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Resume L'enquete serologique (tests HR et IH) porte sur un echantillonnage representatif de la production porcine en Bretagne. L'infection grippale qui n'avait atteint que le tiers des elevages en 1977 diffuse dans 80% des elevages en 1978 et 60% en 1979: le pourcentage d'infectes dans l'effectif controle est passe de 13,5 a 50% puis 36,5%. L'etude de l'infection grippale en fonction du rang de portee et de la specificite des anticorps detectes montre que: —Des virus apparentes a A/PC avaient circule avant 1975. —Des virus apparentes a A/PC/73 et A/VIC/75 ont diffuse dans l'hiver 1975–1976; puis dans l'hiver 1977–1978 apparaissent des infections par des virus portant des antigenes HA apparentes a A/Tex/77. —On trouve, des mai 1978, quelques animaux portant des anticorps anti H1N1. Il n'est detecte aucun anticorps vis-a-vis des souches porcines apparentees a A/Swine/31 et 61. Pour A/NJ/76 des anticorps sont detectes par hemolyse radiale dans 7/25 elevages a partir de mai 1978.

Resume Une epidemie de grippe equine est survenue en France en Automne 1978 et s'est etendue progressivement a l'ensemble du territoire au cours du premier semestre 1979. Elle correspond a la reapparition du virus influenza A equi 2 alors que depuis 1973 il n'y avait que des foyers isoles dus au virus A equi 1. Ce virus A equi 2 n'est pas un variant de la souche A equi 2 Miami 63 et des souches A equi 2 isolees anterieurement en France. La vaccination s'est montree souvent incapable de proteger les chevaux contre cette infection.

A technique for quantitativly evaluating flue antibodies using the passive Hemolysis of sheep red blood cells sensitized by influenza virus is described (Single Radial Hemolysis in agar medium). Compared with Hemagglutination inhibition, this test appears to be equally specific and at the same time better suited for measurement of small amounts of antibodies, in the horse. The test has been used to determine serodiagnosis after infection as well as post-vaccinal immune reactions., Une technique d’évaluation quantitative des anticorps grippaux basée sur l'hémolyse passive d'hématies de mouton sensibilisées par le virus grippal est décrite (hémolyse radiale en milieu gélosé). Comparé à l'inhibition de l’hémagglutination le test paraît également spécifique mais plus apte à apprécier les faibles taux d’anticorps. Il a été utilisé pour déterminer les séro-conversions chez les chevaux convalescents et les réactions immunitaires post-vaccinales., Fontaine M.-P., Fontaine M., Aymard M., Nafti K. Technique d’hémolyse radiale pour la mesure des anticorps anti-influenza chez le cheval. In: Bulletin de l'Académie Vétérinaire de France tome 134 n°1, 1981. pp. 105-112.

Resume Les infections ORL virales de l'enfant sont frequentes. De larges enquetes epidemiologiques ont montre que certains virus avaient un tropisme preferentiel ; les Rhinovirus sont les principaux responsables des rhumes et les virus Parainfluenza sont les plus frequents agents des laryngites aigues. Les pharyngites et angines sont plus souvent d'origine virale que bacterienne : les “virus respiratoires” (Influenza A, RSV, ADV, et Parainfluenza) sont responsables d'epidemies de pharyngites et d'otites moyennes. Dans la surdite, les virus ont aussi un role dominant : la surdite neurosensorielle bilaterale provient d'infections congenitales par le virus de la rubeole et le Cytomegalovirus (CMV). Dans la surdite “soudaine”, de nombreux virus ont ete incrimines : ceux des meningites virales, des Oreillons, de la Rubeole, le virus Influenza B, le virus Varicello-zonateux, le CMV et l'EBV. Parmi les manifestations tumorales, le papillome larynge a HPV est rare. Le role etiologique des virus dans les affections ORL a ete argumente sur des donnees epidemiologiques, mais c'est la presence du virus, de ses antigenes dans les cellules des divers organes qui prouve sa multiplication locale et son role pathogene direct.

Summary The frequency and severity of CMV infections in kidney, bone marrow, heart transplant recipients, in polytransfused patients, in immunodeficiencies and in newborns with congenital or peri-natal infection prompted clinical trials of immunoglobulins (Ig) with anti-CMV activity. Among the various methods for titrating Ig of plasmatic or placental origin, polyvalent or hyperimmune, ELISA would be the most sensitive assay and the neutralizing reaction might be the better reflection of a protective effect. In kidney transplantation, two non-randomized clinical trials have suggested a curative effect in association to other treatments, especially when given early. In bone marrow transplantation, three randomized studies have shown a prophylactic effect on incidence of symptomatic infections, interstitial pneumonias due to CMV, but only in seronegative patients not treated with leucocyte transfusions. No effect was observed on the time of infection, the survival of patients, the incidence of surinfections or graft versus host disease. The prophylactic effect of anti-CMV Ig in kidney and heart transplantation as well as in newborns has still to be documented in randomized trials. The possible clinical benefit for the patients and the mode of preparation of effective anti-CMV antibodies need further investigations.

A rapid and sensitive colorimetric assay has been developed to evaluate the sensitivity of herpes simplex viruses (HSV) to antiviral agents. The chessboard titration of viruses and antiviral drugs and the automatic reading and analysis of the data allows objective and accurate results to be rapidly obtained. Virus sensitivity was expressed as an ED50 value which was the concentration of drug (micrograms/ml) reducing viral cpe by 50%. The ED50 values of antiviral drugs [acetylguanosine (ACV), idoxuridine (IDU), deoxycytidine (IDC) and bromovinyl deoxyuridine] for several HSV reference strains were determined and the method was then applied to clinical specimens. The selection of ACV and IDU resistant mutants was performed on a cloned sensitive HSV 1 ocular strain. We observed cross-resistance between ACV and IDU for the mutants isolated. The resistance to thymidine-kinase-dependent antiviral agents varied in inverse ratio to the thymidine kinase activity induced by HSV strains.

The Blood Transfusion Centers (B.T.C.) are mainly concerned with the selection of CMV infection free blood donors, the screening of the anti CMV antibody high titre plasma donors and the evaluation of specific anti CMV Immunoglobulin preparations. Various serological methods could be used but they are of different value depending the purposes of the B.T.C. The neutralization test (Nt), with the addition of complement is specific and detects the protecting AB against the glycoproteins of the viral envelope. The complement fixation test (CF) using extracts of CMV infected cells as antigen largely varies in its sensitivity according to the quality of the antigen. In any case, the CF test is not sensitive enough to detect a latent CMV infection in a certain percentage of the non immunosuppressed adults, but could be used for the selection of anti CMV antibody high titres carriers. Three sensitive methods: passive haemagglutination, indirect immunofluorescence and indirect ELISA tests, might be used for the detection of latent CMV infections. They detect various AB against various internal and external components of the CMV. They are submitted to various sources of errors. The sensitivity of the indirect IF test is mainly restricted by the quality of the antigen preparation, its specificity by the presence of anti cells antibodies in the sera, the Fc receptors in the antigens and the specificity of the conjugates. The indirect ELISA which is submitted to the same causes of errors is a highly sensitive test, easy to perform, reagents are available, and automatic processors have been developed. When compared with the previous techniques, the ELISA test is suitable for the screening of CMV free donors, when it is performed with an highly sensitive antigen. It could be also used for the screening of high antibody titre carriers: its correlation with the CF test is quite good (r = 0,82). When comparatively applied to the titration of Immunoglobulins preparations, made from plasmas or placentas, for either IM or IV administration, the Elisa test gives AB titres different from those obtained with Nt and indirect IF. The calibration of a standard Immunoglobulin reagent is urgently needed and double blind clinical assays of the protective effect of various preparations of specific anti CMV Immunoglobulins have to be promptly designed.

The effects of repeated topical idoxuridine (IDU) administration of HSV1 strain sensitivity were investigated during 6 serial passages (P1 to P6) in the rabbit. By comparison to placebo treated rabbits, a delay in ulcer cicatrization appeared at P2 and clinical resistance was completed at P3. Clinical cross resistance to acyclovir (ACV) was also tested and demonstrated at P7. In vitro, a plaque reduction test on Vero cells using directly the tear film HSV populations allowed the prediction of the resistance by an early rise in the effective dose 90% (ED 90) value anticipating that in ED 50%. An ED 50 determination by dye-uptake assay on P6 HSV isolate demonstrated a cross resistance to viral thymidine kinase (TK) dependent drugs without any change in Ara-A and PFA sensitivity, according to a 23% TK activity at P6. At the last passage the HSV drug resistant population had an unrestricted corneal pathogenicity. A return to IDU and ACV in vitro sensitivity was demonstrated in group control animals at P2 but not at P4 or P6.

A simple, indirect enzyme immunoassay using purified enterovirus adsorbed on to nitrocellulose has been developed for screening monoclonal antibodies to enteroviruses. The sensitivity of the assay ranged from 10 ng to 1 μg of viral protein and was 10- to 50-fold more sensitive than conventional EIA on microplates. This simple, sensitive and specific assay proved to be a useful and practical tool for detecting monoclonal antibodies which would not be found in a conventional EIA screening procedure.

Résumé En janvier 1981, au cours d'une épidémie d'infections respiratoires survenue chez des enfants âgés de 1 à 3 mois, 9 sujets atteints de bronchiolites sévères ont été hospitalisés dans un service de pédiatrie et 11 cas sont survenus dans le service. Pour le diagnostic rapide direct, les prélèments pharyngés et/ou des aspirations nasales effectués chez 10/11 malades étaient tardifs par rapport à l'apparition des symptômes. Le diagnostic direct n'a été positif que dans 2 cas, et l'isolement d'un virus a toujours été négatif. Pour le diagnostic sérologique, dans 9 cas/16, le premier sérum a été prélevé après 5 jours d'évolution. La réaction d'immunofluorescence (IF) a permis de faire le diagnostic d'une infection à virus respiratoire syncytial dans 13 cas. La r'eaction de fixation du complément (FC) est restée négative dans tous les cas. Pendant la période de novembre 1980 à janvier 1981, on a prélevé les sérums de 32 enfants et 13 adultes hospitalisés pour des infections respiratoires aiguës (bronchites et bronchopneumophathies) et les sérums de 35 adultes hospitalisés dans un service de transplantation rénale. La réaction d'IF indirecte n'a pas été plus sensible que la FC, mais elle a permis:o1)de différencier les infections primaires des réinfections;2)de prouver que dans la majorité de ces réinfections (13 cas/17), on pouvait détecter des IgM;3)de porter un diagnostic de certitude rapide sur un seul sérum dans environ 60% des cas, alors que la FC était négative (1 cas) ou ne permettait qu'un diagnostic présomptif (10 cas).

Summary Different strains of influenza virus H3N2 and H1N1 (Swine) were isolated from foetuses and stillbirths of naturally infected sows during 1981–83 and 1984 outbreaks in Brittany. The significance of these isolates is discussed.

In order to improve the knowledge of the humoral immune response to CMV infection, we developed an immunoblotting technique which allowed a better analysis of the changes in the pattern of anti CMV-polypeptides IgM. We examined 234 sera belonging to 27 renal allograft recipients developing a primary or recurrent CMV infection and 12 non infected recipients. Thus we found that 11 main anti CMV-polypeptides IgM antibodies were present in over 25% of the infected patients. They reacted with proteins whose molecular weights ranged from 32K to 205K. We showed that anti-p 45-47 IgM antibodies were present in 100% of CMV infected recipients and never in the non-infected population. They appeared very early in the course of the infection (5.43 weeks post-graft for primary infection and 5.00 weeks for recurrent ones) and, therefore, constitute a good marker of active infection. Two other CMV-specific IgM antibodies (anti-p 60-64 and anti-p 100) were found exclusively in the course of primary infections. Anti-p 60-64 IgM was observed at a high frequency (57.1%) and with a mean delay of 6.57 weeks post-graft. Therefore, the anti-p 60-64 IgM detection could be helpful for the diagnosis of primary infection. In almost 100% of both primary and recurrent infections, we observed anti-p 140 and anti-p 38 IgM antibodies. Only about 50% of non-infected patients had low levels of anti-p 140 and anti-p 38 IgM. The follow-up of recurrent infections showed that the anti CMV-polypeptides IgM antibodies appeared earlier than in primary infection. When we compared anti-p 45-47 IgM detection by immunoblotting and anti-CMV IgM detected by ELISA we observed that immunoblotting permitted the diagnosis 2.5 weeks earlier for primary infection, and 1 week earlier for recurrent infection, than ELISA. In addition, the detection of anti-p 45-47 IgM antibodies also occurred earlier than virus excretion.

Resume En utilisant la methode de l'hemolyse radiale, on a observe que chez les porcs ont diffuse jusqu'en 1979 a la fois des souches apparentees a A/Port-Chalmers/73 et A/Victoria/75. Les anticorps anti A/Texas/77 sont apparus chez les porcs en meme temps que chez les humains (avril 1978). On n'a detecte d'infection a souches apparentees a A/Swine ni chez l'homme, ni chez les porcs. Des anticorps anti A/H1N1 et A/New Jersey/76 ont ete detectes essentiellement chez les animaux ayant deja des anticorps anti A/Port Chalmers/73 et/ou A/Victoria/75 et/ou A/Texas/77. Il existe une correlation pour la frequence et la specificite des anticorps anti influenza A entre les porcs et les eleveurs. Le renouvellement rapide des porcs dans les elevages permet la persistance des souches d'influenza A dans ce reservoir et des echanges reciproques avec le reservoir humain qui se traduit par un profil immunitaire antigrippal des eleveurs significativement different de celui des autres groupes humains apparies, etudies.

Resume Nous avons traite 12 patients ayant recu une greffe renale ou renale et pancreatique, par le DHPG : (9-(1,3 Dihydroxy-2-propoxymethyl) guanine), pour une infection grave a Cytomegalovirus. Cinq patients presentaient une primo-infection. Le CMV a ete isole du sang (5), de la moelle (1), des urines (9), et a partir du lavage broncho-alveolaire (2). Trois patients presentaient une pneumopathie : le CMV etait associe a une Nocardia et une Legionella . Seulement 2 patients n'avaient pas recu de traitement corticoide a fortes doses pour un rejet. Neuf patients presentaient un pic monoclonal du a une infection a Epstein-Barr Virus, qui a evolue vers un lymphome pulmonaire dans un cas. Le DHPG a ete utilise a la dose de 3 a 10 mg/kg/j pendant 10 a 21 j. Le nombre des leucocytes a augmente rapidement, dans les 3 a 5 j. suivant le debut du traitement, de 3.5 giga/l en moyenne a J1 a 5.6 giga/l a J5. Les cultures de CMV se sont negativees chez 9 patients pendant le traitement et sont restees negatives chez 3 patients apres la fin du traitement, sans que l'on observe de rechute. Le traitement n'a pas entraine d'effets secondaires importants : la leucopenie observee apres le 5 eme jour est restee moderee. Nous pensons que, chez les patients recevant un traitement immunosuppresseur lourd apres la transplantation, le traitement des infections graves a CMV par le DHPG peut eviter les complications viscerales graves et les infections surajoutees.

Resume Le CMV est le virus le plus frequemment transmis par la mere au fœtus. L'incidence de l'infection varie dans le monde de 0,2 a 2,2 %. Dans une enquete portant sur 7 772 femmes ayant accouche a la maternite de l'hopital Edouard-Herriot, nous avons observe un taux de transmission au nouveau-ne de 45,5 % dans les primo-infections et de 3,1 % dans les reinfections, avec excretion virale, mais le risque des complications neuro-sensorielles, chez le nouveau-ne, est peu important. Dans l'etat actuel des connaissances, un depistage systematique ne semble pas justifie.

Summary The authors review the biological properties of enteroviruses and the pathogenic features of the neuromeningeal infections caused by them, and describe the value and methods of interpretation of diagnostic procedures. They then outline the place of the enteroviruses in infectious viral diseases of the nervous system (meningitis, encephalitis, paralytic syndromes) and the epidemiology of these infections, basing their conclusions on W.H.O. statistics and their personal experience of such cases in the Rhone-Alpes region. Epidemiological data concerning meningitis epidemics is often incomplete, and almost inexistent for encephalitic and sporadic paralytic syndromes. In many cases, the etiological diagnosis is not made as this requires a very complete virological diagnosis and precise epidemiological surveys. Fecal excretion of these resistant viruses and their dissemination in water supplies means that epidemiological studies of the environment and the population are necessary, and should be made regularly.

Resume De Novembre 1975 a Juin 1976 et de Novembre 1976 a Avril 1977 un reseau de surveillance de la grippe a ete mis en place en France. Cette surveillance combine un indicateur de sante, l'absenteisme scolaire des enfants de 9 a 12 ans, a la recherche et identification des virus grippaux faites a partir de prelevements de gorge pratiques sur les enfants absents et sur leur entourage familial immediat. Ce reseau qui a compris 198 classes tirees au sort dans 12 villes pendant la periode 75–76 et 267 classes dans 22 villes francaises, dont 2 a La Martinique pendant la periode 76–77, a permis d'obtenir jusqu'a 56 % de prelevements de gorge positifs avec une moyenne qui est montee a 24,2 % pour le reseau 76–77. Il a ete egalement possible de detecter le debut des poussees epidemiques intervenues en France pendant ces periodes et de suivre leur evolution dans le temps et dans l'espace, bien que ces poussees aient presente une faible intensite. Cela permet d'attribuer a cette methode une sensibilite remarquable.

Resume Les auteurs rapportent les manifestations cliniques de l'infection congenitale a cytomegalovirus avec ses trois formes : severes et encephaliques, monosymptomatiques, asymptomatiques. Ils essayent de repondre aux deux questions essentielles : Quels sont les rapports entre l'infection de la mere et la severite de l'infection ? Les formes asymptomatiques laissent-elles des sequelles neurologiques essentiellement sensorielles ? Ils rapportent une enquete prospective faite dans les maternites publiques lyonnaises.

A study is carried on in a group of 16 commercial breeding-finishing units in Brittany (France). The aim of this study is to try to reveal the persistence of activity of the Influenza Virus within these intensive units after an acute epizootic. In each farm two batches of pigs are selected, individually identified and followed from suckling period to slaughter. Serological controls are conducted every month on the same pigs. Both Influenza and Aujeszky's disease antibodies are apprehended. Furthermore nasal swabs and lungs are submitted to analysis for virus isolation purposes and data are collected from each herd for epidemiological studies. Influenza passive H.I. Antibodies rapidly decrease in the piglets. Later a seroconversion is observed in 10% of the investigated piglets. These pigs belong to 4 herds. The conversion happens usually after 3 months of age. All attempts to isolate the virus failed. Special herd conditions may be associated with a persistence of the viral activity inside the units between epizootics: bad demography (unbalance in the breeding stock), inadequate hygiene policy in the fattening house (with permanent arrivals of pigs coming from subsequent batches of sows), a high prevalence of respiratory and specially pulmonary enzootic diseases. A seroconversion against Aujeszky's disease is pointed out in 3 out of the 4 herds concerned with Influenza virus activity suggesting that closely the same conditions may be related both to influenza and Aujeszky's disease virus activity.

Two methods for the differentiation of herpes simplex virus (HSV)--rct and neutralization by specific antisera--have been applied to 8 prototype strains and 105 strains isolated from various clinical cases. The evaluation of the II/I index allows to choose the most specific rabbit antisera. The rct 40 degrees 3 C marker test gives comparable results for HSV grown in RK13 and human fibroblasts as well; it is in agreement with the immunological test in 48% of the cases. The delta tc values used to express the immunological typing allow to differentiate 76% of the strains (types 1 and 2). The others (24%) are equally neutralized by both specific antisera; they represent "intermediate" strains. The infection of man and animal by HSV (type 1, 2 or "intermediate") also produces heterospecific antibodies in variable amount. From clinical and immunological data rises the hypothesis that "intermediate" strains derive from HSV1 strains by antigenic variation during a persistent infection.

A modification of the single radial haemolysis test by treatment with Cl3Cr of the virus coated red blood cells is proposed for a rapid, more sensitive and reproducible serodiagnosis of Influenza infections. The reagents "red blood cells-virus-Cl3Cr" is stable at 4 degrees C for at least 1 month: the modified test gives results within 3 hours, in measuring the H-anti-H specific reactions. The anti-influenza A immune response was studied in patients of different age, bled at different time after exposure. The IgM do not diffuse in the agarose and do not haemolyse. A clear haemolytic area is produced by IgG, partially haemolysed areas occur when there is a competition between specific IgM and IgG and in the case of reactions involving cross-reacting antigenic determinants.

The use of both SEM and TEM techniques in studying the alterations of the columnar ciliated epithelium of the whole respiratory tract of ferrets enables the authors to find a significant discrepancy between tracheal and nasal mucosa destructions. This discrepancy is not a function of the anatomical location of virus instillation. Theoretical and pratical meanings are discussed.

ELISA and complement fixation test (CF) were compared for the determination of the Cytomegalovirus (CMV) humoral immune status of donors and recipients before and after graft. ELISA-IgG was more sensitive than the CF test and permitted a better identification of the high risk donors and recipients. The presence of IgM antibodies in the recipient at the day of transplantation is an index of greater susceptibility to chronic or recurrent infection at a later date. In primary renal allograft recipient the detection of specific IgM antibodies by ELISA provides more rapid diagnosis than that by CF. In bone marrow transplants, ELISA-IgM showed a better correlation with the virus isolation than the CF test. In the reinfected renal allograft patients the presence of IgM was related to clinical manifestations. Using ELISA, specific decreases of CMV antibody titers were detected before virus isolation.

The frequency and severity of CMV infections in kidney, bone marrow, heart transplant recipients, in polytransfused patients, in immunodeficiencies and in newborns with congenital or peri-natal infection prompted clinical trials of immunoglobulins (Ig) with anti-CMV activity. Among the various methods for titrating Ig of plasmatic or placental origin, polyvalent or hyperimmune, ELISA would be the most sensitive assay and the neutralizing reaction might be the better reflection of a protective effect. In kidney transplantation, two non-randomized clinical trials have suggested a curative effect in association to other treatments, especially when given early. In bone marrow transplantation, three randomized studies have shown a prophylactic effect on incidence of symptomatic infections, interstitial pneumonias due to CMV, but only in seronegative patients not treated with leucocyte transfusions. No effect was observed on the time of infection, the survival of patients, the incidence of surinfections or graft versus host disease. The prophylactic effect of anti-CMV Ig in kidney and heart transplantation as well as in newborns has still to be documented in randomized trials. The possible clinical benefit for the patients and the mode of preparation of effective anti-CMV antibodies need further investigations.

The thermal stability and the effect of guanidine on the hemagglutinin and neuraminidase of three strains of mumps virus were compared. The heat inactivation of hemagglutinin resulted in the concomitant loss of neuraminidase. The effect of guanidine at various molarities showed that the neuraminidase was more sensitive than the hemagglutinin and a selective inactivation was obtained after exposure to 1.5 M guanidine. However differences in sensitivity of both activities (hemagglutinin and neuraminidase) to heat and guanidine inactivations were observed among strains and correlated with differential susceptibility to non-specific inhibitors of the strains.

The feasibility of using human cytomegalovirus (CMV)-specific IgA antibody determinations as a signal for early detection of recurrent CMV infections in eight renal transplant recipients was analyzed. Solid phase radioimmunoassay (RIA), enzyme-liked immunosorbent assay (ELISA) and immunoperoxidase assay (IPA) techniques were used for IgA antibody determinations. In parallel, IgG antibodies to CMV were studied by immunoperoxidase assay. A significant rise of CMV-specific IgG antibody titre was observed in all of these patients between 5 and 53 weeks post-transplantation. CMV-specific IgA antibody production was detected close to the time a rise in CMV IgG antibody was observed in seven out of eight patients studied by RIA and ELISA, and in six out of eight patients studied by IPA. In two patients specific CMV IgA antibodies were detected by all three methods before a significant rise of CMV IgG antibody titre was demonstrated. In these patients CMV IgA was detected by RIA earlier than by ELISA and IPA. The potential application of CMV-specific IgA antibody determination for early detection of recurrent CMV infection in renal transplant patients is discussed.

59 sera of 10 immunosuppressed renal allograft recipients who experienced recurrent cytomegalovirus (CMV) infection were analyzed by enzyme-linked immunosorbent assay (ELISA) for CMV IgA antibodies and by the complement-fixation (CF) test. A significant rise of CF titer was evident 4-53 weeks post-transplantation. 9 patients produced CMV IgA in high titers at about the time of CF antibody rise was observed. 1 patient did not produce IgA antibodies to CMV. In 3 of the 9 patients, specific CMV IgA antibodies were detected before the rise if CF titer was demonstrated. CMV IgA antibodies were found to persist for as long as 6 weeks post-transplantation. The potential application of ELISA detection of CMV-specific IgA antibodies as an early indication of CMV infection in kidney transplant patients is discussed.

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.

Summary Representative isolates of the paramyxoviruses duck/Hong Kong/75 and duck/Mississippi/75 were shown to be serologically closely related by haemagglutination and neuraminidase inhibition tests. The structural polypeptides of these viruses were also shown to be similar. For each of the isolates tested, polyacrylamide gel electrophoresis in the presence of SDS revealed a similar polypeptide pattern consisting, under reducing conditions, of seven polypeptides with apparent mol. wt. ranging from 46000 to 190000. Each virus had two glycosylated polypeptides with apparent mol. wt. of 56000 and 71000 to 72000 under reducing conditions and 62000 to 63000 and 135000 to 142000 under non-reducing conditions.

Splenic lymphocytes from BALB/c mice immunized with Parainfluenza 1 virus (PIV-1), HA2 strain, were fused to the non secreting 653 and secreting P3 X 63Ag8 myeloma cell lines. Fusion products were screened for antibody synthesis using an enzyme-linked immunosorbent assay (ELISA) with purified PIV-1. Antibodies were characterized by their biologic specificity and immune fluorescence staining--6 monoclones (2HI and 4 non HI) were used to further analysis by cross reactivity panels using different PIV strains. None of the anti PIV1 monoclones showed any cross reactivity with PIV2 and PIV3 whereas with HI and non HI monoclones antigenic relationships were observed between viruses belonging to serotype 1. Monoclonal antibodies were also applied to the study of host cell related changes in PIV1 proteins.

The spread of influenza A viruses from one animal reservoir to another forms an important part of the epidemiological study of influenza. The precise characterization of viral antigens by monoclonal antibodies makes possible an interesting immunological approach to the transfer of strains from one reservoir to another.This work has shown that the recent porcine strains in France, Belgium, and Spain are closely related antigenically, and distinct from the A/sw/NJ/8/76 strain. Their prototype is strain A/sw/Fin/2899/82.An avian strain, A/ty/Brit/46/83, which has caused limited epidemics of reduced egg-laying among turkeys, has a haemagglutinin identical with that of strain A/sw/2899/82.This immunological finding, combined with epidemiological information (geographical location and absence of any influenza antibody in turkey farms in previous years), suggests that the transfer of influenza viruses has taken place in the direction from pig to turkey.

Between April 3, 1977 and June 6, 1980, 97 children with congenital cataracts and 97 evenly matched control children were examined in order to clarify the biological criteria of congenital rubella and to estimate its importance in the etiology of congenital cataracts. Although the age limit had been fixed at 60 months, the 1978 rubella outbreak accelerated the immunization in young children and resulted in difficulties in interpreting some results. All children presenting with congenital cataracts associated with clinical symptoms of rubella embryopathy displayed anti-rubella antibodies including anti-rubella IgM up to the 13th month: they represent 16% of cases with congenital cataracts in this series. The rubella etiology could not be proven in children with clinically isolated congenital cataracts.

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.

Intra-nasal inoculation of 10-day-old piglets, free of specific pathogenic flora, with swine influenza virus A/H1 N1 and A/H3 N2 produces lesions of viral pneumonia without detectable clinical signs. Following indirect contamination all the strains studied were able to multiply in the respiratory tract; in those cases where no macroscopic lesion was seen, microscopic examination revealed variable modification of the pulmonary tissue depending on the virus causing infection. Influenza virus type H3 N2 are naturally found in many groups of pigs and can therefore play an important role in the respiratory pathology of the hog. Experimental results when compared to findings in the field indicate that the severity of the disease is linked to associated etiological factors as well as to the virulence of the viral strains themselves.

Because of the possible serological cross reactions frequently described in the literature between L. pneumophila and M. pneumoniae or between L. pneumophila and Chlamydia, we decided to determine their frequency with our sera and our own methods. The anti M. pneumoniae and Chlamydia antibodies were researched in 162 sera samples from 46 cases of legionellosis serologically diagnosed and in 51 sera from 26 hyperimmunised rabbits. Conversely, anti L. pneumophila antibodies were researched in 165 sera from mycoplasmosis (61) or chlamydiosis (25 cases). None of the sera from mycoplasmosis or chlamydiosis tested by IFA and MA had antilegionella antibodies. None of the rabbits' sera hyperimmunised with Legionella had anti M. pneumoniae or Chlamydia antibodies. On the contrary, by complement fixation and IFA, out of the 46 cases of legionellosis under study, 6 showed a seroconversion in M. pneumoniae and 2 in Chlamydia. The Ig class determination did not show IgM titers in 7 of these 8 sera. The mechanisms of these cross reactions are discussed: antigens and methods used, booster effect during legionellosis, concurrent mycoplasmosis or chlamydiosis.

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.

From the Revised Nomenclature of WHO, the fowl influenza virus A/Duck/Ukraine/63 (Hav7 Neq2) has the same neuraminidase as the equine virus A/equi 2/Miami/63 (Heq2 Neq2); the A/Chicken Germany "N"/49 virus has the same neuraminidase as the equine virus A/equi 1/Prague/56. A comparative study of the antigenic specificities confirms that the Neq2 neuraminidases are closely connected, whatever their animal origin, and that the fowl strain Hav7 Neq2 can be used for the titration of anti Neq2 antibodies in the serums of animals immunized with the equine virus Heq2 Neq2. The Neqi neuraminidases of various animal origins are connected, but the neuraminidase of the fowl strain Hav2 Neqi is slightly inhibited by the anti Neq1 antibodies of animals immunized with the Heq1 Neq1 virus: to titrate the anti Neq1 antibodies of equine origin, the H72 Neq1 recombinant should therefore be used. The antigenic characterization of the different equine influenza strains isolated since 1967 by the study of their neuraminidase has been completed: The various neuraminidases, like the hemagglutinins of the various strains belonging to the sub-type A equi2 are closely connected; a minor antigenic variation, concerning the two surface antigens, seems to exist between the strain A equi 1/Prague/56 and the strain of the same subtype isolated in 1973.

Treatment for Herpes Simplex virus (HSV) infections was now possible with the use of different antiviral agents. Recently, Acyclovir (ACV) has been introduced as a potent and selective anti Herpes agent with low host cell toxicity. A micromethod for evaluating the drug sensitivity of the HSV strains in vitro was established. This study reports the preliminary results observed with ACV.

The Blood Transfusion Centers (B.T.C.) are mainly concerned with the selection of CMV infection free blood donors, the screening of the anti CMV antibody high titre plasma donors and the evaluation of specific anti CMV Immunoglobulin preparations. Various serological methods could be used but they are of different value depending the purposes of the B.T.C. The neutralization test (Nt), with the addition of complement is specific and detects the protecting AB against the glycoproteins of the viral envelope. The complement fixation test (CF) using extracts of CMV infected cells as antigen largely varies in its sensitivity according to the quality of the antigen. In any case, the CF test is not sensitive enough to detect a latent CMV infection in a certain percentage of the non immunosuppressed adults, but could be used for the selection of anti CMV antibody high titres carriers. Three sensitive methods: passive haemagglutination, indirect immunofluorescence and indirect ELISA tests, might be used for the detection of latent CMV infections. They detect various AB against various internal and external components of the CMV. They are submitted to various sources of errors. The sensitivity of the indirect IF test is mainly restricted by the quality of the antigen preparation, its specificity by the presence of anti cells antibodies in the sera, the Fc receptors in the antigens and the specificity of the conjugates. The indirect ELISA which is submitted to the same causes of errors is a highly sensitive test, easy to perform, reagents are available, and automatic processors have been developed. When compared with the previous techniques, the ELISA test is suitable for the screening of CMV free donors, when it is performed with an highly sensitive antigen. It could be also used for the screening of high antibody titre carriers: its correlation with the CF test is quite good (r = 0,82). When comparatively applied to the titration of Immunoglobulins preparations, made from plasmas or placentas, for either IM or IV administration, the Elisa test gives AB titres different from those obtained with Nt and indirect IF. The calibration of a standard Immunoglobulin reagent is urgently needed and double blind clinical assays of the protective effect of various preparations of specific anti CMV Immunoglobulins have to be promptly designed.