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Comparative investigations were carried out to evaluate the efficiency of concentration (EC) of enteroviruses (poliovirus type 1 and simian rotavirus SA-11) using macroporous glass (brands MPG-1000 VGKh, USSR, and SO1, Czechoslovakia) and membrane filters (MF): (nitrocellulose PNTs 0.45, USSR, Millipore HAWP 0.45, USA, Synpor 0.45, Czechoslovakia as well as polycapromide MF Pall 0.2, FRG, and FMPA 0.55, USSR). To assess the sorption properties of filters, poliovirus preparations and rabbit serum gamma-globulin were labelled with radioactive isotopes. Nitrocellulose filters (Millipore and PNTs) proved to be superior in providing for 64-90% virus sorption and 20-24% protein sorption. Elution experiments using solutions of different chemical nature--protein solutions (triptosophosphate broth and beef extract), amino acid mixture (glycine + arginine), chaotropic salt (sodium trichloroacetate mixed with lysine)--showed that protein solutions better eluted rotavirus SA-11 from nitrocellulose filters and macroporous glass (MPG). The utilization of nitrocellulose filters and MPG as sorbents enables a 10-40-fold concentration of enteroviruses depending on the chosen eluent. Comparisons of EC values for rotavirus SA-11 obtained using porous glass MPS-1000 VGKh and SO1 indicated that MPS-1000 VGKh was superior both with respect to recovery efficiency (R) and concentration factor (CF).

Levels of complement-fixing antibodies against rotaviruses were evaluated in the sera of 900 healthy children aged 1-9 years 300 sera were collected in the People's Democratic Republic of Yemen in September-October 1985, 300 sera were obtained in the Czech Socialist Republic in the same period and another 300 also in the Czech Socialist Republic in September-October 1986. The latter two groups were investigated in the framework of immunological surveys. A complement-fixation antigen was prepared from a simian strain of the rotavirus type SA-11 in a tissue cell line MA-104. The sera from Yemen featured lower mean titres in the age groups and thus the lowest overall titre. As the antibody titre increased, the portion of seropositive sera from Yemen declined by far more rapidly than in the Czech children, where it remained virtually the same. The sera from Yemen showed the lowest negative rate and lowest ratio of high titres. The antibody titre of 1:64 and higher was not detected in children from Yemen, while they occurred in the two groups of Czech children. There was no correlation between antibody titres and probands' sex, nor was there linear dependence of titre magnitude on age. The mean positivity rate in each group as assessed by the antibody titres was the lowest in the sera from Yemen. The percentage of positive sera in all age groups was higher in the Czech children with the exception of children from Yemen aged 6 and 9 years. The aim of the present study was to evaluate the antibody status in infant populations and thus expand knowledge of rotavirus epidemiology.

Excretion of attenuated polioviruses after controlled type 3 poliovaccine administration was studied in the district city of Cheb. The usual type 3 dose, 10(5) TCD50, was doubled in some vaccinees. A total of 972 stool samples collected from primary vaccinees and their family members were examined; three samplings were carried out in most of the subjects. At first sampling, 9 weeks after administration of type 1 + 2 mixture and 1 day before administration of type 3, all poliovirus types were isolated from primary vaccinees, but family members were negative. At second sampling, 14 days after type 3 administration, primary vaccinees displayed suppression of type 1 and 2 replication and a not very pronounced increase in type 3 excretion. Family contacts yielded all types, the least frequent being type 1. At sampling three, 5 months after type 3 administration, the not very clear-cut difference (at 2nd sampling) between vaccinees given the two different type 3 doses was completely obliterated; type 1 was not isolated; and type 2 isolations increased above the 2nd-sampling value. The number of type 1 and 3 isolations decreased in family contacts, in contrast to type 2, where an increase occurred. Excretion of types 1 and 2 at the time of type 3 administration did not demonstrably influence the subsequent excretion of type 3. Mothers were contact infected at a slightly higher rate than other family members. Only a part of excretors among family members of vaccinees excreted virus of the same type as the vaccinees (simultaneously or subsequently).

The excretion of live, attenuated poliovirus vaccine strains was determined in the feces of Prague Infants home children given 10(5) PFU of type 1 and 2 and 2.10(5) PFU of type 3 vaccine in a routine annual mass campaign. The first two faeces specimens examined in each vaccinee prior to immunization were negative for the virus. A total of 476 stool specimens were collected from 37 children at weekly intervals for a period of 18 weeks. The presence of type 1 poliovirus in the faeces of children given monovalent type 1 vaccine was detectable for 9 weeks, with a maximum in first week, and the virus was isolated in 74.2% of vaccinees. The timing of bivalent type 2 and type 3 vaccine was 9 weeks after monovalent type 1 immunization. The excretion of these two types of poliovirus was found to persist for at least 6 weeks. Type 2 poliovirus was isolated in all vaccinees, type 3 in 70.4% of children. The highest percentage of children excreting type 2 poliovirus was recorded in the first week, the excretion of type 3 peaked three weeks after bivaccine administration. The excretion peaks were reached relatively early postvaccination, with type poliovirus reaching the highest titre per 1 g of faeces. After revaccination (one year later) with monovalent type 1 vaccine, the vaccine strain of type 1 poliovirus could be detected for 6 weeks and was present in the highest percentage of positive stool samples.(ABSTRACT TRUNCATED AT 250 WORDS)

The excretion of attenuated polioviruses was studied in a group of nursery children vaccinated with 105TCD50 of each type of virus. The primovaccinated children were found to excrete type 1 poliovirus for 8 weeks, type 2 for 11 weeks after the vaccination with the type 1 + 2 bivaccine. Poliovirus type 1 as eliminated by 78% and type 2 by 98% of the vaccinees. The separately administered type 3 was detectable for 6 weeks and was isolated from 100% of the vaccinees. The highest per cent of children with type 1 excretion positivity was recorded at week 5, with type 2 positivity at week 1 and with type 3 positivity at week 2. The poliovirus excretion peaked early after the vaccination, the titres of the poliovirus type 2 were the highest. The children revaccinated next year with the type 1 + 2 bivaccine eliminated the respective types of virus 1 - 2 weeks; type 3 poliovirus was detectable for 6 weeks after revaccination and was excreted by the highest per cent of vaccines. The contact infections caused by the attenuated polioviruses developed in 9 from 22 children vaccinated previously. The excretion of polioviruses did not last longer than 1 week. The contact infections were most frequently caused by the poliovirus type 2. The examined children, particularly those vaccinated previously, turned out to excrete also other enteroviruses identified as Coxsakieviruses B 4 and B 5 and Echovirus 21. In the primovaccinated these viruses were isolated only from those with the negative excretion of polioviruses.