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Biomedical subjects

T A Swartz

Publications and source records attributed to T A Swartz.

At least 19 recordsLinked to original sources

Preventive strategies against poliomyelitis.

Successful poliomyelitis prevention depends upon the epidemiological characteristics of the infection and the immune status of the population in the area. Presently available polio vaccines may prove very useful for progress with polio control, provided the prevention programme has been adequately chosen and the limitations of the vaccine used have been taken into consideration. In the present and near future, polio prevention should aim at the containment and local elimination of the paralytic disease, which can be obtained with either OPV or E-IPV. The vaccine-associated disease remains an unsolved issue in an OPV programme. The association of OPV and E-IPV offers a clear advantage over the immunization with a single vaccine, particularly with OPV alone. Global eradication of polio, possible in principle, will be difficult to achieve by the year 2000, because of the present global dimensions of polio infection and the unequal environmental development of the world.

Antibodies, Viral

Six years of public health surveillance of measles in France.

Data provided by the Sentinel General Practitioners (SGP) to the French Communicable Diseases Computer Network (FCDN) have been used to present the epidemiological characteristics of measles observed during a 6-year period in France. The estimated annual incidence rates per 100,000 population were 376 in 1985, 603 in 1986 and 983 in 1987, then declined during the following 3 years to 297, 258, and 263 per 100,000 population in 1988, 1989 and 1990 respectively. There is a marked seasonal change with a high early summer peak. The mean age among the cases for the 6 years of study varied from 5.4 to 6.0 years. There is an increase in the percentage of cases with a past history of measles vaccination, from 6.7% in 1985 to 12.8% in 1990. This increase may be interpreted as a consequence of a substantial increase of the vaccine coverage during the same period.

Adolescent

[Alternating rifampicin and ceftriaxone for Neisseria meningitidis eradication in contacts].

Following the occurrence of a case of meningococcal disease in a kibbutz, extensive preventive measures were instituted, consisting of alternate courses of rifampicin (10 mg/kg for 2 consecutive days) and ceftriaxone (single IM injection of 125 mg). Throughout the observation period Neisseria meningitidis was absent from oropharyngeal secretions of all those treated, but was found in those of an untreated control group. The alternate use of rifampicin and ceftriaxone should be considered for the long-term prevention of the occurrence of oropharyngeal carriers of Neisseria meningitidis.

Carrier State

Immunologic memory induced at birth by immunization with inactivated polio vaccine in a reduced schedule.

One hundred forty-one healthy newborns were immunized 24 hours after birth with one dose of inactivated polio vaccine (IPV) of enhanced potency. Following the administration of a second vaccine dose six months later, a considerable proportion of babies responded with neutralizing antibody (NA) to the three poliovirus types. The very rapid occurrence and high antibody titer were indicative of an anamnestic response. Twenty-one infants who still had NA less than 1:4 to one-more poliovirus types after the second vaccine dose responded with very high NA values 7-10 days after a supplementary dose of IPV. It appears that IPV of enhanced potency administered at birth is apt to induce immunologic memory, which should provide the basis for protection against paralytic poliomyelitis in case of exposure to wild poliovirus later in life.

Humans

Use of a combined DTP-polio vaccine in a reduced schedule.

A five-year serologic follow-up and a four-year monitoring of the polio and pertussis morbidity in an area immunized with a 2 + 1 dose schedule of a combined DTP-Po vaccine have shown that: the individual protection against polio measured by the presence of neutralizing antibody persists at a very adequate level five years after the first booster; after three years of a steady high proportion of children with pertussis antibody, a considerable drop is observed and in about 28% of individuals agglutinin levels of less than 1:20 were found five years after booster; the community protection against paralytic poliomyelitis and pertussis is satisfactory up to four years after the introduction of the program. Continuation of immunization with a 2 + 1 dose schedule at a maximal coverage and close seroepidemiologic surveillance are necessary in order to draw definite conclusions, because of the potentially strong impact of very dynamic ecological factors present in our geopolitical area upon the agent-host interrelationship.

Agglutination Tests

A modified schedule for routine pertussis immunization.

As part of a study with a quadruple inactivated vaccine (diphtheria-pertussis-tetanus-polio), the serologic response to the pertussis antigen was investigated in infants at the age of routine immunization, inoculated with one of the following two regimens: either 0.5 ml vaccine at 2 and 3 1/2 months and a booster six months later, or an identical dose of vaccine given at 2, 4 and 6 months and a booster at the age of 12 months. A pertussis agglutination titer of greater than or equal to 1:10 was considered an immune response to the administration of the antigen. Two basic doses of pertussis antigen induced an immune response in about 92% of children, which was very close to that following three basic doses. A 100% seroconversion was observed in both groups one month after the booster dose, and geometric mean values were high in both regimens. At one and two years after the booster, the pertussis agglutinins were present in 100% of children of both groups, with higher geometric mean values in the group given the three basic doses regimen.

Age Factors

Rubella immunity measured by hemagglutination inhibition and enzyme-linked immunosorbent assay.

Evaluation of the immunity to rubella by the hemagglutination inhibition (HI) test and an enzyme-linked immunosorbent assay (ELISA), in a series of 1,697 sera collected from women of childbearing age, showed a 65% agreement; 33% were ELISA-positive and HI-negative at a 1:16 dilution and only 2% were ELISA-negative and HI-positive. Among 241 women given the rubella vaccine following an HI titer of less than 1:16, no change was observed in 208 in the postimmunization HI test, but only 11 were negative when ELISA was used. The retesting by ELISA of 110 preimmunization sera showed that 67 (61%) were positive, and therefore the vaccine had been unnecessarily administered. In a series of 72 HI tests that did not permit interpretation because of a nonspecific reaction, ELISA provided quite clear results. ELISA appears to be a sensitive technique for the evaluation of the true immune status to rubella in sera with low HI levels (less than 1:16), as well as in circumstances where the HI test reacts nonspecifically.

Adult

Rubella in Jerusalem. 2. Clinical and serologic findings in children with congenital rubella.

Forty-eight children born with clinical and serologic manifestations of congenital rubella were followed for a three-year period. Expanded rubella syndrome, multiple anomalies and single defects were found, mostly in the child's first year of life. Some new organic problems were found at a later age in children who had initially been healthy but who had been followed up because of their high antibody levels to rubella. Of the 48 children, 15 (31%) were born to mothers who had had clinically and serologically diagnosed rubella during pregnancy. In 33 children (69%) the mother had had asymptomatic rubella. These findings emphasize the need to identify and immunize seronegative women before pregnancy.

Abnormalities, Multiple

Success and failure of a rubella immunization programme.

A Rubella control programme was started in 1973 in Israel and aimed at: 1) the yearly immunization of all school girls aged 12; and (2) the rapid immunization of females 12 years old from the communal settlements. Both HEP77DE5 and Wistar RA 27/3 (WI-38) strains were used. A 5 year follow-up showed: (a) a vaccination coverage of 95%; (b) a seroconversion rate which approached 100% with persistent protective G. M.-antibody values; (c) about 15% of the females of childbearing age in the general population were devoid of Rubella HI antibody. During 1978 an extensive Rubella epidemic occurred in the general population 15-20% of whom were in the age group 15-44, whilst in the communal settlements no cases were observed in vaccinated people of the same age group.

Adolescent

Influenza surveillance in Israel, 1976--77.

An influenza surveillance program developed and conducted in three districts in Israel during winter 1976--77, was based mainly on morbidity data in the general population, corroborated by sero-epidemiologic surveys on selected groups. This information was supplemented by data on mortality organized according to specific age groups. During the period under study, similar results were observed in each of the three districts surveyed. Two successive waves of influenza were recorded: an early wave due to B/Hong Kong/5/72 followed by an A/Victoria/3/75 outbreak. Both waves were of moderate extent, with the highest frequency of clinical influenza occurring in the youngest group, age 0--14 years. The age-specific mortality rates were highest and rather similar in the extreme age groups 65+ and 0. The search of A/New Jersey/8/76 antibody revealed a considerable proportion of positives with a higher titer in the older age groups. A special serologic survey among Yemenite Jews over 50 years of age, who immigrated to Israel in 1949, showed that the 1918 influenza pandemic also reached that isolated country. The surveillance program provided an early warning system as well as a rather accurate measurement of influenza impact in Israel.

Adolescent

Rubella in Jerusalem. 1. Seroepidemiologic findings in children born after the 1972 rubella epidemic.

Nine hundred and sixty-nine babies born after a severe rubella epidemic were tested at the age of eight months for the presence of hemagglutination inhibition antibodies to the disease. There were 208 (21.9%) seropositive babies with titers of greater than or equal to 1:16. Seven cases of congenital rubella were diagnosed at birth, 14 were confirmed by eight months and two babies, who were considered normal at the age of eight months, developed late signs of the disease. Less than 3% of the mothers of the seropositive babies had had clinically recognized rubella in pregnancy. If positive hemagglutination inhibition antibody to rubella accurately reflects congenitally acquired rubella infection, between 8.1 and 21.9% of the 969 babies had serologic evidence of the disease. For cases of congenital rubella diagnosed by the age of three years, the limits are between 8.9 and 23.7 per 1,000 live births for the risk of the disease at the height of the epidemic. Rubella vaccine was not available in Israel until after the 1972 epidemic, the effects of which justify the continued search for and immunization of seronegative women of childbearing age, in addition to routine immunization of young girls.

Adult

Toxoplasmosis in Israel, 1970--73: evaluation of laboratory data.

Sera from 7,506 patients were examined for toxoplasma antibodies by the Sabin-Feldman dye test and the results were analyzed according to antibody level, by reason for referral, age and sex. Low antibody levels (less than 1:256) were found in 24.7% and significant titers (greater than or equal to 1:256), in 9.96%. The highest prevalence of significant antibody titers was in patients with lymphadenopathy (15.4%). The prevalence of significant titers was high in the age range of 5 to 19 years, whereas the prevalence of low titers rose with age. Toxoplasma antibodies were found in 29% of a control group of 554 apparently healthy adult women, but only in 2.7% was the titer significant.

Adolescent

An extensive rubella epidemic in Israel, 1972: selected epidemiologic characteristics.

An extensive rubella epidemic which occurred in Israel in the spring of 1972 provided an opportunity for several observations: 1) This epidemic had been preceded by another extensive outbreak in 1962. The interepidemic period was characterized by persistence of some rubella activity and occurrence of limited outbreaks at irregular intervals. 2) The crude annual attack rate based on the number of recorded cases among a 2,160,000 Sick Fund insured population was 315 per 10,000; this was about 5.4 times higher than the attack rate calculated from the number of cases reported to the Public Health Offices. In selected areas, where the medical personnel had been canvassed, the attack rate was 1,101 in a population of 19,131. 3) Highest specific attack rates were observed in the age groups 5-9 and 1-4, followed by the age group 10-14. 4) A slight predominance was observed in male cases aged 1-4 and female cases aged 20-24. 5) The peak occurred 1-3 months after the epidemic started, and stopped very quickly at the beginning of the summer, one month after the kindergartens and schools commenced the summer holidays.

Adolescent

Routine administration of oral polio vaccine in a subtropical area. Factors possibly influencing sero-conversion rates.

Poliomyelitis is an important problem of public health in warm-climate countries. Studies of serological responses to vaccination in these countries have given conflicting results but in many investigations the rates have been considerably less than in countries with temperate climates. In this study three possible factors influencing sero-conversion were investigated - the season of the year when vaccine was given, the social status of the mother (as indicated by the number of years of schooling) and the presence of non-poliomyelitis viruses (NPV) in the gut when vaccine was given.Over 200 children about 2 months of age were included in the study. Each was given three doses of trivalent vaccine at 6-week intervals.The sero-conversion rates of the groups fed in winter were excellent but were slightly less good in summer. The differences were greatest in children in the lower socio-economic groups and in children excreting other enteroviruses.The conclusions are that, provided a potent vaccine is used, the factors which diminish the effectiveness of immunization in warm-climate countries can be overcome: (1) by giving three doses of trivalent vaccine; (2) by beginning vaccination at the earliest possible age (when enteroviruses are fewest); (3) by concentrating special attention on the lower socio-economic groups and if necessary by giving a reinforcing dose several months after the third dose has been given - preferably in the colder months.

Antibody Formation