Human coronavirus infection among children with acute lower respiratory tract infection in Thailand

Canine coronavirus infection is intensified by 2,3,7,8-tetrachlorodibenzo-p-dioxin

In humans as well as in animals, the toxic contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) stimulates immunosuppression and increases responsiveness to infectious diseases. The relationship between environmental contaminants and different infectious diseases, including COVID-19, has been described. Nevertheless, reports about the potential impact of TCDD on coronaviruses (CoVs) are limited. In this study, the impact of TCDD (0-100 pg/mL) was assessed during infection in vitro with canine coronavirus (CCoV-II), the alphaCoV causing moderate enteric disease in dogs, although genetic alterations may surprisingly generate new dangerous strains. For instance, outbreaks of lethal infections in dogs were related to highly virulent CCoV strains, and cases of pneumonia and malaise in humans were associated with new canine-feline recombinant strains of CCoV, underlining the cross-species spread capability of CoVs. Herein, during CCoV infection, TCDD induced a substantial growth in virus yield and in the expression of viral nucleocapsid protein in infected groups. Infected cells exhibited alterations in cell morphology, extensively enhanced by TCDD. Moreover, in infection, TCDD modulated the protein levels of aryl hydrocarbon receptor (AHR), a signaling responsive to both environmental contaminant and CoVs infections. Overall, our findings showed that TCDD, playing a role in AHR signaling, may worsen CCoV infection.

Asthma-community acquired pneumonia co-diagnosis in children: a scoping review

OBJECTIVE

This scoping review investigated the existing literature and identified the evidence gaps related to diagnosis and management in children aged 2-18 years presenting to hospitals with a co-diagnosis of asthma and community-acquired pneumonia.

DATA SOURCES

We designed a scoping review following Arksey and O'Malley's scoping review framework and PRISMA extension for a scoping review. We searched literature using five electronic databases: PubMed, CINAHL, Scopus, Web of Science, and Embase from 2003 to June 2023.

RESULTS

A total of 1599 abstracts with titles were screened and 12 abstracts were selected for full review. Separate guidelines including Modified Global Initiative for Asthma (GINA) guidelines; modified Integrated Management of Childhood Illness (IMCI) guidelines; and a consensus guideline developed by the Pediatric Infectious Diseases Society (PIDS) and Infectious Diseases Society of America (IDSA) were used for diagnosing asthma and CAP individually. Chest X-rays were used in 83.3% (10/12) of studies to establish the co-diagnosis of asthma-CAP in children. Variations were observed in using different laboratory investigations across the studies. Infectious etiologies were detected in five (41.7%) studies. In 75% (9/12) of studies, children with asthma-CAP co-diagnosis were treated with antimicrobials, however, bacterial etiology was not reported in 44.4% (4/9) of the studies.

CONCLUSIONS

Our scoping review suggests that chest X-rays are commonly used to establish the co-diagnosis of asthma-CAP and antibiotics are often used without laboratory confirmation of a bacterial etiology. Clinical practice guidelines for the management of asthma and pneumonia in children who present with co-diagnosis may standardize clinical care and reduce variation.

Fungal metabolite 6-pentyl-α-pyrone reduces canine coronavirus infection

Canine coronavirus (CCoV) can produce a self-limited enteric disease in dogs but, because of notable biological plasticity of coronaviruses (CoVs), numerous mutations as well as recombination events happen leading to the emergence of variants often more dangerous for both animals and humans. Indeed, the emergence of new canine-feline recombinant alphacoronaviruses, recently isolated from humans, highlight the cross-species transmission potential of CoVs. Consequently, new effective antiviral agents are required to treat CoV infections. Among the candidates for the development of drugs against CoVs infection, fungal secondary metabolites (SMs) represent an important source to investigate. Herein, antiviral ability of 6-pentyl-α-pyrone (6 PP), a SM obtained by Trichoderma atroviride, was assessed against CCoV. During in vitro infection, nontoxic concentration of 6 PP significantly increased cell viability, reduced morphological signs of cell death, and inhibited viral replication of CCoV. In addition, we found a noticeable lessening in the expression of aryl hydrocarbon receptor (AhR), a strategic modulator of CoVs infection. Overall, due to the variety of their chemical and biological properties, fungal SMs can decrease the replication of CoVs, thus identifying a suitable in vitro model to screen for potential drugs against CoVs, using a reference strain of CCoV (S/378), non-pathogenic for humans.

Distinct T cell polyfunctional profile in SARS-CoV-2 seronegative children associated with endemic human coronavirus cross-reactivity

SARS-CoV-2 infection in children typically results in asymptomatic or mild disease. There is a paucity of studies on SARS-CoV-2 antiviral immunity in African children. We investigated SARS-CoV-2-specific T cell responses in 71 unvaccinated asymptomatic South African children who were seropositive or seronegative for SARS-CoV-2. SARS-CoV-2-specific CD4+ T cell responses were detectable in 83% of seropositive and 60% of seronegative children. Although the magnitude of the CD4+ T cell response did not differ significantly between the two groups, their functional profiles were distinct, with SARS-CoV-2 seropositive children exhibiting a higher proportion of polyfunctional T cells compared to their seronegative counterparts. The frequency of SARS-CoV-2-specific CD4+ T cells in seronegative children was associated with the endemic human coronavirus (HCoV) HKU1 IgG response. Overall, the presence of SARS-CoV-2-responding T cells in seronegative children may result from cross-reactivity to endemic coronaviruses and could contribute to the relative protection from disease observed in SARS-CoV-2-infected children.

Epidemiology of Non-SARS-CoV2 Human Coronaviruses (HCoVs) in People Presenting with Influenza-like Illness (ILI) or Severe Acute Respiratory Infections (SARI) in Senegal from 2012 to 2020

In addition to emerging coronaviruses (SARS-CoV, MERS, SARS-CoV-2), there are seasonal human coronaviruses (HCoVs): HCoV-OC43, HCoV-229E, HCoV-NL63 and HCoV-HKU1. With a wide distribution around the world, HCoVs are usually associated with mild respiratory disease. In the elderly, young children and immunocompromised patients, more severe or even fatal respiratory infections may be observed. In Africa, data on seasonal HCoV are scarce. This retrospective study investigated the epidemiology and genetic diversity of seasonal HCoVs during nine consecutive years of influenza-like illness surveillance in Senegal. Nasopharyngeal swabs were collected from ILI outpatients or from SARI hospitalized patients. HCoVs were diagnosed by qRT-PCR and the positive samples were selected for molecular characterization. Among 9337 samples tested for HCoV, 406 (4.3%) were positive: 235 (57.9%) OC43, 102 (25.1%) NL63, 58 (14.3%) 229E and 17 (4.2%) HKU1. The four types circulated during the study period and a peak was noted between November and January. Children under five were the most affected. Co-infections were observed between HCoV types (1.2%) or with other viruses (76.1%). Genetically, HCoVs types showed diversity. The results highlighted that the impact of HCoVs must be taken into account in public health; monitoring them is therefore particularly necessary both in the most sensitive populations and in animals.

Animal alphacoronaviruses found in human patients with acute respiratory illness in different countries

Here we review the existing evidence of animal alphacoronaviruses (Alphacoronavirus 1 species) circulating in human patients with acute respiratory illness. Thus far, the viruses similar to canine, feline and porcine alphacoronaviruses (including the most recent CCoV-HuPn-2018 and HuCCoV_Z19) have been detected in humans in Haiti, Malaysia, Thailand, and USA. The available data suggest that these viruses emerged in different geographic locations independently and have circulated in humans for at least 20 years. Additional studies are needed to investigate their prevalence and disease impact.

Canine Coronavirus Activates Aryl Hydrocarbon Receptor during In Vitro Infection

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that interacts with substrates, including microbial metabolites. Recent advances reveal that AhR is involved in the host response to coronaviruses (CoVs) infection. Particularly, AhR antagonists decrease the expression of angiotensin-converting enzyme 2 (ACE2) via AhR up-regulation, resulting in suppression of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in mammalian cells. Herein, we report that AhR is expressed in canine fibrosarcoma (A72) cells, where it is considerably activated by infection with genotype II of canine coronavirus (CCoV-II). The pharmacological inhibition of AhR, by CH223191, suppressed cell death signs and increased cell viability. Furthermore, the AhR antagonist induced a meaningful decline in virus yield, accompanied by the inhibition of the expression of viral nuclear protein (NP). Fascinatingly, during CCoV infection, a novel co-expression of NP and AhR expression was found. Taken together, our preliminary findings show that infection with CCoV activates AhR, and pharmacologic AhR inhibition reduces CCoV replication, identifying AhR as a possible candidate target for CCoV antiviral therapy.

Behavioral-biological surveillance of emerging infectious diseases among a dynamic cohort in Thailand

Background

Interactions between humans and animals are the key elements of zoonotic spillover leading to zoonotic disease emergence. Research to understand the high-risk behaviors associated with disease transmission at the human-animal interface is limited, and few consider regional and local contexts.

Objective

This study employed an integrated behavioral–biological surveillance approach for the early detection of novel and known zoonotic viruses in potentially high-risk populations, in an effort to identify risk factors for spillover and to determine potential foci for risk-mitigation measures.

Method

Participants were enrolled at two community-based sites (n = 472) in eastern and western Thailand and two hospital (clinical) sites (n = 206) in northeastern and central Thailand. A behavioral questionnaire was administered to understand participants’ demographics, living conditions, health history, and animal-contact behaviors and attitudes. Biological specimens were tested for coronaviruses, filoviruses, flaviviruses, influenza viruses, and paramyxoviruses using pan (consensus) RNA Virus assays.

Results

Overall 61/678 (9%) of participants tested positive for the viral families screened which included influenza viruses (75%), paramyxoviruses (15%), human coronaviruses (3%), flaviviruses (3%), and enteroviruses (3%). The most salient predictors of reporting unusual symptoms (i.e., any illness or sickness that is not known or recognized in the community or diagnosed by medical providers) in the past year were having other household members who had unusual symptoms and being scratched or bitten by animals in the same year. Many participants reported raising and handling poultry (10.3% and 24.2%), swine (2%, 14.6%), and cattle (4.9%, 7.8%) and several participants also reported eating raw or undercooked meat of these animals (2.2%, 5.5%, 10.3% respectively). Twenty four participants (3.5%) reported handling bats or having bats in the house roof. Gender, age, and livelihood activities were shown to be significantly associated with participants’ interactions with animals. Participants’ knowledge of risks influenced their health-seeking behavior.

Conclusion

The results suggest that there is a high level of interaction between humans, livestock, and wild animals in communities at sites we investigated in Thailand. This study highlights important differences among demographic and occupational risk factors as they relate to animal contact and zoonotic disease risk, which can be used by policymakers and local public health programs to build more effective surveillance strategies and behavior-focused interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07439-7.

Biosensors as Nano-Analytical Tools for COVID-19 Detection

Selective, sensitive and affordable techniques to detect disease and underlying health issues have been developed recently. Biosensors as nanoanalytical tools have taken a front seat in this context. Nanotechnology-enabled progress in the health sector has aided in disease and pandemic management at a very early stage efficiently. This report reflects the state-of-the-art of nanobiosensor-based virus detection technology in terms of their detection methods, targets, limits of detection, range, sensitivity, assay time, etc. The article effectively summarizes the challenges with traditional technologies and newly emerging biosensors, including the nanotechnology-based detection kit for COVID-19; optically enhanced technology; and electrochemical, smart and wearable enabled nanobiosensors. The less explored but crucial piezoelectric nanobiosensor and the reverse transcription-loop mediated isothermal amplification (RT-LAMP)-based biosensor are also discussed here. The article could be of significance to researchers and doctors dedicated to developing potent, versatile biosensors for the rapid identification of COVID-19. This kind of report is needed for selecting suitable treatments and to avert epidemics.

Point of care detection of COVID-19: Advancement in biosensing and diagnostic methods

The recent outbreak of COVID-19 has created much inconvenience and fear that the virus can seriously affect humans, causing health hazards and death. This pandemic has created much worry and as per the report by World Health Organization (WHO), more than 43 million individuals in 215 countries and territories were affected. People around the world are still struggling to overcome the problems associated with this pandemic. Of all the available methods, reverse-transcriptase polymerase chain reaction (RT-PCR) has been widely practiced for the pandemic detection even though several diagnostic tools are available having varying accuracy and sensitivity. The method offers many advantages making it a life-saving tool, but the method has the limitation of transporting to the nearest pathology lab, thus limiting its application in resource limited settings. This has a risen a crucial need for point-of-care devices for on-site detection. In this venture, biosensors have been used, since they can be applied immediately at the point-of-care. This review will discuss about the available diagnostic methods and biosensors for COVID-19 detection.

Review a brief history of coronaviruses in Thailand

As with many countries around the world, Thailand is currently experiencing restrictions to daily life as a consequence of the worldwide transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 is the third respiratory syndrome coronavirus to be introduced into Thailand, following previous importation of cases of the severe acute respiratory syndrome coronavirus (SARS) and the Middle East respiratory syndrome coronavirus (MERS). Unlike SARS and MERS, SARS-CoV-2 was able to establish local transmission in Thailand. In addition to the imported coronaviruses, Thailand has a number of endemic coronaviruses that can affect livestock and pet species, can be found in bats, as well as four human coronaviruses that are mostly associated with the common cold. This article seeks to review what is known on both the endemic and imported coronaviruses in Thailand.

Complicating Infections Associated with Common Endemic Human Respiratory Coronaviruses

Coronaviruses OC43, 229E, NL63, and HKU1 are endemic human respiratory coronaviruses that typically cause mild to moderate upper respiratory infections, similar to the common cold. They also may cause simple and complicated lower respiratory infections, otitis media, asthma exacerbations, gastroenteritis, and a few systemic complications. These viruses are usually seasonal (with winter dominance) and affect nearly all age groups. The seasonal and annual variation in virus prevalence has implications for understanding the concept of acquired immunity and its persistence or diminution. Coronaviruses generally have outbreak potential in susceptible populations of any age, particularly in patients with comorbidities, who tend to have increased clinical disease. These 4 coronaviruses are often found in the context of what appears to be coinfection with other pathogens, but especially other viruses. If coronaviruses are not specifically tested for, the sole detection of a viral copathogen would suggest the pathogen is the causative agent, when a coronavirus may be culpable, or both. The detection of these viruses in circumstances where respiratory viruses are generally sought in clinical samples is, therefore, justified. These pathogens can be chronically shed from the respiratory tract, which is more likely to occur among immunocompromised and complicated patients. These viruses share the potential for genetic drift. The genome is among the largest of RNA viruses, and the capability of these viruses to further change is likely underestimated. Given the potential disease among humans, it is justified to search for effective antiviral chemotherapy for these viruses and to consider uses in niche situations should effective therapy be defined. Whereas SARS-CoV-2 may follow the epidemiological pattern of SARS-CoV and extinguish slowly over time, there is yet concern that SARS-CoV-2 may establish itself as an endemic human respiratory coronavirus similar to OC43, 2299E, NL63, and HKU1. Until sufficient data are acquired to better understand the potential of SARS-CoV-2, continued work on antiviral therapy and vaccination is imperative.

Human Coronaviruses and Other Respiratory Viruses: Underestimated Opportunistic Pathogens of the Central Nervous System?

Respiratory viruses infect the human upper respiratory tract, mostly causing mild diseases. However, in vulnerable populations, such as newborns, infants, the elderly and immune-compromised individuals, these opportunistic pathogens can also affect the lower respiratory tract, causing a more severe disease (e.g., pneumonia). Respiratory viruses can also exacerbate asthma and lead to various types of respiratory distress syndromes. Furthermore, as they can adapt fast and cross the species barrier, some of these pathogens, like influenza A and SARS-CoV, have occasionally caused epidemics or pandemics, and were associated with more serious clinical diseases and even mortality. For a few decades now, data reported in the scientific literature has also demonstrated that several respiratory viruses have neuroinvasive capacities, since they can spread from the respiratory tract to the central nervous system (CNS). Viruses infecting human CNS cells could then cause different types of encephalopathy, including encephalitis, and long-term neurological diseases. Like other well-recognized neuroinvasive human viruses, respiratory viruses may damage the CNS as a result of misdirected host immune responses that could be associated with autoimmunity in susceptible individuals (virus-induced neuro-immunopathology) and/or viral replication, which directly causes damage to CNS cells (virus-induced neuropathology). The etiological agent of several neurological disorders remains unidentified. Opportunistic human respiratory pathogens could be associated with the triggering or the exacerbation of these disorders whose etiology remains poorly understood. Herein, we present a global portrait of some of the most prevalent or emerging human respiratory viruses that have been associated with possible pathogenic processes in CNS infection, with a special emphasis on human coronaviruses.

Human Coronavirus Infections in Israel: Epidemiology, Clinical Symptoms and Summer Seasonality of HCoV-HKU1

Human coronaviruses (HCoVs) cause mild to severe respiratory diseases. Six types of HCoVs have been discovered, the most recent one termed the Middle East respiratory syndrome coronavirus (MERS-CoV). The aim of this study is to monitor the circulation of HCoV types in the population during 2015–2016 in Israel. HCoVs were detected by real-time PCR analysis in 1910 respiratory samples, collected from influenza-like illness (ILI) patients during the winter sentinel influenza survey across Israel. Moreover, 195 HCoV-positive samples from hospitalized patients were detected during one year at Soroka University Medical Center. While no MERS-CoV infections were detected, 10.36% of patients in the survey were infected with HCoV-OC43 (43.43%), HCoV-NL63 (44.95%), and HCoV-229E (11.62%) viruses. The HCoVs were shown to co-circulate with respiratory syncytial virus (RSV) and to appear prior to influenza virus infections. HCoV clinical symptoms were more severe than those of RSV infections but milder than influenza symptoms. Hospitalized patients had similar HCoV types percentages. However, while it was absent from the public winter survey, 22.6% of the patients were HCoV-HKU1 positives, mainly during the spring-summer period.

Molecular epidemiology and characterization of human coronavirus in Thailand, 2012-2013

BACKGROUND

Coronavirus causes respiratory infections in humans. To determine the prevalence of human coronavirus (HCoV) infection among patients with influenza-like illness, 5833 clinical samples from nasopharyngeal swabs and aspirates collected between January 2012 and December 2013 were examined.

RESULTS

HCoV was found in 46 (0.79 %) samples. There were 19 (0.32 %) HCoV-HKU1, 19 (0.32 %) HCoV-NL63, 5 (0.09 %) HCoV-229E, and 3 (0.05 %) HCoV-OC43. None of the sample tested positive for MERS-CoV. The majority (54 %) of the HCoV-positive patients were between the ages of 0 and 5 years. HCoV was detected throughout the 2-year period and generally peaked from May to October, which coincided with the rainy season. Phylogenetic trees based on the alignment of the spike (S) gene sequences suggest an emergence of a new clade for HCoV-229E.

CONCLUSIONS

The data in this study provide an insight into the prevalence of the recent circulating HCoVs in the region.

A six-year descriptive epidemiological study of human coronavirus infections in hospitalized patients in Hong Kong

We conducted a six-year epidemiological study on human coronaviruses (HCoVs) circulating in Hong Kong, using 8275 nasopharyngeal samples from patients with acute respiratory tract infections. HCoVs were detected in 77 (0.93%) of the samples by a pan-HCoV RT-PCR assay. The most frequently detected HCoV species was HCoV-OC43 (0.58%), followed by HCoV-229E (0.15%), HCoV-HKU1 (0.13%) and HCoV-NL63 (0.07%). HCoVs were detected throughout the study period (September 2008–August 2014), with the highest detection rate from September 2010 to August 2011 (22/1500, 1.47%). Different seasonal patterns of each HCoV species in Hong Kong were noted. HCoV-OC43 was predominant in the fall and winter, whereas HCoV-HKU1 showed peak activity in winter, with a few cases occurred in spring and summer. HCoV-229E mainly occurred in winter and spring, while HCoV-NL63 was predominant in summer and autumn. HCoVs most commonly infect the elderly and young children, with median age of 79.5 years (range, 22 days to 95 years). Intriguingly, the detection rate of HCoV-OC43 in the age group of > 80 years (26/2380, 1.09%) was significantly higher than that in the age group of 0–10 years (12/2529, 0.47%) (P < 0.05). These data provides new insight into the epidemiology of coronaviruses.

Human coronaviruses: viral and cellular factors involved in neuroinvasiveness and neuropathogenesis

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Human coronavirus (HCoV) are naturally neuroinvasive in both mice and humans.

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Both transneuronal and hematogenous route may allow virus invasion of the CNS.

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Infection of neurons leads to excitotoxicity, neurodegeneration and cell-death.

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HCoV are potentially associated with human neurological disorders.

Among the various respiratory viruses infecting human beings, coronaviruses are important pathogens, which usually infect the upper respiratory tract, where they are mainly associated with common colds. However, in more vulnerable populations, such as newborns, infants, the elderly and immune-compromised individuals, these opportunistic pathogens can also affect the lower respiratory tract, leading to pneumonia, exacerbations of asthma, and various types of respiratory distress syndrome. The respiratory involvement of human coronaviruses has been clearly established since the 1960s. Nevertheless, for almost three decades now, data reported in the scientific literature has also demonstrated that, like it was described for other human viruses, coronaviruses have neuroinvasive capacities since they can spread from the respiratory tract to the central nervous system (CNS). Once there, infection of CNS cells (neurotropism) could lead to human health problems, such as encephalitis and long-term neurological diseases. Neuroinvasive coronaviruses could damage the CNS as a result of misdirected host immune responses that could be associated with autoimmunity in susceptible individuals (virus-induced neuroimmunopathology) and/or viral replication, which directly induces damage to CNS cells (virus-induced neuropathology). Given all these properties, it has been suggested that these opportunistic human respiratory pathogens could be associated with the triggering or the exacerbation of neurologic diseases for which the etiology remains poorly understood. Herein, we present host and viral factors that participate in the regulation of the possible pathogenic processes associated with CNS infection by human coronaviruses and we try to decipher the intricate interplay between virus and host target cells in order to characterize their role in the virus life cycle as well as in the capacity of the cell to respond to viral invasion.

Human coronaviruses: Clinical features and phylogenetic analysis

Strains of human coronavirus (HCoV), namely HCoV-OC43, HCoV-229E, HCoV-NL63, and HCoV-HKU1, primarily infect the upper respiratory and gastrointestinal tracts and are the most common cause of non-rhinovirus-induced common cold in humans. Although the manifestations of coronavirus infection (i.e., rhinorrhea, sneezing, cough, nasal obstruction, and bronchitis) are generally self-limiting in healthy adults, certain strains such as HCoV-NL63 and HCoV-HKU1 can cause severe lower respiratory tract infection and febrile seizure, especially in infants, people of advanced age, and immunocompromised hosts. In 2003, a novel HCoV strain was identified as the causative agent of the severe acute respiratory syndrome (SARS) epidemic that began in Asia in 2002. The strain has hence been referred to as SARS-CoV. In addition, as recently as September 2012, another novel HCoV, human betacoronavirus 2c EMC2012, was identified as being the cause of fever, renal failure, pneumonia, and severe respiratory distress in two patients in the Middle East. Phylogenetic analysis has revealed highly conserved sequences of ORF1ab, spike, nucleocapsid, and envelope protein genes, but not membrane protein genes, between human betacoronavirus 2c EMC2012 and SARS-CoV. This review focuses on the differences in the genomes of certain HCoV strains, the pathogenesis of said strains, and recent developments in the establishment of therapeutic agents that might aid in the treatment of patients with such infections.

High prevalence of human rhinovirus C infection in Thai children with acute lower respiratory tract disease

OBJECTIVE

To determine the prevalence of human rhinoviruses (HRV) infections in children with lower respiratory disease in Thailand and monitor the association between species of HRV and clinical presentation in hospitalized paediatric patients.

METHOD

Two hundred and eighty-nine nasopharyngeal (NP) suction specimens were collected from hospitalized paediatric patients admitted to King Chulalongkorn Memorial Hospital, Thailand during February 2006-2007. Nucleic acids were extracted from each sample with subsequent amplification of VP4/2 by semi-nested RT-PCR for HRV detection. Other viral respiratory pathogens were also detected by PCR, RT-PCR or real time PCR. Nucleotide sequences of the VP4 region were used for genotyping and phylogenetic tree construction.

RESULT

In total, 87 of 289 specimens were positive for HRV indicating an annual prevalence of 30%. Wheezing or asthma exacerbation was the most common clinical presentation observed in infected patients. Sequence analysis and phylogenetic tree showed that 29 (33%) and 8 (9%) specimens belonged to HRV-A and HRV-B, respectively. Most of the HRV positive samples were HRV-C (58%). Moreover, species C was predominantly found in the paediatric population of Thailand in raining season (p<0.05). The frequency of co-infection of HRV-C with other respiratory viral pathogens was approximately 40%.

CONCLUSION

HRV-C represents the predominant species and is one of the etiologic agents in acute lower respiratory tract infection, causes of wheezing and asthma exacerbation in infants and young children in Thailand.

Human Bocavirus quantitative DNA detection in French children hospitalized for acute bronchiolitis

Background

Human Bocavirus (HBoV) is a newly discovered parvovirus whose role as a causative agent of respiratory disease remains unclear.

Study design

We investigated the presence of HBoV by quantitative PCR in the nasopharyngeal samples of 192 French children consecutively hospitalized for acute bronchiolitis. Other common respiratory viruses were detected using immunofluorescence assays, cell culture detection, or RT-PCR assays.

Results

HBoV was detected in 24 (12.5%) of 192 study children. In 14/192 cases (7%) HBoV was the sole isolate and in 10/192 (5%) it was part of a mixed viral infection. HBoV was the third most common pathogen detected after respiratory syncytial virus (45/192; 23%) and rhinovirus (24/192; 12%). It occurred more often in infants aged 1–12 months (P = 0.002). Median levels of HBoV DNA genome in respiratory samples were significantly higher in patients with single HBoV infection than in patients with mixed respiratory viral infection with HBoV (4 × 10⁸ copies/ml vs. 2 × 10³ copies/ml, P < 0.001).

Conclusions

Our data suggest that HBoV at a high viral load could be an etiologic agent of respiratory tract disease, whereas the exact role of HBoV at a low viral load, as etiological cause or as pathophysiological co-factor of respiratory diseases, remains to be determined.

Human coronavirus infections in rural Thailand: a comprehensive study using real-time reverse-transcription polymerase chain reaction assays

Background. We sought to determine whether infections with human coronaviruses (HCoVs) 229E, OC43, HKU1, and NL63 are associated with pneumonia and to define the epidemiology of HCoV infection in rural Thailand.

Methods. We developed a real-time reverse-transcription polymerase chain reaction (RT-PCR) assay panel for the recognized HCoV types and compared HCoV infections in patients hospitalized with pneumonia, outpatients with influenza-like illness, and asymptomatic control patients between September 2003 and August 2005.

Results. During study year 1, 43 (5.9%) of 734 patients with pneumonia had HCoV infections; 72.1% of the infections were with OC43. During study year 2, when control patients were available, 21 (1.8%) of 1156 patients with pneumonia, 12 (2.3%) of 513 outpatients, and 6 (2.1%) of 281 control patients had HCoV infections. Compared with infection in control patients, infection with any HCoV type or with all types combined was not associated with pneumonia (adjusted odds ratio for all HCoV types, 0.67 [95% confidence interval, 0.26–1.75]; P= .40 ). HCoV infections were detected throughout both study years; 93.6% of OC43 infections in the first year occurred from January through March.

Conclusions. HCoV infections were infrequently detected in rural Thailand by use of sensitive real-time RTPCR assays. We found no association between HCoV infection and illness. However, we noted year-to-year variation in the prevalence of HCoV strains, which likely influenced our results.