Rabies (hydrophobia): diagnosis

The intravital diagnosis of rabies is to determine the viral antigen in the early days of the disease by fluorescent antibodies in corneal prints or in the biopsy of the occiput, and by the detection of antibodies after the 7-10th day of the disease. In unvaccinated patients, the diagnosis of rabies confirms a fourfold increase in antibody titre when examining paired sera. In vaccinated patients, when diagnosed, they rely on the absolute level of neutralizing antibodies in the serum, as well as on the presence of these antibodies in the cerebrospinal fluid. After post-exposure prophylaxis, neutralizing antibodies in the cerebrospinal fluid are usually absent or their titer is low (less than 1:64), while in rabies the neutralizing antibody titer in the cerebrospinal fluid varies from 1: 200 to 1: 160,000. The diagnostic purpose is also used for PCR detection of rabies virus RNA in the brain biopsy.

Posthumous diagnosis of rabies is carried out by several methods. Widely used histological method - express method, in which the answer can be obtained in 1-2 hours with a certainty of 85-90%, it is based on the discovery of Babes-Negri bodies in smears -prints of the brain. Taurus Babes-Negri when processing the drug with acidic paints acquire a ruby color with a basophilic internal structure. Biological diagnostics of rabies is based on infecting laboratory animals (suckling white mice, Syrian hamsters) with the test material and detecting Babes-Negri bodies after the death of animals in the brain tissue; the answer can be obtained in 25-30 days. Immunological methods are also used - the method of fluorescent antibodies or ELISA, as well as a virological method based on the isolation and identification of the rabies virus.

For a postmortem laboratory study, a piece of brain tissue (2-3 g of cerebellum tissue, ammonium horn, cerebral cortex), salivary glands, cornea is used in a person in a sterile dish with a 50% solution of glycerin in physiological saline. The collection of material must be carried out in strict compliance with the anti-epidemic regimen and measures of personal prophylaxis, the delivery to the laboratory is made in a hermetically-packed form, in a refrigerator bag. As a material for laboratory research in animals, the head is most often directed, and if the animal is small, then the whole corpse. The material is placed in plastic bags, then in hermetically sealed containers with ice pieces.

[1], [2], [3], [4], [5], [6], [7], [8], [9],

Indications for consultation of other specialists

The surgeon's consultation is indicated in the presence of multiple ragged and suppurated wounds, a neurologist - with clinico-laboratory symptoms of encephalitis of a different nature.

Indications for hospitalization

List of indications for hospitalization of victims of bites, scratches and numbness in animals and patients with hydrophobia:

• surgical indications (multiple lacerations, bites in the face, neck, hands and fingers);
• aggravated therapeutic history;
• infected bitten wounds (except for the brush);
• infected bitten wounds of the hand;
• weighed allergic anamnesis, persons with unusual post-vaccination reactions and complications of anti-rabies drugs and re-vaccinated;
• burdened neurological anamnesis;
• a burdened psychoneurological history;
• pregnant women affected by animal bites:
• The newborn, affected by animal bites;
• patients with hydrophobia and affected by bites of infected animals.

Differential diagnosis of rabies (hydrophobia)

Differential diagnosis of rabies is carried out with diseases accompanied by the development of similar clinical symptoms.

Differential diagnosis of rabies

Symptom	Rabies	Atropine poisoning	Tetanus	Lissofobia
The incubation period	From 7 days to 1 year and more (usually 30-90 days)	2-4 hours	1-30 days	No
Onset of disease	Gradual	Acute	Sharp, subacute	Acute
Weakness, fatigue	Typical	Typical	Typical	There is
Fever	Typical	Not typical	Typical	Not typical
Sweating	There is	There is	There is	No
Headache	There is	There is	No	There is
Salivation	Expressed. Dry mouth in the stage of paralysis	Dry mouth and throat	There is	No
Changes in the psyche	Constant	There is	No	There is
General excitability	There is	There is	There is	There is
Speech and swallowing disorder	There is	There is	There is	No
Mydriasis	There is	There is	No	No
Psychomotor agitation	There is	There is	No	No
Hallucinations	There is	There is	No	No
Convulsions	There is	There is	Is, against the background of muscle hypertonia	No
Relaxation of muscles after seizures	There is	There is	No	No seizures
Cramps of the muscles of the pharynx. Lockjaw	Periodic	No	Constant	No
Loss of consciousness	There is	There is	There is (before death)	No
Hydrophobia	There is	No	No	No
Paralysis, paresis	There is	No	No	No
Steady progression of the disease	Yes	No	No	No
Hemogram	Leukopenia, aneosinophilia	Not changed	There are no significant changes	Not changed
CSF	Lymphocytic pleocytosis. A slight increase in protein	Not changed	As a rule, not changed	Not changed

[10], [11], [12], [13],