Viruses and hospitalization for childhood lower respiratory tract infection in Malaysia: A prospective study

A review on disease burden and epidemiology of childhood parainfluenza virus infections in Asian countries

Human parainfluenza viruses (HPIVs) are an important cause of acute respiratory tract infections (ARTIs) in children less than 5 years, second only to human respiratory syncytial viruses (HRSVs). Generally, patients infected with HPIVs are treated in outpatient clinics, yet also contribute to ARTI-associated hospitalization in children. Although HPIV infections are well studied in developed countries, these infections remain under-investigated and not considered in the routine laboratory diagnosis of childhood ARTI in many developing countries in Asia. We performed an extensive literature search on the prevalence, epidemiology, and burden of HPIV infections in children less than 5 years in Asia using PubMed and PubMed Central search engines. Based on the literature, the prevalence of HPIV infection in Asia ranges from 1% to 66%. According to many studies, HPIV-3 is the major virus circulating among children; however, several studies failed to detect HPIV-4 due to unavailability of diagnostic tools. In Asian countries, HPIV contributes a substantial disease burden in children. The data in this review should assist researchers and public health authorities to plan preventive measures, including accelerating research on vaccines and antiviral drugs.

Diversity of respiratory viruses detected among hospitalized children with acute lower respiratory tract infections at Hospital Serdang, Malaysia

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Discovery of new viruses have created a renewed interest in the epidemiology of respiratory viruses.

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Respiratory viruses are the major cause of acute lower respiratory tract infections (ALRTIs) in children.

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Assessment of the morbidity of specific etiological agents of ALRTIs is important to determine agent-specific interventions.

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Sensitive and rapid diagnosis of respiratory infections in hospitalized children is cost-effective.

Background

The role of respiratory viruses as the major cause of acute lower respiratory tract infections (ALRTIs) in children is becoming increasingly evident due to the use of sensitive molecular detection methods. The aim of this study was to use conventional and molecular detection methods to assess the epidemiology of respiratory viral infections in children less than five years of age that were hospitalized with ALRTIs.

Methods

The cross-sectional study was designed to investigate the occurrence of respiratory viruses including respiratory syncytisl virus (RSV), human metapneumovirus (HMPV), influenza virus A and B (IFV-A and B), parainfluenzavirus 1, 2, 3 and 4 (PIV 1, 2, 3 and 4), human rhinoviruses (HRV), human enterovirus (HEV), human coronaviruses (HCoV) 229E and OC43, human bocavirus (HBoV) and human adenovirus (HAdV) in hospitalized children with ALRTIs, at Hospital Serdang, Malaysia, from June 16 to December 21, 2009. The study was also designed in part to assess the performance of the conventional methods against molecular methods.

Results

Viral pathogens were detected in 158 (95.8%) of the patients. Single virus infections were detected in 114 (67.9%) patients; 46 (27.9%) were co-infected with different viruses including double-virus infections in 37 (22.4%) and triple-virus infections in 9 (5.5%) cases. Approximately 70% of samples were found to be positive using conventional methods compared with 96% using molecular methods. A wide range of respiratory viruses were detected in the study. There was a high prevalence of RSV (50.3%) infections, particularly group B viruses. Other etiological agents including HAdV, HMPV, IFV-A, PIV 1–3, HBoV, HCoV-OC43 and HEV were detected in 14.5, 9.6, 9.1, 4.8, 3.6, 2.4 and 1.8 percent of the samples, respectively.

Conclusion

Our results demonstrated the increased sensitivity of molecular detection methods compared with conventional methods for the diagnosis of ARTIs in hospitalized children. This is the first report of HMPV infections in Malaysia.

High correlation between human rhinovirus type C and children with asthma exacerbations in Taiwan

BACKGROUND/PURPOSES

Human rhinovirus type C (HRV-C) has been associated with asthma exacerbation (AE) in children in several countries. However, in Taiwan the association between HRV, especially HRV-C, and AE in children has yet to be elucidated. We sought to investigate the prevalence of respiratory viruses in children with acute lower respiratory tract infection (ALRTI) in Taiwan and the association between different types of HRV and AE in children.

METHODS

This prospective study was conducted from 2011 to 2013, and enrolled children with ALRTI, including an asthma exacerbation group (AE; n = 28) and a Non-asthma group (n = 66). Viruses were detected by culture, reverse transcription-polymerase chain reaction, and molecular sequencing of nasopharyngeal swabs.

RESULTS

The prevalence of identified respiratory viruses was 78.6% in the AE group and 65.2% in the Non-asthma group. The prevalence rates of HRV and HRV-C were significantly higher in the AE group than in the Non-asthma group (67.9% vs. 33.3% in HRV, p = 0.002; and 50% vs. 15.2% in HRV-C, p < 0.001). Among the children with HRV, the prevalence of HRV-C (68.4%) was higher than that of the other types of HRV (31.6%, including HRV-A 26.3%, and HRV-B 5.3%) in the AE group but not in the Non-asthma group (40.9% vs. 59.1%).

CONCLUSIONS

HRV is the most predominant viral infection responsible for pediatric AE in Taiwan, and HRV-C is responsible for more of these exacerbations than HRV-A or HRV-B.

Serum lactate dehydrogenase isoenzymes 4 plus 5 is a better biomarker than total lactate dehydrogenase for refractory Mycoplasma pneumoniae pneumonia in children

Although usually self-limiting, Mycoplasma pneumoniae pneumonia (MPP) may lead to clinical or radiological deterioration despite macrolide antibiotic therapy, resulting in the development of refractory MPP (RMPP). Corticosteroids have been used to treat RMPP with beneficial effects. Serum lactate dehydrogenase (LDH) is a suggested biomarker for the use of steroid therapy. Since serum LDH is a non-specific marker and elevated in many inflammatory processes, this study investigates the predicting level of LDH isoenzymes for RMPP. Fifty-four children with non-refractory M. pneumoniae pneumonia (NRMPP) and 16 children with RMPP were enrolled in this study. In comparison to the NRMPP group, the RMPP group showed significantly higher levels of serum LDH. Concerning LDH isoenzymes, the RMPP group showed significantly lower proportions of LDH1 and LDH2, while higher LDH4 and LDH5 percentage. Receiver operating characteristic curve analysis showed that the area under the curve for the total LDH data was 0.812 with a cut-off of 408 IU/L (sensitivity of 75.0%, specificity of 72.2%). The areas under the curve for LDH4, LDH5, and [LDH4 + LDH5] were estimated to be 0.813, 0.818, and 0.829, respectively. The threshold for [LDH4 + LDH5] was estimated to be 109.4 IU/L (sensitivity, 75.0%; specificity, 87.0%). These results indicate that for the initiation of corticosteroid therapy, serum [LDH4 + LDH5] level is a more sensitive biomarker than total LDH.

Molecular epidemiology and clinical features of rhinovirus infections among hospitalized patients in a medical center in Taiwan

BACKGROUND

Human rhinovirus (HRV) can cause severe illnesses in hospitalized patients. However, there are no studies regarding the prevalence of HRV infection, particularly the recently identified HRV-C, in hospitalized patients reported from Taiwan.

METHODS

Respiratory specimens collected from 487 hospitalized patients in designated wards between 2013 and 2014 in a medical center in northern Taiwan were retrospectively detected for HRV. Positive specimens were further determined for genotyping. Medical charts of the HRV-positive patients were reviewed retrospectively.

RESULTS

Totally, 76 patients (15.6%) were HRV positive, of which 60 were pediatric patients. HRV-A was identified in 41 (54%) patients, HRV-B in 6 patients (7.9%) and HRV-C in 29 patients (38%). A total of 47 different genotypes were identified. HRV infections were predominant during fall and winter seasons. 21.1% were affected by HRV alone and 78.9% were found to be co-infected with other microorganisms. The detection rate of HRV in children (18.6%) was significantly higher than in adults (9.6%). Compared with pediatric patients, adult patients were significantly associated with underlying disease, Pneumocystis jirovesii pneumonia co-infection, a diagnosis of pneumonia, fatal outcome, hospital acquisition of HRV, antibiotics administration and requiring intensive care, while pediatric patients were significantly associated with viral co-infection.

CONCLUSIONS

HRV was a common cause of respiratory tract infection in Taiwan, particularly in pediatric patients. Eighty percent of HRV-infected inpatients had other microorganisms co-infection. Adult patients were more likely to be associated with a severe respiratory disease entity.