, but also in spring and winter – year-round.
Leptospirosis affects adults and children, but older children are more likely than others. They become infected after bathing in infected ponds and quarries.
Causes of Leptospirosis in Children
Leptospirosis in children is provoked by leptospira. They belong, according to scientific classification, to the genus Leptospira, a species of L. interrogans, which includes 19 serogroups, uniting more than 200 serovars. In Russia, L. icterochaemorrhagioer L. grippotyphosae, L. rotona are most common.
The leptospira structure is as follows: it is a spiral wound around an axial thread, the length of which is up to 40 nm, the thickness is from 0.3 to 0.5 nm. The ends of the leptospira are bent, resembling hooks.
The causative agents of leptospirosis in children are mobile. Dispute and no flagella. They are gram-negative – poorly stained with aniline dyes. Leptospira grow on nutrient media and the embryo of a chicken fetus. They are unstable in the environment. They die instantly when exposed to direct sunlight, boiling, drying, and also when treated with disinfectants in ordinary concentrations.
Leptospira can live in water for more than a month. In the soil, they remain viable for up to 3 months. A shorter period – up to several days – they live on food. Freezing leptospira does not harm.
Pathogenesis during Leptospirosis in Children
Pathogenesis
The infection enters the body through the mucous membranes of the mouth, nose, eyes, gastrointestinal tract, as well as damaged skin. Leptospira does not cause inflammatory processes at the site of introduction. The pathogen enters the regional lymph nodes through the lymphatic pathways. Then the infection enters the bloodstream, spreading with it through the body of the child. Leptospira sediment mainly in parenchymal organs: kidney, liver, spleen. There they multiply and enter the general bloodstream, which is called re-leptospieremia. So the clinical manifestations begin.
Together with blood (probably with lymph), the pathogen along with toxins spread throughout the body of the child. This leads to damage to the kidneys, liver, adrenal glands, spleen, meninges, etc.
Mass death of leptospira begins at the end of the first or at the beginning of the second week from the time of the disease. The toxic phase of the pathogenesis of leptospirosis starts. Toxins that are secreted by the causative agents of the disease cause damage to the blood capillaries, which leads to an increase in their permeability. As a result, multiple hemorrhages (hemorrhages) appear in the internal organs and skin (universal capillarotoxicosis).
Leptospira relatively easily overcomes the blood-brain barrier and can cause damage to the central nervous system, which in its manifestations and course is similar to serous meningitis and meningoencephalitis.
Pathomorphology
The skin is icteric in color, multiple hemorrhages are observed in the internal organs and on the mucous membranes. Histological examination of the liver reveals severe granular dystrophy, edema of the interstitial tissue, necrosis and fatty degeneration of individual hepatocytes. Common necrosis is not.
The kidneys are enlarged, they have nephrosonephritis, multiple hemorrhages under the capsule and parenchyma. Histological examination shows dystrophy and necrosis, mainly of the convoluted tubules. Often there are changes in inflammatory and dystrophic changes in the lung tissue, skeletal muscle, heart muscle, central and autonomic nervous system, spleen, etc.
Immunity for leptospirosis is antimicrobial. In response to leptospira infection, antibodies of the IgM class are formed in the body first, and then IgG. After the illness is transferred to the children, immunity is formed. There is a small likelihood of recurring diseases, but they are caused by other leptospira serotypes, against which there is no immunity.
Symptoms of Leptospirosis in Children
Most infected children carry the infection without showing any visible symptoms. If symptoms are pronounced, from infection to their manifestation takes 6 to 14 days, sometimes more – about 20 days.
Leptospirosis in children begins acutely, body temperature – 39-40 ° C, the child is shivering. Older children complain of headaches, dizziness, insomnia and severe muscle pain, weakness. Pain most often occurs in the calf muscles, also in the abdomen, back, chest. When walking and palpating, muscle pain intensifies. At rest, they do not disappear.
External examination shows such signs:
- conjunctivitis
- hyperemia of the face
- puffiness of face
- scleral vascular injection
- pain in the eyes
- photophobia
- herpetic eruptions on the lips and wings of the nose (not in all cases).
The peak of the disease occurs in 3-6 days. At this time, in 50% of sick children, a polymorphic, symmetrically located rash begins (scarlet-like, measles, in severe cases – hemorrhagic).
There is a chance of nosebleeds, extensive hemorrhages on the mucous membranes and skin. Lymph nodes are enlarged, they fix hepato- and splenomegaly.
Infrequently, sick children have jaundice, which in some cases is expressed by slight staining of the sclera, and in part by a bright yellow skin tone.
Urine is a shade reminiscent of beer; feces are discolored. In the blood serum, the content of conjugated and to a lesser extent unconjugated bilirubin was increased, the activity of liver cell enzymes (AlAT, AsAT, etc.) was moderately increased, the content of prothrombin and other coagulation factors was reduced, and sedimentary samples were weakly positive.
Symptoms of myocarditis, pneumonia, arthritis may occur. Dry tongue is observed, coated with a touch of brown. The abdomen is soft, painful in the projection of an enlarged liver.
More than 30% of sick children show symptoms of meningitis, such as repeated vomiting, a sharp headache, stiff neck, positive symptoms of Kernig, Brudzinsky.
Increased intracranial pressure. First, neutrophilic cytosis is observed in the blood, and then moderate lymphocytic. Increased protein content. Within normal limits, glucose and chloride.
At the peak of the manifestation of the disease, kidney damage usually appears, which manifests itself in a decrease in urine output, Pasternatsky’s symptom (becomes positive), in the determination of protein, red blood cells, hyaline and granular cylinders in urine sediment. Severe cases are even manifested by azotemia and anuria. In peripheral blood, neutrophilic leukocytosis with a shift to the left to myelocytes, aneosinophilia is noted; ESR increased (up to 50 mm / h).
Lestopyrosis can be of such forms (depending on the severity of symptoms):
- light
- moderate
- heavy.
Lethospirosis passes for a long time, often the disease has a wave-like course. The temperature is increased for 5-10 days, then it becomes lower, the general condition of the patient improves. But in frequent cases, after 3-10 days, the temperature again becomes elevated. Head and muscle pains also intensify, less significant organ damage appears.
Such repeated manifestations of the disease can occur 3 or 4 times. Because of them, the disease lasts 5 weeks or more. But the timely use of antibiotics allows you to stop the wave-like course.
Complications can arise not only due to the attachment of the bacterial flora, but as a result of the main process. Complications include acute renal and hepatic failure, eye damage (iridocyclitis, uveitis, opacification of the vitreous body), and bleeding. The addition of a bacterial infection leads to such complications of leptospirosis as stomatitis, otitis media, pneumonia.
Diagnosis of Leptospirosis in Children
Diagnosis of leptospirosis is due to the sudden onset of the disease, high body temperature, muscle pain, polymorphic, often hemorrhagic rash, damage to the kidneys, liver and according to data indicating possible pathways of infection (for example, a child has a sip of water when swimming in a pond).
To confirm the diagnosis, a bacteriological and serological examination is prescribed. In the acute period, the pathogen can be detected by direct microscopy of the blood and cerebrospinal fluid, and from the 2nd week of the disease – and in the urine.
Leptospirae look under a microscope as thin, convoluted whitish threads against a dark background. Also, a more accurate method is used for diagnosis – the isolation of culture on nutrient media. PCR is used, as well as infection of laboratory animals, which subsequently reveals leptospira stained with silver nitrate.
In serological diagnostics, the ELISA method with separate determination of IgM and IgG antibodies, the microagglutination reaction with live cultures of leptospira are used. Also relevant is the RNGA method (diagnostic titer 1:80 and higher).
Leptospirosis is distinguished from similar diseases – hepatitis B, sepsis, typhoid fever, flu, hemorrhagic fevers, icteric forms of infectious mononucleosis, and also from listeriosis.
Leptospirosis Treatment in Children
Children with leptospirosis should observe bed rest and a dairy-vegetable diet (necessary due to damage to the kidneys and liver).
In the early stages of the disease, antibiotics are administered as prescribed by the attending physician. Penicillin gives a certain effect. This drug is administered by intramuscular injection at a dose of 100,000-150,000 units per 1 kg of the body of a sick child per day in 4-6 doses. Derivatives of tetracycline, chloramphenicol succinate, semisynthetic penicillins, especially 3rd and 4th generation cephalosporins, also have an effect. The course of treatment for leptospirosis with antibiotics is from a week to 10 days.
Along with antibiotic therapy, a specific polyvalent immunoglobulin with a high content of antibodies against widespread leptospira serovars is used. For children, intramuscular administration of immunoglobulin in an amount of 3 to 5 mm is indicated. In severe intoxication, according to the doctor’s decision, corticosteroid hormones are used (the course of treatment is 5-7 days). Recommended general strengthening, symptomatic and syndromic therapy.
In case of acute renal and hepatic insufficiency, plasmapheresis, hemodialysis, hemosorption and other methods of therapy are used for treatment. If the diagnosis was made on time, and adequate treatment was carried out, the prognosis is favorable. But in the specialized scientific literature outbreaks of leptospirosis with a mortality rate of 20% or more are described, which is a rather high indicator. Fatal cases occur due to toxic toxic shock and acute renal hepatic failure.
Prevention of Leptospirosis in Children
Among preventive measures, an important place is given to the fight against the source of leptospirosis in children. Fighting involves veterinary surveillance of livestock, the destruction of rodents, the protection of places for bathing people, the protection of water sources and food from pollution by rodent secretions, rational reclamation, etc.
It is forbidden to bathe in contaminated water, use meat of sick animals for food without sufficient heat treatment and drink raw water.
If there is an appropriate epidemic indication, mass immunization of animals and people who are at risk of infection is carried out. Immunization is carried out with a killed leptospirosis vaccine containing a suspension of 3 types of leptospira. The vaccine is administered twice with an interval of 7 to 10 days.
After vaccination, immunity to tapeospirosis persists for about 1 year, therefore, revaccination is recommended after a year. Specific prevention is not developed.