Human Respiratory Syncytial Virus

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Respiratory syncytial virus
Respiratory Syncytial Virus (RSV) EM PHIL 2175 lores.jpg

The HRSV in a TEM image

Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Phylum : Negarnaviricota
Subphylum : Haploviricotina
Class : Monjiviricetes
Order : Mononegavirals
Family : Pneumoviridae
Genre : Orthopneumovirus
Type : Human Respiratory Syncytial Virus
Taxonomic characteristics
Genome : (-) ssRNA linear
Baltimore : Group 5
Symmetry : helical
Cover : available
Scientific name
Human orthopneumovirus
Short name
HRSV
Left

The Human Respiratory Syncytial Virus ( HRSV or RSV ; English: Human orthopneumovirus , formerly: Human Respiratory Syncytial Virus ) is an enveloped virus with single-stranded minus RNA from the family of Pneumoviridae (formerly family Paramyxoviridae , subfamily Pneumovirinae and the genus Orthopneumovirus ).

The species occurs in the two most common subtypes A and B and the rarer types S2 and RSS-2. It is closely related to two animal pathogenic species, the bovine respiratory syncytial virus (BRSV, English: Bovine orthopneumovirus ) and the murine pneumonia virus (MPV, English: Murine orthopneumovirus ).

It was first described in 1956 in chimpanzees in which RSV was recognized as the cause of Coryza .

The virus attacks the respiratory tract , especially the mucous membranes of the upper respiratory tract and the ciliated epithelium of the trachea and bronchi . Among other things, it causes the affected cells to fuse to form syncytia , which is what gave the virus its name.

transmission

Human respiratory syncytial viruses are mostly transmitted via smear infections and droplet infections and cause symptoms in the upper respiratory tract: runny nose ( rhinitis , cold ), cough , acute bronchitis , otitis media . The incubation period is two to eight days.

Diagnosis

The virus can be detected using ELISA or using the polymerase chain reaction (PCR).

Forms of disease

The infection of calves with bovine respiratory syncytial virus (BRSV) has a similar course to the infection of HRSV in small children and is therefore used for model studies for the development of vaccines and therapeutic agents .

Infants and young children

An RSV infection in infants manifests itself with symptoms such as a fever of 38 to 39.5 ° C, runny nose, cough and difficulty breathing . The impaired breathing makes drinking difficult and the patient often shows weak drinking.

Due to the narrow and short airways, the bronchi and bronchioles are often affected - bronchiolitis can occur, which can hinder the uptake of oxygen. Signs of insufficient oxygen saturation in the blood are paleness, bluish discoloration of the lips or fingernails ( cyanosis ), indentations below the costal arch (subcostal) and between the ribs ( intercostal ) and faster breathing ( tachypnea ) with nostrils. Dehydration is also considered to be a sign of a serious condition.

In small children and especially in infants, there are often more severe courses that may require in-patient treatment in the hospital, especially in the case of infants.

In the hospital, the patient is constantly monitored so that action can be taken immediately if the condition worsens. Oxygen saturation and the amount of water you drink are the most important indicators. If necessary, the ECG and respiratory rate are also monitored. If oxygen saturation is insufficient, oxygen is given, in severe cases with pressure ventilation . If the patient does not drink enough, the use of a gastric tube may be necessary to prevent dehydration.

During the first year of life 40–70% and by the end of the second year almost all children had the disease once. This does not protect against renewed infection, but the course of the disease is less severe than with the first infection.

About 2% of the initial infections are so severe that they are hospitalized . In hospitalized cases, the mortality is around 1.7%. In England, the course of the disease was tracked in 2009 children hospitalized for RSV infection, 35 of whom ultimately died. Pre-existing diseases and nosocomial infections with RSV were identified as risk factors for a particularly severe course with a fatal outcome .

In the course of the disease, pseudocroup develops in 5% of the sick children .

Infection with RSV is considered a risk factor for sudden infant death syndrome (SIDS) in infants .

A disease that has been overcome does not generate lasting immunity ; re-infections can occur for life, which are mild in healthy people.

Complications

The infection can be acute, especially if a bacterial superinfection occurs. In such severe cases, intensive care monitoring may be necessary.

RSV infections can overlap with waves of influenza. Calculations from the USA suggest significantly more deaths from influenza , the excess mortality from influenza would be three times as high as that from RSV.

An estimated 600,000 people worldwide die each year, directly or indirectly, from RSV infections.

prevention

For infants and children at high risk, there is the option of passive immunization with the monoclonal antibody palivizumab , which is only reserved for special risk cases for reasons of cost. This immunization also only provides protection for a few weeks and must therefore be repeated monthly during the HRSV season (October / November to March / April).

Vaccination with attenuated or killed viruses is currently not possible. According to reports in 2013, US researchers developed a vaccine that achieved a high level of protection in animal experiments. Clinical studies of the vaccine in humans have been ongoing since 2015 .

research

In 2014, Gilead Sciences developed an oral RSV entry inhibitor (former name: GS-5806), which showed a significant reduction in virus levels and disease severity in a double-blind placebo- controlled exposure study on 140 healthy adult volunteers.

See also

literature

Web links

Individual evidence

  1. ICTV Master Species List 2018b.v2 . MSL # 34, March 2019
  2. a b ICTV: ICTV Taxonomy history: Akabane orthobunyavirus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  3. Blount RE Jr., J. A Morris, R. E Savage: Recovery of cytopathogenic agent from cimpanzees with coryza. In: Proceedings of the Society for Experimental Biology and Medicine. (Proc Soc Exp Biol Med) July 1956, Vol. 92, No. 3, pp. 544-549.
  4. RS Virus - Research Approaches In: Lung Information Service of the Helmholtz Zentrum München , September 28, 2016, accessed on February 15, 2019.
  5. RKI -Ratgeber für Ärzte: Respiratory syncytial virus infections (RSV), section incubation time .
  6. Robert Koch Institute: Respiratory syncytial virus infections: RKI advice for doctors . In: Epidemiological Bulletin . No. 19, 2011; First published: 03/2004.
  7. ^ Rüdiger Dörries, Herbert Hof: Dual series of medical microbiology. 4. completely revised. and exp. Edition. Thieme, Stuttgart / New York (NY) 2009, ISBN 978-3-13-125314-9 .
  8. ^ Christian P. Speer, Manfred Gahr: Pediatrics. 2nd Edition. Springer, Heidelberg / Berlin 2005, ISBN 3-540-20791-0 .
  9. a b K. Thorburn: Pre-existing disease is associated with a significantly higher risk of death in severe respiratory syncytial virus infection. In: Archives of Disease in Childhood . 2009, Vol. 94, No. 2, pp. 99-103, PMID 18653625 .
  10. Respiratory Syncytial Virus. In: Pschyrembel. 262nd edition. De Gruyter, Berlin / Boston, Mass. 2010, ISBN 978-3-11-021152-8 .
  11. Pediatrics. In: Hanns Ackermann: ALLEX - everything for the exam: the compendium for the 2nd EP. Volume B: Clinical Subjects. Thieme, Stuttgart / New York (NY) 2012, p. 590.
  12. W. Thompson, DK Shay, E. Weintraub, L. Brammer, N. Cox, L. Anderson, K. Fukuda: Mortality associated with influenza and respiratory syncytial virus in the United States. In: Journal of the American Medical Association . (JAMA) 2003, Vol. 289, No. 2, pp. 179-186, doi : 10.1001 / jama.289.2.179 .
  13. rme / aerzteblatt.de: RS virus: First vaccine in animal experiment successful. In: aerzteblatt.de . November 4, 2013, accessed March 11, 2015 .
  14. RS virus: Strong immune response from new experimental vaccine - Lung Information Service. Retrieved July 3, 2020 .
  15. John P. DeVincenzo, Richard J. Whitley, Richard L. Mackman, et al .: Oral GS-5806 Activity in a Respiratory Syncytial Virus Challenge Study. In: New England Journal of Medicine . 2014, Volume 371, Edition 8 of August 21, 2014, pp. 711-722; doi : 10.1056 / NEJMoa1401184 .