Victor M. Villarejos

Role of saliva, urine and feces in the transmission of type B hepatitis.

Abstract To identify vehicles of transmission of Type B hepatitis virus, feces, urine and saliva of chronic carriers of the hepatitis antigens and patients with acute Type B hepatitis were examined...

Specific Immune Adherence Assay for Human Hepatitis A Antibody. Application to Diagnostic and Epidemiologic Investigations

Summary A specific immune adherence (IA) test for hepatitis A antibody in human serum was described employing liver extract of marmosets infected with CR326 strain human hepatitis A virus. Persons with hepatitis A, but not hepatitis B, developed hepatitis A IA antibody soon after onset of the acute illness and this persisted thereafter. There was very close agreement in the tests for human hepatitis A immune adherence, complement fixing (CF) and neutralizing antibodies. IA antibodies appeared to develop somewhat later than CF or neutralizing antibody. A limited epidemiologic study of a family outbreak of hepatitis A and B in Costa Rica showed simultaneous occurrence of the two diseases and was supportive of the concept that susceptible persons in a country with high hepatitis A prevalence generally acquire their infections at an early age and are immune thereafter. Most persons of high socioeconomic level in an area of low hepatitis A incidence may proceed to adulthood without experience with hepatitis A. Persons of low socioeconomic level, however, such as commercial blood bank donors and prisoners, show high incidence of hepatitis A antibody. Hepatitis IA and CF antibodies persisted in human subjects for at least 7 hr after hepatitis A virus infection. Captive chimpanzees and grivet and rhesus monkeys, not given hepatitis A virus, showed evidence of previous experience with human hepatitis A or an antigenically related virus based on tests for hepatitis A antibody. Other subhuman primates, rodents, and swine, not given hepatitis A virus, were without hepatitis A antibody. The IA test provides an excellent tool for diagnostic and epidemiologic investigations of hepatitis A and should be of considerable value to detect hepatitis A virus in attempts to propagate the virus in cell culture. There was considerable difference in hepatitis A IA antibody content of different lots of commercial human immune globulin, though the majority titered 1:4000 or 1:8000.

A specific complement-fixation test for human hepatitis a employing CR326 virus antigen. Diagnosis and epidemiology.

Summary A specific diagnostic complement-fixation test for hepatitis A antibody in human serum was described employing livers of marmosets infected with CR326 strain human hepatitis A virus. Persons with hepatitis A, but not hepatitis B, developed hepatitis A CF antibody shortly after the onset of illness and this persisted thereafter. Good agreement was noted in the development of CF and neutralizing antibodies in hepatitis A cases. Hepatitis A was shown to occur in a person with hepatitis B antigenemia and hepatitis B occurred in persons with hepatitis A antibody. Most persons with hepatitis A who were tested, but none of those with hepatitis B, developed increased anticomplementary activity in their sera at the time of onset of illness. At least one patient with hepatitis A developed antibody against normal liver that persisted. The possible implications of this in relation to pathogenesis and to nonspecific diagnostic tests in hepatitis were discussed. A limited epidemiologic study of a family outbreak of hepatitis in Costa Rica and of a group of young adults in our laboratory was supportive of the concept that susceptible persons in an epidemic country acquire their infections at an early age and are immune thereafter; persons in areas of relatively low incidence may proceed into adulthood without experience with hepatitis A. The CF test should provide an excellent tool for diagnosis and for epidemiologic investigation of hepatitis A and should be of considerable value to detect hepatitis A virus in attempts to propagate the virus in cell culture. The authors are grateful to Dr. A. A. Tytell for advice, to W. Fisher, M. Johnston, F. Banker, P. Giesa and L. Hoover for excellent technical assistance, and to Dr. P. Conti for perfusion of the marmoset livers.

Etiologic relationship of marmoset-propagated CR326 hepatitis A virus to hepatitis in man.

Summary Studies were conducted to define the etiologic relationship of CR326 hepatitis virus recovered in marmosets to hepatitis A in man. CR326 virus exhibited physical-chemical properties considered characteristic of human hepatitis A virus, viz, small size and heat, ether and acid stability. A serum neutralization test carried out with CR326 virus in S. mystax marmosets is described and the factors influencing the results are given. Tests of paired sera from 8 cases of hepatitis A and 2 cases of hepatitis B were carried out including coded paired sera from 3 human subjects given MS-1 strain hepatitis A and 1 given MS-2 strain hepatitis B virus of human source. All subjects with hepatitis A developed antibody that neutralized CR326 virus; there was no such antibody response in persons with hepatitis B. All of 3 samples of human immune globulin neutralized the CR326 agent. Neutralization was highly effective since marmosets given the neutralized virus remained susceptible to reinfection with the agent; by contrast recovered animals that had been given non-neutralized virus were immune to reinfection. All evidences to establish the relationship of CR326 virus to human hepatitis A are summarized.

Clinical and Laboratory Studies of Combined Live Measles, Mumps, and Rubella Vaccines Using the RA 27/3 Rubella Virus

Abstract Eleven lots of combined bivalent and trivalent vaccines containing the measles (Moraten), mumps (Jeryl Lynn), and rubella (RA 2713) viruses gave satisfactory results in tests in initially seronegative children (measles, 493 children; mumps, 377; rubella, 586). There was no apparent suppression of antibody response against any of the viruses in the vaccines. The clinical reactions observed were mild and inconsequential. Substitution of the HPV 77-DE strain employed heretofore with the RA 27/3 is technically acceptable and offers the advantage of higher titer, slightly greater seroconversion rate, and more solid immunity against reinfection in nature.

Recovery of Hepatitis Agents in the Marmoset from Human Cases Occurring in Costa Rica

Summary Marmosets inoculated with blood specimens from human cases of hepatitis A but not from cases of hepatitis B developed hepatitis with elevation in serum enzymes and characteristic histopathologic changes. The marmoset was highly reliable for detecting, propagating and studying human hepatitis A with minimal spurious results. The authors are grateful to Dr. W. J. McAleer and his staff for devising and performing enzyme assays, to F. Banker for capable handling of marmoset bleeding and inoculations, to P. Giesa, B. Keech, L. Hoover, W. Pouch, and F. Roach for technical assistance and to Dr. P. Conti for maintenance of the health of the animals. The pathologic examinations were made by Drs. A. Phelps, G. E. Dagle, and J. H. Vickers.

Seroepidemiologic investigations of human hepatitis caused by A, B, and a possible third virus.

Summary Seroepidemiologic studies were made of normal subjects in populations in the United States and Costa Rica and in family outbreaks of hepatitis in Costa Rica. Hepatitis A affected a majority of children of very young age in Costa Rica, while such experience in persons of high socioeconomic status in the United States did not occur before middle life. Persons of low socioeconomic status (paid plasma donors) and residents and attendants of institutions for the mentally retarded showed a far greater incidence of hepatitis A antibody than did their counterparts in the open community. Hepatitis A and B epidemics occurred in families in Costa Rica with rapid spread to other susceptible members of the group. The disease was clinically apparent in roughly half the cases, whether the responsible agent be hepatitis A or B. Five cases of nonhepatitis A or B (hypothetical hepatitis C) were found and all but one of them were subclinical. The authors are indebted to M. A. Chacón, D. Jimenez E., and A. Rivas E. and to P. Giesa, L. Hoover, W. P. M. Fisher, and M. Johnston for valuable technical assistance.

Clinical and laboratory studies of KMcC strain live attenuated varicella virus.

Abstract Small-scale studies were carried out to test the KMcC strain varicella virus at various passage levels for clinical and serologic responses in order to find an optimal level of attenuation for vaccine purpose. Virus at passage 50 induced antibody responses, caused only minimal clinical reactions, and will be studied further. The clinical reactions to vaccine virus were very mild at all virus passage levels and were limited to mild transient fever and papular rash that became vesicular in a small proportion of individuals. The immune response to vaccination was accompanied by protection against natural challenge and antibody induced by vaccine virus persisted for at least 3.5 years, the longest period observed. Attenuation of virus appeared to be accompanied by alteration in the proportion of incomplete virus particles formed and by the degree of spontaneous release of virus from infected cells.

Development and utilization of complement-fixation and immune adherence tests for human hepatitis A virus and antibody.

The reliable propagation of CR326 strain of human hepatitis A virus in Saguinus mystax marmosets has permitted the development of specific serum neutralization, complement-fixation (CF), and immune adherence (IA) assays for hepatitis A antigen and antibody. The CF and IA assay were made possible by the use of livers of CR326-infected marmosets as a source of hepatitis A antigen. All assays were shown to be specific for hepatitis A. Patients with hepatitis B did not show development of hepatitis A antibody. Hepatitis A antibody appeared following onset of illness, and, in the longest time period studied, has persisted for seven years. Epidemiologic studies have been performed on several Costa Rican families with outbreaks of hepatitis, with the IA and CF assays. Also, several populations in the U.S.A. were studied. These indicated a high incidence of hepatitis A at an early age in Costa Rica and a relatively low incidence of hepatitis A antibody among adults in the U.S.A. It was shown that human immune globulin can be standardized for hepatitis A antibody content by the IA assay. Finally, the IA assay indicated probable hepatitis A antibody in uninoculated chimpanzees, grivet monkeys, and rhesus monkeys.

Suitability of the rufiventer marmoset as a host animal for human hepatitis A virus.

Summary The rufiventer marmoset, which closely resembles marmosets designated as S. labiatus, Marikina labiata, and Jacchus rufiventer, proved to be an equally satisfactory host animal as S. mystax for studies of human hepatitis A virus. C. jacchus, C. argentata, S. weddelli, and S. oedi-pus marmosets were not satisfactory. Rufiventer marmosets were highly susceptible to infection with hepatitis A virus. Following viral adaptation, livers of rufiventer marmosets produced satisfactory CR326 virus antigen for IA tests in terms of both amount and specificity. Importantly, rufiventer marmosets inoculated with rufiventer-adapted CR326 virus showed enzyme elevations and high titers of viral antigen in their livers as early as 7 days after virus inoculation. These findings may be of importance in understanding the pathogenesis of hepatitis A, indicating that a primary viral infection can cause hepatitis without need for a secondary autoimmune response to liver tissue. We gratefully acknowedge the expert technical assistance of F. S. Banker, Dr. P. A. Conti, W. P. M. Fisher, J. R. Gehret, P. A. Giesa, B. J. Harder, Dr. O. L. Ittensohn, M. Johnston, and R. A. Machlowitz.