Epidemiological characteristics of meningococcal infection in a number of territories of the RSFSR (1969-1984)

In this work the dynamics and morbidity level in respect of meningococcal infection at 11 territories of the RSFSR at the period of 1969-1984 are analyzed. The study covered altogether 16 cities and 211 districts. The role of big cities as the sources of infection spreading into rural areas and further "fixation" of this infection mainly in regions with a population of 60,000 and more had been established. The data on meningococcal morbidity and carriership among different age groups are presented. The study has shown a pronounced increase in the incidence rate of meningococcal infection among children aged up to 2 years, as well as an increase in the proportion of these children among patients with meningococcal infection in recent years.     

The epidemiological characteristics of meningococcal infection in the USSR

The epidemiological analysis of morbidity in meningococcal infection in the USSR in the period of 1969-1987 showed that the second rise of the morbidity level occurred in 1984 and was followed by its decrease in most of the regions of the USSR. This study also revealed that the characteristic feature of the second rise of morbidity in meningococcal infection was a considerable involvement of young children (aged up to 3 years), as well as the increased etiological role of group B meningococci in cases of meningococcal infection and the circulation of these microorganisms among the population. Besides, the preservation of the etiological importance of group A meningococci in many regions of the USSR, especially among adults, was noted. In this connection, the use of Soviet group A meningococcal polysaccharide vaccine on epidemiological indications was considered to be epidemiologically substantiated.     

Epidemiological surveillance of meningococcal infection and the prediction of the development of an epidemic process

The signs necessary for the prognostication of the development of the epidemic process have been formulated on the basis of the epidemiological analysis of materials obtained in the process of trials of the system for the surveillance of meningococcal infection with the use of previously established characteristics. The data on the prevalence of meningococcal infection among different age groups and on the seasonal distribution of the infection as well as on the serogroups of meningococci isolated from patients, have been shown to be of importance for prognostication.     

Antibodies to meningococcal lipopolysaccharide in different forms of meningococcal infection

The results of the determination of antibodies to lipopolysaccharide (LPS) in 270 patients with different forms of meningococcal infection and in 816 healthy persons by means of the passive hemagglutination test are presented. The role of antibodies to LPS in the formation of humoral immunity to meningococci in sick children and adults is shown. Different forms of meningococcal infection have been found to have their specific features of the accumulation of antibodies to LPS. As revealed, the time of the sanation of liquor and the level of antibodies to LPS are unrelated, which indicates that antibodies to LPS may play some role in the pathogenesis of meningococcal infection.     

Epidemiological surveillance and control of poliomyelitis in the Republic of Cuba

Organization and performance of Poliomyelitis Epidemiological Surveillance and control in Cuba are described. Since the first vaccination campaign the average of vaccinated population is of 90% and over. Annual and cyclic epidemic peaks disappeared after oral polio vaccination. During 20 years only 7 sporadic cases were diagnosed; the last one in 1979. Surveillance of disease and immunity of infant population was carried out by clinical examination, isolation techniques for Polio and other enteroviruses and by testing neutralizing antibodies in 0-4 years of age population samples from 1963 to 1979. Satisfactory high antibody levels have been maintained up to date after using different combinations of Polio viruses in vaccines and by having regulated the dose intervals. Subsequent virologic investigation in children under age 3, from nurseries of several provincial capitals, leads us to think that there is no Poliovirus circulation in the country. Behavior of the disease and the laboratory finding indicators reveal very successful results in Poliomyelitis elimination programmes.     

The evolution of meningococcal infection in Mongolia]

On the basis of the generalization and analysis of the results of bacteriological and immunological investigations the epidemic process of meningococcal infection (MI) in Mongolia was found to undergo definite changes during the last 20 years. Group A meningococci prevailing in the etiology of MI were replaced by strains belonging to group B affecting mainly young children (aged up to 3 years). MI morbidity rate caused by group B meningococci was found to be higher in Mongolia than in other countries of the world. These data substantiate the necessity of using more effective remedies for the control of this infection and, in particular, specific immunization with vaccines against group B meningococci; profound study of the properties of the circulating meningococcal strains is to be carried out.     

Incidence of meningococcal infection in the RSFSR]

The authors present characteristics of meningococcus infection epidemic process in case of sporadic cases and under epidemic conditions (1965--1976). A scheme of epidemiological analysis suggested by the authors permitted to differentiate and to record the incidence of various clinical forms of meningococcus infection, to present data on the age, seasonal characteristics, focality, etc. Comparison of intensive morbidity indices for 10 years, both at the individual administration territories and in the Republic as a whole demonstrated morbidity level of 1.5--2.0 to be one of prognostic signs of the beginning epidemic. The main features differentiating the sporadic and epidemic morbidity periods were revealed. The presence of group diseases, a greater percentage of children among those who fell ill, and marked signs of seasonality and territorial difference characterized the period of rise caused by meningococcus of serological group A.     

Epidemiological characteristics of Angola

The epidemiological analysis of infectious morbidity for recent years has been made and the main nosological forms existing in Angola (malaria, tuberculosis, lepra, African trypanosomiasis, plague, intestinal diseases, etc.) have been briefly characterized on the basis of primary medical reports and the data provided by the literature and experimental work. This analysis creates the necessary prerequisites which enable the local public health organs to determine the regularities of the epidemic process, thus making it possible to take rational prophylactic measures and to organize proper epidemiological supervision.     

The characteristics of the serological diagnosis of meningococcal infection in children in the 1st years of life

The results of clinico-immunological examination of 181 children, aged 1 month to 6 years, with generalized forms of meningococcal infection are presented. In children under observation antimeningococcal antibodies to group-specific meningococci of the main groups A, B and C were determined over the course of the disease by passive hemagglutination (PHA) test and enzyme immunoassay (EIA). The level and frequency of seroconversion were found to depend on the patient's age and the severity of the clinical course of meningococcal infection. Antibody level was found to increase simultaneously with respect to several meningococcal polysaccharides: A, B in 18.5% and A, B, C in 3.3% of cases. In the clinical interpretation of data obtained in the PHA test and EIA not only the patient's age, the form and duration of meningococcal infection, but also serotherapy should be taken into consideration, as the latter may distort the serological results.     

The phenomenon of HLA antigen modification in meningococcal infection

212 patients with the generalized forms of meningococcal infection have been examined. The intensity and quality of lymphocytotoxic reaction in the acute phase and the convalescence period of the disease have been analyzed and the blank calculation has been made at different clinical forms of meningococcal infection. The formation of modified tissue antigens at the acute stage of the disease in the presence of intoxication is shown and the probable role of the intensity of bacteremia in this formation is discussed.     

Criteria of the epidemiological surveillance of meningococcal infection

The results of studies carried out with the use of the unified, specially developed methods in eight regions of the USSR are generalized. Basing on the analysis of the results, the leading role of serogroup A meningococci in the rise of morbidity is emphasized, the relation of the morbidity level to the serogroup composition of meningococci circulating among healthy population is revealed, the necessity of carrying out selective bacteriological surveys with a view to establish the serogroups of meningococci circulating among the population is shown. The expedient criteria to be used in the system of epidemiological surveillance of meningococcal infection are presented.     

The role of fibronectin in the pathogenesis of meningococcal infection

We have characterized an interaction of 20 strains of Neisseria meningitidis serogroups A, B, C, 29E, W-135 and Z with immobilized fibronectin of human plasma. The adhesion of meningococci to fibronectin was determined by the extent of piliated cells and did not depend on the meningococcal serogroup. Binding of non-piliated or weakly piliated strains (2-5% of piliated cells in the stock) was sufficiently greater than those piliated (8-10%), where the adhesion to fibronectin was not at all observed. The examination of two well-piliated strains showed that the loss of pili resulted in the increase of bacterial adhesion to fibronectin. Constants of association and dissociation of piliated and non-piliated strains to fibronectin were calculated. The role of meningococci-fibronectin interaction in the pathogenesis of meningococcal infection is discussed.     

自然人群乙型肝炎病毒慢性感染者HBV DNA的流行病学分析

目的了解寿光市自然人群乙型肝炎病毒(hepatitis B virus,HBV)慢性感染者HBV DNA的流行病学特征,为乙型肝炎的防治提供依据。方法采集2012年寿光市3个镇街道居民体检发现的HBs Ag阳性者静脉血5 m L,以实时荧光定量聚合酶链反应(FQ-PCR)法检测血清HBV DNA载量,分析HBV DNA与性别、年龄、有无乙肝/肝癌家族史、密切接触史、输血史等因素的相关性。结果在2 026例HBs Ag阳性感染者中,HBV DNA阳性率为49.41%(1 001/2 026),HBV DNA载量的平均值为6.27×107拷贝/m L。其中男性HBV DNA阳性率为53.28%(585/1 098),女性为44.83%(416/928),差异有统计学意义(χ2=14.370,P<0.01);HBV DNA均值男性为(6.72×107±2.07×108)拷贝/m L,女性为(5.56×107±1.44×108)拷贝/m L,差异无统计学意义(t=0.447,P>0.05)。HBVDNA阳性率与年龄呈负相关(r=-0.983),与HBV感染的主要影响因素乙肝/肝癌家族史、密切接触史、输血史等均无关。结论 HBV DNA阳性率与慢性HBV感染者的性别、年龄有关,与HBV感染的主要影响因素无关。     

Increased specificity of immunoenzyme analysis for diagnosing meningococcal infection

The ELISA test system for the detection of polysaccharide antigens of meningococci, groups A and C, on the basis of the neutralization of specific antibodies has been developed. The specificity of this reaction is determined by the chemically pure preparations of group A and C meningococcal polysaccharides. The sensitivity of this test system based on the neutralization of antibodies is not inferior to that of ELISA with the use of double antiserum.     

Epidemiological characteristics of platelet aggregability.

The epidemiological characteristics of platelet aggregability were established in 958 participants in the Northwick Park Heart Study. The main analyses were based on the dose of adenosine diphosphate at which primary aggregation occurred at half its maximum velocity. Aggregability increased with age in both sexes, was greater in whites than blacks (particularly among men), and tended to decrease with the level of habitual alcohol consumption. Aggregability was, however, greater in women than men and in nonsmokers than smokers. There was no relation between aggregability on the one hand and obesity, current or past oral contraceptive use, menopausal state, or blood cholesterol and triglyceride concentrations on the other. Aggregability was somewhat, though not significantly, higher in men with a history of ischaemic heart disease and in those with electrocardiographic evidence of ischaemia than in those without. There was a strong association between the plasma fibrinogen concentration and aggregability. The widely held concept of platelet aggregability and its implications is probably an oversimplification. In the prevention of thrombosis it may be as useful to consider modifying external influences on platelet behaviour, such as plasma fibrinogen concentration or thrombin production, as it is to rely solely on platelet active agents.