Middle Eastern Respiratory Syndrome( MERS coronavirus) - Causes, symptoms and treatment. MF.
In recent years, more and more often in the media and public health authorities there is information about the spread of a new seriously leaking infection with the defeat of the lungs. The epidemic of SARS, which arose in 2002-2003 in China and ended fatal for 10% of cases, is still fresh in memory, as a new version of the virus appeared that could cause a serious infection with its epidemic spread. The last outbreak of BVRS in 2015 in South Korea is particularly alarming due to its gradual spread.
Middle Eastern Respiratory Syndrome( MIDS - MiddleEastrespiratorysyndrome) is an acute infectious disease caused by a new coronavirus( BVRS-CoV, MERS-CoV), transmitted from animals and humans, characterized by the occurrence of a respiratory infection of varying severity from mild manifestations to severe pneumonia, often ending lethal.
BSRC patients
Official information( WHO, Rospotrebnadzor)
In September 2012, the first time in Saudi Arabia, a disease with respiratory damage caused by a new variety of coronavirus was registered. The new coronavirus of the Middle Eastern Respiratory Syndrome( BVRS-Co-B) was isolated for the first time. It was retrospectively revealed that the cases of infection in Saudi Arabia took place already in April 2012.It is believed that the circulation of the virus among animals occurs only within the Arabian Peninsula. Since the registration of the first patient, sporadic cases( that is, isolated) have been registered in Saudi Arabia( 85% of all cases), Oman, Qatar, the United Arab Emirates, Iran, Jordan, Kuwait, Yemen, Egypt, Tunisia. The reservoir of infection in these countries is camels. The lethality reached 36%.Outside the Middle East, the infection also leaked in 2012.Cases of the disease are registered in Turkey, Germany, Austria, Italy, the Netherlands, Greece, France, the United Kingdom. Most of them were imported. Out of 15 cases, 7 ended lethal. To date, the last case of infection was registered in Germany in March 2015.
BVRS - Arabian Peninsula - endemic region
The International Committee on Taxonomy of Viruses on May 15, 2013 decided to use the following abbreviation for mentioning this virus: MiddleEastrespiratorysyndromecoronavirus( MERS-CoV) or coronavirus of the Middle Eastern Respiratory Syndrome( BVRS-CoV).It is this name that is recommended for use in literary and scientific medical sources.
The largest outbreak of BVRS outside the Middle East has been recorded and is taking place in the Republic of Korea. Since May 20( the time of the first patient's appearance), 126 people have been ill on June 12, 2015( 125 in Korea and 1 in China), 10 of which are fatal( the hourly monitoring is on the official WHO website).The majority of patients become infected in close contact with the patient( family members, medical personnel) without proper personal protective equipment, often the infection occurs in the medical institutions. Under supervision are more than 2,5 thousand contact, closed thousands of educational institutions.
According to the WHO, from September 2012 to June 2015, 1218 people with laboratory-confirmed BVRS-Cov, of whom 449 have lethal, fell ill.
BSRS outbreak in the Republic of Korea
Causes of BSRC
The causative agent is a new type of coronavirus from the family Coronaviridae, a similar subfamily, the genus Betacoronavirus, subgenus C, called the coronavirus of the Middle Eastern Respiratory Syndrome( BVRS-CoV) or MiddleEastrespiratorysyndromecoronavirus( MERS-CoV).BVRS-CoV is a particularly dangerous agent of lethal pneumonia. It is the representative of a large family of coronaviruses, containing RNA in its genome.
BVRS virus
Source of infection.
Natural reservoir of infection - animals: diseased camels, contents in their biological fluids BVRS-Cov( dangerous milk, urine, blood, meat).Initially, suspicion of a reservoir of infection fell only on bats, and it is believed that it was bats that became the source of infection for camels.
BVRS natural reservoir( Egyptian burial sack)
BVRS tank infection - camel
Another source of infection is a sick person with a clinically expressed form of the disease.
The transmission mechanisms have not been adequately studied. The infection of a person from a sick animal occurs through transmission factors - raw camel milk, insufficiently thermally processed camel meat, camel's urine. Alleged ways of infection from the animal - food, contact.
A person from a sick person becomes infected only with close contact without personal protective equipment - caring family members, medical personnel. Among the ways of infection is not excluded contact-household, respiratory. Free circulation of the virus in the air during the outbreak of infection is not recorded, therefore, the free transmission of the virus from a person to a person is not confirmed.
The population's susceptibility to BSRC is universal, however, it is noted that the majority of cases are registered in the adult age group of persons with chronic diseases, that is, with different immunodeficiency. During outbreaks, transmission of infection is recorded in medical institutions among persons without personal protective equipment. Often infected patients who are in the same room with a patient BVRS.
Clinical symptoms of the Middle Eastern respiratory syndrome
Symptoms are similar to the manifestation of an acute respiratory viral disease of varying severity - from asymptomatic to severe forms with the development of pneumonia and an unfavorable outcome. The incubation period is from 2-3 days to 2 weeks. Leading syndromes are:
1) ITS( infectious-toxic syndrome) - subfebrile and febrile fever, symptoms of intoxication( headache, dizziness, weakness, myalgia, pain in the eyeballs, loss of strength) 2) Respiratory Syndrome -the appearance of a cough in the initial dry periods without sputum, sometimes exhausting. In severe cases, pneumonia is fast enough to attach to the weakness, high fever, a cough that becomes productive( clear, viscous sputum appears).
The complication is the development of RDS( respiratory distress syndrome): the appearance of dyspnea and respiratory failure against the background of the above symptoms of the disease. Against the backdrop of severe current, respiratory arrest may occur, which requires resuscitation.
Often, symptoms of BVRS include symptoms of gastrointestinal tract damage( abdominal pain, diarrhea), and kidney failure.
Mortality with BVRS is 30-35%.Most often, an unfavorable outcome occurs in elderly patients with immunodeficiency and concomitant lung diseases, diabetes, oncology and others.
Immunity after the transferred BVRS short, repeated infection is not ruled out.
Diagnosis of the Middle Eastern Respiratory Syndrome
1. Preliminary diagnosis - clinical epidemiological. The clinical symptoms of
infection are quite nonspecific. Differential diagnosis should be carried out with the whole group of ARVI, and in favor of BVRS in the case of severe form will indicate the rapid development of viral pneumonia and respiratory failure. A carefully collected epidemiological anamnesis can confirm a doctor in suspicion of BVRS.WHO recommends that a person with symptoms of ARVI complicated by RDS should be considered as a potential patient with BVRS in the presence of a stay in a dysfunctional territory( Middle East) within the next 14 days preceding the disease.
2. The final diagnosis is made after a laboratory test and a positive test for BVRS-CoV.
A) One of the important methods of early diagnosis of BVRS is the RT-PCR method in biological material( blood, urine, secret from the nose, more reliable results - when examining samples from the lower DP - tracheal aspirates, bronchoalveolar rinses).RT-PCR will identify the genetic material of the virus in the early stages of the disease.
B) Serological diagnosis of paired samples of blood serum taken at intervals of 21 days for the presence of specific antibodies( ELISA, RSA, RNGA), diagnostic titers can be detected after 5-6 days from the time of infection. The first serum in the first week of illness.
C) Virological method - virus isolation in the cell culture by their infection and subsequent virus production.
BSRC diagnosis
Materials for the study are sent to the laboratory as early as possible. In the event of a delay, freezing with dry ice is required. Transportation( in individual containers and after special labeling) in accordance with international rules for the transport of materials containing especially dangerous viruses( transport without appropriate security measures can lead to infection of the employee carrying out transportation).
Table 1. Types of clinical specimens for BBCBC testing and recommendations for sample handling
| Sample type | Transport medium | Transport to laboratory | Dangerous goods category | Note |
| Combined nasal and throat swab | Transport medium for viruses | On the ice. | Biological substance, Category B( Biological substance, Category B) | |
| virus was detected in this type of specimen | ||||
| nasopharyngeal swab Complete blood for detection of | virus EDTA anticoagulant | Take during the 1st week of disease | ||
| Sputum( with natural expectoration *) | does not apply | On ice. When transporting more than 24 hours - freezing with dry ice | Ensure that the material is obtained from the lower | |
| Broncho alveolar flushing( by bronchoalveolar lavage) | Possible reduction of the virus concentration, but the material is suitable | |||
| Tracheal aspirate | ||||
| Nasopharyngeal aspirate | ||||
| Tissuesample( including lung tissue), taken by biopsy | Transport medium for viruses or fiz.solution | |||
| Serum for serological examination or detection of | virus not used | Paired samples after 21 days |
Treatment of the Middle East Respiratory Syndrome
1. Organizational and Regime Measures is hospitalization for epidemic indications. Patients in suspicion of BVRS are hospitalized in separate wards. Bed rest for the entire period of fever and with the development of severe forms with complications. A balanced diet.
2. Medical therapy includes:
- Etiotropic therapy with interferon drugs - wellferon, betaferon in adequate dosages equivalent to the treatment of chronic viral hepatitis C. In severe forms, ribavirin is effective at a concentration of 8-12 mg / ml intravenously. Only such high doses are able to exert a cytopathic effect on BVRS-CoV.
- Detoxification therapy( hemodez, reimbyrin, rheopolyglucin and other infusion solutions) with an average volume of up to 800 ml / day.
- Postindromal therapy( GCS, surfactant preparations and others).
Antibiotic therapy for the threat of bacterial attachment.
3. If necessary, intubation and transfer to mechanical ventilation.
BVRS - ward with patient
Prevention of Middle Eastern Respiratory Syndrome
No specific prevention( vaccination) has been developed.
In areas that are disadvantaged in BVRS:
- observe personal hygiene( hand washing) after visiting markets, farms, barns and other places where camels are located;
- avoid any contact with sick animals;
- do not eat raw camel milk and meat( milk should be pasteurized, and meat - sufficient thermal treatment);
WHO does not regulate restrictions on visits to disadvantaged areas in BCCR, trade and monitoring of persons arriving from the Middle East, but recommends vigilance, strengthen surveillance measures for SARS among passengers or migrants - workers from the Middle East.
1) In connection with this, the RF Ministry of Health recommends refraining from traveling to troubled Middle Eastern countries without special need.
2) It is advisable for medical workers who provide assistance to patients with BSRC not to neglect personal protective equipment for the prevention of airborne and contact-household infection routes - individual mask, gown, gloves, eye protection.
3) Persons staying from countries of the Middle East should remain alert for 2 weeks( incubation period) from the moment of arrival and if symptoms of acute respiratory viral infection occur, urgently consult a doctor at the place of residence, immediately informing about the fact of such a trip.
4) Medical workers in the case of a patient with symptoms of acute respiratory viral infection, especially severe its form, must collect an epidemic of anamnesis about the fact of going to any country in the Middle East in the previous from the disease for 2 weeks.
5) Rospotrebnadzor provides readiness of the laboratories of the Centers for Hygiene and Epidemiology and the Center for specific studies for coronavirus infection.
6) Rospotrebnadzor organized a continuum of work with legal entities that can carry out tour operator activities.
The doctor infektsionist Bykova N.I.