Distribution and Trends of Human Parainfluenza Viruses in Hospitalised Children

Epidemiological Characteristics of Parainfluenza Virus Type 3 and the Effects of Meteorological Factors in Hospitalized Children With Lower Respiratory Tract Infection

OBJECTIVE

To investigate the relationship between meteorological factors and Human parainfluenza virus type 3 (HPIV-3) infection among hospitalized children.

METHODS

All hospitalized children with acute lower respiratory tract infections were tested for viral pathogens and enrolled, at the second affiliated hospital of Wenzhou medical university, between 2008 and 2017. Meteorological data were directly obtained from Wenzhou Meteorology Bureau's nine weather stations and expressed as the mean exposure for each 10-day segment (average daily temperatures, average daily relative humidity, rainfall, rainfall days, and wind speed). The correlation between meteorological factors and the incidence of HPIV-3 was analyzed, with an autoregressive integrated moving average model (ARIMA), generalized additive model (GAM), and least absolute shrinkage and selection operator (LASSO).

RESULTS

A total of 89,898 respiratory specimens were tested with rapid antigen tests, and HPIV-3 was detected in 3,619 children. HPIV-3 was detected year-round, but peak activities occurred most frequently from March to August. The GAM and LASSO-based model had revealed that HPIV-3 activity correlated positively with temperature and rainfall day, but negatively with wind speed. The ARIMA (1,0,0)(0,1,1) model well-matched the observed data, with a steady R² reaching 0.708 (Ljung-Box Q = 21.178, P = 0.172).

CONCLUSION

Our study suggests that temperature, rainfall days, and wind speed have significant impacts on the activity of HPIV-3. GAM, ARIMA, and LASSO-based models can well predict the seasonality of HPIV-3 infection among hospitalized children. Further understanding of its mechanism would help facilitate the monitoring and early warning of HPIV-3 infection.

Climate variability and seasonal patterns of paediatric parainfluenza infections in the tropics: An ecological study in Singapore

OBJECTIVES

Evidence of the relationship between climate variability, air pollution and human parainfluenza virus (HPIV) infections has been inconsistent. We assessed this in a paediatric population from a highly urbanized tropical city-state.

METHODS

We analysed all reports of HPIV infections in children <5 years old obtained from a major specialist women and children's hospital in Singapore. Assuming a negative binomial distribution and using multivariable fractional polynomial modelling, we examined the relations between climate variability, air quality and the risk of HPIV infections, adjusting for time-varying confounders.

RESULTS

We identified 6393 laboratory-confirmed HPIV infections from 2009 to 2019. Every 1 °C decline in temperature was associated with a 5.8% increase (RR: 0.943, 95% Confidence Interval [95% CI]: 0.903-0.984) in HPIV infection risk 6 days later. Every 10% decrease in relative humidity was associated with a 15.8% cumulative increase in HPIV risk over the next 6 days (cumulative RR: 0.842, 95% CI: 0.771-0.919). Rainfall was positively associated with HPIV risk 2 days later (RR: 1.021, 95% CI: 1.000-1.043). A within-year seasonal rise of HPIV was driven by HPIV-3 and HPIV-1 and preceded by a seasonal decline in temperature. Gender was an effect modifier of the climate-HPIV relationship. Air quality was not associated with HPIV risk.

CONCLUSIONS

This study demonstrates a close association between HPIV infection risk and tropical climate variability. The climate dependence and seasonal predictability of HPIV can inform the timing of community campaigns aimed at reducing infection risk and the development of hospital resources and climate adaption plans.

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.

Human parainfluenza virus circulation, United States, 2011-2019

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Human parainfluenza virus type 3 is the most commonly reported parainfluenza virus followed by types 1, 2, and 4, respectively.

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Each parainfluenza virus type exhibited a unique circulation pattern.

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Parainfluenza type 4 circulated annually and peaked during the winter months.

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There was no remarkable distinction in regional versus national seasonal circulation patterns.

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The majority of parainfluenza virus detections with available age data occurred among children aged ≤2 years.

Background

Human parainfluenza viruses (HPIVs) cause upper and lower respiratory tract illnesses, most frequently among infants and young children, but also in the elderly. While seasonal patterns of HPIV types 1–3 have been described, less is known about national patterns of HPIV-4 circulation.

Objectives

To describe patterns of HPIVs circulation in the United States (US).

Study design

We used data from the National Respiratory and Enteric Virus Surveillance System (NREVSS), a voluntary passive laboratory-based surveillance system, to characterize the epidemiology and circulation patterns of HPIVs in the US during 2011–2019. We summarized the number of weekly aggregated HPIV detections nationally and by US census region, and used a subset of data submitted to NREVSS from public health laboratories and several clinical laboratories during 2015–2019 to analyze differences in patient demographics.

Results

During July 2011 - June 2019, 2,700,135 HPIV tests were reported; 122,852 (5 %) were positive for any HPIV including 22,446 for HPIV-1 (18 %), 17,474 for HPIV-2 (14 %), 67,649 for HPIV-3 (55 %), and 15,283 for HPIV-4 (13 %). HPIV testing increased substantially each year. The majority of detections occurred in children aged ≤ 2 years (36 %) with fluctuations in the distribution of age by type.

Conclusions

HPIVs were detected year-round during 2011–2019, with type-specific year-to-year variations in circulation patterns. Among HPIV detections where age was known, the majority were aged ≤ 2 years. HPIV-4 exhibited an annual fall-winter seasonality, both nationally and regionally. Continued surveillance is needed to better understand national patterns of HPIV circulation.