**7. Treatment**

Antiviral drugs have been developed targeting viral proteins that can be inhibited by small molecular receptors or larger biotherapeutics. Consequently, most approved antiviral drugs are highly specific for a particular virus or family of viruses (e.g., neuraminidase inhibitors and adamantanes for influenza). The benefits of this approach are that there is greater selectivity and may lower the risk of adverse host effects. The disadvantages are that there is a limited antiviral spectrum, and greater risk of antiviral resistance [72].

Treatment of Influenza Virus Neuraminidase, is essential interrupting intercellular viral propagation. Selective inhibitors, e.g., oseltamivir, peramivir, and zanamivir have been used to prevent infection during the first 24–72 hours, improving clinical symptoms and reducing morbidity and mortality. Reductions in the incidence of pneumonia in patients has been observed in numerous studies who received treatment in the early stages of infection [73].

**Virus family**

Adenoviridae

Coronaviridae

Bunyaviridae

Herpesviridae

Herpes simplex virus 1 (HSV-1) herpes simplex

virus 2 (HSV-2), herpesvirus 6, herpesvirus 7,

and herpesvirus 8 Varicella-zoster virus (VZV),

Cytomegalovirus (CMV), Epstein-Barr virus

(EBV)

Orthomyxoviridae

Papovaviridae

Paramyxoviridae

Picornaviridae

rhinovirus

(Picornaviruses)—enteroviruses,

20–30 nm nonenvelope cubic

Pleconaril

> symmetry RNApositive strand

coxsackievirus, echovirus, enterovirus 71,

(Paramyxoviruses)—parainfluenza virus,

respiratory syncytial virus (RSV), human

metapneumovirus (hMPV), measles virus

(Polyomavirus)—JC virus, BK virus

H1N1

(Orthomyxoviruses)—Influenza A,B virus,

200–300 nm enveloped

Oseltamivir, peramivir,

Influenza vaccine

End of

autumn and

winter

chemoprophylaxis

zanamivir, amantadine,

and rimantadine

pleomorphic RNA

single stranded

18–28 nm nonenvelope Icosahedral

Limited treatments,

Vaccines, e.g., Gardasil,

All year

Cervarix

surgical removal

DNA single strand

150–200 nm,

Ribavirin protease inhibitors

Preventive measures,

End of

autumn,

beginning of

winter

http://dx.doi.org/10.5772/intechopen.71608

measles vaccination

for immune serum

immunoglobulin

Alfa interferon

All year

Pneumonia of Viral Etiologies

203

(intranasal)

(e.g., lopinavir/ritonavir)

Ribavirin

enveloped helical

symmetry RNAnegative strand

(Arboviruses)—Hantavirus

(Coronaviruses)—SARS, MERS

75–160 nm, envelope,

Supportive therapy

Preventive measures,

Winter

e.g., hand hygiene

helical, nucleocapsid,

ssRNA (positive sense)

90–100 nm, envelope

Supportive therapy

Preventive measures,

Widespread,

all year

e.g., limit vector

breeding

spherical virions.

RNA- single stranded

130-300 nm,

Acyclovir, ganciclovir, and

V-Z immunoglobulin

All year

Intravenous

immunoglobulin

Vaccine

enveloped, doublestranded DNA

foscarnet

Adenoviruses

 **Virus**

**Morphology** 90–100 nm, nonenvelope, icosahedral nucleocapsid, doublestranded DNA

**Treatment** Cidofovir and brincidofovir

Hand hygiene, oral

All year

vaccine for military

recruits

**Prevention**

**Seasonality**


**6. Laboratory testing**

202 Contemporary Topics of Pneumonia

assay [70].

**7. Treatment**

protracted nucleic acid excretion [71].

Laboratory diagnosis of viral pneumonia has relied on detection of virus or viral antigen in upper-respiratory specimens (e.g., nasopharyngeal aspirates) and lower respiratory samples

Traditional microbiological methods for detection of respiratory tract pathogens are relatively slow, often are not sensitive and are influenced by previous antibiotic therapy. Molecular diagnostics on the other hand hold much potential for detection of both common and atypical pathogens causing CAP. Analysis can be completed in hours, rather than days, for detection

There are >200 known respiratory viruses, but accurate data on how many are etiological agents in CAP are lacking. The discovery of 6 new respiratory viruses since 2000—including metapneumovirus (hMPV), the severe acute respiratory syndrome coronavirus, influenza virus strain H5N1, coronavirus strains NL63 and Hku1, and human bocavirus—has pre

sented new challenges for comprehensive viral diagnostics [69]. The significance of respira

tory viral infections in patients with sepsis is underestimated. During the winter season, viral such as coronavirus, influenza A virus, human metapneumovirus, and respiratory syn

cytial virus are clinically underdiagnosed in 70% of patients detected by the multiplex PCR

Quantitative multiplex PCR testing of respiratory secretions is recognized as a highly sensi

tive method for the diagnosis with the ability to detect viral pathogens and atypical bacterial pathogens. An acute viral infection can be confirmed with detection of influenza virus, para

influenza virus, RSV, or hMPV. The presence of nucleic acid from adenoviruses, bocaviruses, coronaviruses or rhinoviruses is often found in asymptomatic persons. In the future the study of the virus concentration over time will contribute to distinguishing acute infections from

Antiviral drugs have been developed targeting viral proteins that can be inhibited by small molecular receptors or larger biotherapeutics. Consequently, most approved antiviral drugs are highly specific for a particular virus or family of viruses (e.g., neuraminidase inhibitors and adamantanes for influenza). The benefits of this approach are that there is greater selec

tivity and may lower the risk of adverse host effects. The disadvantages are that there is a

Treatment of Influenza Virus Neuraminidase, is essential interrupting intercellular viral propagation. Selective inhibitors, e.g., oseltamivir, peramivir, and zanamivir have been used to prevent infection during the first 24–72 hours, improving clinical symptoms and reduc

ing morbidity and mortality. Reductions in the incidence of pneumonia in patients has been observed in numerous studies who received treatment in the early stages of infection [73].

limited antiviral spectrum, and greater risk of antiviral resistance [72].








(e.g., induced sputum) by culture or immunofluorescence microscopy.

of typical pathogens and weeks for detection of atypical pathogens [68].


Laninamivir octanoate, a new neuraminidase inhibitor administered by inhalation, can be effective in the treatment of IV infection, including oseltamivir-resistant strains. They are exclusively specific to influenza virus type A. However, side effects and rapid development of resistances, has meant that they have fallen into disuse. Immunomodulators are also being

Ribavirin has shown effectiveness in the management of acute episodes of pneumonia or for improving respiratory parameters during recovery. Meta-analysis studies performed in chil

dren, indicated that inhaled ribavirin can reduce hospital stay and time on ventilator times during pneumonia, however, the overall mortality rates are not affected. Ribavirin has also been used in severely immunocompromised patients, e.g., lung transplant recipients with positive outcomes. General use of bronchodilators, antibiotics, or corticosteroids are not rec

Acyclovir (Zovirax), inhibits viral DNA synthesis by competitively binding to viral DNA poly

is currently the treatment of choice for HSV pneumonia. The dosage of acyclovir should be decreased in patients with underlying renal insufficiency. Adverse reactions are infrequent, but renal impairment secondary to precipitation of acyclovir in the tubules can occur in 5–10% of patients if not properly rehydrated. Having a proven HSV pneumonia appears to be associ

ated with high morbidity in solid tumor patients. This group of patients have been shown to benefit from acyclovir therapy [76]. There is little doubt that intravenous acyclovir is beneficial

Supportive treatment was only available for other respiratory viruses until recently, However, some antiviral drugs are currently under investigation. Cidofovir is an acyclic nucleoside phosphonate analog of cytidine monophosphate. Upon conversion to its diphosphate form it leads to viral DNA chain termination. Limitations of cidofovir include poor cellular uptake and nephrotoxicity. Brincidofovir, a derivative of cidofovir which is active against doublestranded DNA viruses, is a major improvement in anti-adenovirus therapy [77]. Lung transplant recipients with metapneumovirus infections have been treated with success using intravenous ribavirin. Rhinovirus and Enterovirus, have been successfully used in limited


205





every 8 hours

2

Pneumonia of Viral Etiologies

http://dx.doi.org/10.5772/intechopen.71608

studied for reducing viral-mediated inflammation and its effect on the host [74].

ommended in the American pediatric guidelines for SRV bronchiolitis [75].

merase. Due to poor absorption, intravenous acyclovir at a dosage of 250 mg/m

in the rare cases of varicella-zoster pneumonia in immunocompromised patients.

studies using Pleconaril, which is incorporated into the virus capsid (**Table 1**) [78].

Measures in infectious infection control, particularly of the respiratory tract, involve using bar

rier methods preventing infection. Use of gloves, masks and hand-washing have been shown to be effective in reducing transmission rates in the health care centers. Isolation of patients during the clinical phase of the disease is also strongly recommended and reduces overall incidence. Immunization plays a very important role in prevention, but is only available for a few viruses. As the population ages and rates of pneumonia increase. Hospitalizations for pneumonia will continue to show an upward trend unless effective intervention strategies are devised and implemented. This includes recommending immunization with PPV and annual

**8. Prevention**

Laninamivir octanoate, a new neuraminidase inhibitor administered by inhalation, can be effective in the treatment of IV infection, including oseltamivir-resistant strains. They are exclusively specific to influenza virus type A. However, side effects and rapid development of resistances, has meant that they have fallen into disuse. Immunomodulators are also being studied for reducing viral-mediated inflammation and its effect on the host [74].

Ribavirin has shown effectiveness in the management of acute episodes of pneumonia or for improving respiratory parameters during recovery. Meta-analysis studies performed in children, indicated that inhaled ribavirin can reduce hospital stay and time on ventilator times during pneumonia, however, the overall mortality rates are not affected. Ribavirin has also been used in severely immunocompromised patients, e.g., lung transplant recipients with positive outcomes. General use of bronchodilators, antibiotics, or corticosteroids are not recommended in the American pediatric guidelines for SRV bronchiolitis [75].

Acyclovir (Zovirax), inhibits viral DNA synthesis by competitively binding to viral DNA polymerase. Due to poor absorption, intravenous acyclovir at a dosage of 250 mg/m<sup>2</sup> every 8 hours is currently the treatment of choice for HSV pneumonia. The dosage of acyclovir should be decreased in patients with underlying renal insufficiency. Adverse reactions are infrequent, but renal impairment secondary to precipitation of acyclovir in the tubules can occur in 5–10% of patients if not properly rehydrated. Having a proven HSV pneumonia appears to be associated with high morbidity in solid tumor patients. This group of patients have been shown to benefit from acyclovir therapy [76]. There is little doubt that intravenous acyclovir is beneficial in the rare cases of varicella-zoster pneumonia in immunocompromised patients.

Supportive treatment was only available for other respiratory viruses until recently, However, some antiviral drugs are currently under investigation. Cidofovir is an acyclic nucleoside phosphonate analog of cytidine monophosphate. Upon conversion to its diphosphate form it leads to viral DNA chain termination. Limitations of cidofovir include poor cellular uptake and nephrotoxicity. Brincidofovir, a derivative of cidofovir which is active against doublestranded DNA viruses, is a major improvement in anti-adenovirus therapy [77]. Lung transplant recipients with metapneumovirus infections have been treated with success using intravenous ribavirin. Rhinovirus and Enterovirus, have been successfully used in limited studies using Pleconaril, which is incorporated into the virus capsid (**Table 1**) [78].
