Clinical characteristics and molecular epidemiology of human metapneumovirus in children with acute lower respiratory tract infections in China, 2017 to 2019: A multicentre prospective observational study

Human metapneumovirus (HMPV) infection is one of the leading causes of hospitalization in young children with acute respiratory illness. In this study, we prospectively collected respiratory tract samples from children who were hospitalized with acute lower respiratory tract infection in six hospitals in China from 2017 to 2019. HMPV was detected in 145 out of 2733 samples (5.3%) from the hospitalized children. The majority of HMPV-positive children were under the age of two (67.6%), with a median age of one year. HMPV can independently cause acute lower respiratory tract infection in young children, while all patients showed mild clinical symptoms. Of all the co-infected patients, HMPV was most commonly detected with enterovirus (EV) or rhinovirus (RhV) (38.0%, followed by respiratory syncytial virus (RSV) (32.0%). The highest detection rate occurred from March to May in both northern and southern China. Out of 145 HMPV positive samples, 48 were successfully typed, of which 36 strains were subgrouped into subtypes A2c (75%), eight strains were included in subtype B1 (16.7%), and four strains were included in subtype B2 (8.3%). Moreover, 16 A2c strains contained 111-nucleotide duplications in the G gene. Twenty-seven complete HMPV genomes were successfully obtained, and 25 (92.6%) strains belonged to subtype A2c, whereas one strain was included in subgroup B1 and another was included in subgroup B2. A total of 277 mutations were observed in the complete genomes of 25 A2c strains. All results presented here improve our understanding of clinical characteristics and molecular epidemiology of HMPV infection in children.     

The epidemiology of acute intestinal infections of undetermined etiology in children

Materials obtained in the study of conditions for contacting acute enteric infections of uncertain etiology, based on the analysis of the age structure of patients, the structure of clinical diagnoses and the monthly dynamics of cases registered in one of the districts of Moscow for 3 years (1984-1986), are presented. An important role of the alimentary factor in the spread acute enteric infections of uncertain etiology among the population of different age groups and everyday contacts in the spread of such infections among young children has been shown. The authors put forward a suggestion concerning the formation of natural immunity to infective agents, serving as etiological factors in the development of enteric infections of uncertain etiology, in children of preschool age.     

Prophylactic efficacy of reaferon in viral hepatitis A and acute respiratory infections in children

Reaferon, the analog of human alpha 2-interferon obtained by gene engineering techniques, was studied with a view to its use for the prevention of hepatitis A. The study involved children of preschool age in Tashkent. In a strictly controlled trial children aged 2-6 years received the preparation orally in a dose of 1 X 10(6) I. U. or the diluent alone used as placebo. The preparation was administered to 1,100 children and the placebo to 1,078 children. The preparation and placebo were administered twice a week for two months. On the whole, during that period hepatitis A morbidity in both test and control groups of children was the same (5.1% and 4.9% respectively), but among children of nursery age receiving Reaferon the incidence of hepatitis A and acute respiratory viral infections was lower than among those receiving the placebo, though this difference was statistically significant only for cases of acute respiratory infections.     

Risk factors for acute respiratory tract infections in children

Acute respiratory tract infections (ARTI) are the most common cause of childhood morbidity and an important public health problem. The aim of this study was to identify the significant risk factors for ARTI in children. The study took place in Ivankovo which is a rural area of Eastern Slavonia and with small socio-economic differences. The study population were 159 children who were 3-5 years old at the time of the study, and who were registrated at doctor's office Ivankovo. The study was conducted retrospectively through a questionnaire from January 2008 to December 2008. The risk factors studied were the gender, breastfeeding history, any atopic manifestation in the form of atopic eczema, rhinoconjuctivitis and/or asthma, the size of the family, parents smoking habits and main form of childcare. The number of ARTI requiring the consultation of a doctor throughout 2007 were measured; and whether ARTI had been treated with antibiotic or there were recommendation for symptomatic treatment only. Results of this research show that the risk factor for consulting a doctor because ofARTI in children was passive exposure to cigarette-smoke. For receiving antibiotics because of ARTI in children, the risk factors were passive exposure to cigarette-smoke and atopic manifestation. By giving the available evidence, parents must be told that ceasing smoking offers a significant opportunity to reduce the risk of ARTI in their children.     

Risk factors for lower respiratory complications of rhinovirus infections in elderly people living in the community: prospective cohort study.

OBJECTIVE: To assess the role of rhinoviruses in elderly people living in the community. DESIGN: Prospective community based surveillance of elderly people, without intervention. Subjects were telephoned weekly to identify symptomatic upper respiratory tract infections. Symptoms and impact of illnesses were monitored, and specimens were collected for diagnostic serology and human rhinovirus polymerase chain reaction. SETTING: Leicestershire, England. SUBJECTS: 533 subjects aged 60 to 90. MAIN OUTCOME MEASURES: Symptoms, restriction of activity, medical consultations, and antibiotic use during 96 rhinovirus infections. Adjusted odds ratios for lower respiratory syndromes with respect to smoking and health status. RESULTS: A viral cause was established in 211 (43%) of 497 respiratory illnesses; rhinoviruses were identified in 121 (24%) and as single pathogens in 107. The median duration of the first or only rhinovirus infection in the 96 people with 107 rhinovirus infections was 16 days; 18 of the 96 patients were confined to bed and 25 were unable to cope with routine household activities. Overall, 60 patients with rhinovirus infections had lower respiratory tract syndromes; 41 patients consulted their doctor, 31 of them (76%) receiving antibiotics. One patient died. Logistic regression analysis showed that chronic medical conditions increased the estimated probability of lower respiratory rhinovirus illness by 40% (95% confidence interval 17% to 68%) and smoking by 47% (14% to 90%). There were almost six times as many symptomatic rhinovirus infections as influenza A and B infections. CONCLUSIONS: Rhinoviruses are an important cause of debility and lower respiratory illness among elderly people in the community. Chronic ill health and smoking increase the likelihood of lower respiratory complications from such infections. The overall burden of rhinovirus infections in elderly people may approach that of influenza.     

Molecular epidemiology and clinical characterization of group A rotavirus infections in Tunisian children with acute gastroenteritis

Rotaviruses are the most common cause of severe viral gastroenteritis in early childhood worldwide. Thus, the objectives of our study were to determine the molecular epidemiology and the clinical features of rotavirus gastroenteritis in Tunisia. Between January 2003 and April 2007, a prospective study was conducted on 788 stool samples collected from children under 12 years of age who were suffering from acute gastroenteritis. Rotavirus was detected by multiplex RT-PCR in 27% (n = 213) of samples, among them 79.3% (n = 169) cases were monoinfections. The frequency of rotavirus infections was significantly higher among inpatients (29%) than among outpatients (13%) (P < 0.001). The seasonal distribution of rotavirus diarrhea showed a winter peak, with an unusual peak from June to September. The mean duration of hospitalization was 6.5 ± 8.1 days and the mean age was 15.8 ± 22.8 months for rotavirus monoinfections. Fever, vomiting, abdominal pain, and dehydration were observed in 88, 98, 13, and 80 cases, respectively, in children with rotavirus monoinfections. G3P[8] (45.6%) and G1P[8] (23.9%) were the most common genotypes found in our study. The determination of rotavirus infection prevalence and the characterization of the rotavirus strains circulating will help us to better understand the molecular biology and epidemiology of the disease in our country.     

Bacterial infections in the early period after liver transplantation in adults: A prospective single-center cohort study

Liver transplantation (LT) is a potentially curative treatment for terminal stage hepatic diseases. Bacterial infections are the main causes of mortality and morbidity in the early period after LT. Identifying the risk factors could help in minimizing their development. We prospectively investigated the incidence, characteristics, and risk factors of bacterial infections among the recipients during hospitalization after LT and assigned a predictive score. All 389 consecutive adults who underwent LT at the main referral hospital of LT in Iran during 1 year were enrolled prospectively in a cohort study. Infection group consisted of 143 recipients (36.8%). Urinary tract and surgical site infections were the most frequent ones. Gram-negative bacteria were more prevalent than Gram-positive ones. Independent risk factors were female sex (relative risks = 2.13), age ≤ 43.5 years (3.70), hospital stay ≥ 9.5 days (5.22), abdominal reoperation (3.03), vancomycin-resistant Enterococci colonization (5.52), hospitalization 3 months prior to LT (3.25), mechanical ventilation ≥48 hr (4.93), and renal replacement therapies (13.40). We developed a risk score for the prediction of bacterial infections with an area under the receiver operating characteristic curve of 0.85 (95% CI, 0.81–0.89) with sensitivity of 88% and specificity of 64%. In the infection group, mortality was higher than in controls (18.9% vs. 2.0%) with longer hospitalization (16 vs. 10 days; P < 0.001). We detected a high rate of bacterial infections leading to longer hospital stay and higher mortality rate. The formulated risk score can help predict bacterial infections; however, it requires clinical validation in further studies.     

A microplate method for isolation of viruses from infants and children with acute respiratory infections

Between December 1984 and December 1986, a microplate technique was adopted for isolation of viruses from infants and children with acute respiratory infections. By using two kinds of tissue culture microplates, i.e., the HHVM plate, containing human embryonic fibroblast (HEF), HEp-2, Vero and MDCK cells, and the MK plate which contains secondary monkey kidney cells, 1,080 field viruses were isolated from 1,061 (24.9%) out of 4,254 throat swabs. Of these 1,080 isolates, 1,003 (92.9%) were recovered in the HHVM plates and the remaining 77 (7.1%) in the MK plates. With the HHVM plate, influenza A and B viruses were cultivated in MDCK, RS virus in HEp-2, parainfluenza and mumps viruses in Vero, adenoviruses in both HEF and HEp-2, polioviruses in HEF, HEp-2 and Vero, coxsackie B viruses in both HEp-2 and Vero, rhino and echo viruses in HEF, herpes simplex virus in both HEF and HEp-2, and cytomegalovirus in HEF, although MK were more sensitive than Vero to parainfluenza and coxsackie B viruses. There was no difference in the rate of isolation of viruses between the microplate and ordinary tube methods. Cross contamination in the microplates was negligible for routine work.     

Plasmodium vivax and mixed infections are associated with severe malaria in children: a prospective cohort study from Papua New Guinea

Background

Severe malaria (SM) is classically associated with Plasmodium falciparum infection. Little information is available on the contribution of P. vivax to severe disease. There are some epidemiological indications that P. vivax or mixed infections protect against complications and deaths. A large morbidity surveillance conducted in an area where the four species coexist allowed us to estimate rates of SM among patients infected with one or several species.

Methods and Findings

This was a prospective cohort study conducted within the framework of the Malaria Vaccine Epidemiology and Evaluation Project. All presumptive malaria cases presenting at two rural health facilities over an 8-y period were investigated with history taking, clinical examination, and laboratory assessment. Case definition of SM was based on the World Health Organization (WHO) criteria adapted for the setting (i.e., clinical diagnosis of malaria associated with asexual blood stage parasitaemia and recent history of fits, or coma, or respiratory distress, or anaemia [haemoglobin < 5 g/dl]). Out of 17,201 presumptive malaria cases, 9,537 (55%) had a confirmed Plasmodium parasitaemia. Among those, 6.2% (95% confidence interval [CI] 5.7%–6.8%) fulfilled the case definition of SM, most of them in children <5 y. In this age group, the proportion of SM was 11.7% (10.4%–13.2%) for P. falciparum, 8.8% (7.1%–10.7%) for P. vivax, and 17.3% (11.7%–24.2%) for mixed P. falciparum and P. vivax infections. P. vivax SM presented more often with respiratory distress than did P. falciparum (60% versus 41%, p = 0.002), but less often with anaemia (19% versus 41%, p = 0.0001).

Conclusion

P. vivax monoinfections as well as mixed Plasmodium infections are associated with SM. There is no indication that mixed infections protected against SM. Interventions targeted toward P. falciparum only might be insufficient to eliminate the overall malaria burden, and especially severe disease, in areas where P. falciparum and P. vivax coexist.     

Etiological structure of acute respiratory viral infections in children hospitalized in 1981-1999

The role of influenza and parainfluenza viruses, respiratory syncytial viruses and adenoviruses in the etiological structure of morbidity in acute respiratory virus infections (ARVI) in children hospitalized during the 19 year period is analyzed. As the result of examination of 56,287 patients by direct immunofluorescent test, respiratory viruses were detected in 21% of cases. The seasonal character, periodicity and level of ARVI morbidity were established. According to medical records, in the 1990s ARVI took a more severe course in children than that observed in the 1980s. In addition, the data on morbidity among children regarding rotavirus infection and ARVI were found to be similar.     

Characteristics of acute respiratory viral infections in children under conditions of technogenic environmental pollution

The results of observations on children with acute virus respiratory infections (ARVI) and who had long been residents of zones with different levels of technogenic pollution of the atmospheric air are presented. The technogenic pollution of the environment has been found to exert influence on the spread and clinical course of ARVI in children, this influence being the more pronounced, the higher is the level of xenobiotics in the atmospheric air. The severity of the disease is noted to depend on the development of a number of syndromes, aggravating the course of ARVI, such as the neurotoxic and bronchoobstructive syndromes. Bronchical and ENT lesions are the most frequent complication of the main disease. The child population residing under the conditions of high technogenic environmental pollution should be regarded as a group of risk subject to the aggravated course of ARVI, and the examination of sick children should be made with due regard to this circumstance.     

Pulmonary function and incident bronchitis and asthma in children: a community-based prospective cohort study

Background

Previous studies revealed that reduction of airway caliber in infancy might increase the risks for wheezing and asthma. However, the evidence for the predictive effects of pulmonary function on respiratory health in children was still inconsistent.

Methods

We conducted a population-based prospective cohort study among children in 14 Taiwanese communities. There were 3,160 children completed pulmonary function tests in 2007 and follow-up questionnaire in 2009. Poisson regression models were performed to estimate the effect of pulmonary function on the development of bronchitis and asthma.

Results

After adjustment for potential confounders, pulmonary function indices consistently showed protective effects on respiratory diseases in children. The incidence rate ratios of bronchitis and asthma were 0.86 (95% CI 0.79–0.95) and 0.91 (95% CI 0.82–0.99) for forced expiratory volume in 1 second (FEV₁). Similar adverse effects of maximal mid-expiratory flow (MMEF) were also observed on bronchitis (RR = 0.73, 95% CI 0.67–0.81) and asthma (RR = 0.85, 95% CI 0.77–0.93). We found significant decreasing trends in categorized FEV₁ (p for trend = 0.02) and categories of MMEF (p for trend = 0.01) for incident bronchitis. Significant modification effects of traffic-related air pollution were noted for FEV₁ and MMEF on bronchitis and also for MMEF on asthma.

Conclusions

Children with high pulmonary function would have lower risks on the development of bronchitis and asthma. The protective effect of high pulmonary function would be modified by traffic-related air pollution exposure.