Treatment with acyclovir of varicella pneumonia in pregnancy

Influenza and Viral Pneumonia

Influenza and other respiratory viruses are commonly identified in patients with community-acquired pneumonia, hospital-acquired pneumonia, and in immunocompromised patients with pneumonia. Clinically, it is difficult to differentiate viral from bacterial pneumonia. Similarly, the radiological findings of viral infection are in general nonspecific. The advent of polymerase chain reaction testing has enormously facilitated the identification of respiratory viruses, which has important implications for infection control measures and treatment. Currently, treatment options for patients with viral infection are limited but there is ongoing research on the development and clinical testing of new treatment regimens and strategies.

Influenza and Viral Pneumonia

Influenza and other respiratory viruses are commonly identified in patients with community-acquired pneumonia, hospital-acquired pneumonia, and in immunocompromised patients with pneumonia. Clinically, it is difficult to differentiate viral from bacterial pneumonia. Similarly, the radiological findings of viral infection are nonspecific. The advent of polymerase chain reaction testing has enormously facilitated the identification of respiratory viruses, which has important implications for infection control measures and treatment. Currently, treatment options for patients with viral infection are limited, but there is ongoing research on the development and clinical testing of new treatment regimens and strategies.

Microbiology laboratory and the management of mother-child varicella-zoster virus infection

Varicella-zoster virus, which is responsible for varicella (chickenpox) and herpes zoster (shingles), is ubiquitous and causes an acute infection among children, especially those aged less than six years. As 90% of adults have had varicella in childhood, it is unusual to encounter an infected pregnant woman but, if the disease does appear, it can lead to complications for both the mother and fetus or newborn. The major maternal complications include pneumonia, which can lead to death if not treated. If the virus passes to the fetus, congenital varicella syndrome, neonatal varicella (particularly serious if maternal rash appears in the days immediately before or after childbirth) or herpes zoster in the early years of life may occur depending on the time of infection. A Microbiology laboratory can help in the diagnosis and management of mother-child infection at four main times: (1) when a pregnant woman has been exposed to varicella or herpes zoster, a prompt search for specific antibodies can determine whether she is susceptible to, or protected against infection; (2) when a pregnant woman develops clinical symptoms consistent with varicella, the diagnosis is usually clinical, but a laboratory can be crucial if the symptoms are doubtful or otherwise unclear (atypical patterns in immunocompromised subjects, patients with post-vaccination varicella, or subjects who have received immunoglobulins), or if there is a need for a differential diagnosis between varicella and other types of dermatoses with vesicle formation; (3) when a prenatal diagnosis of uterine infection is required in order to detect cases of congenital varicella syndrome after the onset of varicella in the mother; and (4) when the baby is born and it is necessary to confirm a diagnosis of varicella (and its complications), make a differential diagnosis between varicella and other diseases with similar symptoms, or confirm a causal relationship between maternal varicella and malformations in a newborn.

Acute respiratory failure in pregnancy

Respiratory failure affects up to 0.2% of pregnancies, more commonly in the postpartum period. Altered maternal respiratory physiology affects the assessment and management of these patients. Respiratory failure may result from pregnancy-specific conditions such as preeclampsia, amniotic fluid embolism or peripartum cardiomyopathy. Pregnancy may increase the risk or severity of other conditions, including thromboembolism, asthma, viral pneumonitis, and gastric acid aspiration. Management during pregnancy is similar to the nonpregnant patient. Endotracheal intubation in pregnancy carries an increased risk, due to airway edema and rapid oxygen desaturation following apnea. Few data are available to direct prolonged mechanical ventilation in pregnancy. Chest wall compliance is reduced, perhaps permitting slightly higher airway pressures. Optimizing oxygenation is important, but data on the use of permissive hypercapnia are limited. Delivery of the fetus does not always improve maternal respiratory function, but should be considered if benefit to the fetus is anticipated.

Respiratory disease in pregnancy

Many physiological and anatomical changes of pregnancy affect the respiratory system. These changes often affect the presentation and management of the various respiratory illnesses in pregnancy. This article focuses on several important respiratory issues in pregnancy. The management of asthma, one of the most common chronic illnesses in pregnancy, remains largely unchanged compared to the nonpregnant state. Infectious respiratory illness, including pneumonia and tuberculosis, are similarly managed in pregnancy with antibiotics, although special attention may be needed for antibiotic choices with more pregnancy safety data. When mechanical ventilation is necessary, consideration should be given to the maternal hemodynamics of pregnancy and fetal oxygenation. Maintaining maternal oxygen saturation above 95% is recommended to sustain optimal fetal oxygenation. Cigarette smoking has known risks in pregnancy, and current practice guidelines recommend offering cognitive and pharmacologic interventions to pregnant women to assist in smoking cessation.

Pulmonary Disorders in Pregnancy

Pregnancy is associated with some profound changes in the cardiovascular, respiratory, immune, and hematologic systems that impact the clinical presentation of respiratory disorders, their implications in pregnancy, and the decisions to treat. In addition, concerns for fetal well-being and safety of various interventions complicate the management of these disorders. In many circumstances, especially life-threatening ones, decisions are based upon a careful assessment of the risk benefit ratio rather than absolute safety of drugs and interventions. In this chapter, we review some of the common respiratory disorders that internists or obstetricians may be called upon to manage.

Clinical focus: infections in pregnancy

Pregnant women are particularly susceptible to a number of infectious diseases, such as influenza, hepatitis E, malaria, and tuberculosis. The management of many other infections-including urinary tract infections, human immunodeficiency virus, and sexually transmitted diseases-is also made more complex by pregnancy; even if some infections do not pose a great risk to the expectant mother, they can impact fetal and neonatal development, thus posing a treatment challenge to physicians. By focusing on the most important diseases that physicians may encounter in pregnant patients, this review outlines the challenges associated with managing important infectious diseases in the pregnant population and references the most recent evidence and international treatment guidelines.

Varicella pneumonia complicating pregnancy: a report of seven cases

Background: Pneumonia is the most common complication of varicella-zoster infection in adults and has potentially devastating effects when complicating pregnancy. Due to the significant morbidity and mortality associated with this complication during pregnancy and the small number of reported cases in the literature, we present this report to help educate physicians who care for pregnant women.

Cases: Seven patients are presented in this report. These patients presented at various stages in pregnancy, from 17 to 31 weeks of gestation. Three of the patients had unremarkable hospital courses. Three of the patients had hospital stays over 21 days in duration. One patient died from complications of varicella pneumonia after 31 days of hospitalization. The obstetric outcomes of the 7 patients described include 1 non-viable delivery at 20 weeks gestation, 3 term deliveries, 2 preterm deliveries, and 1 patient who has not yet delivered. All of the patients presented were treated with intravenous acyclovir therapy. Of the patients described, 3 required intubation and ventilatory support. Other complications encountered include disseminated intravascular coagulation (DIC), adult respiratory distress syndrome (ARDS), metabolic encephalopathy, pneumothorax, superimposed bacterial pneumonia, and sepsis.

Conclusion: The course and treatment of varicella pneumonia complicating pregnancy are discussed. Current recommendations regarding the use of varicella-zoster immune globulin (VZIG) are also reviewed.

Varicella complications: Is it time to consider a routine varicella vaccination?

Background/Aim. Varicella is a common and benign disease of childhood. Complications are rare, but in some patients, even without risk factors, severe, life threatening complications could be seen. The aim of this study was to establish the type and frequency of varicella complications among hospitalized patients over an 8-year period. Methods. This retrospective analysis included medical charts of the patients hospitalized in the Infectious Disease Clinic, Belgrade, Serbia, from 2001-2008 (4.85% of all registered patients with varicella in Belgrade, 2001-2008). Among hospitalised patients dermografic characteristics were analyzed: hospitalisation lenght, presence and type of complications, presence of immunocompromising conditions and outcome of the disease. The diagnosis of varicella was made on clinical grounds, and in persons > 40 years, with negative epidemiological data of contacts, serological confirmation (ELISA VZV IgM/IgG BioRad?) and avidity of IgG antibodies were done to exclude the possibility of disseminated herpes zoster. Results. A total of 474 patient were hospitalized over an 8-year period. The age of patients was from 5 months to 75 years (mean 22.4 ? 16.1, median 23.5 years). The majority of patients were adults (n = 279; 58.9%) and 195 (41.1%) patients were ? 15 years old. Complications were found in 321/474 (67.7%) patients. The registered complications were: varicella pneumonia (n = 198; 41.38%), bacterial skin infections (n = 40; 8.4%), cerebelitis (n = 28; 5.9%), bacterial respiratory infection (n = 21; 4.4%), viral meningitis (n = 10; 2.31%), encephalitis (n = 9; 1.9%), thrombocytopenia (n = 2; 0.4%); 11 (2.3%) patients had more than one complication, among them were sepsis, myopericarditis and retinal hemorrhages. When complications were analyzed according to the age, there were no statistical significance, but when type of complication was analyzed statistical significance was found (p < 0.05). In adults, pneumonia was the most common complication: 173/279 (62%), followed by skin infections (2.9%), bacterial respiratory infections (2,2%), and more than one complication (2.3%). Pneumonia was more common in adults than in children (7 : 1). In children skin infections were the most common complications (16.4%), followed by cerebelitis (13.3%), viral pneumonia (12.8%), bacterial respiratory infections (7.7%), encephalitis (3.6%), and more than one complication (4.1%). Neuroinfections were more common in children than in adults (6:1), as well as bacterial skin infections (4 : 1). Two patients died (0,4%). Conclusion. There was no difference in the incidence of varicella complication in children and adults, but the type of complication differed. In children the most common complications were skin and neurological infections, while in adults it was varicella pneumonia. These data provide a baseline for estimating the burden of varicella in Belgrade and support the inclusion of varicella vaccine in childhood immunisation program in Serbia.

Community-acquired pneumonia in pregnancy

Community-acquired pneumonia is a common disease worldwide, with considerable morbidity and mortality. In the United States, pneumonia complicates 0.5 to 1.5 per 1,000 pregnancies. Physiologic adaptations in the respiratory and immunologic systems may increase susceptibility to pulmonary infections as well as alter their clinical course. Bacterial, viral and fungal pathogens all cause pneumonia in pregnancy, although the causative agent is identified in only 40-60% of cases. The most common single pathogen is Streptococcus pneumoniae, which is identified in 15-20% of community-acquired pneumonia cases in pregnancy. Recent recommendations by the Infectious Diseases Society of America and the American Thoracic Society on the management of community-acquired pneumonia address diagnostic techniques and management schemes for bacterial and viral pneumonias. These guidelines are discussed in the setting of the pregnant woman with community-acquired pneumonia.

Varicella vaccination in Europe: are we ready for a universal childhood programme?

Safe and effective vaccines against varicella zoster virus (VZV), the aetiological agent of varicella and shingles, have been available in Europe for the last 5-10 years. The USA has had a universal childhood vaccination policy since 1995 and this has resulted in a dramatic decrease in the incidence, morbidity and mortality related to varicella. The economic and medical burden of VZV has led to discussions regarding both the desirability and feasibility of a similar routine immunisation policy for all European children. This article examines the epidemiology of varicella in Europe and how the data emerging from the USA can be used to achieve adequate prevention of the disease. It looks into the current evidence of the health economic evaluation of universal varicella vaccination and explores the concerns surrounding such a policy, including the postulated impact on the incidence of zoster. In conclusion, the Society of Independent European Vaccination Experts (SIEVE) recommends that the immunisation of susceptible adolescents needs to be urgently implemented, in addition to the current recommendations targeting high-risk patients, their close contacts with a negative history of varicella and seronegative health-care workers. A universal policy, optimally incorporating a two-dose schedule, will be needed to finally reduce the burden of disease of varicella from a societal point of view. The SIEVE recommends the implementation of such a policy as soon as financially and practically possible.

The management of respiratory infections during pregnancy

Respiratory infections that complicate pregnancy are encountered frequently, and they encompass a broad range of disorders. Although respiratory infections usually are not seen more commonly in pregnancy, they often result in greater morbidity and mortality secondary to the physiologic adaptations that occur during pregnancy. Pregnant patients who have one of these disorders require higher level of surveillance and intervention.

Pneumonia in pregnancy

OBJECTIVE

Historically, pneumonia during pregnancy has been associated with increased morbidity and mortality compared with nonpregnant women. The goal of this article is to review current literature describing pneumonia in pregnancy. This review will identify maternal risk factors, potential complications, and prenatal outcomes associated with pneumonia and describe the contemporary management of the varied causes of pneumonia in pregnancy.

RESULTS

Coexisting maternal disease, including asthma and anemia, increase the risk of contracting pneumonia in pregnancy. Neonatal effects of pneumonia in pregnancy include low birth weight and increased risk of preterm birth, and serious maternal complications include respiratory failure. Community-acquired pneumonia is the most common form of pneumonia in pregnancy, with Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae accounting for most identified bacterial organisms. Beta-lactam and macrolide antibiotics are considered safe in pregnancy and are effective for most community-acquired pneumonia in pregnancy. Viral respiratory infections, including varicella, influenza, and severe acute respiratory syndrome, can be associated with maternal pneumonia. Current antiviral and respiratory therapies can reduce maternal morbidity and mortality from viral pneumonia. Influenza vaccination can reduce the prevalence of respiratory hospitalizations among pregnant women during influenza season. Pneumocystis pneumonia continues to carry significant maternal risk to an immunocompromised population. Prevention and treatment of Pneumocystis pneumonia with trimethoprim/sulfamethoxazole is effective in reducing this risk.

CONCLUSIONS

Prompt diagnosis and treatment with contemporary antimicrobial therapy and intensive care unit management of respiratory compromise has reduced the maternal morbidity and mortality due to pneumonia in pregnancy. Prevention with vaccination in at-risk populations may reduce the prevalence and severity of pneumonia in pregnant women.

Influenza and pneumonia in pregnancy

Influenza is a significant cause of morbidity and mortality from febrile respiratory illness worldwide. Influenza in pregnant women has historically been associated with a higher rate of morbidity and mortality. Pneumonia is the sixth leading cause of death in the United States, and it is the number one cause of death from an infectious disease. Although pregnant women do not get pneumonia more often than nonpregnant women, it can result in greater morbidity and mortality because of the physiologic adaptations of pregnancy. Pregnant patients who have either of these conditions require a higher level of surveillance and intervention.

Antiviral and antiretroviral use in pregnancy

The history of antiviral and antiretroviral therapy is recent compared with many other medical therapies, including traditional antibiotics in pregnancy. There are few long-term data on which to base decisions of management in pregnancy. Accessing up-to-date information is critical to optimizing the safety of care for mothers and their infants. Exposure to medications in pregnancy can be toxic to a fetus in a gestational age-dependent manner. Determination of safe medications for pregnancy must take into consideration the need for certain medications and the possibility of inadvertent exposure in early pregnancy because of unplanned pregnancies. This article reviews the most commonly used antiviral and antiretroviral agents and places emphasis on the issues regarding use in pregnancy.

Pharmacokinetics of intravenous acyclovir, zidovudine, and acyclovir-zidovudine in pregnant rats

The pharmacokinetics and placental transfer of acyclovir and zidovudine monotherapies and acyclovir-zidovudine combination therapy were compared in the pregnant rat. Timed-pregnancy Sprague-Dawley rats were used for the study. Doses of 60 mg of each drug/kg of body weight in monotherapy and in combination therapy were given by intravenous bolus, and samples of maternal plasma, amniotic fluid, fetal tissue, and placental tissue were collected over a period of 8 h postdose. Concentrations of each drug in the various matrices were measured by high-performance liquid chromatography. All data were analyzed by using WinNonlin. A one-compartment model with first-order elimination was used to fit the AZT plasma data from the combination therapy rats, but the plasma data from the other groups were fit to a two-compartment model. Tissue data were analyzed by noncompartmental analysis to generate area-under-the-concentration-time-curve values. Implementation of the combination therapy altered the pharmacokinetics of each drug compared to its monotherapy pharmacokinetics. The combination of these two drugs may potentiate fetal and amniotic fluid exposures to each drug.

Novel agents for the therapy of varicella-zoster virus infections

Varicella-zoster virus (VZV), a member of the herpesvirus family, is responsible for both primary (varicella or chickenpox) as well as recurrent (zoster or shingles) infections. Acyclovir has been the mainstay for treating VZV infections in both immunocompetent and immunocompromised patients. Recently, newer anti-VZV drugs, i.e., valaciclovir (the oral prodrug form of acyclovir) and famciclovir (the oral prodrug form of penciclovir) have been developed and have enlarged the therapeutic options to treat VZV infections. Both acyclovir and penciclovir are dependent on the virus-encoded thymidine kinase (TK) for their intracellular activation. Although emergence of drug-resistant strains does not occur in immunocompetent patients, several reports have documented the isolation of drug-resistant VZV strains following long-term acyclovir therapy in immunocompromised patients. Mutations at the level of the TK are responsible for development of resistance to drugs that depend on the viral TK for their phosphorylation (i.e., acyclovir and penciclovir). Foscarnet, a direct inhibitor of the viral DNA polymerase, which does not require activation by the viral TK, is the drug of choice for the treatment of TK-deficient VZV mutants emerging under acyclovir therapy. Recently, emergence of foscarnet-resistant strains has also been reported. Both TK-deficient strains and foscarnet-resistant mutants are sensitive to the acyclic nucleoside phosphonate cidofovir, CDV, HPMPC, (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine. This agent does not depend on the virus-encoded TK, but on cellular enzymes for its conversion to the diphosphoryl derivative, which then inhibits the viral DNA polymerase.

Chickenpox pneumonia: case report and literature review

The incidence of primary chickenpox infection in young adults appears to be rising in the UK and other developed countries. The infection is more severe in adults than in children and complications, including pneumonia, are more frequent. An illustrative case of severe chickenpox pneumonia in an immunocompetent, non-pregnant adult smoker is presented. The epidemiology and pathology of the disease is discussed and a review of current management in the emergency department and the intensive care unit is presented. Strategies for the prevention of chickenpox pneumonia are also discussed.

Prolonged extracorporeal life support (ECLS) for varicella pneumonia

OBJECTIVE

To review the institutional experience of a national tertiary referral center for extracorporeal life support (ECLS) in severe varicella pneumonia.

DATA SOURCES

Hospital records and ECLS flow sheets.

STUDY SELECTION

All pediatric (nonneonatal) and adult patients who were treated for varicella pneumonia with ECLS at the University of Michigan Medical Center between 1986 and 1995.

DATA EXTRACTION

Diagnosis of varicella pneumonia was made by history of recent exposure to chickenpox, progressive dyspnea, fever, a characteristic diffuse, vesicular rash, and a supporting chest roentgenogram. Indications for ECLS included a shunt fraction of > 30% or PaO2/FlO2 ratio of < 80 despite maximal conventional therapy, which included aggressive diuresis, blood transfusions to optimize oxygen-carrying capacity, pressure-controlled/inverse-ratio ventilation, and intermittent prone positioning.

DATA SYNTHESIS

Between 1986 and 1995, 191 patients were referred for ECLS. Among these patients, there were 51 (27%) cases of viral pneumonia, of which nine cases were due to acute varicella-zoster infection. Intravenous acyclovir was administered to eight of the nine patients. Of the nine patients, two patients improved using conventional ventilator management, and seven patients underwent ECLS. Overall survival on ECLS was 71% (5/7). The mean (+/-SD) alveolar-arterial oxygen gradient and PaO2/FlO2 ratio were 533 +/- 101 torr (71.3 +/- 13.5 kPa) and 67 +/- 24, respectively. The median duration of mechanical ventilation before ECLS and the subsequent duration of ECLS were 4 and 12.8 days, respectively. One of the deaths was from progressive right heart failure secondary to pulmonary hypertension and the other death was from overwhelming Pseudomonas sepsis.

CONCLUSIONS

Early recognition of imminent pulmonary failure and rapid institution of ECLS are critical in the successful management of severe, life-threatening varicella pneumonia.

Potential benefit of acyclovir for chickenpox acquired from household contacts. The Italian Acyclovir-Chickenpox Study Group

As a part of a trial of acyclovir treatment of chickenpox in otherwise healthy children, the assessment of disease features and evolution showed a significantly more severe clinical picture at onset in the 215 patients with intrafamiliar exposure to varicella, compared with the remaining 486 with community-acquired infection, although the disease course proved similar by the third day of antiviral therapy. Children with household exposure to varicella are likely to suffer from a more severe disease, and might especially benefit from acyclovir treatment.

Another vaccine, another treadmill?

OBJECTIVE

Attention is drawn to possible disadvantages arising from the introduction of universal varicella vaccination in infancy.

METHODOLOGY

Comparisons are made between universal infant varicella vaccination and the current measles immunization programme, and a review of current literature on age-specific complications of varicella and cost-benefit analyses of varicella vaccination.

RESULTS

Universal infant vaccination will cause a greater proportion of varicella cases to occur in adults, including pregnant women, who are at greater risk of serious complications compared to children. Although economic costs resulting from lost time from work will fall dramatically, health costs may rise.

CONCLUSIONS

Universal infant vaccination should only be considered if measles is first controlled, and then only if more information on duration of protection becomes available and combined measles-mumps-rubella-varicella vaccines are approved.

Severe pneumonia in pregnancy three months after resolution of cutaneous zoster

A 22 weeks pregnant women was affected by a life-threatening pneumonia and a paresis of the proximal muscles with cerebrospinal fluid pleocytosis. Her past medical history had been unremarkable except for recurrent episodes of paraumbilical herpes zoster. The clinical findings suggested a dissemination of varicella-zoster virus without skin lesions. Acyclovir was added to the therapy, and the clinical picture began to improve. Varicella-zoster virus DNA was detected in placental tissue by DNA-hybridisation analysis.

The transfer of the nucleoside analog ganciclovir across the perfused human placenta

OBJECTIVE

The purpose of this study was to compare the maternal-fetal placental transfer of the antiviral nucleoside analog ganciclovir to that of acyclovir and to investigate the mechanism of transport.

STUDY DESIGN

The ex vivo human placental cotyledon model was used. Carbon 14-labeled antipyrine was used as the reference compound to determine the clearance index of both antiviral agents. Dinitrobenzylthioinosine was used as a nucleoside transport inhibitor to help determine the transfer mechanism of each agent.

RESULTS

The clearance index for ganciclovir was 0.17 +/- 0.08 and 0.20 +/- 0.10 at 1 and 10 micrograms/ml maternal concentrations. This was similar to the clearance index for acyclovir, which was 0.17 +/- 0.06 and 0.18 +/- 0.12, respectively. The clearance index for ganciclovir was not significantly affected by the addition of 5 mumol/L dinitrobenzylthionosine to the perfusate (0.25 +/- 0.09 vs 0.20 +/- 0.05). The same was true for acyclovir (0.29 +/- 0.06 vs 0.22 +/- 0.07). When the closed system and maternal ganciclovir concentrations of 1.0, 10.0, and 100 micrograms/ml were used, the percent fetal levels compared with maternal levels at 1 hour were 17.2%, 19.2%, and 17.3%, respectively. For acyclovir the fetal levels were 15.6%, 9.1%, and 8.9% compared with maternal levels.

CONCLUSION

The antiviral agents ganciclovir and acyclovir appear to cross the placenta by simple diffusion, at least at therapeutic levels, and this transfer is not affected by the nucleoside transport inhibitor dinitrobenzylthioinosine.