Analysis of the trends in typhoid-paratyphoid morbidity in the USSR]

Mathematico-statistical analysis of typhoid-paratyphoid infection morbidity in the USSR during 1900--1940 revealed a regular many-year cyclic recurrence of the changes in the morbidity level. The intensity of the morbidity level reduction at the periods of decline--in 1900--1917, 1920--1928, and in 1932--1939--was similar. A successive reduction of morbidity of this group of infections, by 6.45% on the average, annually, occurred in 1930--1976. The character of reduction of typhoid-paratyphoid infections morbidity level in the USSR during that period is well described by the exponential function.     

Epidemiologic analysis morbidity with meningococcal infections in the USSR]

The authors present the analysis of the incidence of epidemic cerebrospinal meningitis in the USSR from 1937 to 1974, and of meningococcus infection from 1965 to 1974. A rise of the meningococcus infection incidence from 1969 to 1974 was recorded 28 years after the elevation of 1940-1942 and was 1.5 times below this latter rise. The rise in 1969-1974 was characterized by marked signs peculiar to the infection with the droplet transmission mechanism; among those who contracted the disease prevalence was seen among children aged under 14 years (63-72%). A marked affection of juveniles was noted. Three types of the dynamic of the meningococcus infection incidence in the republics located in different climatic-geographical zones of the USSR were noted: slow, gradual increase of the level, interrupted and explosive. Such character was determined in the dynamics of the seasonal elevations of morbidity. Antiepidemic measures including a complex of nonspecific measures could not be assessed as sufficiently effective. This finds reflection in the natural course of the epidemic process of the meningococcus infection which remains uncontrolled. From the patients with generalized form of the disease meningococci of group A were isolated in 80-100% of cases, from the number of those typed. The group-specific reference of the nasopharyngeal strains depended on the epidemic situation: strains of serological group A prevailed at the period of the morbidity elevation, and other serological groups (particularly of C and B) increased at its decline.     

Infectious morbidity in the USSR: its structure, levels, dynamics and economic significance

Taking well-grounded strategic decisions on the control of infectious diseases requires the knowledge of modern epidemiological situation with respect to the total infectious pathology. The structure, levels and dynamics of morbidity in infectious diseases, registered according to Form No. 85 (Infection), on the territory of the USSR are considered. Besides, the evaluation of the economic damage inflicted to the national economy of the USSR by infectious morbidity is presented.     

The first case of HIV infection in a citizen of the USSR]

The first AIDS patient was a homosexual male who contacted HIV infection in 1982 in Tanzania. In December 1985 the first sign of Kaposi's sarcoma was noted in this patient. HIV infection was diagnosed in him only in February 1987. He was treated with AZT, reaferon, immunoglobulin and underwent electronic therapy. His state of health was stable till February 1991. Then he got severe bacterial pneumonia, candidosis. Pancytopenia progressed. The dose of AZT (0.8 g daily) was increased and intensive antibiotic therapy and the course of diflucan were prescribed. In spite of this treatment the number of CD4 lymphocytes catastrophically decreased (CD4 = 0.01 x 10(9)/l) and the patient died. Thus, more than 63 months passed from the date of the appearance of the first symptoms of AIDS in the patient to his death.     

The importance of Shigella boydii in shigellosis morbidity in the USSR

The etiological role of S. boydii in Shigella infections registered at different territories of the USSR in 1986-1987 was analyzed. As established by this analysis, S. boydii infection occurred mainly at the territories with unsatisfactory water supply of the population; from these territories the infection spread to ther territories of the USSR. The dominating serovars causing S. boydii dysentery, as well as Shigella infections, at different territories of the USSR was shown to be identical, which was indicative of the fact that the immunological factor had no influence on the etiological structure of Shigella infections, determined by the activity of the main routes of the transfer of infection. On the whole, S. boydii serovars 2, 4 and 1 were found to prevail in the USSR.     

Anguillicolosis: dynamics of the infection over two decades

The dynamics of the infection of the European eel Anguilla anguilla L. by the Asian nematode Anguillicola crassus Kuwahara, Niimi and Itagaki, 1974 (i.e. anguillicolosis) was monitored over 2 decades in an oligohaline canal in southern France (Camargue, Mediterranean coast). Since the first mention of the parasite in this canal in 1985, which was also the first record in France, prevalence of pre-adult and adult forms has risen from 32 to 73%. However, during the last 7 yr (1997 to 2003), prevalence seems to have stabilized around values of 60 to 70% and parasite load, though inter-annual variation is substantial, shows no sign of increase (intensity for the last 5 yr: min. = 3.70, max. = 9.66, mean = 6.01). Our results thus confirm the dynamic pattern observed elsewhere in Europe, i.e. a rapid spread following the introduction of the parasite in a water system and then stabilization around ceiling levels. We review possible mechanisms that may explain such a leveling off in the infection spread. We particularly document the possibility that repetitive infections may render the infected organ, i.e. the swimbladder, unsuitable for further A. crassus establishment. In support of this hypothesis, we showed that the infection rate is lower among eels with severely damaged swimbladders.     

Root dynamics in a salt marsh over three consecutive years

The minirhizotron technique has been used to study root development in a salt marsh in the western part of the Nationalpark Niedersächsisches Wattenmeer during a three-year period. The objective of our study was to evaluate root depth distribution and seasonal changes in growth activities of natural plant root systems. Root number was counted at monthly intervals in the top soil layer (0–0.2 m) for every 2 cm soil depth. The number of roots was regarded as an easily detectable parameter reflecting root growth and decay.In general, highest rooting intensity was found in the soil's subsurface layer (0–0.08 m). The number of roots significantly decreased in deeper horizons of the soil. There was also a significant increase and decrease in the number of roots in the course of a year. The highest rooting intensity was found in late winter to early spring, which substantially decreased towards mid summer when the plants were in their reproductive phase. The data indicate that there is a clear seasonal pattern of root growth of salt marsh species.     

Zonal characteristics of the dynamics of viral hepatitis A morbidity over a period of many years (based on data from the Ukrainian SSR)

The previously established zonal character of the prevalence of viral hepatitis A in the Ukraine is a stable epidemiological regularity observed for more than 30 years (1952-1985). Zonal differences in the dynamics of the epidemic process of viral hepatitis A were established. These differences became particularly hepatitis manifest in the years of periodic rises in the morbidity rate which is also irregular within zonal and regional boundaries. The main typological variants of the dynamics of the epidemic process ("urban" and "rural") were defined. Typological approach appears to be useful in the provision of information necessary for the proper functioning of epidemiological surveillance and for taking measures aimed at epidemics control.     

近百年来欧亚大陆草地螟发生的时空动态

【目的】草地螟LoxostegesticticalisL.是一种世界性害虫,主要分布在北温带36°N-55°N范围内。明确草地螟在整个欧亚大陆的发生动态,对于阐明其灾变机理具有重要意义。【方法】通过查阅有关中、俄草地螟的文献资料,分析1900年以来欧亚大陆草地螟的发生情况。【结果】从20世纪20年代中期至今,草地螟在欧亚大陆先后于1925-1936年、1948-1960年、1969-1989年和1995-2014年出现了4个大的群发期。在1925-1936年、1969-1989年和1995-2014年3个群发期内,存在着草地螟重发生区沿着欧亚大草原东西向蔓延的现象。在1948-1960年这个群发期,草地螟主要发生范围局限在东北亚地区。此外,草地螟种群在不同区域内呈现出不同的暴发周期。在俄罗斯欧洲部分,草地螟的暴发周期为10年左右,但在1937-1968年间出现了长达30余年的间歇期。在我国东北及华北地区,草地螟的暴发周期为20年左右。在俄罗斯西伯利亚,由于其位于欧亚大陆两个主要的发生基地之间,无论草地螟重发生区自西向东还是自东向西传播,都会在当地造成危害,因此发生也更频繁。【结论】草地螟在欧亚大陆的猖獗为害具有群发性,重发生区会沿着欧亚大草原东、西向蔓延。草地螟在一个地区内的间歇性猖獗不仅与当地的环境因素有关,还可能受到草地螟重发生区在大陆尺度上转移的影响。     

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.     

The dynamics of mediterranean shrubs species over 12 years following perturbations

The response of woody species to experimental burning, cutting andploughing was studied for a period of twelve years in a shrub community in NWSpain. The treatments represent the perturbations most frequently imposed bymanon these shrub communities throughout history. The response to burning is muchfaster than the response to cutting. The response to ploughing is slower due tothe regeneration mechanism that species use: germination. In general, thedominant species, Erica australis, influences theregeneration patterns of the rest of the species, which make up the community.There is a significant increase in the cover of woody species until the fourthyear, and of herbaceous species until the third year. Subsequently,Erica australis attains dominance, returning to itsoriginal spatial occupancy and cover values, removing the herbaceous speciesandnegatively influencing the growth of woody ones like Halimiumumbellatum, Halimium alyssoides and Quercuspyrenaica. Both Erica australis andChamaespartium tridentatum regenerated by sprouting in theburnt and cut plots, and by germination in the ploughed plot.Arctostaphylos uva-ursi only recovers after burning andploughing. Halimium alyssoides, Halimium umbellatum, Ericaumbellata and Calluna vulgaris regenerate bygermination in the three plots. Differences in cover values and spatialoccupancy during the first years of succession tend to be eliminated twelveyears after treatment and most of the species tend to recover their initialcover values. These shrubland communities have a high degree of resilience dueto the strong sprouting potential of the component species.