Emergency situations in the North Caucasus and role of specific immunoprophylaxis in eradication and prevention of epidemiological consequences

Information on emergency situations (ES) on the territory of the North Caucasus from the 90s of the last century till the present moment is presented. The importance of the specific immunoprophylaxis of infections for the liquidation of epidemiological aggravations in ES and for their prevention is shown. Information on the scope of specific immunoprophylaxis in the zones of ES and on different approaches to its carrying out. The conclusion was made on the expediency of making corrections in the normative documents of the Ministry of Health of the Russian Federation, regulating planned vaccinations and vaccinations made on epidemic indications in connection with different kinds of ES.     

Prevention of epidemiological consequences during an extreme situation caused by the natural disaster in the Republic of North Ossetia-Alania

Information on the organization of interaction between different services responsible for restoration works, sanitary cleaning, disinfection under the conditions of the emergency situation is presented. The activity of the sanitary and epidemiological services in the areas in the Republic of North Ossetia-Alania, affected by high flood, is described. Measures aimed at the epidemiological surveillance of acute enteric infections, the control of the quality of drinking water and foodstuffs, the bacteriological study of material samples taken from humans, vaccinal and phage prophylaxis have taken an important place in the work of the institutions of sanitary and epidemiological surveillance. As the result of all these measures the sanitary and epidemiological service has managed to prevent the aggravation of the sanitary and epidemiological situation in the republic.     

Basic measures for prevention of the epidemiological consequences of a natural disaster in the North Caucasus in 2002

The system of organizational and prophylactic measures, carried out with a view to prevent epidemiological aggravations in connection with the natural calamity in the Southern Federal District of the Russian Federation in 2003, is described. Proposals on the improvement of the system of preventive measures, including the monitoring of the epidemiological, sanitary and hygienic situation, personnel training, technical provision, the cooperation of different services and departments, capable of ensuring the liquidation of the consequences of emergency situations of the natural character, are made.     

The epidemiological consequences of leprosy-tuberculosis co-infection

While in antiquity both leprosy and tuberculosis were prevalent in Europe, leprosy declined thereafter and, simultaneously, tuberculosis prevalence increased. Since both diseases are caused by mycobacterial infections, it has been suggested that there might be a causal relationship between both epidemics.Chaussinand observed the inverse prevalence of leprosy and tuberculosis and suggested that individuals with a latent tuberculosis infection are protected from acquiring leprosy. His cross-immunity hypothesis has been countered more recently by a co-infection hypothesis. The latter suggestion, proposed by Donoghue, states that people being infected with multi-bacillary leprosy are more susceptible to tuberculosis, which leads to increased mortality from the disease.This study utilizes mathematical modeling to explore the epidemiological consequences of the co-infection hypothesis for realistically confined parameter values. While the co-infection hypothesis appears plausible at first glance, a second thought reveals that it comprises also substantial consequences for tuberculosis epidemics: if co-infection raises the mortality rate above that of purely tuberculosis infected persons, then tuberculosis might as well be eradicated by leprosy. It is the specific interplay of both increased susceptibility towards tuberculosis and increased death rate when co-infected that determines the epidemiological fate.As a result of this analysis, it is shown that there is a large parameter region where the eventual disappearance of leprosy could indeed be explained by co-infection. This parameter region is considerably larger than that predicted by the cross-immunity hypothesis. This shows that the co-infection hypothesis should be considered a significant alternative to the cross-immunity hypothesis. The time scales at which the effects of co-infection are observed depend critically on the spatial distribution of the individuals but reach epidemiologically realistic values for rather immobile individuals with local interaction.     

The epidemiological consequences of immune priming

Exposure to low doses of pathogens that do not result in the host becoming infectious may ‘prime’ the immune response and increase protection to subsequent challenge. There is increasing evidence that such immune priming is a widespread and important feature of invertebrate host–pathogen interactions. Immune priming clearly has implications for individual hosts but will also have population-level implications. We present a susceptible–primed–infectious model—in contrast to the classic susceptible–infectious–recovered framework—to investigate the impacts of immune priming on pathogen persistence and population stability. We describe impacts of immune priming on the epidemiology of the disease in both constant and seasonal environments. A key result is that immune priming may act to destabilize population dynamics. In particular, when the proportion of individuals becoming primed rather than infected is high, but this priming does not confer full immunity, the population may be strongly destabilized through the generation of limit cycles. We discuss the implications of our model both in the context of invertebrate immunity and more widely.     

Imperfect vaccination: some epidemiological and evolutionary consequences

An aim of some vaccination programmes is to reduce the prevalence of an infectious disease and ultimately to eradicate it. We show that eradication success depends on the type of vaccine as well as on the vaccination coverage. Vaccines that reduce the parasite within-host growth rate select for higher parasite virulence and this evolution may both increase the prevalence of the disease and prevent disease eradication. By contrast, vaccines that reduce the probability of infection select against virulence and may lead more easily to eradication. In some cases, epidemiological feedback on parasite evolution yields an evolutionary bistable situation where, for intermediate vaccination coverage, parasites can evolve towards either high or low virulence, depending on the initial conditions. These results have practical implications for the design and use of imperfect vaccines in public- and animal-health programmes.     

Non‐cultivated grass hosts of yellow dwarf viruses in Ethiopia and their epidemiological consequences on cultivated cereals

The yellow dwarf (YD) disease complex epidemics in cultivated cereals grown in a specific period of the year mainly depend on the presence of potential reservoir alternative hosts harbouring both the viruses and the vectors over the off‐season and serve as a source of inoculum in subsequent cropping season, further spread being supported by efficient aphid vectors. As such, an extensive and intensive exploration to generate base line information on the identity and prevalence of YD viruses [barley yellow dwarf virus (BYDV)‐PAV, BYDV‐MAV and BYDV‐SGV; cereal yellow dwarf virus (CYDV)‐RPV; and maize yellow dwarf virus (MYDV)‐RMV] on wild annual and perennial grasses and forage cereals alternative hosts was conducted consecutively during 2013–2015 main‐ and short‐rainy seasons in cereals growing belts of Ethiopia. Random sampling was employed to collect the samples that were tested by the tissue blot immunoassay (TBIA) to identify the YDVs associated with the hosts using a battery of virus‐specific polyclonal antibodies. Of 13,604 samples analysed, YDVs were detected in 392 (2.9%) samples, which consisted of various wild grasses, forage cereals and three cultivated crops. YDVs were identified from at least 26 grass species and forage cereals, some of them are new records, and some are previously documented hosts. To our knowledge, this is the first report of YDV infection of Andropogon abyssinicus (FresenR.Br. ex Fresen.) (BYDV‐PAV), Avena abyssinica Hochst (BYDV‐PAV), Bromus pectinatus Thunb. (BYDV‐PAV and BYDV‐MAV), Eragrostis tef (Zuccagni) Trotter (BYDV‐PAV), Eragrostis sp. (BYDV‐PAV), Hyparrhenia anthistrioides Stapf. (BYDV‐PAV), Panicum coloratum L. (BYDV‐PAV), Polypogon monspeliensis (L.) Desf. (BYDV‐PAV), Setaria pumila (Poir.) Roem & Schult (BYDV‐PAV, BYDV‐SGV and MYDV‐RMV), Setaria australiensis (Scribn. & Merrill) Vickery (BYDV‐PAV, BYDV‐MAV and CYDV‐RPV) and Snowdenia polystachya (Fresen.) Pilg (BYDV‐PAV, BYDV‐MAV, BYDV‐SGV, CYDV‐RPV and MYDV‐RMV).     

Viral hepatitis E: its epidemiological characteristics in the Republic of Tajikistan

The characteristic feature of the Republic of Tajikistan, as well as other republics of Central Asia, is the wide spread of virus hepatitis E. The epidemiology of this grave disease, recently known as virus hepatitis non A, non B with the fecal-oral mechanism of transmission of this infection, has been yet insufficiently studied. The article points out to the specific character of this infection which essentially differs, both epidemiologically and clinically, from other enteric hepatitis (hepatitis A), also hyperendemic for the republic. The results of the study of the immunostructure of the population with respect to both hepatitis E and hepatitis A are presented.     

Shigellosis and other acute intestinal infections in the Republic of Tajikistan: the epidemiological patterns

Acute enteric infections (AEI), including shigellosis, are characterized by their extremely wide spread in Tajikistan. Their hyperendemicity is due to a high activity of the water route of transmission under the conditions of hot climate. The morbidity level of AEI both in the republic as a whole and in its individual territories has been found to directly depend on the degree of the potential epidemiological danger of the water supply system, as well as on the quality of water used by the population in the presence of its pronounced deficiency. The important role of breast feeding for the prophylaxis of AEI among young children is shown.     

Spike sequences and their consequences

Spatio-temporal patterns of spikes have an advantage of representing information by their spike composition similar to words of languages. First we review the models of neuronal coding, then we discuss technical aspects of detecting spatio-temporal spike patterns. We argue by presenting data from rat hippocampus that spike trains recorded simultaneously from multiple pyramidal cells are not independent. Their hidden dependency structure can be revealed by spike 'sequences', defined as a set of neurons which fire in a specific temporal order with certain delay between successive spikes. The only way to prove their existence in vivo is to show that they recur with higher than by-chance frequency. We observed that 'sequences' possess 'compositional' features and that a given spike composition is time scale invariant. We illustrate that the same neuron can be a part of different 'sequences' and 'sequences' recur in a temporally compressed fashion during slow wave sleep. The statistical significance of 'sequences' is testable. Their biological significance has been implicated by experiments where recurrence rate of the sequences during different behavioral sessions were compared. As consistent with the 'replay hypothesis' of memory consolidation, new sequences generated during the wake state are persistent during the subsequent sleep. Thus, information acquired during the wake state and represented by spatio-temporal patterns of spikes may transfer to the neocortex during sleep. Our results suggest that 'sequences' reflect the activation of specific but configurable circuitries during exploratory behavior, followed by spontaneous re-activation of the same circuitry during sleep. Whether the delay structure of spikes as a combination is an effective input to single neurons downstream or 'sequence' components are being processed in parallel pathways and evaluated independently is an open question.     

Genetic epidemiological study of populations in three regions of Chuvashia Republic

Comprehensive population genetic and medical genetic studies were performed in three raions (districts) of Chuvashia. The population of these districts is more than 90% Chuvash. About 70% of the families that completed reproduction had two or three children. The proportion of families with four or more children was 18%. The duration of generation was 27.6 years. The differential fertility and differential mortality indices in the Chuvash population were estimated at 0.33 and 0.076, respectively. The total index of differential selection was 0.403, which is typical of modern urbanized populations. Mean values of local inbreeding calculated from Malecot's model of isolation by distance were 0.00124 and 0.00377 for the urban and rural populations, respectively, of the districts studied. The prevalence rates of autosomal dominant (AD), autosomal recessive (AR), and X-linked diseases were found to be 0.47, 0.52, and 0.35 per 1000, respectively, in the urban population and 1.62, 1.14, and 0.31 per 1000, respectively, in the rural population. Significant correlation between the local inbreeding and prevalence rates of AD and AR diseases was found. A total of 43 AD and 43 AR diseases were identified. Some of them were not found in previous studies on other populations.     

Morbidity in sexually transmitted infections in the Republic of North Ossetia-Alania and the improvement of epidemiological surveillance

The present situation in sexually transmitted diseases (STD) in the Republic of North Ossetia-Alania is characterized as unfavorable. Morbidity in different nosological forms has been found to show different tendencies. The causes of elevated morbidity in STD observed in recent years have social, economic, psychological, ethical and moral, rather than medical character. The main trends in the improvement of epidemiological surveillance on STD have been determined.     

Stressors,Supports and the Social Ecology of Displacement: Psychosocial Dimensions of an Emergency Education Program for Chechen Adolescents Displaced in Ingushetia,Russia

This study explored the psychosocial benefits of an emergency education intervention serving adolescents displaced by the war in Chechnya. It set out to describe key stressors and sources of social support available to youth served by the International Rescue Committee's (IRC) emergency education program. Interviews were conducted with 57 Chechen adolescents living in spontaneous settlements in Ingushetia, Russia in the fall of 2000. Of particular interest was the degree to which the education program addressed specified psychosocial goals. Findings indicated that young people and their families faced a number of physical and emotional stressors. The data indicated that the emergency education program provided benefits by enriching sources of social support, providing meaningful activity and a sense of hope for the future, and creating a space for young people to spend time and connect to others. However, the contrast between the desire of adolescents “to live like other kids” and the options available to them presented a dilemma for the emergency education program: adolescents craved normalcy, but for any intervention to be delivered, it had to first begin with creative and adaptive strategies that were by no means a complete replacement for formal, mainstream education. The programmatic and policy implications of these findings are presented here.