HIV infection in Saint Petersburg: the changing face of the epidemic

The specific features of the epidemiological situation in St. Petersburg at the first stage (1987-1995) and the second stage (1986-1999) of the development of HIV infection are described. During this period morbidity in HIV infection, starting from the insignificant rate of growth, sharply increased. For the first time injecting drug users were noted to come out to the foreground in the structure of the contingent of persons affected by HIV infection (57.5% and 72.6% in 1998 and 1999 respectively). Such change on the epidemic situation requires corrections in the strategy and tactics of preventive measures and medical assistance. To control HIV infection among drug users, only the combination of medical assistance given by narcologists with the realization of all elements of the program "Harm Reduction" can be effective.     

STD门诊生殖器溃疡性疾病的病原学研究

目的 了解生殖器溃疡性疾病（GUD）的发病率、病因及其与HIV感染的关系。方法 用暗视野显微镜检查（D-F）、梅毒血清学试验（STS）、酶免疫法（EIA）检测HSV抗原和HD培养等方法检测322例生殖器溃疡标本中TP、HSV和HD,并进行血清HIV抗体检测。结果 在8 999例STD门诊患者中,GUD患者322例（3.58%,322/8 999）;在322例GUD患者中,梅毒85例（26.4%,85/322）,生殖器疱疹74例（26.09%,84/322）,软下疳0例（0,0/322）,病因不明的GUD为153例（47.52%,153/322）;其中GUD患者的HIV感染率为1.86%（6/322）,梅毒患者的HIV感染率为4.70%（4/85）,生殖器疱疹患者的HIV感染率为1.19%（1/84）,其他GUD的HIV感染率为0.65%（1/153）。比较三者的HIV感染率发现,梅毒的HIV感染率高于生殖器疱疹和其他GUD患者（4.70%vs1.19%,χ^2=0.24,P＞0.05,OR=3.04,95%CI=0.31-29.93;4.70% vs 0.65%,χ^2=1.29,P＞0.05,OR=5.63,95%CI=0.58-55.06）,但两者差异无显著性;GH患者的HIV感染率与其他GUD患者的HIV感染率相比,差异无显著性（1.19% vs 0.65%,χ^2=0.00,P＞0.05,OR=1.85,95% CI=0.11-30.00）。结论 在性病门诊中,GUD的主要病因为梅毒和生殖器疱疹,且存在混合性感染;梅毒与HIV的感染有一定关系.     

A strategy for the control of HIV infection and viral hepatitides against the background of the narcotic abuse epidemic

The presence of the epidemic of drug addiction in the Russian Federation is stated: for the recent 10 years the number of drug addicts increased 3.5-fold. The questioning of several thousand drug addicts has revealed that 60% of them have hepatitis B, 80% have hepatitis C, 10% have syphilis. The strategy of controlling HIV infection among drug addicts is proposed. It includes, in the first place, the prevention of the secondary infection from HIV-infected addicts; in the second place, the detection of HIV-infected persons in groups of drug addicts, difficult to establish contacts with; in the third place, the primary prophylaxis within the program "Harm reduction" in the most susceptible groups of drug addicts. The thesis that the prevention of HIV infection must become the prevention of drug addiction by rendering multi-stage assistance to HIV-infected persons, including mainly drug addicts, is substantiated.     

Incorporation of variability into the modeling of viral delays in HIV infection dynamics

We consider classes of functional differential equation models which arise in attempts to describe temporal delays in HIV pathogenesis. In particular, we develop methods for incorporating arbitrary variability (i.e., general probability distributions) for these delays into systems that cannot readily be reduced to a finite number of coupled ordinary differential equations (as is done in the method of stages). We discuss modeling from first principles, introduce several classes of non-linear models (including discrete and distributed delays) and present a discussion of theoretical and computational approaches. We then use the resulting methodology to carry out simulations and perform parameter estimation calculations, fitting the models to a set of experimental data. Results obtained confirm the statistical significance of the presence of delays and the importance of including delays in validating mathematical models with experimental data. We also show that the models are quite sensitive to the mean of the distribution which describes the delay in viral production, whereas the variance of this distribution has relatively little impact.     

The etiological structure of the morbidity from influenza and other ARDs on the territory of Russia in the season of 1997-1998

The antigenic properties of 51 strains of influenza virus A(H1N1), isolated in different cities of Russia during the epidemic of 1998, were studied. Most of these strains (49) proved to be similar to virus A/Bern/07/95 in the antigenic structure of hemagglutinin, but 2 strains isolated in Ulan-Ude were found to be closely related to new antigenic variants of this virus: A/Beijing/262/95 and A/Fukuoka/c7/98. The analysis of the antigenic structure of influenza-like diseases (ILD) in different cities of Russia revealed that adenoviruses causing up to 10.9-14.6% of all acute respiratory virus infections dominated at the pre- and post-epidemic periods. RS-viruses, parainfluenza viruses of types 2 and 3 circulated during the whole season (their proportion was 5.1-6.6%). The intensity of the circulation of influenza viruses A(H1N1) and A(H3N2) increased, starting from January, and continued till April 1998; its peak was observed in February-March in most of the cities of Russia (up to 37.5-41.6% according to the results of immunofluorescent diagnostics and 53-73% of ILD according to the results of the hemagglutination inhibition test). The occurrence of influenza B during this season was very low.     

The evolution of risky behaviour in the presence of a sexually transmitted disease

Sexually transmitted diseases (STDs) are widespread in nature, often sterilizing their hosts or causing other pathogenic effects. Despite this, there is a widespread occurrence of behaviours that are likely to increase the risk to an individual of contracting an STD. Here, we examine the evolution of behaviours such as promiscuity or mate choice that increase the risk of contracting an STD, but also provide a fitness benefit. As might be expected, the balance between risk and fitness benefit defines the optimal strategy, but this relationship is not straightforward. In particular, we often predict the coexistence of highly risky and highly risk-averse individuals. Surprisingly, very safe strategists that only suffer a small cost will tend to coexist with highly risky strategists rather than outcompete them as might have been expected. Rather than selecting for monogamy or for reduced mate choice, therefore, the presence of an STD may often lead to variability in either promiscuity or mate choice.     

The role of host phenology in determining the incidence of an insect sexually transmitted infection

Changes in the timing of life history events within the year alter the degree to which the activity patterns of different species coincide, making the dynamics of interspecific interactions sensitive to the phenology of the interacting parties. For parasites, the availability of suitable hosts to infect represents a crucial determinant of dynamics, and changes in the host (and parasite) phenology may thus alter disease epidemiology and the conditions for disease maintenance. We tested the hypothesis that the incidence of a sexually transmitted mite infection, Coccipolipus hippodamiae, in Adalia bipunctata ladybird beetles in Sweden was determined by host phenology, namely presence/absence of sexual contact between cohorts of the host. We observed that the pattern of mite presence/absence across Swedish A. bipunctata populations was highly reproducible between years, implying a persistent biological/ecological basis underlying the incidence. Further, ladybirds from populations where the mite was absent were able to acquire mites during copulation, develop a mite infection, and transmit infection onward, indicating an ecological (rather than biological) driver of mite incidence. Observations of ladybird phenology in natural populations provided evidence of sexual contact between overwintered and new cohort adults in populations where the mite was present. In contrast, new cohort ladybirds in the two northern Swedish populations where the mite was not present had not had sexual contact with the overwintered generation, creating a ‘hard stop’ to mite transmission. We conclude that variation in host phenology may be an important driver of the incidence of sexually transmitted infections (STIs) by determining the presence/absence of sexual contact between generations. More generally, we hypothesize that sensitivity to variation in host phenology will be highest for parasites like STIs that infect one host species, one host life stage and are directly transmitted on contact between host individuals.     

Four new mutations and polymorphic variants of the low density lipoprotein receptor in patients with familial hypercholesterolemia in Saint Petersburg

In a collection of DNA samples from 100 unrelated patients with clinical features of familial hypercholesterolemia (FH), a search for mutations of exons 4 and 10 of the low-density lipoprotein (LDL) receptor gene was performed using heteroduplex and single-strand conformational polymorphism (SSCP) analyses followed by sequencing of amplified DNA fragments. Four new mutations of the LDL receptor gene were identified: C146R (c.499 T > C), A130P (c.451 G > C), G128G (c.477 T > C), and C188Y (c.626 G > A). Mutation A130P was assigned to the same chromosome with allele variant 447C. Two polymorphic sites in exon 10 of the LDL receptor gene (1413G/A and 1545C/T) were found in the Russian population for the first time. Based on the data obtained, familial hypercholesterolemia was confirmed in seven patients.     

Prevalence of scrapie infection in Great Britain: interpreting the results of the 1997-1998 abattoir survey

An accurate estimate of the prevalence of scrapie infection in the Great Britain (GB) sheep flock is essential when assessing any potential risk to human health through exposure to sheep transmissible spongiform encephalopathies (TSEs). One method for assessing the prevalence is to sample sheep intended for human consumption using a diagnostic test capable of detecting infected animals prior to the onset of clinical signs. An abattoir survey conducted in Great Britain in 1997-1998 tested brain samples from 2809 apparently healthy sheep of which none was found to be positive for scrapie by histopathology or immunohistochemistry (IHC) although 10 were positive for scrapie-associated fibrils (SAF). Subsequently, the tonsils from a subset of the animals sampled were examined using IHC, one of which tested positive. To interpret these results we use a likelihood-based approach, which accounts for the variation in the prevalence of infection with age and test sensitivity and specificity with stage of infection. Combining the results for all of the diagnostic tests yields an estimate of the prevalence of scrapie infection in the GB sheep flock of 0.22% (95% confidence interval: 0.01-0.97%). Moreover, our analysis suggests that all of the diagnostic tests used are very specific (greater than 99%). Indeed, only SAF detection yields a specificity estimate of less than 100%, which helps to account for the high number of samples found to be positive for SAF.     

HIV infection in patients attending clinics for sexually transmitted diseases in England and Wales. Collaborative Study by Consultants in Genitourinary Medicine and the Public Health Laboratory Service.

A national study of the prevalence of HIV antibody designed to monitor sexual spread of HIV infection in England and Wales was made of homosexual and heterosexual patients attending sexually transmitted disease clinics in four districts in 1985, seven in 1986, and 14 in 1987. Patients were invited to participate and were counselled. Among homosexual men in two clinics in south east England, HIV antibody was found in 92 (12.9%) of 711 in 1985, 65 (15.2%) of 428 in 1986, and 81 (14.6%) of 556 in 1987: corresponding findings in the other regions were 16 (5.0%) of 321, 41 (6.3%) of 654, and 21 (3.1%) of 678. The prevalence of HIV antibody was higher in homosexual than bisexual men, in patients aged 25 years or more, or with one or more specified minor complaints. Among heterosexual patients in the south east in 1986, HIV antibody was found in seven (3.0%) of 230 men and three (1.3%) of 233 women and in 1987 in 10 (1.0%) of 962 men and seven (0.7%) of 949 women. In other areas corresponding findings in 1986 were two (0.2%) of 950 men and three (0.4%) of 752 women and in 1987 were three (0.06%) of 5312 men and one (0.02%) of 4778 women. All but one of the heterosexual patients with the antibody were intravenous drug abusers or had had sexual contacts in or were from an area abroad with a high prevalence of AIDS. Failure to identify a heterosexual patient with HIV antibody not in a risk group (other than that of being an attender at the clinic) or who did not have a sexual partner in a risk group suggests that their prevalence in the patient population of the clinics in the south east is less than one in 700 and in the other regions less than one in 3000. Refusals to participate increased during the study but comparisons of patients who agreed and refused in terms of age, the presence of symptoms suggesting AIDS, travel abroad, and number of sexual partners a month showed little evidence of selective bias.     

The status of the morbidity and the main trends in the improvement of the epidemiological surveillance of sexually transmitted infections in the city of Moscow

The present situation in sexually transmitted diseases (STD) is regarded as unfavorable. Differing tendencies in morbidity levels for various nosological forms have been established. The continuing growth of syphilis morbidity among children is considered to be specially alarming, and an increase in the number of cases of congenital syphilis is noted. The reasons of the growth of STD morbidity have not only medical, but mainly socio-economical, psychological, ethical and moral character. The main trends in the improvement of epidemiological surveillance on STD have been determined.     

实时荧光聚合酶链反应检测性病患者泌尿生殖道沙眼衣原体的临床分析

采用实时荧光聚合酶链反应（PCR ）检测性病患者泌尿生殖道沙眼衣原体,进行临床和实验室分析。采集380例男女性病患者泌尿生殖道分泌物,进行多形核白细胞数检测和荧光PCR。结果显示,216例男性患者中,尿道多形核白细胞数≥5个者占92．59％,荧光PCR检测沙眼衣原体阳性62例,阳性率为28．70％;沙眼衣原体合并淋病奈瑟菌感染30例,合并感染率为13．89％。164例女性患者中,87例宫颈管内多形核白细胞数≥10个（占53．05％）,荧光PCR检测沙眼衣原体阳性33例（占20．12％）。结果提示,性病门诊开展实时荧光PCR检测沙眼衣原体可提高检测阳性率和控制沙眼衣原体传播。     

Correlation of viral replication activity, the clinical phase of the disease and immunologic deterioration in HIV infection

The authors have studied the relationship among HIV replicative activity, expressed by HIV isolation from peripheral blood lymphocytes and p24 antigenemia detection, and the evolution of infection, in terms of stage of disease and T4 cells absolute number, in a group of 120 infected subjects. Data presented indicate that the expression of viral gene products is related both to clinical and immunological deterioration and suggest that viral replication plays a central role in the progression of the disease.     

The comparative characteristics of the indices of lymphocyte and neutrophil functional activity in patients with HIV infection and chronic viral hepatitis B]

In 34 patients with human immunodeficiency virus (HIV) infection at the asymptomatic stage and 29 patients with chronic viral hepatitis B at the period of exacerbation (of these 14 patients had chronic persistent hepatitis and 15 patients had chronic active hepatitis) the complex study of the functional activity of lymphocytes and neutrophils was carried out by cytochemical methods with the simultaneous determination of the content of immunoregulating lymphocyte subpopulations. In patients with chronic active hepatitis a decrease in the percentage and the absolute number of helper T-lymphocytes and the ratio of CD4/8 in comparison with those in patients with HIV infection were revealed. At the same time patients with HIV infection exhibited more pronounced decrease in the activity of all lymphocytic enzymes under study (neutrophil esterase, acidic phosphatase and succinate dehydrogenase in lymphocytes), as well as in the activity of myeloperoxidase and the content of cation proteins and glycogen in neutrophils in comparison with patients having chronic active hepatitis.     

Cytokine involvement in viral permissiveness and the progression of HIV disease

Many viruses have evolved novel means of exploiting host defense mechanisms for their own survival. This exploitation may be best exemplified by the interrelationships between certain viruses and the host cytokine networks. Many viruses, including the human immunodeficiency virus type-1 (HIV-1), rely on the liberation and cellular action of host immune cytokines to expand their host cell range, to regulate their cellular expression, and to maintain their dormant state until the proper extracellular conditions arise. As again exemplified by HIV-1, viruses may also take an active role regulating cytokine expression and cell surface cytokine receptors. Because the viral life cycle, and in particular the HIV-1 life cycle, is so intertwined with cytokine regulatory networks, these networks represent potential points for therapeutic intervention. As our understanding of cellular cytokine pathways involved in viral infection and replication continues to expand, so too will our ability to design rational anti-viral therapies to alter multiple steps along the viral life cycle.