Clinical and laboratory study of newborns with lower respiratory tract infection due to respiratory viruses

Decreased Passive Immunity to Respiratory Viruses through Human Milk during the COVID-19 Pandemic

Infants may develop severe viral respiratory tract infections because their immune system is still developing in the first months after birth. Human milk provides passive humoral immunity during the first months of life. During the COVID-19 pandemic, circulation of common respiratory viruses was virtually absent due to the preventative measures resulting in reduced maternal exposure. Therefore, we hypothesized that this might result in lower antibody levels in human milk during the pandemic and, subsequently, decreased protection of infants against viral respiratory tract infections. We assessed antibody levels against respiratory syncytial virus (RSV), Influenza virus, and several seasonal coronaviruses in different periods of the COVID-19 pandemic in serum and human milk using a Luminex assay. IgG levels against RSV, Influenza, HCoV-OC43, HCoV-HKU1, and HCoV-NL63 in human milk were reduced with a factor of 1.7 (P < 0.001), 2.2 (P < 0.01), 2.6 (P < 0.05), 1.4 (P < 0.01), and 2.1 (P < 0.001), respectively, since the introduction of the COVID-19 restrictions. Furthermore, we observed that human milk of mothers that experienced COVID-19 contained increased levels of IgG and IgA binding to other respiratory viruses. Passive immunity via human milk against common respiratory viruses was reduced during the COVID-19 pandemic, which may have consequences for the protection of breastfed infants against respiratory infections. IMPORTANCE Passive immunity derived from antibodies in human milk is important for protecting young infants against invading viruses. During the COVID-19 pandemic, circulation of common respiratory viruses was virtually absent due to preventative measures. In this study, we observed a decrease in human milk antibody levels against common respiratory viruses several months into the COVID-19 pandemic. This waning of antibody levels might partially explain the previously observed surge of hospitalizations of infants, mostly due to RSV, when preventative hygiene measures were lifted. Knowledge of the association between preventative measures, antibody levels in human milk and subsequent passive immunity in infants might help predict infant hospital admissions and thereby enables anticipation to prevent capacity issues. Additionally, it is important in the consideration for strategies for future lockdowns to best prevent possible consequences for vulnerable infants.

Dynamics of COVID-19 Lockdown on Blood Indices and Its Impact on Individuals' Immunological Health Status: A Cohort Study in Madinah, Saudi Arabia

Objective

The complete blood count (CBC) is an essential blood test that has been used for decades to assess individuals’ overall health status. This study aimed to investigate the contributions of lockdown conditions to individuals’ overall health status using blood indices as biological markers. During lockdown, people are limited to confined spaces, have access to limited nutritional supply options, experience increased stress, and are exposed to other environmental factors.

Methods

Our study’s target population included all outpatients who were severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-negative and requested CBC assessments as part of their routine health checks. A total of 2414 CBC results were included, covering a period from February 2019 to December 2020. The average of different blood indices during the COVID-19 lockdown was compared to the 10-month period preceding the lockdown.

Results

The average counts of RBCs, hemoglobin, and hematocrit showed a significant increase during the lockdown period, which lasted from May 2020 to September 2020. Reductions were observed for the RBC distribution width, total white blood cell count, platelets, and platelet distribution width.

Conclusion

Our findings suggested that the overall health status of individuals improved during the lockdown period in the short term, but health status might be adversely affected under these conditions of a longer period. Both RDW and PDW could be used as indicators for the overall health status when assessed against other blood indices.

Seroprevalence of anti-Chlamydia trachomatis IgM in neonatal respiratory tract infections in Hungary

Purpose. To determine the seroprevalence of specific IgM indicative of respiratory tract infection (RTI) due to Chlamydia trachomatis (CT) among symptomatic infants.Methodology. A descriptive study was conducted on young infants up to 5 months old at the Bacterial Sexually Transmitted Infections Reference Laboratory, National Centre for Epidemiology, Budapest, covering the period 2008-2016. Serum samples from infants suffering from RTIs were screened with a micro-immunofluorescence test (Focus, Cypress, USA) for the presence of anti-Chlamydia trachomatis-specific IgM. A parallel Bordetella pertussis screening was performed by an indirect immunofluorescence test (Euroimmun, Lübeck, Germany) that detected specific IgM.Results.The CT-specific serum IgM was highly reactive in 50 (19.1 %) of the 262 neonates with RTIs, while all proved negative for Bordetella pertussis-specific IgM.Conclusion. Vertically transmitted C. trachomatis must be regarded as a common pathogen among symptomatic neonates with RTIs in Hungary. Routine screening and treatment of pregnant women could be one option to help prevent these conditions. Focused laboratory testing based on raised clinical awareness should enable early diagnosis and appropriate therapy for symptomatic infants.

The frequency of influenza and bacterial coinfection: a systematic review and meta-analysis

Aim

Coinfecting bacterial pathogens are a major cause of morbidity and mortality in influenza. However, there remains a paucity of literature on the magnitude of coinfection in influenza patients.

Method

A systematic search of MeSH, Cochrane Library, Web of Science, SCOPUS, EMBASE, and PubMed was performed. Studies of humans in which all individuals had laboratory confirmed influenza, and all individuals were tested for an array of common bacterial species, met inclusion criteria.

Results

Twenty‐seven studies including 3215 participants met all inclusion criteria. Common etiologies were defined from a subset of eight articles. There was high heterogeneity in the results (I² = 95%), with reported coinfection rates ranging from 2% to 65%. Although only a subset of papers were responsible for observed heterogeneity, subanalyses and meta‐regression analysis found no study characteristic that was significantly associated with coinfection. The most common coinfecting species were Streptococcus pneumoniae and Staphylococcus aureus, which accounted for 35% (95% CI, 14%–56%) and 28% (95% CI, 16%–40%) of infections, respectively; a wide range of other pathogens caused the remaining infections. An assessment of bias suggested that lack of small‐study publications may have biased the results.

Conclusions

The frequency of coinfection in the published studies included in this review suggests that although providers should consider possible bacterial coinfection in all patients hospitalized with influenza, they should not assume all patients are coinfected and be sure to properly treat underlying viral processes. Further, high heterogeneity suggests additional large‐scale studies are needed to better understand the etiology of influenza bacterial coinfection.

RT-PCR detection of respiratory pathogens in newborn children admitted to a neonatal medium care unit

BACKGROUND

This study aimed to determine the prevalence of respiratory pathogens among newborns admitted to a neonatal medium care unit (NMCU) and to identify clinical predictors.

METHODS

A 1-y observational study was performed of neonates admitted to an NMCU in Amsterdam, The Netherlands. Nasopharyngeal samples were collected for the detection of respiratory viruses and bacteria by real-time PCR (RT-PCR). Cycle threshold (Ct) values were provided to estimate viral load. Predictors for the presence of study pathogens were identified.

RESULTS

From October 2010 through September 2011, 334 neonates (median age 1.3 d, 53.6% male) were included. Overall, 37 respiratory pathogens were detected in 34 children (10.2%): parainfluenza-1 (n = 9), human rhinovirus (n = 7), parainfluenza-3 (n = 6), respiratory syncytial virus (RSV, n = 6), Streptococcus pneumoniae (n = 3), adenovirus (n = 2), human coronavirus (n = 2), influenza A (n = 1), and bocavirus (n = 1). Neonates with higher viral loads (Ct <35; n = 11) were more often clinically ill than those with lower viral loads (Ct ≥35; n = 23). Two variables significantly contributed to the detection of study pathogens: age (odds ratio (OR) 1.21 for each day older; 95% confidence interval 1.12-1.30) and rhinorrhea (OR 6.71; 95% confidence interval 1.54-29.21).

CONCLUSION

Respiratory pathogens seem to play a role in neonates admitted to an NMCU. The influence of respiratory pathogen detection on clinical management remains to be determined.

Unrecognized viral respiratory tract infections in premature infants during their birth hospitalization: a prospective surveillance study in two neonatal intensive care units

OBJECTIVE

To determine the frequency and effects of nosocomial respiratory viral infections (RVIs) in premature neonates, including those who may be asymptomatic.

STUDY DESIGN

We performed a year-long surveillance for RVIs in infants <33 weeks gestational age admitted to 2 Syracuse neonatal intensive care units. Infants were enrolled within 3 days of neonatal intensive care unit admission and were sampled for RVIs until discharge using a multiplex polymerase chain reaction assay capable of detecting 17 different respiratory viruses or subtypes.

RESULTS

Twenty-six of 50 prematurely born infants (52%) tested positive for a respiratory virus at least once during their birth hospitalization. Testing positive for a respiratory virus was significantly associated with longer length of stay (70 days vs 35 days, P = .002) and prolonged ventilatory support (51 vs 13 days, P = .002). Infants who tested positive for a respiratory virus during their birth hospitalization had more than twice the rate of developing bronchopulmonary dysplasia (P < .05).

CONCLUSION

Nosocomial RVIs were frequent in our study population, despite the absence of clinical indicators of illness. Length of hospital stay was significantly longer and a diagnosis of bronchopulmonary dysplasia was more common in infants who had respiratory viruses detected.

Correlation between inflammatory mediators in the nasopharyngeal secretion and in the serum of children with lower respiratory tract infection caused by respiratory syncytial virus and disease severity

OBJECTIVE

To determine whether the concentrations of inflammatory mediators (CCL5, soluble intercellular adhesion molecule type 1 [sICAM-1], TNF-alpha, IL-6 and IL-10) in the nasopharyngeal secretion and in the serum of children with lower respiratory tract infection (LRTI) caused by respiratory syncytial virus (RSV) correlate with the clinical markers of disease severity.

METHODS

Between July of 2004 and December of 2005, 30 children less than three months of age, diagnosed with LRTI caused by RSV and admitted to a neonatal ICU, were included in this study.

RESULTS

The severity of disease at hospital admission, as determined with a modified clinical scoring system, presented a significant positive correlation with sICAM-1 and IL-10 concentrations in the nasopharyngeal secretion, as well as with IL-6 concentrations in the serum, of the patients. In addition, serum IL-6 concentrations presented a significant positive correlation with the duration of oxygen therapy and with the length of hospital stay.

CONCLUSIONS

At hospital admission, the concentrations of sICAM-1 and IL-10 in the nasopharyngeal secretion, as well as the concentration of IL-6 in the serum, could be used as markers of severity in patients with LRTI caused by RSV. The serum levels of IL-6 determined at admission could also be used to predict prolonged oxygen supplementation and hospital stay.

Fatal influenza B virus pneumonia in a preterm neonate: case report and review of the literature

Although less common than influenza A, influenza B infections can cause significant mortality and morbidity in children who are immunocomprised and have underlying medical conditions. We report a preterm neonate with fatal influenza B virus pneumonia. This infant presented with signs and symptoms indistinguishable from any other cause of sepsis.

Rapid detection and clinical features of infants and young children with acute lower respiratory tract infection due to respiratory syncytial virus

During December to the end of February of 2003 and 2004, a total of 282 nasopharyngeal aspirates were obtained from infants and young children admitted to the Buraidah Maternity and Pediatric Hospital, Al-Qassim, Saudi Arabia, and clinically diagnosed as suffering from acute lower respiratory tract infections. The aspirates were tested for the presence of respiratory syncytial virus using direct fluorescein-labeled monoclonal antibody assay. Of the 282 specimens, 128 (45.4%) were found to be positive for respiratory syncytial virus. The most positive specimens came from patients less than one year old (51.3%), and were associated with bronchopneumonia (56.7%) or bronchiolits (55.4%). Coughing (100%) and tachpnea (98%) were significantly more frequent in infants with respiratory syncytial virus infection, followed by wheezing, crepitation and retraction, each representing 66%. Three deaths were reported. The availability of a rapid viral diagnostic assay will be an important tool for physicians to make more accurate treatment decisions and therefore reduce unnecessary antibiotic usage and hospital stay for the patients.

Incidence of respiratory viruses in preterm infants submitted to mechanical ventilation

The objectives of this study were to determine the incidence of infection by respiratory viruses in preterm infants submitted to mechanical ventilation, and to evaluate the clinical, laboratory and radiological patterns of viral infections among hospitalized infants in the neonatal intensive care unit (NICU) with any kind of acute respiratory failure. Seventy-eight preterm infants were studied from November 2000 to September 2002. The newborns were classified into two groups: with viral infection (Group I) and without viral infection (Group II). Respiratory viruses were diagnosed in 23 preterm infants (29.5%); the most frequent was respiratory syncytial virus (RSV) (14.1%), followed by influenza A virus (10.2%). Rhinorrhea, wheezing, vomiting and diarrhea, pneumonia, atelectasis, and interstitial infiltrate were significantly more frequent in newborns with nosocomial viral infection. There was a correlation between nosocomial viral infection and low values of C-reactive protein. Two patients with mixed infection from Group I died during the hospital stay. In conclusion, RSV was the most frequent virus in these patients. It was observed that, although the majority of viral lower respiratory tract infections had a favorable course, some patients presented a serious and prolonged clinical manifestation, especially when there was concomitant bacterial or fungal infection.