Epidemic parotitis (mumps)

Epidemic parotitis (parotitis epidemics, synonyms - parotitis infection, mumps, earwax, "trench" disease, "soldier" disease).

Mumps is an acute, contagious, systemic viral infection, usually causing an increase and soreness of the salivary glands, most often parotid. Complications include orchitis, meningoencephalitis and pancreatitis. The diagnosis is clinical, treatment is symptomatic. Vaccination is highly effective.

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

Epidemiology

Epidemic parotitis (mumps) is traditionally referred to as childhood infections. At the same time, mumps in infants and under 2 years of age are found edoxic. From 2 to 25 years the disease is very common, it again becomes rare after 40 years. Many doctors attribute epidemic parotitis to a disease of school age and military service. The incidence rate in US troops during the Second World War was 49.1 per 1,000 troops. In recent years, epidemic parotitis in adults is more common in connection with the mass vaccination of children. At the most part of vaccinated already in 5-7 years the concentration of protective antibodies is considerably reduced. This contributes to an increase in susceptibility to adolescent and adult disease.

The source of the causative agent is a person with epidemic parotitis who starts to isolate the virus 1-2 days before the appearance of the first clinical symptoms and up to the 9th day of the disease. The most active release of the virus into the environment occurs in the first 3-5 days of the disease. The virus is excreted from the body of the patient with saliva and urine. It is established that the virus can be found in other biological fluids of the patient: blood, breast milk, cerebrospinal fluid and in the affected glandular tissue.

The virus is transmitted by airborne droplets. The intensity of virus release into the environment is small due to the absence of catarrhal phenomena. One of the factors that accelerate the spread of the mumps virus is the presence of concomitant ARI, in which the excretion of the causative agent into the environment is increased due to coughing and sneezing. The possibility of infection through household items (toys, towels) infected with the patient's saliva is not ruled out. The vertical way of transmission of mumps from a pregnant woman to a fetus is described. After the disappearance of the symptoms of the disease, the patient is not contagious. Susceptibility to infection is high (up to 100%). "Sluggish" mechanism of transmission of the pathogen, prolonged incubation, a large number of patients with erased forms of the disease, which makes it difficult to identify and isolate them, leads to the fact that outbreaks of mumps in children's and teenage groups have been proceeding for a long time, wavy for several months. Men suffer from this disease 1.5 times more often than women.

Typical seasonality: the maximum incidence falls on March-April, the minimum - for August-September. Among the adult population, epidemic outbreaks are recorded more often in closed and semi-closed collectives - barracks, hostels. Ship commands. The incidence of morbidity is noted with a periodicity of 7-8 years. Epidemic parotitis (mumps) is referred to as controlled infections. After the introduction of immunization practices, the incidence has significantly decreased, but only in 42% of the countries of the world vaccination against mumps is included in national vaccination calendars. Because of the constant circulation of the virus, 80-90% of people over 15 years of age are found to have anti-parotid antibodies. This indicates a wide spread of this infection, and believe that in 25% of cases, epidemic parotitis is inapparent. After the transferred disease in patients, stable lifelong immunity is formed, repeated diseases are extremely rare.

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

Causes of the mumps

The cause of mumps is the Pneumophila parotiditis virus, which is pathogenic to humans and monkeys.

Refers to paramyxovirus (family Pammyxoviridae, genus Rubulavirus). Antigenically close to the parainfluenza virus. The genome of the mumps virus is represented by a single-stranded spiral RNA surrounded by nucleocapsid. The virus is characterized by pronounced polymorphism: in shape it represents rounded, spherical or irregular elements, and the sizes can vary from 100 to 600 nm. Has hemolytic. Neuraminidase and hemagglutinating activity associated with glycoproteins HN and F. The virus is well cultivated in chick embryos, guinea pig kidney, monkey, Syrian hamster, and human amniotic cells, is environmentally unstable, inactivated by exposure to high temperature, ultraviolet irradiation, drying, quickly disintegrates in disinfecting solutions (50% ethyl alcohol, 0.1% formalin solution, etc.). At a low temperature (-20 ° C), it can persist in the environment for up to several weeks. The antigenic structure of the virus is stable. Only one virus serotype is known, which has two antigens: V (viral) and S (soluble). The optimal pH of the medium for the virus is 6.5-7.0. Of laboratory animals are most sensitive to the mumps epidemic parotitis virus. Who manage to reproduce the disease by introducing a virus-containing material into the duct of the salivary gland.

The virus enters the respiratory tract and mouth. It is in saliva up to 6 days, until the salivary gland swells. It is also found in the blood and urine, in cerebrospinal fluid with CNS damage. The transferred disease leads to permanent immunity.

Pig is less contagious than measles. The disease is endemic in densely populated areas, there may be an outbreak in organized groups. Epidemics often occur in nonimmunized populations with an increase in incidence in early spring and late winter. Mumps can occur at any age, but more often between 5 and 10 years of age; it is unusual in children under 2 years, especially under 1 year. 25-30% of cases - inapparant forms.

Other causes of increased salivary glands:

• Purulent mumps
• HIV mumps
• Other viral mumps
• Metabolic disorders (uremia, diabetes mellitus)
• Mikulich syndrome (chronic, usually painless parotitis and laryngeal edema of unknown nature, which develops in patients with tuberculosis, sarcoidosis, SLE, leukemia, lymphosarcoma)
• Malignant and benign swelling of the salivary gland
• Drug-mediated parotitis (for example, when taking iodides, phenylbutazone or propylthiouracil)

[13], [14]

Pathogenesis

The virus of mumps (mumps) enters the body through the mucous membrane of the upper respiratory tract and conjunctiva. It has been shown experimentally that the application of the virus to the mucous membrane of the nose or cheek leads to the development of the disease. After penetration into the body, the virus multiplies in the cells of the epithelium of the respiratory tract and spreads with blood flow to all organs, of which the most sensitive are saliva, sex and pancreas, and the central nervous system. On the hematogenous spread of infection shows early viremia and damage to various organs and systems that are distant from each other. The phase of viremia does not exceed five days. The defeat of the central nervous system and other glandular organs can occur not only after, but also simultaneously, earlier and even without the defeat of salivary glands (the latter is observed very rarely).

The nature of the morphological changes in the affected organs has not been studied enough. It was established that the defeat of connective tissue predominates, and not of glandular cells. In this case, for an acute period, the development of edema and lymphocytic infiltration of the interstitial space of the glandular tissue is typical, but the mumps virus can simultaneously affect the glandular tissue itself. In a number of studies, it has been shown that, in addition to edema, orchitis also affects the testicle parenchyma. This causes a decrease in the production of androgens and leads to a violation of spermatogenesis. A similar character of the lesion is also described for the defeat of the pancreas, which may result in the atrophy of the islet apparatus with the development of diabetes mellitus.

[15], [16], [17], [18], [19], [20],

Symptoms of the mumps

Epidemic parotitis (mumps) has no generally accepted classification. This is explained by different interpretations by specialists of the manifestations of the disease. A number of authors believe that the symptoms of mumps are a consequence of the defeat of the salivary glands, and the defeat of the nervous system and other glandular organs as complications or manifestations of the atypical course of the disease.

The position, according to which the lesions not only of the salivary glands but also other localization caused by the mumps virus, are pathogenetically justified as symptoms of mumps and not complications of the disease. Moreover, they can manifest themselves in isolation without lesion of salivary glands. At the same time, lesions of various organs as isolated manifestations of mumps infection are rarely observed (atypical form of the disease). On the other hand, the erased form of the disease, which was diagnosed before the scheduled vaccination, during almost every outbreak in the children's and adolescents' groups and during routine examinations, can not be considered atypical. Asymptomatic infection is not considered as a disease. The classification should also reflect the often unfavorable long-term consequences of mumps. The severity criteria in this table are not included, since they are completely different for different forms of the disease and do not have a nosological specificity. Complications of mumps are rare and do not have any characteristic features, so they are not considered in the classification.

The incubation period of mumps is between 11 and 23 days (usually 18-20). Often the unfolded picture of the disease is preceded by a prodromal period.

In some patients (usually in adults) 1-2 days before the development of a typical picture, prodromal symptoms of mumps are observed in the form of weakness, malaise, hyperemia of the oropharynx, muscle pain, headache, sleep and appetite disorders. Typically acute onset, chills and fever to 39-40 ° C. Early symptoms of mumps (mumps) - tenderness behind the ear lobe (symptom Filatova). The swelling of the parotid gland often appears towards the end of the day or on the second day of the illness first on one side, and after 1-2 days in 80-90% of patients on the other. In this case, usually notice a noise in the ears, pain in the ear, worse with chewing and talking, trismus is possible. The parotid gland is clearly visible. The gland fills a hole between the mastoid process and the lower jaw. With a significant increase in the parotid gland, the auricle protrudes and the earlobe rises to the top (hence the alternative name "mumps"). Edema spreads in three directions: anteriorly - on the cheek, down and behind - on the neck and upwards - on the region of the mastoid process. Puffiness is especially noticeable when examining the patient from the back of the head. The skin above the affected gland is strained, of ordinary color, with palpation of iron has a test consistency, moderately painful. The maximum degree of swelling reaches on the 3-5th day of the disease, then gradually decreases and disappears, as a rule, on the 6-9th day (in adults on the 10-16th day). During this period, salivation is reduced, the mucous membrane of the mouth is dry, the patients complain of thirst. The stenons of the duct are clearly visible on the mucous membrane of the cheek in the form of a hyperemic edematous ring (Mursu symptom). In most cases, not only the parotid but also the submandibular salivary glands are involved in the process, which are defined as weakly painful spindle-like swelling of the test consistency, in case of a hypoglossal lesion, swelling is noted in the chin and under the tongue. The defeat of only submandibular (submaxillitis) or sublingual glands is very rare. Internal organs with isolated parotite, as a rule, are not changed. In a number of cases, patients notice tachycardia, noise at the apex and muffling of heart sounds, hypotension. The defeat of the central nervous system manifests itself as a headache, insomnia, adynamia. The total duration of the febrile period is usually 3-4 days. In severe cases - up to 6-9 days.

A common symptom of mumps (mumps) in adolescents and adults is testicular damage (orchitis). The frequency of mumps orchitis directly depends on the severity of the disease. In severe and moderately severe forms, it occurs in approximately 50% of cases. Possible orchitis without lesion of salivary glands. Signs of orchitis noted on the 5-8th day of the disease against a background of decrease and normalization of temperature. The patient's condition deteriorates again: body temperature rises to 38-39 ° C, chills, headache, nausea and vomiting are possible. There are severe pain in the scrotal and testicles, sometimes radiating to the lower abdomen. The testicle increases 2-3 times (to the size of the goose egg), becomes painful and dense, the skin of the scrotum is hyperemic. Often with a cyanotic shade. More often one egg is affected. Expressed clinical manifestations of orchitis persist for 5-7 days. Then the pain disappears, the testicle gradually decreases in size. In the future, it can be noted signs of its atrophy. Almost 20% of patients have orchitis combined with epididymitis. The adherence of the testicle is palpated as an oblong painful swelling. This condition leads to a violation of spermatogenesis. Data were received on the erased form of orchitis, which can also be the cause of male infertility. In mumps orchitis, a mild infarct is described due to thrombosis of the prostate and pelvic organs. An even more rare complication of parotitic orchitis is priapism. Women can develop oophoritis, bartholinitis, mastitis. It is rarely found in female patients during the post-pubertal period with oophoritis. Not affecting fertility and not leading to sterility. It should be noted that mastitis can develop in men.

A common symptom of mumps is an acute pancreatitis, often asymptomatic and diagnosed only on the basis of increased activity of amylase and diastase in the blood and urine. The frequency of pancreatitis, according to various authors, varies widely - from 2 to 50%. It often develops in children and adolescents. Such a spread of data is associated with the use of various criteria for the diagnosis of pancreatitis. Pancreatitis usually develops on the 4th-7th day of the disease. They observe nausea, repeated vomiting, diarrhea, pains of the shingles in the middle part of the abdomen. With severe pain syndrome, sometimes stress the muscles of the abdomen and symptoms of irritation of the peritoneum. A significant increase in the activity of amylase (diastase) is characteristic. Which lasts up to one month, while other symptoms disappear within 5-10 days. The defeat of the pancreas can lead to atrophy of the islet apparatus and the development of diabetes.

In rare cases, it is possible to damage other glandular organs, usually in combination with salivary glands. Thyroiditis, parathyroiditis, dacryoadenitis, thymoiditis are described.

The defeat of the nervous system is one of the frequent and significant manifestations of parotitis infection. Most often observed serous meningitis. There are also meningoencephalitis, neuritis of the cranial nerves, polyradiculoneuritis. Symptoms of parotid meningitis are polymorphic, so the diagnostic criterion can only be the detection of inflammatory changes in the cerebrospinal fluid.

There are cases of epidemic mumps occurring with the syndrome of meningism, with the intactness of the cerebrospinal fluid. On the contrary, often without the presence of meningeal symptoms, inflammatory changes in the cerebrospinal fluid are noted, so data on the frequency of meningitis, according to various authors, vary from 2-3 to 30%. Meanwhile, timely diagnosis and treatment of meningitis and other CNS lesions significantly affects the long-term consequences of the disease.

Meningitis is more common in children aged 3-10 years. In most cases, it develops on the 4-9th day of the disease, i.e. In the midst of the defeat of the salivary glands or on the background of the subsidence of the disease. However, it is also possible the appearance of symptoms of meningitis simultaneously with the defeat of salivary glands and even earlier. Possible cases of meningitis without lesions of salivary glands, in rare cases, in combination with pancreatitis. The onset of meningitis is characterized by a rapid rise in body temperature to 38-39.5 ° C, accompanied by an intense headache of a diffuse nature, nausea and frequent vomiting, hyperesthesia of the skin. Children become lethargic, adynamic. Already on the first day of the disease, meningeal symptoms of mumps (mumps) are noted, which are moderately expressed, often not in full, for example, only a symptom of planting ("tripod"). In young children, cramps, loss of consciousness, in older children - psychomotor agitation, delirium, hallucinations. General cerebral symptoms usually regress within 1-2 days. Preservation for a longer time indicates the development of encephalitis. An important role in the development of meningeal and cerebral symptoms is played by intracranial hypertension with an increase in LD to 300-600 mm of water. Careful drop by evacuation of the cerebrospinal fluid during lumbar puncture to the normal level of LD (200 mm of water) is accompanied by a marked improvement in the patient's condition (cessation of emesis, clarification of consciousness, decrease in the intensity of the headache).

Spinal-cerebral fluid in mumps is transparent or opalescent, pleocytosis is 200-400 in 1 μl. The protein content is increased to 0.3-0, b / l, sometimes up to 1.0-1.5 / l. Rarely observe a reduced or normal level of protein. Cytosis, as a rule, lymphocytic (90% and above), in the 1-2 days of the disease can be mixed. The concentration of glucose in the blood plasma - within normal values or increased. The recovery of cerebrospinal fluid occurs after the regress of the meningeal syndrome, by the 3rd week of the disease, but can be prolonged, especially in older children, up to 1-1.5 months.

In meningoencephalitis, 2-4 days after the development of the meningitis pattern, on the background of the weakening of meningeal symptoms, general cerebral symptoms develop, focal symptoms appear: the flattening of the nasolabial fold, the deviation of the tongue, the revival of tendon reflexes, anisoreflexia, muscle hypertonia, pyramidal signs, oral automatism symptoms, ataxia, intentional tremor, nystagmus, transient hemiparesis. In young children, cerebellar disorders are possible. Parotite meningitis and meningoencephalitis proceed benignly. As a rule, full recovery of CNS functions occurs. But sometimes intracranial hypertension may persist. Asthenia, loss of memory, attention, hearing.

Against the background of meningitis, meningoencephalitis, sometimes in isolation, neuritis of the cranial nerves, most often of the VIII pair, is possible. In this case, they note dizziness, vomiting, worse when the body position changes, nystagmus. Patients try to lie motionless with their eyes closed. These symptoms are associated with a lesion of the vestibular apparatus, but cochlear neuritis is also possible, which is characterized by the appearance of noise in the ear, hearing loss, mainly in the high frequency zone. The process is usually one-sided, but often complete restoration of hearing does not occur. It should be borne in mind that with a pronounced parotitis, a short-term decrease in hearing is possible due to edema of the external auditory canal.

Polyradiculoneuritis develops against the background of meningitis or meningoencephalitis. It is always preceded by the defeat of the salivary glands. At the same time, the appearance of radicular pain and symmetrical paresis of predominantly distal parts of the extremities is typical, the process is usually reversible, and possibly the defeat of the respiratory muscles.

Sometimes, usually on the 10-14th day of the disease, more often in men, polyarthritis develops. In general, large joints (humeral, knee) are affected. Symptoms of mumps (mumps), as a rule, are reversible, result in complete recovery within 1-2 weeks.

Complications (sore throat, otitis, laryngitis, nephritis, myocarditis) are extremely rare. Changes in blood during epidemic parotitis are insignificant and characterized by leukopenia, relative lymphocytosis, monocytosis. An increase in ESR, in adults sometimes marked with leukocytosis.

Forms

The clinical classification of mumps includes the following clinical forms.

• Typical.
  • With isolated lesions of salivary glands:
    • clinically pronounced:
    • stupid.
  • Combined:
    • with the defeat of salivary glands and other glandular organs;
    • with the defeat of salivary glands and nervous system.
• Atypical (without lesion of salivary glands).
  • With lesion of glandular organs.
  • With the defeat of the nervous system.
• Outcomes of the disease.
  • Complete recovery.
  • Recuperation with residual pathology:
    • diabetes;
    • infertility:
    • defeat of the central nervous system.

[21], [22], [23], [24], [25]

Diagnostics of the mumps

The diagnosis of mumps is based mainly on a characteristic clinical picture and epidemiological history, and in typical cases does not cause difficulties. Of the laboratory methods of confirming the diagnosis, the most evident is the isolation of the mumps virus from the blood, the secretion of the parotid gland, urine, spinal fluid and pharyngeal flushes, but in practice this is not used.

In recent years, serological diagnostics of mumps has been used more often, ELISA, RAC and RTGA are most often used. High IgM titer and low IgG titer in the acute period of infection can be a sign of mumps. Finally, it is possible to confirm the diagnosis 3-4 weeks later when the antibody titer is repeated, with an increase in the IgG titer 4 times or more is of diagnostic significance. With the use of RSK and RTGA, cross reactions with the parainfluenza virus are possible.

Recently, the diagnosis of mumps (mumps) with the use of PCR of the epidemic mumps virus has been developed. For diagnosis, the activity of amylase and diastase in the blood and urine is often determined, the content of which increases in most patients. This is especially important not only for the diagnosis of pancreatitis, but also for the indirect confirmation of the parotitic etiology of serous meningitis.

[26], [27], [28],

Differential diagnosis

Differential diagnosis of mumps is primarily carried out with bacterial parotitis, salivary stone disease. The increase in salivary glands is also noted in sarcoidosis and tumors. Parotite meningitis is differentiated with serous meningitis of enterovirus etiology, lymphocytic choriomeningitis, and sometimes tuberculous meningitis. It is especially important to increase the activity of pancreatic enzymes in the blood and urine in mumps. The most dangerous are cases when the edema of the subcutaneous tissue of the neck and lymphadenitis, which occurs in toxic forms of diphtheria of the oropharynx (sometimes with infectious mononucleosis and herpesvirus infections). The doctor takes parotitis. Acute pancreatitis should be differentiated with acute surgical diseases of the abdominal cavity (appendicitis, acute cholecystitis).

Parotite orchitis differentiate with tubercular, gonorrheal, traumatic and brucellosis orchitis.

Symptoms of intoxication

There is

Pain when chewing and opening the mouth in the area of salivary glands

There is

An increase in one or more salivary glands (parotid, submandibular)

There is

Simultaneous defeat of salivary glands and pancreas, testes, milk glands, development of serous meningitis

There is

The research is completed. Diagnosis: epidemic parotitis.

In the presence of neurologic symptoms, the consultation of a neurologist is shown, with the development of pancreatitis (pain in the abdomen, vomiting) - a surgeon, with the development of orchitis - the urologist.

Symptoms	Nosological form
	Parotitis	Bacterial parotitis	Sialolithiasis
Start	Acute	Acute	Gradual
Fever	Precedes local changes	Appears one-time or later local changes	Not typical
One-sided defeat	Two-sided may affect other salivary glands	As a rule, one-sided	Usually one-sided
Pain	Not typical	Characteristic	Stitching, paroxysmal
Local soreness	Minor	Expressive	Minor
Consistency	Plosnovata	Dense in the future - fluctuation	Thick
Stenov duct	Symptom Mursu	Hyperemia, purulent discharge	Mucous discharge
Picture of blood	Leukopenia lymphocytosis ESR - no change	Neutrophilic leukocytosis with a shift to the left. Increased ESR	No specific changes
Skin over the gland	Ordinary coloration, tense	Hyperemic	Not changed

Treatment of the mumps

Hospitalized patients from closed children's groups (orphanages, boarding schools, military units). As a rule, treatment of mumps (mumps) is performed at home. Hospitalization is indicated for severe disease (hyperthermia over 39.5 ° C, signs of central nervous system damage, pancreatitis, orchitis). In order to reduce the risk of complications, regardless of the severity of the disease during the entire period of fever, patients must comply with bed rest. It was shown that in men who did not observe bed rest during the first 10 days of the disease, orchites developed 3 times more often. In acute period of the disease (before the 3-4th day of illness), patients should receive only liquid and semi-liquid food. Given the violation of salivation, much attention should be paid to oral care, and during the convalescence it is necessary to stimulate the secretion of saliva, using, in particular, lemon juice. For prophylaxis of pancreatitis, it is expedient to have a milk-vegetable diet (table number 5). The abundant drink is shown (fruit drinks, juices, tea, mineral water.) Headache is prescribed metamizole sodium, acetylsalicylic acid, paracetamol. It is expedient to desensitize treatment of mumps (mumps). To reduce the local manifestations of the disease on the salivary glands area, light-and-light therapy (sun-lamp) is prescribed. When orchitis is used prednisolone for 3-4 days at a dose of 2-3 mg / kg per day, followed by a decrease in the dose of 5 mg daily. It is mandatory to wear a suspensions for 2-3 weeks to ensure an elevated position of the testicles. In acute pancreatitis appoint a sparing diet (in the first day - a hunger diet). Cold is shown on the abdomen. For reduced pain syndrome, analgesics are administered, aprotinin is used. If suspected of having meningitis, a lumbar puncture is indicated, which is not only diagnostic but also therapeutic. In addition, analgesics, dehydration therapy with furosemide (lasix) at a dose of 1 mg / kg per day, and acetazolamide are also prescribed. With severe cerebral syndrome, dexamethasone is prescribed 0.25-0.5 mg / kg per day for 3-4 days with meningoencephalitis - nootropic drugs for 2-3 weeks.

Approximate terms of incapacity for work

Terms of incapacity for work are determined depending on the clinical course of mumps, the presence of meningitis and meningoencephalitis, pancreatitis. Orchitis and other specific lesions.

[29], [30],

Clinical examination

Epidemic parotitis (mumps) does not require medical examination. It is carried out by an infectious disease doctor, depending on the clinical picture and the presence of complications. If necessary, attract specialists of other specialties (endocrinologists, neurologists, etc.).

[31], [32], [33], [34], [35], [36]

Prevention

Patients with epidemic parotitis are isolated from children's groups for 9 days. Contact persons (children under the age of 10 who were not infected with mumps and unvaccinated) are subject to disconnection for a period of 21 days, and in cases of exact date of contact, from the 11th to the 21st day. Wet the premises with a disinfectant and ventilate the premises. For children who had contact with the patient, during the isolation period, medical supervision is established.

The basis of prevention is vaccine prophylaxis within the national calendar of preventive vaccinations. Vaccination is carried out with a mulled culture live live vaccine taking into account contraindications at 12 months and booster at 6 years. The vaccine is administered subcutaneously in a volume of 0.5 ml under the scapula or in the outer surface of the shoulder. After the introduction of the vaccine, short-term fever may occur, catarrhal events on 4-12 days, very rarely - an increase in salivary glands and serous meningitis. For emergency prevention of unvaccinated against mumps and neoblevshim vaccine is administered no later than 72 hours after contact with the patient. Also certified are parotitic-measles live live dry vaccine and vaccine against measles, mumps and rubella live attenuated lyophilized (manufactured in India).

Anti-parotid immunoglobulin and serum immunoglobulin are ineffective. Effective vaccination with live mumps vaccine, which does not cause local systemic reactions and requires only one injection, is vaccinated against measles, mumps and rubella. Postcontact vaccination does not protect against mumps.

[37], [38],

Forecast

With uncomplicated epidemic parotitis, recovery usually occurs, although after 2 weeks a relapse may occur. Pig has usually a favorable prognosis, although effects such as one-sided (rarely bilateral) hearing loss or facial nerve palsy can remain. Rarely are post-infection encephalitis, acute cerebellar ataxia, transverse myelitis and polyneuritis.

[39]