Comparative study of poliovirus excretion after vaccination of infants with two oral polio vaccines prepared on Vero cells or on primary monkey kidney cells.

A comparative study was designed to assess the bioequivalence of 2 oral poliovaccines (OPV) produced on 2 different cell systems: primary monkey kidney (PMK) cells and the Vero cell line. The Vero cell line has been used to overcome the problem of obtaining a regular supply of high quality monkeys that are devoid of latent viruses. For this study, 9 children were vaccinated with PMK-OPV and 12 children with Vero-OPV. The comparison covered poliovirus excretion, reversion of polioviruses in the 5'-noncoding region, and immunogenicity. Major molecular markers in the 5'-noncoding region related to neurovirulence already had been identified at position 480 for type 1, position 481 for type 2, and position 472 for type 3 poliovirus. Two nucleic-acid based methods were designed for studying these positions: a RT-PCR followed by sequencing, which required preliminary culture and cloning; and a type-specific nested PCR followed by sequencing, which enabled direct detection and genotyping of polioviruses. Twenty-eight stool specimens were analyzed by this second method with no PCR inhibition problem. The use of Vero cell line did not modify the global pattern of poliovirus excretion, reversion frequency, or seroconversion. These results provide additional support for the use of the well-characterized Vero cell line in OPV manufacturing.

[Risk of transmission of cytomegalovirus infection from mother to newborn infant]. / Risque de transmission de l'infection à cytomégalovirus de la mère au nouveau-né.

A systematic prospective study of the incidence of cytomegalovirus (CMV) infection during pregnancy and contamination of the neonate was set up in a Maternity Hospital in Lyons. Over 7,000 pregnancies have been followed up since 1982 with serological and virological investigations. CMV infection was found in 5 p. 100 of patients. A urine collection was obtained at birth in 641 of the neonates. CMV was isolated in 16 cases and the transmission of the infection was studied with respect to the immune status of the mother. When CMV infection was demonstrated in the mother by serology and excretion of the virus, 45.5 p. 100 of babies were contaminated (10/22). In cases of reinfection, the incidence of neonatal contamination was 3.1 p. 100 (3/98). Ten of the 11 primary infections diagnosed were associated with viral excretion and the infection was transmitted to the child in 50 p. 100 of cases (5/10). The high incidence of transmission of CMV infection after a primary maternal infection supports data previously published by Stagno and Kumar in the U.S.A. and Ahlfors in Sweden.

Oral poliovirus vaccine in tropical Africa: greater impact on incidence of paralytic disease than expected from coverage surveys and seroconversion rates.

During the first 5 years of a poliomyelitis control programme in Yaounde, Cameroon, a maximum of 35% of children aged 12-23 months were estimated to have received three doses of trivalent oral vaccine. Despite this low immunization coverage and low seroconversion rates, which were determined concurrently, the estimated incidence of paralytic poliomyelitis decreased by 85%.A detailed study of immunized children and of children living in the same households suggests that community spread of the vaccine virus and cross-immunity may have partly been responsible for the dramatic decrease in the incidence of paralytic disease, and that competing non-polio enterovirus infection was not a cause for the low seroconversion rates. These results suggest that immunization coverage and seroconversion rates alone are not sufficient criteria for determining the effectiveness of control programmes that use oral poliovirus vaccine in tropical Africa; surveillance of the incidence of paralytic disease must also be carried out.

Recovery of reoviruses from tap water.

Samples of piped water were taken from the source of the springs in ten villages in Lorraine. Usually this water has not been subjected to disinfection. The water was tested for fecal indicator bacteria, phages and animal viruses. Of the ten samples examined, seven contained no fecal indicator bacteria, phages or animal viruses, in three samples, however, Reovirus type 2 was found. Among the three positive samples only one contained fecal bacteria and phages. Consequently, the two other samples could be regarded as drinking water, despite the presence of viruses. Such an approach poses the problem of testing drinking water for viruses and suggests that viral tests should be undertaken as part of the water quality control.

[Enterovirus circulation in the waste waters of the Lorraine region. Evaluation of a survey 1976-1981]. / Circulation des entérovirus dans les eaux usées de la région lorraine. Bilan de la surveillance au cours de la période 1976-1981.

A survey of the presence of viruses in wastewater has been conducted during 6 years in 19 treatment plants of the lorraine area. The results presented in this paper show the presence of numerous viral species in the 1938 samples analyzed from 1976 to 1981 and large variations of the annual positivity rate linked to the circulation of enteric viruses in the population. By direct inoculation to cell cultures the search of virus is positive in only 15% of the samples. On the other hand a previous concentration step allows to obtain an increase of positive samples. Taking into account the important aptitudes of polio and non poliovirus to survive in water, the survey of wastewater could be a good indicator of their presence in the population. The isolation of non vaccinal polioviruses confirm the need of the continuation of the vaccination program, but perhaps also a reevaluation of the rule of the living oral vaccine because of the presence of so called "intermediary strains".

Viral pollution of seawater at Barcelona.

A virological study of sea water was carried out at Barcelona (Spain) in June and September 1979. Three beaches were sampled in June; the September samples were taken in front of an outlet at 2, 5, 20 and 1,000 m offshore. All of the samples from the 3 beaches contained viruses, at rates varying from 0.12 to 1.72 MPNCU/l. Vaccinal poliovirus type 3 and coxsackie B5 predominated. For the offshore samples, 55% were positive with rates ranging from 0.15 to 0.36 MPNCU/l. Vaccinal poliovirus type 3 was clearly predominant. There was no significant difference in viral pollution rates between 2m and 1,000 m offshore.

Injections and paralytic poliomyelitis in tropical Africa.

A case-control study was conducted in Yaoundé, United Republic of Cameroon, to evaluate the hypothesis that intramuscular inoculations predisposed young children to paralysis if they were later exposed to poliomyelitis virus. Thirty-three cases with lower motor neuron disease and 66 neighbourhood controls were studied. Poliovirus was isolated from 39% of the paralytic cases but from only 18% of the comparison group. Controls were more likely to have had serological evidence of previous exposure to all three poliovirus types while most of the paralytic cases had been exposed to a poliovirus for the first time. Two-thirds of the paralytic cases but only 11% of the comparison group had been ill, visited a medical facility, and received multiple injections, primarily with quinine and penicillin, in the month prior to the onset of poliomyelitis. There was a strong temporal relationship between these injections and the onset of paralysis. The increased relative risks (15 and 32, respectively) of paralysis associated with inoculations in the two weeks immediately prior to onset of disease were felt to represent the treatment of symptoms related to poliomyelitis. However, the increased relative risks (13 and 27, respectively) three and four weeks prior to onset were felt to be consistent with the hypothesis that intramuscular injections provoked paralysis. Overestimation of this measure of the effect because of bias in the control group is discussed.

[Network for the epidemiological survey of the enteroviruses in sewage (author's transl)]. / Organisation de la surveillance de la circulation des entérovirus dans les eaux d'égouts.

Poliomyelitis still occurs each year in France: 27 cases in 1973, 21 cases in each of 1974 and 1975, 8 cases in 1976. Because of the risk, a survey of the spread of poliovirus in healthy populations and in sewage was organized by the Ministry of Health according to the departmental note DGS/HP/1st/250, 9-2-73. The Laboratoire d'Epidémiologie Virale of the Laboratoire National de la Santé was in charge of the technical aspects of the survey. A preliminary questionnaire was sent to each D.D.A.S.S. (Direction Départementale de l'Action Sanitaire et Sociale) in order to find out the local possibilities for sampling and preliminary treatment of the sewage samples. In 1974, all the samples were sent to the Laboratoire d'Epidémiologie Virale. Since 1975, samples have been sent to a local virology laboratory when available. The sewage samples were concentrated according to SHUVAL's or LUND's methods depending on the local conditions. Both methods tested in our laboratory were found equally efficient. In order to improve their technical laboratory methods, the virologists collaborating in this survey joined together in a working group "Virus et Eaux". For isolating the enteroviruses, we recommend the inoculation of each concentrated sample into primary monkey kidney cells grown in vials; an overlay of agar is added after inoculation. This plaque method allowed us to isolate several strains from one sample. It was possible to demonstrate that polioviruses differing in serotypes and thermosensitivity might be detectable in the same sample. Few of the isolated polioviruses (11/272) showed the same thermoresistance as did the wild strains. Certain enterovirus serotypes are known to be responsible for epidemics of meningitis and neurological disorders. It was of interest to identify non-poliomyelitic enteroviruses isolated from sewage. The study of enterovirus spread in sewage in comparison with that in healthy children is in progress.

Poliomyelitis survey in Middle-East countries.

The poliomyelitis survey was started in 1976 in Bahrain and Kuwait. For each paralytic case, diagnosis was done by virus isolation, neutralizing antibody titration and specific IgM characterization. More than 90% of the infants who were ill were less than 2 years old. In Bahrain, 17 paralytic cases in 1976 and 12 in 1977 occurred between January and July (annual incidence was respectively 7.7 and 5.4/100,000). The first epidemic was due to poliovirus type 2, the second one to poliovirus type1. From 29 cases, 13 occurred in vaccinated infants of which 9 received 3 or 4 oral vaccine doses. For 3 infants, paralysis occurred less than one month after vaccination. All the isolates were wild polioviruses (rct). In Kuwait, 119 cases were examined, and of them, 57 occurred between August 76 and May 77 (incidence 5.7/100,000). Poliovirus type 1 was responsible for 61% of cases, type 2 for 5% and type 3 for 12%. From October 1976 to December 1977, 350 stools samples were collected from contacts: 19% of them carried poliovirus (12% type 1, 1% type 2 and 6% type 3). All the viruses isolated from both paralytic cases and contacts were wild strains (rct). Of 119 cases, 35 occurred in vaccinated infants from which 4 had received 3 or 4 oral vaccine doses. For 11 infants paralysis occurred less than one month after vaccination. The virus spread was evaluated (i) just before vaccination in 337 infants or children from June to December 76: 8% carried poliovirus Sabin-like strains (and 18% non polioviruses), and (ii) one month after vaccination in 75 infants: 37% carried poliovirus Sabin-like strains.