Objective. To establish a probable source of infection using phylogenetic analysis in the investigation of cases of HIV infection. Materials and methods. HIV genome sequencing was carried out using the kit ViroSeq (Celera). The phylogenetic tree was constructed using the maximum likelihood method in the Mega 6 program. As a comparison group, 40 samples of HIV-infected patients from the Krasnoyarsk region were used, as well as 25 nucleotide sequences of various HIV subtypes taken from the international GenBank database. The reliability of the resulting tree was evaluated in bootstrap analysis, a branch rotation test for a thousand random constructions.Results and discussion. The paper presents five cases of epidemiological investigations with a probable nosocomial and occupational mechanism of HIV infection transmission in the Krasnoyarsk region. In 2013, a study was conducted on the infection of three persons treated in the same hospital with an HIV-infected patient. A close genetic relationship of HIV was shown in newly identified individuals, the probable source could not be examined due to death. Second epidemiological investigation in 2013. The association of cases of infection between a newly diagnosed woman with HIV infection and a patient with a previously established HIV status is shown. Both persons were simultaneously in the same medical institution. To determine the direction of transmission of the virus, a test for the duration of infection was used. In 2014, after receiving medical care in four medical organizations, the patient was confirmed to be HIV positive. In all hospitals there were persons with a confirmed diagnosis of HIV infection. Three of them have been examined. The absence of a phylogenetic relationship was confirmed, the fourth died, the material could not be obtained from him. In 2015, a nurse was injured while caring for an HIV-positive patient. Phylogenetic analysis showed a high degree of genetic relationship between these cases of infection. In 2016, after a car accident, two patients were hospitalized in the intensive care unit. After some time, both were diagnosed with HIV infection. Four HIV-infected patients were in intensive care at the same time. Phylogenetic analysis was carried out in two newly identified individuals and one putative source. The association of infections in newly identified patients was shown, the alleged source could not be established.Conclusion. The use of molecular genetic methods in epidemiological investigations significantly improves the quality and accuracy of deciphering epidemic chains of HIV infection.

Aim : to assess the incidence, prevalence of HIV infection and population dynamics in populations with negative, zero and positive natural increase. Materials and Methods : Computer probabilistic modeling by the Monte Carlo method of the epidemic process of HIV infection in populations with different natural population growths was carried out. The parameters that are minimally necessary for such a description are used – population, birth rate, mortality, HIV prevalence, probability of HIV transmission. Results and discussion : When modeling the epidemic process, two main scenarios of the spread of HIV infection in a population without diagnostic, therapeutic and preventive effects were established. With a negative or zero population growth and a random distribution of healthy and infected individuals in the simulated space, the population density gradually decreases. At some point, the probability of contact of the infected and healthy person becomes less than the probability of an infected person to live up to this event. Under such conditions, the complete elimination of the virus from the population is theoretically possible. With a positive natural increase, it is possible to form a stable state in which the periods of increase in population size, incidence and prevalence of HIV infection change in a cyclical decline. HIV prevalence in countries such as Swaziland, Botswana and Lesotho has been at the level of 25–30% for many years. In this case, the population steadily grows. Based on the conducted simulation studies, it can be assumed that in these territories an evolutionarily stable balance was formed between the share of healthy and HIV-infected people in which the prevalence does not occur above 30%. Conclusions . The development of the epidemic process of HIV infection is determined by the dynamics of natural population growth. With a negative or zero natural growth and a random distribution of individuals in the simulated space, a complete elimination of the virus from the population is theoretically possible. With a positive natural increase, it is possible to form an evolutionarily stable cyclic balance between the proportion of healthy and HIV-infected people.

Relevance. According to US scientists, the percentage of people who do not know about their positive status is 20% of all people living with HIV. Moreover, this group provides 49% of new infections. Therefore, it can be assumed that information about HIV status has a significant epidemiological effect. Aim. To assess the change in risk behavior of HIV-infected persons after informing about the diagnosis and the frequency of occurrence of nonspecific symptoms of HIV infection. Materials and methods. For information on changing the behavior profile was developed, consisting of three sections. The first and third sections are aimed at elucidating the characteristics of sexual and drug behavior from the moment of probable infection to the moment of diagnosis, in comparison with the time period from the moment of reporting the diagnosis to the present. The second section of questions is aimed at determining the frequency of occurrence of nonspecific symptoms of early HIV infection. In the survey agreed to participate in 79 HIV-infected patients. The reliability of the results obtained was determined using the Wilcoxon Sign Test. Results. The message of the diagnosis of HIV infection contributed to the desire to abandon the systematic use of intravenous drugs. The proportion of people who denied drug use increased from 13 to 65% (p < 0.05). The number of people infected intensively (30 and more doses / month) using drugs has more than halved – from 38 to 17% (p < 0.05). The number of people denying drug use in groups increased from 10 to 45% (p < 0.05). From 55 to 12% (p < 0.05), the proportion of people who pass their syringe (needle) to another person to inject drugs has decreased. The number of persons who noted the presence of more than 5 partners per year after diagnosis decreased three times (p < 0.05). Only 23% of the respondents did not present any complaints in the period preceding the detection of HIV infection. Symptoms of acute respiratory disease marked 48%, 37% had fever, and other non-specific clinical manifestations of HIV infection. Conclusion. Communicating a positive HIV status to a patient reduces the likelihood of HIV transmission by drugs by 3–4 times and sexually by 2–3 times by changing risky behavior. Nonspecific symptoms of an acute viral disease before the detection of HIV infection were recorded in 48% of cases.

Aim: to assess the incidence, prevalence of HIV infection and population dynamics in populations with negative, zero and positive natural increase.Materials and Methods: Computer probabilistic modeling by the Monte Carlo method of the epidemic process of HIV infection in populations with different natural population growths was carried out. The parameters that are minimally necessary for such a description are used – population, birth rate, mortality, HIV prevalence, probability of HIV transmission.Results and discussion: When modeling the epidemic process, two main scenarios of the spread of HIV infection in a population without diagnostic, therapeutic and preventive effects were established. With a negative or zero population growth and a random distribution of healthy and infected individuals in the simulated space, the population density gradually decreases. At some point, the probability of contact of the infected and healthy person becomes less than the probability of an infected person to live up to this event. Under such conditions, the complete elimination of the virus from the population is theoretically possible. With a positive natural increase, it is possible to form a stable state in which the periods of increase in population size, incidence and prevalence of HIV infection change in a cyclical decline. HIV prevalence in countries such as Swaziland, Botswana and Lesotho has been at the level of 25–30% for many years. In this case, the population steadily grows. Based on the conducted simulation studies, it can be assumed that in these territories an evolutionarily stable balance was formed between the share of healthy and HIV-infected people in which the prevalence does not occur above 30%.Conclusions. The development of the epidemic process of HIV infection is determined by the dynamics of natural population growth. With a negative or zero natural growth and a random distribution of individuals in the simulated space, a complete elimination of the virus from the population is theoretically possible. With a positive natural increase, it is possible to form an evolutionarily stable cyclic balance between the proportion of healthy and HIV-infected people.

Introduction. Available data indicate that the effectiveness of the strategy of "90-90-90" varies considerably between countries. For example, Australia with figures 90-90-79 (2016) has not achieved the negative trend of the incidence and prevalence, while Niger 35-90-57 performance demonstrates a stable decrease in the HIV epidemic. One possible explanation for the observed processes may have different development of the epidemic process in populations that differ by demographic characteristics. From this we can assume that the epidemic control in a strategy of «90-90-90» or any other strategies will differ significantly in such self-regulating systems.Aim: modeling the dynamics of the epidemic process in populations with different probability of HIV transmission and negative, zero, positive population growth.Materials and methods: Computer probabilistic modeling by the Monte Carlo method was carried out. The following parameters were used to describe the epidemic process: population size, birth rate, mortality, HIV prevalence, lethality among patients with HIV/AIDS and probability of HIV transmission. The values of these parameters were close to the UNAIDS global statistics. It is assumed that the effective management of the epidemic reduce the probability of HIV transmission in the population. The dynamics of the population size, incidence and prevalence of HIV infection in populations with negative, zero, positive natural growth and the probability of HIV transmission in the population from 50% to 10% has been consistently studied. Statistical processing carried out by the Student method.Results and discussion. In populations with a negative population growth and a probability of HIV transmission of 0.5, incidence and prevalence at the initial stage are characterized by an increasing trend, reach peak values and decrease to zero. When reducing the probability of HIV transmission peak becomes plateau or directly take the downward shape. In general terms, similar patterns are recorded at zero population growth. The incidence and prevalence of HIV infection with a positive population growth are changing cyclically up and down. Change transmission probabilities range from 0.5 to 0.2 is characterized by a decrease in the frequency and amplitude of peaks increasing incidence and prevalence. When transmission probabilities at 0.1 epidemic process drops sharply. According to the simulation, any managerial impact in countries with negative population growth should be effective. Practical evidence does not contradict theory. For example, indicators "56-66-59" in Ukraine led to a decrease in the incidence. Management actions in populations with positive population growth that reduce the probability of HIV transmission by 20% or 40% are ineffective. When reaching 80%, the epidemic process abruptly stops.Conclusions. The effect of reducing the probability of HIV transmission in populations with a negative and zero population growth is expressed as a linear reduction in incidence and prevalence (at fixed lethality). In populations with a positive natural growth reduction transmission probabilities less than 40% strategically not effective, and when it reaches 80% potentiated abrupt cessation epidemic process.

Aim:to compare the incidence of recent cases of HIV infection in the population, recorded by the presence of p24 antigen and in thekit distinguish recent from longstanding infection.Materials and methods. Evaluation of recent HIV infection was carried out through studies of two cohorts of patients: 1) persons with negative / undetermined result of an immune blot and p24 antigen; 2) individuals with positive immune blot who were additionally studied using a test system to determine the duration of infection. Randomly in 2011, 2013, 2014 and 2015, 22%, 17%, 44% and 6% of all newly identified patients with a positive immune blot, respectively, were examined. Statistical processing, correlation coefficient and confidence intervals were calculated using Student’s t-test.Results.There is a close correlation between the detection rate of the p24 antigen of HIV and the frequency of occurrence of recent cases of infection registered among newly identified individuals with positive immune blot (the period of probable infection is less than 9 months). Correlation coefficient =0,91, p<0,05.Conclusion. The established dependence allows one to estimate the recent cases of infection in the population by a calculated method using only the frequency of occurrence of the p24 antigen included in the standard diagnostic algorithm of HIV infection. A formula is proposed in accordance with which it is necessary to add 0,6±0,2 to the frequency of occurrence of the p24 antigen expressed per 1000 individuals covered by screening. With a probability of 95%, the true value of the frequency of occurrence of recent cases of infections in a population will be in the calculated confidence interval.

Background:The information about the dynamics of the viral population and migration events that affect the epidemic in different parts of the Russia is insufficient. Possibly, the huge size of the country and limited transport accessibility to certain territories may determine unique traits of the HIV-1 evolutionary history in different regions.Objective:The aim of this study was to explore the genetic diversity of HIV-1 in the Krasnoyarsk region and reconstruct spatial-temporal dynamics of the infection in the region.Methods:The demographic and virologic data from 281 HIV-infected individuals in Krasnoyarsk region collected during 2011-2016 were analyzed. The time to the most recent common ancestor, evolutionary rates, population growth, and ancestral geographic movements was estimated using Bayesian coalescent-based methods.Results:The study revealed moderate diversity of the HIV-1 subtypes found in the region, which included A6 (92.3%), CRF063_02A (4.3%), B (1.1%), and unique recombinants (2.5%). Phylogenetic reconstruction revealed that the A6 subtype was introduced into Krasnoyarsk region by one viral lineage, which arose around 1996.9 (1994.5-1999.5). The phylogeography analysis pointed to Krasnoyarsk city as the geographical center of the epidemic, which further spread to central neighboring districts of the region. At least two epidemic growth phases of subtype A6 were identified which included exponential growth in early-2000s followed by the decline in the mid/late 2010s.Conclusion:This study demonstrates a change in the genetic diversity of HIV-1 in the Krasnoyarsk region. At the beginning of the epidemic, subtype A6 prevailed, subtypes B and CRF063_02A appeared in the region later.

Most HIV-1 tropism studies have involved non-A subtypes. Our aim was to study the prevalence of R5- and non-R5-tropic HIV-1 variants and the tropism occurrence relative to the CD4 counts, treatment experiences, transmission routes and other features of infection in Russia, where subtype A is presumably predominant. In this multicenter, single-step, cross-sectional, epidemiologic study, 943 HIV-1-infected patients were enrolled at 12 AIDS centers throughout Russia. Viral tropism was determined using a genotype method-based kit. The V3 loop sequences were analyzed using the geno2pheno resource. The tropism was successfully predicted for 823 (87.3%) patients. Frequencies of R5-tropic and non-R5-tropic viruses in successfully analyzed samples were 70.2% (578) and 29.8% (245), respectively. Co-receptor usage correlated significantly only with the treatment experiences (p = 0.018) and CD4 counts (p = 0.004). But there was no dependence of R5/non-R5 co-receptor usage frequencies on presence/absence of a therapy change (p = 0.664) or HIV infection duration (p = 0.458). According to the env sequences, 457 (83.6%) of the samples in study were subtype A and 70 (12.8%) were subtype B. This indicates a stabilizing of immune system and thus little emergence of X4 viruses. We suggest that CCR5-antagonists could be used in both naïve and experienced patients in Russia after determination of HIV tropism.

The study of the main regularities of the epidemic process in a closed population was carried out using a simple computer model. In a plane, points move at random. A few points are infected, the rest are not. When an infected and healthy point contacts, infection occurs. It is further assumed that the epidemic process will be controlled if the number of detected HIV infected persons at each time point is equal to or greater than the increment of infections in the previous period of time. An estimate of the minimum screening coverage necessary to perform this task. As a result of the research, it has been established that the rate of the epidemic process slows down due to a decrease in the probability of contact of the infected subject with a healthy individual. As a consequence, the minimum coverage required for screening is also reduced. In Krasnoyarsk Regional AIDS Center during 2011–2014 conducted the identification of early cases of infections among newly identified HIV infected individuals. The information obtained makes it possible to calculate effective screening coverage for a given period of time, which also has the same declining trend as in the model experiment, from 49% to 39%, respectively.

Aim: to conduct an analysis of the HIV infection management system adopted in the Russian Federation, to formulate the basic principles of optimization of this model for epidemiological and economic indicators. Materials and methods: the methods of system analysis were used in the work. The decomposition of the existing HIV management system into structural components made it possible to identify the most informative data collected in the standard Center of AIDS prevention. The optimal criteria for the management of the epidemic process of HIV infection have been determined, and functional links have been established between the parameters necessary to increase the efficiency available in the practical healthcare system. Results: the data with information sufficiency (sex, age, etc.) and redundancy (social groups, contingents of the surveyed population) were identified. The main principle of optimization of the HIV management system is formulated: to distribute the available financial resources, personnel, material resources between screening, treatment activities and preventive work in such a way that the rate of growth of new cases of infection is maximally close to zero (for a given level of funding). To develop such a system requires a mathematical model of the epidemic process. The principle of developing such a model: the use of data available in practical public health services, the possibility of adaptation to any territory with certain epidemiological features. The output should be the calculation of the optimal distribution of available financial resources, the forecast for the development of the epidemic in this distribution and the determination of the minimum amount necessary, at which the rate of epidemic development will acquire a negative trend. The structure of such a model, the required parameters and methods of mathematical modeling are described.

In this paper analyzed the publications of international databases HighWire, PubMed, Google Scholar in the period 1981–2016 years. Proposed an original classification models. All the basic mathematical models developed for the human immunodeficiency virus are categorized into 2 levels: organism and population. The organism level is divided into models of virus and human interaction (HIV replication, study of the kinetics of viral population in the development of the disease, the molecular mechanisms of inte- raction with immune cells) and models of the inhibitory effect of anti-retroviral drugs (simulations of different therapeutic schemes, the development of resistance mutations HIV in cell reservoirs, treatment as a preventive measure). The population level can be divided into models of spread of HIV in a population (the circulation of different genotypes of HIV, the analysis of human population structure by age, sex and risk of contingent and trends in different geographical areas, the study of factors contributing to the spread of HIV infection) and management models, making the most effective use of health care system resources for the counteract the epidemic (preventive work analysis, evaluation of the economic costs of screening, therapeutic activities, forecasting the socio-eco- nomic impact). The authors consider the most significant achievements of each of these groups, and highlight unresolved problems

The pol and env genome regions of the HIV-1 genetic variants circulating in the irkutsk region of russia in 1999 and 2012 were compared. The results of this work showed the dominance of the HIV-1 subtype a IDU-A genetic variant (100%) in this region. No primary resistance mutations in the pol gene in the treatment-naive patients were found. The heterogeneity of the viral population was found to be significantly increased based on the pol and env analysis among HIV-variants isolated in 2012 (12.88% and 2.16%) from the intravenous drug users as compared to HIV-variants that caused the outbreak of the HIV infection in 1999 (1.64% and 0.47%). In addition, the comparison of genetic distances of the pol and env gene sequences in the viruses isolated in 2012 from the HIV-positive persons infected through heterosexual intercourse and intravenous drug use demonstrated that the transmission route influenced the variability of the virus population. Among the viruses of IDU-A variant circulating in the area in 2012 the prevalence of X4-tropic variants was 24.7%.

The epidemiological situation for HIV infection in Russia remains to be extremely stringent, which requires a search for new, more efficient and cost-effective solutions aimed at countering the epidemic. The inclusion of laboratory studies with the use of a test system for the determination of the remoteness of HIV infection in routine surveillance practices will permit to determine the frequency of occurrence of early cases of infections among newly diagnosed HIV-positive persons. The analysis of this criterion at the population level will help to objectively evaluate the effectiveness of prevention, control activities carried out in a particular area. The increase of objectivity in the determination of the time elapsed from the moment of infection of HIV-1 with the use of the test system DSEIA-HIV-Ab-TERM provides the opportunity to use the obtained results in the epidemiological investigation for the purpose of more accurate and complete identification of contact persons. The determination of the probable period of infection may also be required in the solving the question on the prescription of antiretroviral therapy as a complementary study in the monitoring of HIV drug resistance. The aim of this work was to determine the effectiveness of the new test system DS-EIAHIV-Ab-TERM for the determination of the likely timing of HIV-1 infection. There were studied serum samples (plasma) of blood of HIV-infected persons with epidemiologically established time of infection (n = 281) and samples of commercial seroconversion panels. Results of the performed study showed that the probability of a correct detection of the remoteness of HIV-1 infection for samples from individuals with the most probable time of the established fact of infection was 95%, for samples of commercial seroconversion panels - 100%. The data demonstrated the high efficacy of the test system DS-“EIAHIV-Ab-TERM” in the determination of the most probable timing of infection with human immunodeficiency virus type 1, that in combination with the speed and simplicity of the procedure allows to recommend it for use in the laboratory practice.

КГБУЗ «Красноярский краевой центр по профилактике и борьбе со СПИДом и инфекционными заболеваниями», 660049, г. Красноярск, РоссияПредставлены результаты молекулярно-эпидемиологического анализа вариантов вируса иммунодефеци-та человека 1-го типа (виЧ-1), распространенных в благовещенске и Хабаровске. Показано, что в благо-вещенске, как и по России в целом, доминирует штамм iDU-a подтипа a1 (92,5%). в Хабаровске отмечена гетерогенность циркулирующих вариантов виЧ-1. наряду с вариантами iDU-a (66%) распространены ви-русы подтипов B (12,6%), c (4,4%) и рекомбинантная форма crF02_ag (17%). Методом филогенетического анализа не подтверждается версия о проникновении вариантов виЧ-1 из Китая и японии.Ключевые слова: ВИЧ-1; подтипы; мутации лекарственной устойчивости.

A molecular analysis of HIV-1 subtypes and recombinants circulating in cities in the Russian Far East was performed. The study included samples from 201 outpatients from Vladivostok, Khabarovsk, and Blagoveshchensk. In most parts of Russia, patients are infected with HIV-1 subtype A, known as the IDU-A variant. Subtype B, including the IDU-B variant, is rare in Russia but widespread in the Ukraine, and the CRF02_AG is prevalent in Central Asian countries and Siberia, Russia. One of the challenges of this study in the Far East was to determine whether the molecular landscape of HIV infection in this region is influenced by the bordering countries, including China and Japan, where a distinct set of HIV subtypes is circulating, such as B', C, and CRF01_AE. The distribution of HIV-1 genetic variants in the cities studied was as follows: subtype A (IDU-A), 55.7%; subtype B, 25.3% (IDU-B variant-24.3%); subtype C, 10.0%; CRF02_AG, 1.5%; and CRF63_02A1, 7.5%. A phylogenetic analysis confirmed the relationship of subtype A viruses with the IDU-A variant predominating in Ukraine, Russia and other former Soviet Union (FSU) countries, of subtype B viruses with IDU-B in the Ukraine and of CRF02_AG variants with variants in Uzbekistan, Russia, and other former USSR countries. Subtype C sequences were not uniform, and most clustered between each other and HIV-1 sequences originating from Africa; there was only one sample possibly related to Chinese variants. Thus, despite close cultural and commercial relationships among Russia, China, and Japan, the distribution of HIV-1 subtypes in the Russian Far East is still primarily influenced by contacts with the countries of the former USSR.

The results of the molecular-epidemiological analysis of the HIV-1 variants circulating in Blagoveshchensk and Khabarovsk (Russian Far East) were presented. In Blagoveshchensk HIV-1 IDU-A variants were dominated (92.5%), similar to the regions of the European part of Russia. In Khabarovsk the heterogeneity of circulating HIV-1 variants was noted. In addition to IDU-A variants (66.0%), the strains of subtype B (12.6%), C (4.4%) and recombinant strain form CRF02_AG (17.0%) were identified. Using the phylogenetic analysis method the version of the penetration of HIV-1 variants from China and Japan was not supported.

AIM To evaluate diagnostic value of p24 antigen detection for algorithm of confirmatory diagnostics of HIV-infection. MATERIALS AND METHODS Concurrently with Western blot assay (WB, "New Lav Blot1", Bio-Rad), tests for detection of p24 antigen of HIV (Genetic Systems HIV-1 Ag EIA", "VectoHIV-1 p24-antigen confirming test", and "DS-EIA-HIV-AG-SCREEN") were used for confirmation of first-positive result of immuno-enzyme assay. RESULTS p24 HIV antigen was detected in serum samples in 8.4% of patients with equivocal result of WB and in 4.2% of patients with negative and positive results of WB. Presence of p24 was correlated with high viral load, and, in patients with confirmed diagnosis, with low CD4 cells count (<500 cells/ml). p24 was detected in more than 30% of persons with confirmed seroconversion after primary testing. CONCLUSION In groups of persons with negative and equivocal results of WB assay, detection of HIV p24 antigen points to the presence of infection and could be the reason for the final diagnosis. Detection of p24 in patients with positive result of WB assay allows to consider them as probable candidates for highly active antiretroviral therapy.

Introduction. Available data indicate that the effectiveness of the strategy of "90-90-90" varies considerably between countries. For example, Australia with figures 90-90-79 (2016) has not achieved the negative trend of the incidence and prevalence, while Niger 35-90-57 performance demonstrates a stable decrease in the HIV epidemic. One possible explanation for the observed processes may have different development of the epidemic process in populations that differ by demographic characteristics. From this we can assume that the epidemic control in a strategy of «90-90-90» or any other strategies will differ significantly in such self-regulating systems. Aim: modeling the dynamics of the epidemic process in populations with different probability of HIV transmission and negative, zero, positive population growth. Materials and methods : Computer probabilistic modeling by the Monte Carlo method was carried out. The following parameters were used to describe the epidemic process: population size, birth rate, mortality, HIV prevalence, lethality among patients with HIV/AIDS and probability of HIV transmission. The values of these parameters were close to the UNAIDS global statistics. It is assumed that the effective management of the epidemic reduce the probability of HIV transmission in the population. The dynamics of the population size, incidence and prevalence of HIV infection in populations with negative, zero, positive natural growth and the probability of HIV transmission in the population from 50% to 10% has been consistently studied. Statistical processing carried out by the Student method. Results and discussion. In populations with a negative population growth and a probability of HIV transmission of 0.5, incidence and prevalence at the initial stage are characterized by an increasing trend, reach peak values and decrease to zero. When reducing the probability of HIV transmission peak becomes plateau or directly take the downward shape. In general terms, similar patterns are recorded at zero population growth. The incidence and prevalence of HIV infection with a positive population growth are changing cyclically up and down. Change transmission probabilities range from 0.5 to 0.2 is characterized by a decrease in the frequency and amplitude of peaks increasing incidence and prevalence. When transmission probabilities at 0.1 epidemic process drops sharply. According to the simulation, any managerial impact in countries with negative population growth should be effective. Practical evidence does not contradict theory. For example, indicators "56-66-59" in Ukraine led to a decrease in the incidence. Management actions in populations with positive population growth that reduce the probability of HIV transmission by 20% or 40% are ineffective. When reaching 80%, the epidemic process abruptly stops. Conclusions. The effect of reducing the probability of HIV transmission in populations with a negative and zero population growth is expressed as a linear reduction in incidence and prevalence (at fixed lethality). In populations with a positive natural growth reduction transmission probabilities less than 40% strategically not effective, and when it reaches 80% potentiated abrupt cessation epidemic process.