The HIV infection epidemic in the city of Irkutsk under the conditions of drug abuse prevalence

The data on the spread of HIV infection in Irkutsk and Irkutsk Province, starting from March 9, 1999, are presented. The simultaneous appearance of 17 multiple morbidity foci of HIV infection, involving 2,227 persons into the epidemic, within the period of 8 months was noted. The age structure of the epidemic process was represented by 1,846 adults aged 18-50 years (83%), 256 adolescents aged 16-17 years (12.9%), 78 children aged 10-15 years (3.5%) and 17 persons of other ages (0.53%). The leading role in the age structure of the epidemic process belonged to young people aged 10-29 years (90.4% of cases). The epidemiological analysis made it possible to establish the fact that the epidemic was linked with the intravenous injection of heroin. The viral contamination of the drug is not excluded also in the process of its preparation for injection.     

Late observations in a familial foci of hepatitis B using a full set of specific markers of the infection

The complete set of specific markers of hepatitis B has been identified, thus making it possible to evaluate the spread of this infection in family foci, as well as the intensity and dynamics of the epidemic process, under the conditions of prolonged observations. The study has shown that the spread of hepatitis B infection is determined by the presence of HBeAg in antigen-positive patients with viral hepatitis B and HBsAg carriers.     

Everyday contact spread of viral hepatitis B

The results obtained in the study of the characteristic features of the spread of viral hepatitis B under the conditions of family foci are presented. Children with viral hepatitis B have been found to infect 4-5 persons per 1,000 contacts, while adults infect not more than 1 person per 1,000 contacts. The results of the study have led to the conclusion that the idea of the potential danger of hepatitis B patients as the source of infection depends on the forms of the infectious process taken into account in evaluating its epidemiological significance. Latent cases of hepatitis B virus infection appear more frequently among the contacts of sick children than among those of sick adults, but the manifest forms of the disease are more frequently caused by infection contacted from sick adults.     

Epidemiological significance of carriers of hyaluronidase-active meningococci

To find out the epidemiological role of the carriers of hyaluronidase-positive meningococcal strains, their spread in the foci of meningococcal infection, as well as outside these foci, was studied. For this purpose, altogether 5059 persons from 40 family foci of infection and 40 organized groups were examined. The number of carriers of hyaluronidase-active meningococci, detected among those of them who had contacts with sick persons, was 13 times greater than among the persons having no such contacts. In preschool institutions with unfavorable morbidity situation this number was 16 times greater than in those with favorable situation. In the family foci carriers of hyaluronidase-active meningococci constituted 80-88 %. The percentage of the carriers of hyaluronidase-active meningococci causing cases of the generalized form of meningococcal infection varied in different groups. According to the results obtained in this study, the threshold percentage of such carriers constituted 30 in preschool institutions, 36 in boarding schools and 50 in common school and in hostels for adults.     

The role of respiratory tract viruses in the etiology of obstructive bronchitis in infants

Out of 524 children with acute respiratory infections in 141 obstructive bronchitis was diagnosed (OZO). Seventy cases could be linked to viral infection. Viral infections tested (influenza virus A, B, parainfluenza typ 1-3, RSV, adenoviruses) were more frequently associated with OZO than other acute respiratory infections of unknown etiology. Majority infections induced by influenza virus A and parainfluenza virus typ 2 were accompanied by OZO symptoms. Of the highest risk of acquiring OZO despite of viral infection participation, were children of 4-12 months of age. OZO associated viral infections prevailed during autumn-winter season, while in spring-summer period undetermined factors were the major cause of OZO. In serum samples of children with OZO, despite of etiology of the disease, higher level of IgE was found than in a group of children without the symptoms. In the case of OZO of unestablished etiology the level of serum IgE was significantly higher than in the cases when viral etiology of the disease was found.     

Spread of viral hepatitis in organized children's collectives and the methods for its early diagnosis]

The authors present the results of observations over 407 children aged from 2 months to 16 years from the foci of viral hepatitis in children's collective bodies. During the quarantine a determination was made in children of the glutamic-pyroracemic, glutamic-oxalic transaminases (GPT and GOT, respectively) and of the hepatitis B antigen (HBAg). A necessity of using the enzymatic tests for the purpose of early diagnosis of viral hepatitis was shown, since 84% of the cases developing in the next focus coursed as an unicteric form without any markked clinical signs; HBAg was revealed in 6.1% of the children examined. A complex examination of the personnel and of the persons who came in contact with the patients with viral hepatitis showed the ways of spread of hepatitis B in a collective body; it was found that the viral hepatitis B infection took place both by parenteral and enteral routes. The expediency of active observation over the children, recipients of blood and plasma, with determination in them of the activity of the enzymes and HBAg for early diagnosis of parenteral infection was substantiated. It was also shown that the incidence of the unicteric forms of viral hepatitis in a focus of infection depended not on the periods of gamma-globulin administration but on the age of children who contracted the infection. Thus, the prevalence of the unicteric forms of the disease over the icteric ones in children under 3 years of age was more pronounced than in older children.     

Distinctive and critical roles for cellular immunity and immune-inflammatory response in the immunopathology of Sendai virus infection in mice

Respiratory viral infections result in severe pulmonary injury, to which host immune response may be a significant contributor. At present, it is not entirely clear the extent to which lung injury is a necessary consequence of host defense. In this report, we use functional genomics approach to characterize the key roles of cellular immunity and immune-inflammatory response in the immunopathology of Sendai virus infection in resistant C57BL/6J and susceptible DBA/2J mice. Infected mice manifested an immune-inflammatory response characterized by the pulmonary influx of neutrophils and mononuclear cells. DBA/2J mice mounted a vigorous immune response, with significant up-regulation of cytokine/chemokine genes in two successive waves through the course of infection. Whereas, C57BL/6J mice displayed an efficient immune response with less severe pathology and clusters of immune-inflammatory responsive genes were exclusively up-regulated on day 4 in this strain. Overall, DBA/2J mice exhibited a dysregulated hyper-inflammatory cytokine/chemokine cascades that does not limit viral spread resulting in a predisposition to severe lung pathology. This response is similar to severe human respiratory paramyxovirus infections, which will serve as a model for the elucidation of hyper-immune inflammatory response that result to severe immunopathology in respiratory viral infections.     

Roles of the gut microbiota in severe SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. The pathophysiological mechanisms linking gut dysbiosis and severe SARS-CoV-2 infection are poorly understood, although gut microbiota disorders are related to severe SARS-CoV-2 infections. The roles of the gut microbiota in severe SARS-CoV-2 infection were compared with those in respiratory viral infection, which is an easily understood and enlightening analogy. Secondary bacterial infections caused by immune disorders and antibiotic abuse can lead to dysregulation of the gut microbiota in patients with respiratory viral infections. The gut microbiota can influence the progression of respiratory viral infections through metabolites and the immune response, which is known as the gut–lung axis. Angiotensin-converting enzyme 2 is expressed in both the lungs and the small intestine, which may be a bridge between the lung and the gut. Similarly, SARS-CoV-2 infection has been shown to disturb the gut microbiota, which may be the cause of cytokine storms. Bacteria in the gut, lung, and other tissues and respiratory viruses can be considered microecosystems and may exert overall effects on the host. By referencing respiratory viral infections, this review focused on the mechanisms involved in the interaction between SARS-CoV-2 infections and the gut microbiota and provides new strategies for the treatment or prevention of severe SARS-CoV-2 infections by improving gut microbial homeostasis.     

Spatial patterns of protein expression in focal infections of human cytomegalovirus

Human cytomegalovirus (HCMV) is a medically significant human pathogen that infects a wide range of cell and tissue types. During infection, HCMV activates a variety of signal transduction pathways that induce profound changes in cellular processes and dramatically affect cellular gene expression patterns. To better define how these virus-host interactions affect the local microenvironment and influence the spatial and temporal spread of HCMV, we initiated HCMV focal infections on normal human dermal fibroblast monolayers and monitored viral gene expression patterns and infection spread over 45 days. To establish baseline temporal measurements of HCMV infection and spread in cell monolayers, we characterized the influence of three experimental variables on viral gene expression: cell plating density, the presence of serum, and neutralization of cellular antiviral responses with an antibody against interferon-beta. We found that high cell plating density or the inclusion of serum correlated with enhanced HCMV infection spread. Dramatic differences in the expression pattern of the viral immediate early 2 (IE2) gene were observed under these conditions as compared to low plating density or the absence of serum. In the latter case round, uniform foci were observed with a clear wave of IE2 expression visible in advance of a late stage viral protein, envelope glycoprotein B. By contrast, larger irregular foci with arms of IE2 expression were observed in the presence of serum. Addition of the antibody had little effect on the rate of spread, which is consistent with the knowledge that HCMV represses antiviral responses during infection. This experimental system provides a useful means to visualize and quantify complex virus-host interactions.     

Prevention of acute enteric infections and viral hepatitis A in the Krasnodar Territory appearing in connection with a natural disaster in 2002

Materials on the sanitary and epidemiological situation in the Krasnodar Territory in connection with emergency situations (intensive snowfalls, heavy showers, high floods) in 2002 are presented. The scope of the destruction of the systems ensuring the life provision of the population in the affected regions of the territory is shown. To carry out the epidemiological surveillance on acute enteric infections, to make corrections of the planned prophylactic measures, as well as the timely solutions of problems connected with controlling the epidemiological situation, the daily monitoring of the level and dynamics of infectious morbidity in individual settlements among different age and professional groups, as well as the foci of infections, was established. 65 cases of acute enteric infection and 4 cases of viral hepatitis A were registered in the affected areas, which did not exceed the average morbidity figures for many years. A complex of sanitary, hygienic and prophylactic measures was carried out by the sanitary and epidemiological service of the territory, which made it possible to maintain human morbidity in acute enteric infections and viral hepatitis A in the affected areas on the sporadic level.     

The spread of HB virus infection in familial foci in a territory hyperendemic for hepatitis B

Epidemiological surveillance with the use of highly sensitive techniques for the indication of markers of hepatitis B (HB) virus infection in their dynamics has made it possible to find out that at a territory, hypersensitive for HB, along the existing high risk of this infection as the result of parenteral medical manipulations the intensive natural transmission of HB virus infection occurs under the conditions of everyday contacts with sources of the infection, patients with chronic forms of HB virus infection being of the highest epidemic importance. Under these conditions, children aged up to 7 years have been found to belong to the highest risk group. As a consequence, children of this age should be covered in future by specific preventive measures against HB. The spread of the epidemic process of HB virus infection in family foci is usually manifested by anicteric (usually not diagnosed) forms of this infection. All these circumstances make it expedient to develop antiepidemic and prophylactic measures in the foci of HB.     

Social contacts and the locations in which they occur as risk factors for influenza infection

The interaction of human social behaviour and transmission is an intriguing aspect of the life cycle of respiratory viral infections. Although age-specific mixing patterns are often assumed to be the key drivers of the age-specific heterogeneity in transmission, the association between social contacts and biologically confirmed infection has not previously been tested at the individual level. We administered a questionnaire to participants in a longitudinal cohort survey of influenza in which infection was defined by longitudinal paired serology. Using a variety of statistical approaches, we found overwhelming support for the inclusion of individual age in addition to contact variables when explaining odds of infection: the best model not including age explained only 15.7% of the deviance, whereas the best model with age explained 23.6%. However, within age groups, we did observe an association between contacts, locations and infection: median numbers of contacts (or locations) reported by those infected were higher than those from the uninfected group in every age group other than the youngest. Further, we found some support for the retention of location and contact variables in addition to age in our regression models, with excess odds of infection of approximately 10% per additional 10 contacts or one location. These results suggest that, although the relationship between age and incidence of respiratory infection at the level of the individual is not driven by self-reported social contacts, risk within an age group may be.     

Respiratory viruses augment the adhesion of bacterial pathogens to respiratory epithelium in a viral species- and cell type-dependent manner

Secondary bacterial infections often complicate respiratory viral infections, but the mechanisms whereby viruses predispose to bacterial disease are not completely understood. We determined the effects of infection with respiratory syncytial virus (RSV), human parainfluenza virus 3 (HPIV-3), and influenza virus on the abilities of nontypeable Haemophilus influenzae and Streptococcus pneumoniae to adhere to respiratory epithelial cells and how these viruses alter the expression of known receptors for these bacteria. All viruses enhanced bacterial adhesion to primary and immortalized cell lines. RSV and HPIV-3 infection increased the expression of several known receptors for pathogenic bacteria by primary bronchial epithelial cells and A549 cells but not by primary small airway epithelial cells. Influenza virus infection did not alter receptor expression. Paramyxoviruses augmented bacterial adherence to primary bronchial epithelial cells and immortalized cell lines by up-regulating eukaryotic cell receptors for these pathogens, whereas this mechanism was less significant in primary small airway epithelial cells and in influenza virus infections. Respiratory viruses promote bacterial adhesion to respiratory epithelial cells, a process that may increase bacterial colonization and contribute to disease. These studies highlight the distinct responses of different cell types to viral infection and the need to consider this variation when interpreting studies of the interactions between respiratory cells and viral pathogens.     

280例呼吸道感染儿童呼吸道病毒病原学检出情况及流行规律分析

目的:了解呼吸道感染儿童呼吸道病毒病原学检出情况及其流行规律,为儿童呼吸道感染的预防、诊断及治疗提供病原学依据。方法:选取2016年1月-2017年12月期间中国人民解放军中部战区总医院收治的280例呼吸道感染患儿为研究对象,分析患儿呼吸道分泌物中呼吸道病毒的检出情况,并分析呼吸道感染儿童呼吸道病毒感染与年龄、季节、疾病类型的关系。结果:280例呼吸道感染患儿中共检出98份阳性标本,阳性率为35.00%,其中有2份标本中检出2种病毒感染,混合感染阳性率为0.71%;在所有病毒类型中,呼吸道合胞病毒(RSV)病毒感染阳性率最高。1岁患儿的病毒感染阳性率最高,与其他年龄段病毒感染阳性率比较差异有统计学意义(P0.05)。呼吸道感染患儿春季、冬季的病毒感染阳性率明显高于夏季、秋季(P0.05)。不同呼吸道感染疾病类型患儿病毒感染阳性率比较差异有统计学意义(P0.05),以喘息性肺炎、毛细支气管炎、肺炎患儿病毒感染阳性率较高。结论:RSV是呼吸道感染儿童呼吸道病毒感染的主要致病病原体,1岁的婴幼儿较易感染,春季、冬季为其高发季节,且以肺炎、毛细支气管炎、喘息性肺炎患儿的病毒感染阳性率较高。     

569例呼吸道感染住院儿童7种常见呼吸道病毒病原学分析

目的了解呼吸道感染住院患儿呼吸道病毒的分布情况。方法选取2015年7月至2016年6月呼吸道感染的住院患儿病例,抽取鼻咽分泌物,采用直接免疫荧光法检测常见的7种病毒,即呼吸道合胞病毒(RSV)、甲型流感病毒(IVA)、乙型流感病毒(IVB)、副流感病毒1型(PIV1)、副流感病毒2型(PIV2)、副流感病毒3型(PIV3)、腺病毒(IVD)。结果共有569例样本送检,193例病毒检测阳性(33.92%),其中有3例为2种病毒的混合感染。男性共369例,女性共200例。其中RSV、PIV3、ADV的感染率居前三位。呼吸道病毒的感染率随着患儿年龄的增长逐渐下降,除新生儿外,6个月内的婴幼儿呼吸道病毒检出率最高。RSV检测阳性率自11月开始呈增高趋势,12月最高,达55.86%。PIV3的检出高峰出现在7月,达13.64%。结论 RSV是本地区儿童呼吸道感染最常见的病毒。呼吸道病毒的检出率与年龄、季节等因素有关。     

Phase changes in the population of group A streptococci and their influence on the course of the epidemic process of tonsillitis

This work presents the data on the complex evaluation of the population of group A streptococci, studied at each of four phases (reservation, epidemic transformation, epidemic spread, reservational transformation) of the course of the epidemic process of streptococcal infection of the respiratory tracts (tonsillitis) in an organized group of adults. The characterization of the phases of the infective agent in accordance with the level of the carrier state, the size of streptococcal foci and the virulence of streptococci is given. Thus, the study shows that the heterogeneity of group A streptococci with respect to their virulence reaches its maximum level at the phases of reservation and epidemic spread and its minimum level at the phases of epidemic and reservational transformation. The size of streptococcal foci in carriers and the virulence of streptococci isolated from them are the inter-related unidirectional signs of the population of the infective agent and, at the same time, the main factors responsible for the phase character of the epidemic process and the morbidity level in tonsillitis.     

Aetiology of Acute Respiratory Tract Infections in Hospitalised Children in Cyprus

In order to improve clinical management and prevention of viral infections in hospitalised children improved etiological insight is needed. The aim of the present study was to assess the spectrum of respiratory viral pathogens in children admitted to hospital with acute respiratory tract infections in Cyprus. For this purpose nasopharyngeal swab samples from 424 children less than 12 years of age with acute respiratory tract infections were collected over three epidemic seasons and were analysed for the presence of the most common 15 respiratory viruses. A viral pathogen was identified in 86% of the samples, with multiple infections being observed in almost 20% of the samples. The most frequently detected viruses were RSV (30.4%) and Rhinovirus (27.4%). RSV exhibited a clear seasonality with marked peaks in January/February, while rhinovirus infections did not exhibit a pronounced seasonality being detected almost throughout the year. While RSV and PIV3 incidence decreased significantly with age, the opposite was observed for influenza A and B as well as adenovirus infections. The data presented expand our understanding of the epidemiology of viral respiratory tract infections in Cypriot children and will be helpful to the clinicians and researchers interested in the treatment and control of viral respiratory tract infections.     

Certain data concerning the analysis of the foci of infectious hepatitis in cases of subsequent occurrence of the disease in families

Materials of epidemiological analysis of familial infectious hepatitis nidality in 104 families are presented. The data obtained pointed to the preponderant affection of children constituting 97.1% of primary and 87.7% of subsequent cases in familial foci. Infection was brought to the families by schoolchildren in 57.7% of the cases, and by organized preschoolchildren--in 31.7% of the cases. The greatest affection of schoolchildren aged from 7 to 14 years in the foci with subsequent occurrence of the disease (77.7%) was explained by their marked age activity. This led to the conclusion that mass prophylaxis with alpha-globulin of these particular groups of children was of primary importance. The differences of the specific ratio of adults who contracted the disease in familial foci and in the region as a whole pointed to the possibility of infection of adults outside the family and on the prevalence in them of serum hepatitis.     

Non-invasive Imaging of Sendai Virus Infection in Pharmacologically Immunocompromised Mice: NK and T Cells,but not Neutrophils,Promote Viral Clearance after Therapy with Cyclophosphamide and Dexamethasone

In immunocompromised patients, parainfluenza virus (PIV) infections have an increased potential to spread to the lower respiratory tract (LRT), resulting in increased morbidity and mortality. Understanding the immunologic defects that facilitate viral spread to the LRT will help in developing better management protocols. In this study, we immunosuppressed mice with dexamethasone and/or cyclophosphamide then monitored the spread of viral infection into the LRT by using a noninvasive bioluminescence imaging system and a reporter Sendai virus (murine PIV type 1). Our results show that immunosuppression led to delayed viral clearance and increased viral loads in the lungs. After cessation of cyclophosphamide treatment, viral clearance occurred before the generation of Sendai-specific antibody responses and coincided with rebounds in neutrophils, T lymphocytes, and natural killer (NK) cells. Neutrophil suppression using anti-Ly6G antibody had no effect on infection clearance, NK-cell suppression using anti-NK antibody delayed clearance, and T-cell suppression using anti-CD3 antibody resulted in no clearance (chronic infection). Therapeutic use of hematopoietic growth factors G-CSF and GM-CSF had no effect on clearance of infection. In contrast, treatment with Sendai virus—specific polysera or a monoclonal antibody limited viral spread into the lungs and accelerated clearance. Overall, noninvasive bioluminescence was shown to be a useful tool to study respiratory viral progression, revealing roles for NK and T cells, but not neutrophils, in Sendai virus clearance after treatment with dexamethasone and cyclophosphamide. Virus-specific antibodies appear to have therapeutic potential.