№ 2 (2013)

The Russian Federation assists needy countries in controlling poliomyelitis, forgotten tropical diseases, influenza, HIV infection, tuberculosis, and malaria, in strengthening the global system to prevent and combat the consequences of natural disasters and other infections by gratuitous aid in reinforcing the laboratory network, training the staff, delivering the vaccines and test systems made in Russia, and in rendering organizational and methodical help.

The paper gives the results of an epidemiological monitoring of meningococcal infection and purulent bacterial meningitides in the Russian Federation in the period 2002-2011. It shows the epidemiological features of meningococcal infection, the etiology of bacterial meningitides, age-specific features, the serogroup characteristics of meningococci, and the status of laboratory diagnosis and analyzes the results of multilocus sequence typing of biosamples containing Neisseria meningitidis DNA from different regions of the Russian Federation.

Non-meningococcal purulent bacterial meningitides (NMPBM) are one of the severest neuroinfections accompanied by high mortality and incidence of neurological sequels. The incidence of NMPBMs is not officially registered, which allows one to assign them to the least studied infections. The Russian Reference Center for Bacterial Meningitis Monitoring makes a personified record of all bacterial meningitis cases, which could more clearly characterize the basic epidemiological parameters of NMPBM in the Russian Federation.

34 meningococcal strains and 22 samples of cerebrospinal fluid containing N. meningitidis DNA were collected in the Russian regions from patients with systemic meningococcal disease and characterized by multilocus sequence typing and genetic determination of antigenic features (serogroup, subtype, allele of a variable region of FetA protein). Serogroup B (31 specimens) and serogroup C (20 specimens) meningococci prevailed. The majority of serogroup B and C meningococci (33 specimens) belonged to one of 5 clonal complexes. Four complexes were already present in database http://pubmlst.org/neisseria/: «ST-41/44 complex/Lineage» (18 specimens, 35%), «ST-18 complex» (4 or 8%), «ST-226 complex» (1 or 2%) и «ST-37complex» (1 or 2%). 5 sequence types (9 specimens or 18%), which were genetically related to ST-9396, formed a new clonal complex identified in this study. 17 sequence types found in 18 (35%) specimens do not belong to any known clonal complex. This pattern is typical for sporadic morbidity. At the same time, the sequence types and clonal complexes of meningococci found in the investigated Russian regions were also present in European countries; this does not point to the fact there are substantial genetic features of Russian N. meningitidis serogroup B and C strains.

The paper considers the current views of the development of infection from mucosal colonization (carriage), including bacteremia, to acute purulent meningitis caused by the human commensal bacteria Neisseria meningitidis, Streptococcus pneumoniae, and Streptococcus agalactiae, etc. To reach the subarachnoid space, the pathogens of acute purulent meningitides use different virulence factors. Emphasis is laid on the role of bacterial capsules. Mucosal colonization manifests itself in microcolony and biof ilm formation. However, only a limited number of genotypes, the so-called hyperinvasive lineages, are able to cross the epithelial barrier and to enter the bloodstream. The epithelial barrier is overcome via transcellular (meningococcus) or transcellular and paracellular (pneumococcus, Serogroup B streptococcus) routes. The pathogens survive and multiply in the blood due to the capsules and complement-inactivating system. The blood-brain barrier is overcome mainly through the paracellular route although the role of transcytosis for meningococcus cannot be ruled out. Successfully overcoming both the epithelial barrier and the blood vessel endothelium requires the involvement of Type IV pili and other bacterial adhesins. The close interaction of the microorganism with the brain capillary endothelium gives rise to activated host cell signaling pathways, leading to the breakage of very strong bonds between the vascular wall cells. This underlines the need for mon itoring the clonal structure of circulating pathogens of acute purulent meningitides as an important element of epidemiological surveillance.

The paper gives the results of examining the clinical and epidemiological features of enterovirus meningitides (EVM) in children in the Orenburg Region in 2006-2011, by using the records available in the Board, Russian Inspectorate for the Protection of Consumer Rights and Human Welfare in the Orenburg Region, and analyzing 90 EVM cases in the children treated in an Orenburg municipal city clinical infectious diseases hospital and followed up for 12 months. EVM has been found to take the lead in the pattern of the clinical forms of enterovirus infection in children. There are dominant groups of EVM pathogens: ЕСНО viruses (serotypes 6, 9, 19, and 30); the most vulnerable age groups: children aged 7-14 (51.4%) and 3-6 (27.1%) years; the clinical features of EVM and outcomes in children treated and untreated with wiferon as part of basic therapy. There is a preponderance of its severe forms (93%) with the development of functional impairments of the central nervous system: cerebrasthenic (36%) and neurosis-like (27%) syndromes persisting within 12 months in one third of the children untreated with wiferon. The use of this drug reduced the time of regression of the major clinical syndromes of EVM and the risk of neurological disorders in the convalescent period. Thefindings provide a rationale for the expediency of incorporating wiferon into the combination basic therapy for EVM in children.

The paper gives current recommendations for the use of the new hepatitis C virus (HCV) protease inhibitor telaprevir to treat chronic hepatitis C in HIV-infected patients who have and have not received antiviral therapy before. It also provides data of trials evaluating the efficacy and safety of telaprevir in combination with pegylated interferon and ribavirin in patients with mixed infection (HIV/HCV) and HCV genotype 1 who have not received therapy for chronic hepatitis C. Prognostic criteria for the possibility of achieving a sustained virological response to treatment are defined. Drug interactions between HCV protease inhibitors and antiretroviral drugs are described.

As of now, both traditional and novel risk factors are used to assess the risk of cardiovascular disease (CVD). HIV infection is considered as an independent cardiovascular risk. Despite the fact that a large number of investigations have been conducted, there is yet no consensus of opinion on for what reason CVD is more common in HIV-infected patients than in the general population. Our investigation revealed the magnitude of traditional and novel risk factors in HIV-infected patients with the natural history of HIV infection and preserved immune function. These patients were not found to have proatherogenic shifts in the lipid and carbohydrate prof iles; at the same time they had a significantly higher level of tumor necrosis factor-a. After differentiation by smoking status, a higher level of insulin was detected in smokers infected with HIV than in non-smokers.