Anaplasmosis

2024 Author: Rachel Wainwright | [email protected]. Last modified: 2023-12-15 07:39

The content of the article:

Causes and risk factors
Forms of the disease
Symptoms
Diagnostics
Treatment
Possible complications and consequences
Forecast
Prevention

Anaplasmosis is an acute transmissible infectious disease with a polymorphic clinic, the causative agent of which, anaplasma (Anaplasma phagocytophillum), is transmitted by ixodid ticks.

Until 1991, when human anaplasmosis was first diagnosed in the United States, it was believed that ixodid ticks could only transmit the pathogens of tick-borne encephalitis and borreliosis (Lyme disease). At the moment, in the structure of tick-borne vector-borne diseases, anaplasmosis ranks second in frequency of occurrence. On the territory of the Russian Federation, infection with anaplasmosis pathogens occurs in 6–19% of ixodid ticks.

The disease is characterized by seasonality, which coincides with the period of greatest activity and increased number of vectors and falls on the spring-summer. A sick person does not pose an infectious danger to the environment.

Synonym: human granulocytic anaplasmosis (HAG).

The causative agent of anaplasmosis is a small bacterium anaplasma

Causes and risk factors

The causative agent of the disease is a small bacterium anaplasma. It is an intracellular parasite that multiplies in human blood cells.

When a tick bites, along with its saliva, anaplasma enters the systemic circulation, where it colonizes mature neutrophils (granulocytes). The bacterium delivered to the tissues of the internal organs with the blood flow provokes inflammatory changes in them. Further multiplication of anaplasma in blood cells leads to suppression of immunity and, as a result, the addition of secondary bacterial, viral and fungal infections.

In addition to ticks, agricultural and wild animals are the reservoir of infection in nature: rodents, artiodactyls, canines, as well as birds, the migration of which contributes to the widespread spread of infected ticks. Anaplasmia in animals persists for several weeks; during this period they become a source of infection for previously intact (uninfected) ticks.

The main risk factors for the development of anaplasmosis:

contact with agricultural and wild animals, especially in the spring and summer period;
neglect of protective equipment when being in places where mites are most likely to accumulate (in forest and forest park areas).

Ixodid ticks are the main carriers of anaplasma bacteria, the causative agent of anaplasmosis

Forms of the disease

In accordance with the severity of the clinical picture of the disease, the following forms are distinguished:

asymptomatic (subclinical);
manifest.

Depending on the severity of the course, anaplasmosis is mild, moderate and severe.

Symptoms

The disease manifests itself in a wide range of various symptoms, the severity of which varies depending on the severity of the course. The incubation (latent) period ranges from 3 days to 3 weeks (on average, up to 14 days) from the moment the pathogen enters the human body.

With a mild form of the disease, the symptoms resemble the clinic of an acute respiratory viral infection:

acute onset;
a sharp increase in body temperature (more than 38.0–38.5 ° C);
tremendous chills;
general weakness;
nausea, decreased or complete lack of appetite;
headache;
muscle and joint pain;
in some cases, pain and sore throat, cough, vomiting, diarrhea, a feeling of heaviness in the right hypochondrium.

With a moderate course, the symptoms are more varied and intense, the following are added to the previously described manifestations:

neurological disorders (headache, dizziness);
indomitable vomiting;
dyspnea;
decrease in urination up to anuria;
swelling;
bradycardia, lowering blood pressure;
heaviness and a feeling of fullness in the right hypochondrium.

In a severe course of the disease, more characteristic of persons with immunodeficiency, the following are noted:

high persistent fever lasting up to 2-3 weeks;
intense neurological symptoms, often with cerebral symptoms (impaired consciousness of varying severity (from a state of stunning to coma), generalized convulsive seizures);
bleeding (the appearance of traces of blood in feces and vomit, urine staining pink);
interruptions in the work of the heart, arrhythmia.

Diagnostics

Diagnosis based on the clinical picture is significantly difficult due to the nonspecificity of manifestations.

For a correct diagnosis, a thorough collection of anamnestic data is required, confirming the fact of a tick bite, living or staying in an area endemic for vector-borne infections, visiting a forest, a forest park zone in the previous period up to 3 weeks.

The following laboratory tests are carried out:

a general blood test (leukopenia is detected with a neutrophilic shift of the leukocyte formula to the left, a moderate increase in ESR, possibly anemia and a total decrease in the number of all blood cells);
general urine analysis (hypoisostenuria, proteinuria, hematuria of varying severity are established);
biochemical blood test (to increase the activity of liver enzymes (AST, ALT, LDH), creatinine and urea, an increase in the concentration of C-reactive protein);
direct dark-field microscopy of a thin smear stained according to Romanovsky - Giemsa (the most informative in the acute period, with a high concentration of the pathogen, allows you to identify anaplasma colonies in blood cells);
polymerase chain reaction (PCR) to identify the DNA of the pathogen (in this case, blood plasma, cerebrospinal fluid of the victim or the tick itself are used in case of timely detection);
enzyme immunoassay (ELISA);
indirect reaction of immunofluorescence (NRIF).

Tick testing helps to identify the DNA of the pathogen

Instrumental research is being carried out:

radiography of the lungs (signs of bronchitis or pneumonia, an increase in regional lymph nodes are established);
ECG (signs of conduction disturbances are determined);
Ultrasound of the abdominal organs (for enlargement of the liver, diffuse changes in organ tissues).

Treatment

Approximately half of the patients diagnosed with anaplasmosis require hospitalization and inpatient treatment.

The main method of treatment is etiotropic antibiotic therapy with tetracycline drugs. If antibacterial drugs are prescribed within 3 days after tick suction, a shortened antibiotic prophylaxis regimen is used (5–7 days).

For children, pregnant and lactating women, the drugs of choice are Amoxicillin or protected penicillins in age-specific dosages.

Taking antibiotics is the main treatment for anaplasmosis

If necessary, the following are used as additional funds:

anti-inflammatory drugs;
hepatoprotectors;
vitamin preparations;
antipyretics;
analgesics;
drugs for the treatment of concomitant disorders (neurological, cardiac, respiratory, etc.).

Possible complications and consequences

Complications of HAS as monoinfection are rare; the severity of the course increases with tick-borne viral-bacterial mixed infections, which lead to:

to bleeding;
to acute renal failure;
to acute liver failure;
to respiratory failure;
to hepatitis;
to meningoencephalitis;
to infectious toxic shock;
to coagulopathy;
to myocarditis;
to atypical pneumonia;
to coma, death.

Forecast

With timely initiation of therapy, the prognosis is favorable. However, in patients with severe concomitant pathology, immunodeficiency conditions, the disease can lead to the development of severe, sometimes life-threatening complications, and death.

Prevention

Reducing the number of ticks in natural foci with the help of pest control measures.
The use of acaricides and protective clothing that covers the body surface as much as possible when in places where ticks are suspected.
Compliance with hygiene standards when interacting with farm animals.
Avoiding contact with wild animals.
In case of detection of a sucked tick, its early removal followed by mandatory research.

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Olesya Smolnyakova Therapy, clinical pharmacology and pharmacotherapy About the author

Education: higher, 2004 (GOU VPO "Kursk State Medical University"), specialty "General Medicine", qualification "Doctor". 2008-2012 - Postgraduate student of the Department of Clinical Pharmacology, KSMU, Candidate of Medical Sciences (2013, specialty "Pharmacology, Clinical Pharmacology"). 2014-2015 - professional retraining, specialty "Management in education", FSBEI HPE "KSU".

The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!