Viral pneumonia: Difference between revisions

'''Viral pneumonia''' is a [[pneumonia]] caused by a [[virus]] . Pneumonia is an infection that causes inflammation in one or both of the lungs. The [[Pulmonary alveolus|pulmonary alveoli]] fill with fluid or pus making it difficult to breathe.<ref name=":2">{{Cite web|title=Pneumonia {{!}} NHLBI, NIH|url=https://www.nhlbi.nih.gov/health-topics/pneumonia|access-date=2020-11-30|website=www.nhlbi.nih.gov}}</ref> Pneumonia can be caused by [[Bacterial pneumonia|bacteria]], viruses, fungi, or parasites.<ref name=":2" /> Viruses are the most common cause of pneumonia in children, while in adults bacteria are a more common cause.<ref name=":0">{{Cite journal|last1=Ruuskanen|first1=Olli|last2=Lahti|first2=Elina|last3=Jennings|first3=Lance C|last4=Murdoch|first4=David R|date=2011-04-09|title=Viral pneumonia|url=http://www.sciencedirect.com/science/article/pii/S0140673610614596 |journal=The Lancet|language=en|volume=377|issue=9773|pages=1264–1275|doi=10.1016/S0140-6736(10)61459-6|pmid=21435708|pmc=7138033|issn=0140-6736}}</ref>

[[Symptom]]s of viral pneumonia include [[fever]], non-productive [[cough]], [[runny nose]], chest pain and systemic symptoms (e.g. [[myalgia]], [[headache]]). Different viruses cause different symptoms.

Diagnosis, like with any infection, relies on the detection of the infectious cause. With viral pneumonia, samples are taken from the upper and/or lower respiratory tracts.<ref name=":02">{{Cite journal|last1=Ruuskanen|first1=Olli|last2=Lahti|first2=Elina|last3=Jennings|first3=Lance C|last4=Murdoch|first4=David R|date=2011-04-09|title=Viral pneumonia|url=http://www.sciencedirect.com/science/article/pii/S0140673610614596 |journal=The Lancet|language=en|volume=377|issue=9773|pages=1264–1275|doi=10.1016/S0140-6736(10)61459-6|pmid=21435708|pmc=7138033|issn=0140-6736}}</ref> The samples can then be run through [[polymerase chain reaction]] (PCR), allowing for amplification of the virus as that allows better detection if present in the sample.<ref name=":22">{{Cite web|title=Pneumonia {{!}} NHLBI, NIH|url=https://www.nhlbi.nih.gov/health-topics/pneumonia|access-date=2020-11-30|website=www.nhlbi.nih.gov}}</ref> Other ways for a diagnosis to be obtained is by ordering a [[Chest radiograph|chest x-ray]], blood tests, [[pulse oximetry]], and a medical/family history to see if there are any known risks or previous exposures to a person with viral pneumonia.<ref name=":22" /> If the person is in serious condition and in the hospital there are more invasive studies that can be run to diagnosisdiagnose the person.<ref name=":22" />

* ''[[Hantavirus]]es''<ref>{{cite journal |first1=Thomas V. |last1=Colby |first2=Sherif R. |last2=Zaki |first3=Richard M. |last3=Feddersen |first4=Kurt B. |last4=Nolte |year=2000 |title=Hantavirus Pulmonary Syndrome Is Distinguishable From Acute Interstitial Pneumonia |journal=Archives of Pathology & Laboratory Medicine |date=October 2000 |volume=124 |issue=10 |pages=1463–1466 |pmid=11035576 |doi=10.10435858/00032000-9985(2000)124<-1463:-HPSIDF>2.0.CO;2 |doi-broken-date=2021-01-11 |url=https://www.archivesofpathology.org/doi/full/10.1043/0003-9985%282000%29124%3C1463%3AHPSIDF%3E2.0.CO%3B2 }}</ref>

Viral pneumonia was first described by [[Hobart Reimann]] in 19381984, in an article published by [[JAMA (journal)|JAMA]], ''An Acute Infection of the Respiratory Tract with Atypical Pneumonia: a disease entity probably caused by a filtrable virus.'' Reimann, Chairman of the Department of Medicine at [[Thomas Jefferson University|Jefferson Medical College]], had established the practice of routinely typing the pneumoccocalpneumococcal organism in cases where pneumonia presented. Out of this work, the distinction between viral and bacterial strains was noticed.<ref>{{Cite web|url=https://jdc.jefferson.edu/cgi/viewcontent.cgi?article=1009&context=wagner2|title=Thomas Jefferson University: Tradition and Heritage|last=John H|first=Hodges MD|date=1989|editor-last=Wagner, MD|editor-first=Frederick B|website=Jefferson Digital Commons|series=Part III, Chapter 9: Department of Medicine|page=253|publication-date=1989}}</ref>

The best prevention against viral pneumonia is vaccination against [[Influenza vaccines|influenza]], [[Varicella vaccine|chickenpox (varicella zoster)]], [[Zoster vaccine|herpes zoster]], [[Measles vaccine|measles]], [[respiratory syncytial virus vaccine]] (RSV), [[rubella]], and [[Adenovirus vaccine|adenovirus]] vaccine. <ref name=":03">{{Cite journal|last1=Ruuskanen|first1=Olli|last2=Lahti|first2=Elina|last3=Jennings|first3=Lance C|last4=Murdoch|first4=David R|date=2011-04-09|title=Viral pneumonia|url=http://www.sciencedirect.com/science/article/pii/S0140673610614596 |journal=The Lancet|language=en|volume=377|issue=9773|pages=1264–1275|doi=10.1016/S0140-6736(10)61459-6|pmid=21435708|pmc=7138033|issn=0140-6736}}</ref><ref name=":12">{{Citation|last1=Freeman|first1=Andrew M.|title=Viral Pneumonia|date=2020|url=http://www.ncbi.nlm.nih.gov/books/NBK513286/|work=StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=30020658|access-date=2020-11-11|last2=Leigh|first2=Jr}}</ref> Besides vaccination there are no other ways to prevent viral pneumonia besides basic hygiene skills like covering the mouth when coughing or sneezing, staying home when sick, and washing your hands frequently.

In cases of viral pneumonia where influenza A or B are thought to be causative agents, patients who are seen within 48 hours of symptom onset may benefit from treatment with [[oseltamivir]], or [[zanamivir]], or [[peramivir]]. <ref name=":1">{{Citation|last1=Freeman|first1=Andrew M.|title=Viral Pneumonia|date=2020|url=http://www.ncbi.nlm.nih.gov/books/NBK513286/|work=StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=30020658|access-date=2020-11-11|last2=Leigh|first2=Jr}}</ref> [[Human respiratory syncytial virus|Respiratory syncytial virus]] (RSV) has no direct acting treatments, but [[ribavirin]] is indicated for severe cases.<ref name=":1" /> [[Ribavirin]] has also been known to be used as a treatment for [[Human parainfluenza viruses|Parainfluenzaparainfluenza Virusvirus]], and [[Adenoviridae|Adenovirusadenovirus]].<ref name=":1" /> [[Herpes simplex virus]] and [[varicella-zoster virus]] infections are usually treated with [[Aciclovir|acyclovir]], whilst [[ganciclovir]] is used to treat [[cytomegalovirus]].<ref name=":1" /> There is no known efficacious treatment for pneumonia caused by [[SARS|SARS coronavirus]], [[MERS|MERS coronavirus]], or [[hantavirus]]. Other forms of care are largely supportive like oxygen supplementation, treatment of comorbidities, and controlling other symptoms, fever and cough, with medications.<ref name=":1" />

There are roughly 450 million cases of pneumonia every year. Of those case, viral pneumonia counts for about 200 million cases which includes about 100 million children and 100 million adults. <ref name=":04">{{Cite journal|last1=Ruuskanen|first1=Olli|last2=Lahti|first2=Elina|last3=Jennings|first3=Lance C|last4=Murdoch|first4=David R|date=2011-04-09|title=Viral pneumonia|url=http://www.sciencedirect.com/science/article/pii/S0140673610614596 |journal=The Lancet|language=en|volume=377|issue=9773|pages=1264–1275|doi=10.1016/S0140-6736(10)61459-6|pmid=21435708|pmc=7138033|issn=0140-6736}}</ref> Viral pneumonia is more prevalent in the very young, less than 5 years old, and in the very old, more than 75 years old. <ref name=":04" /> Developing countries have a higher rate of incidence when it comes to viral pneumonia. On average, developing countries have an incidence rate five times higher than that of developed countries. <ref name=":04" /> Being pregnant can also affect the chances of developing viral pneumonia. <ref name=":13">{{Citation|last1=Freeman|first1=Andrew M.|title=Viral Pneumonia|date=2020|url=http://www.ncbi.nlm.nih.gov/books/NBK513286/|work=StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|pmid=30020658|access-date=2020-11-11|last2=Leigh|first2=Jr}}</ref> As with all infectious diseases, viral pneumonia preys on the immunocompromised as well as individuals with one or more comorbidities especially those with: