Congenital Cytomegalovirus Pneumonitis and Treatment Response Evaluation Using Viral Load during Ganciclovir Therapy: a Case Report

Pulmonary Complications of Cytomegalovirus Infection in Neonates and Infants: A Systematic Review of Case Reports and Pooled Analysis

BACKGROUND

Cytomegalovirus (CMV) causes intrauterine infections in 0.67% of neonates, with 12.7% displaying symptoms at birth. CMV can lead to severe multiorgan involvement, and mortality in symptomatic cases is around 30%. Pulmonary complications are rare in infants with CMV. This review assesses pulmonary complications and outcomes in infants with CMV infection.

METHODS

A systematic literature search was conducted using PubMed, SCOPUS and Ovid SP to retrieve case reports on pulmonary complications in infants with congenital or perinatal CMV infection. Descriptive analysis and pooled analysis were conducted for the case reports.

RESULTS

A total of 28 articles with 38 patients were included in this systematic review. The reported pulmonary complications in the case reports were CMV pneumonitis (34.2%), persistent pulmonary hypertension of the newborn (18.4%), emphysema and chronic lung disease (15.8%), diaphragmatic dysfunction (13.2%), lung cysts and calcifications (10.5%), Pneumocystis jirovecii infection (7.9%), pulmonary hypoplasia (5.3%) and bronchial atresia (2.6%). Seven (18.4%) of 38 patients passed away because of the pulmonary complications of CMV infection. Congenital transmission ( P = 0.0108), maternal CMV ( P = 0.0396) and presence of neonatal comorbidities ( P = 0.0398) were independent risk factors for mortality.

CONCLUSIONS

This systematic review demonstrated infrequent occurrence of severe pulmonary involvement in CMV infection but should be considered in infants with persistent or severe respiratory symptoms.

Cytomegalovirus pneumonitis in infants: The challenge in diagnosis among pediatricians

Cytomegalovirus (CMV) pneumonitis infections might present mild or severe illnesses and need sophisticated diagnostic tools, so it remains a diagnostic challenge. We reported five infants diagnosed with CMV pneumonitis who were initially and undiagnosed by the pediatrician in secondary private or public health hospitals with no improvement with standard and escalation of antibiotics treatment for bronchopneumonia as the initial diagnoses. As all cases occurred during the COVID-19 pandemic, they proved negative COVID-19 identified by polymerase chain reaction (PCR) SARS-CoV-2. We diagnosed acquired perinatal pneumonitis CMV in all claims based on clinical criteria, imaging studies, CMV serology, and PCR-CMV urinary tests as diagnostic tools. They showed clinical improvement after two weeks of valganciclovir therapy. Other organs' involvement was considered to be evaluated, including brain-evoked response audiometry (BERA) and eye examination. The physician should consider the possibility of CMV pneumonitis, who did not respond to standard and escalation of antibiotics treatment after initial diagnoses of bronchopneumonia.

Severe herpes virus 6 interstitial pneumonia in an infant with three variants in genes predisposing to lung disease

Infections due to human herpesvirus 6 (HHV-6) are frequent during early childhood. Usually, they have a favorable clinical course. Conversely, HHV-6 congenital infections occur in about 1% of neonates and may present with more severe clinical pictures. HHV-6 can be found in lung tissues and bronchoalveolar lavage (BAL) samples from patients with pneumonia and in immunocompromised patients can cause mild to severe pneumonia. In neonates, the role of HHV-6 in the genesis of severe pneumonia is poorly defined still now. We describe a healthy infant with a late-onset (15 days of life) severe interstitial pneumonia and heavy HHV-6 genome load, persistently detected in its BAL fluid. The baby underwent high-frequency oscillatory ventilation, hydroxychloroquine, steroids, and ganciclovir for 6 weeks and at 9 months she died. Next-generation sequencing of genes known to cause neonatal respiratory insufficiency revealed the presence of a "probably pathogenetic" heterozygous variant in the autosomal recessive DRC1 gene, a heterozygous variant of unknown significance (VUS) in the autosomal recessive RSPH9 gene, and a heterozygous VUS in the autosomal recessive MUC5B gene. HHV-6 infection should be considered in the differential diagnosis of late-onset severe respiratory distress in neonates and the co-occurrence of genetic predisposing factors or modifiers should be tested by specific molecular techniques. The intensity of HHV-6 genome load in BAL fluid could be an indicator of the response to antiviral therapy.

siRNAs and viruses: The good, the bad and the way forward

There are no available antivirals for many viruses or strains, while current antivirals are limited by toxicity and drug resistance. Therefore, alternative strategies, such as RNA interference (RNAi) are required. RNAi suppresses gene expression of any mRNA, making it an attractive candidate for antiviral therapeutics. Studies have evaluated siRNAs in a range of viruses, with some showing promising results. However, issues with stability and delivery of siRNAs remain. These may be minimized by modifying the siRNA structure, using an efficient delivery vector and targeting multiple regions of a virus's genome in a single dose. Finding these solutions could accelerate the progress of RNAi-based antivirals. This review highlights selected examples of antiviral siRNAs, limitations of RNAi and strategies to overcome these limitations.