Characteristics of self-regulation of the epidemic process of infection caused by the Epstein-Barr virus (Herpesviridae: Lymphocryptovirus, HHV-4)

INTRODUCTION

Among the available scientific literature, there are no publications addressing processes of self-regulation in the parasite-host population systems with reference to chronic infections, including the infection caused by the Epstein-Barr virus (EBV infection). The aim of the study is to assess manifestations of the epidemic process of chronic EBV infection through the lens of the basic tenets of the theory of self-regulation of parasitic systems.

MATERIALS AND METHODS

The study was performed using data from scientific publications selected from such database sources as Scopus, Web of Science, Cochrane Library, PubMed, CyberLeninka, RSCI, etc. The list of analyzed publications included published articles of the authors of this study, reporting the results of the retrospective epidemiological analysis of the incidence of infectious mononucleosis in Russia in general and in Moscow in particular, as well as the results of the laboratory tests regarding the detection frequency of specific antibodies to EBV proteins.

RESULTS

The chronic course of EBV infection promotes a close long-term interaction between the pathogen and the host. The genetic variability of the pathogen and the functions of specific and nonspecific human immune defense systems play a key role in the interaction between two heterogeneous populations and underlie their phasal self-transformation. A variety of social and natural factors (adverse chemical, physical, biological, climatic impacts, etc.) trigger the reactivation of chronic EBV infection, thus providing the continuous existence of additional sources of infection in the host population.

CONCLUSION

The analysis of the manifestations of chronic EBV infection in the context of the theory of self-regulation of parasitic systems promotes the understanding of the factors underlying the unevenness of its epidemic process. The obtained data can be adjusted for other infections having similar transmission mechanisms and virus life cycles (including other herpes infections) to map out strategies to control the epidemic process of chronic infections spread by aerosol transmission of the pathogen.

[The epidemic process of whooping cough at contemporary stage in the Republic of Kyrgyzstan]

The causes of epidemic outbreaks of pertussis infection in the Kyrgyz Republic were studied in order to optimize immunological surveillance of this infection. The object of the study was the epidemic process of whooping cough, and the subject of the study was the incidence of pertussis infection in 2009-2018 and official data on the outbreak of pertussis in 2018. To diagnose pertussis the bacteriological method was applied. The bacteriological inoculation of the samples was carried out in the laboratory of the Republican Clinical Infectious Diseases Hospital. The smear from posterior pharyngeal wall was collected from 2153 patients. The level of pertussis antibodies was determined by enzyme-linked immunosorbent assay (ELISA) using the RIDASCREEN Pertussis IgG test system (R-Biopharm, Germany) in various series. The study data testifies that despite the vaccine prevention and high inoculation coverage, the epidemic increases occurred in incidence of whooping cough in 2015 and 2018 with an intensive rate of 4.7 and 9.6 per hundred thousand of population, respectively. The evaluation of vaccination status of patients demonstrated that out of them 80.7% were non-immunized; the percentage of vaccinated patients made up to 13.1%. The analysis of the age structure testifies that the main group of the diseased consisted of children under one year of life (63.1%), the second group consisted of children aged 1-4 years (33.1%). The severe forms of infection were observed among children under one year of age (95.8%). According to the territorial distribution, the largest percentage of cases fall on Bishkek - 70% (426 cases) and Chuyskaya Oblast - 22.4% (137 cases). The sero-epidemiological study revealed high proportion of seronegative individuals in all studied groups, and the highest percentage was observed in the group of children 5-9 years old and adolescents of 15-19 years old - 62.8% and 62%, respectively.

Modeling of epidemic spreading with white Gaussian noise

Motivated by the need to include the different characteristics of individuals and the damping effect in predictions of epidemic spreading, we build a model with variant coefficients and white Gaussian noise based on the traditional SIR model. The analytic and simulation results predicted by the model are presented and discussed. The simulations show that using the variant coefficients results in a higher percentage of susceptible individuals and a lower percentage of removed individuals. When the noise is included in the model, the percentage of infected individuals has a wider peak and more fluctuations than that predicted using the traditional SIR model.