[Blood picture findings in children with Parvovirus B19 infections (fifth disease/erythema infectiosum)]. / Blutbildbefunde bei Kindern mit Parvovirus B19-Infektion (Ringelröteln/Erythema infectiosum).

The human parvovirus B19 provokes erythema infectiosum ("e.i."); moreover there is a wide range of diseases due to parvovirus B19 without exanthema/rash. The erythropoietic blast cells of the bone marrow seems to be the main target cells for this virus. Therefore in cases of prenatal infection the consequences are extremely similar to fetal erythroblastosis ("non-immunological" fetal hydrops). In postnatal life the parvovirus B19 infection causes hyporegenerative phases of the erythropoiesis with anaemia after 3-4 weeks. We studied the white blood cell count (WBC), erythrocytes and thrombocytes in children suffering from (serologically well documented) parvovirus B19 infection with exanthem/"e.i." (group 1; n = 23), without exanthem (group 2; n = 46) and with unknown febrile exanthematous rashes (group 3; n = 76). We did not find any characteristic data in the WBC for a diagnosis of parvovirus B19 infection. However we have for the first time documented a significant thrombocytopenia in "e.i." (group 1) not found in group 2. The thrombocytopenia appears earlier than the anaemia, because the lifespan of thrombocytes is considerably shorter than that of erythrocytes. These data suggest that parvovirus B19 attacks not only "erythropoietic" blast cells but also immature bone marrow cells, which are later responsible for the thrombocytopoiesis.

[The blood picture in exanthema subitum (Zahorsky)/ critical 3-day fever-exanthema in young children]. / Das Blutbild beim Exanthema subitum (Zahorsky)/kritisches Dreitagefieber-Exanthem der Kleinkinder.

Exanthema subitum was described in 1910 by John Zahorsky/USA; in 1986 and 1988 the human herpesvirus 6 (HHV 6) was discovered as the causative agent of the disease and serologic tests were established for diagnostics (specific IgM and IgG antibodies). Up to this time the diagnosis was based on the typical clinical course: the prodromal febrile stage (3 days) followed by the onset of a (more or less characteristic) rash closely connected with the normalisation of the body temperature. Usually a typical white blood cell count was described for diagnostics on the first day of exanthema: leukocytopenia with eosino- and granulocytopenia associated with consequent lymphocytosis. We analysed the hematologic data for children with a serologically documented HHV6 infection including exanthema (group 1: n = 9), without exanthema (group 2: n = 11) or with a serologically unexplained febrile rash (group 3: n = 13). In children with exanthematous HHV6 infection (exanthema subitum) granulocytopenia and a decreased thrombocyte count (mean values) is the rule. But the total white blood cell count and the mean values for eosinophils did not differ between the groups studied.

[Seroprevalence of antibodies to human herpesvirus 6 (exanthema subitum; critical 3-day fever-exanthema in young children) in the population of Northern Germany]. / Seroprävalenz von Antikörpern gegen das humane Herpesvirus 6 (HHV6) (Exanthema subitum; kritisches Dreitagefieber-Exanthem der Kleinkinder) in der Bevölkerung Norddeutschlands.

We tested 989 sera of all age groups (patients and blood donors) from north eastern Germany (West Pomerania and Mecklenburg) and found 820 cases (82.9%) of specific human herpes virus type 6 (HHV 6) antibodies (IgG) gy indirect immunofluorescent assay. The seroprevalence rose to 83.6% when the 7 HHV 6-IgM positive results (0.7%) were included; moreover a further 23 sera (2.3%) showed specific HHV 6 antibodies of both classes (IgM and IgG). The antibody prevalence was constantly high at 90% from the age of 8 months up to the 71-80 years group, and it only decreased in the age group over 80. 93.2% of the newborn infants showed HHV 6-IgG antibodies (of maternal origin) in the cord blood; this prevalence is identical with that for females of reproductive age (92.7% in the 3rd decade, 93.7% in the 4th decade). No sex differences in seroprevalence were observed. The main immunization occurs in the first year of life but infection with HHV 6 at a later age is also well documented. We found the lowest seroprevalence in the 3rd and 4th postnatal months (when maternal immunity had disappeared); later the seroprevalence of specific antibodies rose very rapidly and by the 8th month the rate was the same as for the adult group. The theoretical possibility of prenatal infection due to HHV 6 exists, but the real risk of a first infection during pregnancy is very low, because only 7-8% are susceptible in this group.

[Seroprevalence of human parvovirus B 19 antibodies (Sticker's disease/erythema infectiosum) in the DRG population]. / Seroprävalenz von Antikörpern gegen das humane Parvovirus B 19 (Ringelröteln/Erythema infectiosum) in der DDR-Bevölkerung.

We tested 638 human sera of all age groups (patients and blood donors) from the northern area of the G.D.R. and found 216 cases (33.9%) of specific parvovirus B19 antibodies (IgG) by antibody capture ELISA. The seroprevalence rose to 36.7% when the 18 parvo B19-IgM- and/or parvo B19-DNA-positive results were included. The antibody prevalence was 24.9 (27.8% resp.) in the 0-10 years group and increased continuously in the following age groups up to 61.1% (69.4% resp.) in the 51-60 years group. 50% of the newborn infants showed parvo B19-IgG-antibodies in the cord blood (of maternal origin). No sex differences in seroprevalence were observed. Parvovirus B19 is obviously very prevalent in the G.D.R. population. The main immunization occurs in the first 30-40 years of life but infection with parvo B19 at a later age is also well documented. Hence it follows that 35-45% of all G.D.R. females of reproductive age are susceptible to a parvovirus B19 infection.

[Vascular purpura and other cardiovascular alterations in children with acute parvovirus B19 infection. Report of 3 personal cases]. / Vaskuläre Purpura und andere Gefäss- und Kreislaufalterationen bei Kindern mit akuter Parvovirus B19-Infektion. Bericht über 3 eigene Beobachtungen.

Most frequent skin manifestation of parvovirus B19 infection is the erythema infectiosum (fifth disease; Sticker's disease). Vascular purpura (some cases of Henoch-Schönlein purpura) has been reported in virus infections such as infectious mononucleosis (Epstein-Barr virus), hepatitis B, cytomegalovirus etc., and human parvovirus B19 could be another cause. Clinical course, procedure of diagnostics and therapy in 3 own serologically established cases of vascular purpura or severe alterations of the blood circulation due to parvovirus B19 infection are presented. Parvovirus B19 (or other viruses) as a trigger for vascular purpura and alteration of the blood vessel wall and blood circulation could explain the childhood predominance and seasonal clustering of that disease. Furthermore an individual disposion (in form of special HLA type?) for the development of vascular purpura can be suggested.

[New knowledge of Zahorsky exanthema subitum (critical 3-day fever-exanthema, roseola infantum]. / Neue Erkentnisse zum Exanthema subitum Zahorsky (kritisches Dreitagefieber-Exanthem, Roseola infantum.

A survey is given on the history, characteristic symptoms and recent data of the etiology of exanthem subitum (Zahorsky's disease, sixth disease, roseola infantum). Some cases are presented and modern diagnostic techniques for atypical cases are discussed. The disease is caused by an infection with the human herpesvirus-6 (HHV 6; syn.:, "human B-lymphotropic virus", HBLV). Most babies and small children have an asymptomatic infection usually leading to lifelong immunity. The typical "exanthem subitum" develops only in a minority of the infected and susceptible persons. We suggest that the novel human herpesvirus-6 also has the potential of lifelong persistence in humans and can then be shedd at any age in case of acquired immunodeficiencies. World-wide research in this field is carried out by several working groups and new data will be available in a few years.

[The critical 3-day fever-exanthema in young children (exanthema subitum, Zahorsky roseola infantum)--what is new?]. / Das kritische Dreitagefieber-Exanthem der kleinen Kinder (Exanthema subitum, Roseola infantum Zahorsky)--was gibt es Neues?

As to the present knowledge the critical rose rash of infants (exanthema subitum, roseola infantum) means to be an exanthematous infectious disease that, occurring preferably in elder babes and younger infants (1st--3rd year of life), is caused by the newly detected herpesvirus (now the sixth one) pathogenic for man. The natural contamination in our latitude is intense (60-75%), and the probably lifelong immunity in the majority of cases is acquired in infancy. Though experts in the clinical subject do stress all the time the exanthema subitum to be the most frequent exanthematous disease in early infancy and infancy, infection chains tested to exanthema, respectively epidemics are observed decidedly seldom. Consequently, most of all infections use to develop clinically inperceptibly or even with other symptoms (and without an exanthema); the exanthema up to now obligatory for establishing the diagnosis uses to appear only in the minority of all cases and in the great majority of them the seroconversion is clinically silent. The prognosis of the exanthema subitum is in force to be good; the disease is the special field of activity for ambulatorily acting physicians (paediatrist, general practitioner). To begin with, the status diagnostically unclear and high-febrile for several days, the central-nervous excitability occurring in many cases, and in some children the appearing of dramatic febrile convulsions, as well as gastroenteric symptoms perpetually give rise to differential diagnostic considerations and sometimes even to a (false) antibiotic therapy. In case of an affection by herpesviruses principally a latency (persistence) of the virus lasting for years (possibly even lasting for life) in human beings is to be taken into account; this condition is also current for HHV 6. On occurring of an immune debility a release and a discharge of herpesviruses--not only by children suffering from an exanthema subitum (!)--are possible so that human beings of each age may come into question to be the source of infection. Double infections of human immune cells (for instance HHV 6 and HIV 1 simultaneously) already have been found. The necessary studies in order to clarify essential clinical and virological problems are world-widely in full activity, and new cognitions (further symptoms of diseases associated with HHV 6, possibly affections in prenatal infections and so on) are soon to be taken into account.