Sociodemographic correlates of neutralizing poliovirus and hepatitis A virus antibodies as markers of different modes of acquiring immunity.

The prevalence and sociodemographic correlates of antibodies against poliovirus and hepatitis A virus (HAV) were compared in a random sample of 457 military recruits in Israel inducted during 1987. Lower socioeconomic status (SES) was associated with a higher prevalence of anti-HAV antibodies (67.3 vs 32.5 percent), whereas the reverse was true for type 1 poliovirus (78.4 vs 89.5 percent). While the high prevalence of anti-HAV antibodies observed in the lower SES groups reflects considerable natural exposure to enteroviruses, immunity against poliovirus appears to be determined primarily by compliance with vaccination.

Natural killer (NK) cell response after vaccination of volunteers with killed influenza vaccine.

Many experiments have shown convincingly that natural killer (NK) cell activity against viral infections is an important early defence mechanism in mice. Since the NK response occurs soon after infection, often long before clinical signs of disease become manifest, it has been difficult to design studies to monitor accurately NK cell kinetics following infection, without actually administering pathogens to volunteers. There is therefore little data pertaining to the role of NK cells in humans. Nevertheless, a number of studies have shown elevated NK activity in response to herpes simplex and influenza virus infections in humans. Our study was designed to show that NK activity could be provoked in humans by exposure to viral particles without actual live viral infection. The development of NK cell response in the peripheral blood of volunteers shortly after vaccination with killed influenza trivalent vaccine was studied. The results demonstrate that killed virus vaccine induces and augments NK cell activity for relatively long periods. Such data may prove valuable for designing possible modes of augmenting NK activity as a therapeutic tool.

Adenovirus type 3 infection with systemic manifestation in apparently normal children.

Between July 1983 and February 1984, eight children with adenovirus Type 3 infection, proven by virus isolation from sputum, stool or nasopharyngeal swabs and a fourfold increase in complement fixation antibody titers against the virus, were treated in our department. All eight patients had fever lasting at least 7 days, hepatomegaly, diffuse pulmonary infiltrates and abnormal liver function tests. Seven of the patients exhibited dyspnea and pulmonary wheezing. Six of the patients developed changes in state of consciousness, and three had repeated convulsions. EEG patterns in three of the patients were compatible with encephalopathy. Other clinical manifestations included: follicular tonsillitis in two patients, diarrhea in two, pneumothorax in one, and shock with disseminated intravascular coagulation in one. The spectrum of adenovirus Type 3 infection reported here has been described previously only in the viral hemorrhagic fevers. This adenovirus Type 3 infection shares the potential for disseminated disease that has been described previously for Type 7, simulating Reye's syndrome.

Immunogenicity of a single dose of trivalent influenza vaccine including A/Philippines (H3N2): results of a field trial.

During 1982, a new A(H3N2) influenza virus subtype, A/Philippines/2/82, was identified, and this strain was combined with previous A(H1N1) and B influenza virus strains in the trivalent inactivated vaccine recommended for the 1983-1984 influenza season. Prior to the widescale use of this vaccine in Israel, a group of 106 young male soldiers was vaccinated under controlled conditions. Before vaccination, antibody titers greater than or equal to 1:40 were found in 14.1% against A/Philippines (H3N2), 18.1% against A/England/333/80 (H1N1), and 13.3% against B/Singapore/222/79. Two weeks following vaccination, 78.9% of the vaccinees for whom repeated blood samples were available, had antibody titers in this range for A/Philippines (H3N2), 92.9% for A/England (H1N1), and 80.0% for B/Singapore. The vaccine was only mildly reactogenic, and there were no cases of absence from work following vaccination. Thus the antibody response of young subjects to a single dose of a vaccine containing a new A(H3N2) subtype was found to be satisfactory, and the side effects experienced were minimal.

Determination of human IgG and IgM class antibodies to West Nile virus by enzyme linked immunosorbent assay (ELISA).

An enzyme-linked immunosorbent assay (ELISA) was developed and used for the detection of IgG and IgM antibodies to West Nile virus in human sera. Thirteen paired sera of clinical cases and 24 control sera taken randomly from a blood bank repository were tested. The sera were reacted in microtiter plates coated with PEG-treated WNV antigen. IgG or IgM antibodies were quantitated by the use of alkaline-phosphatase-conjugated anti-human IgG or IgM antibodies. Of the 24 randomly collected serum samples, 7 were positive in the IgG-ELISA test. One positive by the IgM-ELISA was found to contain rheumatoid factor. In 12 of 13 paired sera of clinical cases, IgM as well as IgG antibodies were detected in the second serum sample taken about 3 wk after the onset of clinical signs. The IgM positive sera were screened for rheumatoid factor (RF) on IgG-coated plates. None of them contained RF. Antibody titers obtained by ELISA showed a good correlation with titers obtained by hemagglutination inhibition, complement fixation, and neutralization tests. The ELISA tests for detection of IgM and IgG antibodies to WNV therefore can replace the other serological methods for epidemiological surveillance and diagnostic purposes.

Measles, measles vaccination, and risk of subacute sclerosing panencephalitis (SSPE).

Between the years 1968 and 1979, 87 cases of subacute sclerosing panencephalitis (SSPE) appeared among the Israeli-born population. The incidence of SSPE dropped sharply in 1977, 10 years (the median age at onset of SSPE) after introduction of mass antimeasles vaccination, and remained low in 1978 and 1979. Most of the SSPE cases reported measles at an age significantly younger than that of the general population. This pattern did not change after introduction of antimeasles vaccination. Incidence was significantly lower (p less than 10(-9) in the vaccinated population than in the unvaccinated population. Occurrence of SSPE in some children who were vaccinated against measles could be explained by incomplete vaccine efficacy, or by older age at vaccination, which allows the possibility of prior exposure to measles. There was no indication that measles vaccine can induce SSPE.

Increase in laboratory-confirmed cases of herpes genitalis and neonatal herpes infections in Israel.

Jewish women have been considered to be at low risk for genital herpes simplex virus Type 2 (HSV-2) infections. During the period 1973 to 1981, genital herpes simplex infections were laboratory confirmed in 129 cases (81 women and 48 men). Until 1976, only sporadic cases were reported to our laboratory. Since then, the number of cases has gradually increased, reaching 31 new reported cases in 1981. The age distribution was typical for a sexually transmitted disease, with the peak of infection at childbearing age (20 to 39 years). As a result, rising morbidity of neonates--due to active genital herpes virus infection in the mother during delivery--could be expected, and monitoring of high-risk pregnancies for prevention of perinatal infections was introduced. Of 14 pregnant women monitored, herpesvirus was isolated in 4 in the last week before delivery, and cesarean section was advised. In addition, during the last 3 years, neonatal herpes was confirmed in six, and suspected in three neonates whose mothers were not monitored for genital herpesvirus infection during pregnancy.

Cigarette smoking as a risk factor for epidemic a(h1n1) influenza in young men.

We studied an outbreak of A(H1N1) influenza in an Israeli military unit of 336 healthy young men to determine the relation of cigarette smoking to the incidence of clinically apparent influenza and to the influenza-antibody response. Of 168 smokers, 68.5 per cent had influenza, as compared with 47.2 per cent of nonsmokers (P less than 0.0001). Influenza was also more severe in the smokers; 50.6 per cent of the smokers lost work days or required bed rest, or both, as compared with 30.1 per cent of the nonsmokers. The proportion of all influenza in smokers that was attributable to smoking was 31.2 per cent (95 per cent confidence intervals, 16.5 to 43.1 per cent). For severe influenza, the attributable risk in the smokers was 40.6 per cent (95 per cent confidence intervals, 21.6 to 54.8 per cent). A quarter of all severe morbidity from influenza in the overall study population was attributable to smoking. Antibody levels to A/USSR/90/77(H1N1) antigen were higher in smokers but not markedly so. We conclude that smoking is a major determinant of morbidity in epidemic influenza and may contribute substantially to incapacitation in outbreaks in populations that smoke heavily.

Genital herpes simplex infections in Israel: 1973 throughout 1980.

Ninety-eight cases of genital herpes simplex virus infection (HSV-2) were confirmed by laboratory examinations during the years 1973-80. Until 1975 there were less than five cases per year, but from 1976 the number of cases gradually increased, reaching 24 in 1980. The age distribution is typical of a sexually transmitted disease; and since the peak of susceptibility is at childbearing age, an increase in neonatal HSV infection could be expected. In 1980, laboratory testing confirmed neonatal HSV infection in four newborns. The need to monitor pregnancies in women at high risk for HSV-2 infection is stressed.

The relationship between epidemic influenza (A(H1N1) and ABO blood group.

An outbreak of influenza caused by the A(H1N1) subtype in military recruits in February 1978 afforded an opportunity to study the association of ABO blood groups with influenza morbidity and serological response. Fifty-eight per cent of 336 recruits became clinically ill. There was no differential distribution of clinical influenza by blood group. However, seroconversion to a titre of greater than or equal to 20 was significantly and appreciably higher in groups A and B than O and AB. Also, among those with serologically confirmed clinical influenza, the occurrence was significantly higher in groups A and B than groups O and AB.

The antigenicity of whole virus versus subunit trivalent influenza vaccines -- a field trial in the Israel Defence Forces, 1978.

A single dose of a commercial trivalent influenza subunit vaccine (SV) and two whole virus vaccines (WVV) were compared in a randomized, placebo-controlled field trial of subjects under 23 years of age in the Israel Defence Forces. Sixty percent of SV recipients and 29% and 37% of WVV recipients showed no measurable response to the H1N1 subtype (A/USSR). When the prevaccination titer to H1N1 was less than 10, SV did not differ significantly from the placebo, and when greater than or equal to 10, the SV was poorer than the WVV. Response to the H3N2 (A/Texas) component was excellent, but when the prevaccination titer was less than 10, SV appeared less immunogenic than WVV. All three vaccines performed equally against the B/Hong Kong strain.

Seroepidemiologic aspects of varicella zoster virus infections in an Israeli Jewish population.

Sera from 872 healthy subjects among the Jewish population of Israel were examined for antibodies to varicella zoster virus (VZV) by a simplified technique for the detection of immunofluorescent antibody to membrane antigen. The difference in the geometric mean titer of antibodies to the virus among the the different age groups was highly significant (P less than 0.0001). The highest titers were found in the five-to-seven-years and 21-to-30-years age groups. In 211 subjects, aged 17 to 40 years, the antibody titres were not influenced by sex or ethnic origin. The percentage of seronegative subjects (titer less than 2) was relatively high--between 18.7 and 32.9% in the 21-to-60-years age groups--and it was 19.5% in the population of childbearing age. The importance of screening for VZV immune status in pregnant women is emphasized.

Stimulation of antibodies to Epstein-Barr virus (EBV) in acute viral infections.

Acute and convalescent sera from 77 patients with serologically confirmed influenza, measles and adenovirus infections and from 36 healthy controls were tested for the level of antibodies to Epstein-Barr (EB) virus. In the three groups of patients significantly higher titers of antibodies to EB viral capsid antigen (VCA) were found as compared to the controls. In 19 patients twofold or higher rise in antibody titers between the first and second blood sample was demonstrated. It is suggested that in patients with influenza, measles or adenovirus infections, involvement of lymphocytes leads to reactivation of EB virus and antibody formation is stimulated.

Fluorescence and neutralizing antibodies to herpes simplex virus in the cerebrospinal fluid of patients with central nervous system diseases.

Herpes simplex virus antibodies were studied in 73 patients with various diseases of the central nervous system. In 29 patients, there were rising titers of fluorescence and neutralizing antibodies to herpes simplex virus in the cerebrospinal fluid (CSF). The CSF antibodies were predominantly IgG. In one patient, IgM was found during the fourth, but not during the eighth week of illness. The CSF antibody titers did not correlate with the serum antibody titers or with the severity of the neurologic defect. No fluorescence antibodies were found in the CSF of 52 of 53 control patients. The presence of CSF fluorescence antibodies may be of considerable value in the diagnosis of herpes simplex encephalitis. However, the absence of these antibodies in the early stage of the disease does not exclude the possibility of infection with herpes simplex virus.