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Biomedical subjects

S O Foster

Publications and source records attributed to S O Foster.

At least 19 recordsLinked to original sources
PubMed1985

Cost-effectiveness of immunization in The Gambia.

Cost-effectiveness studies were carried out in The Gambia to estimate costs of preventing childhood morbidity and mortality through immunization. For the four priority diseases--neonatal tetanus, pertussis, measles and poliomyelitis--costs per case prevented ranged from $1.30 for pertussis to $655.54 for poliomyelitis. In terms of preventing childhood deaths through immunization, measles at $40.83 per death prevented, pertussis at $99.85 per death prevented and neonatal tetanus at $152.53 per death prevented were most cost-effective. For developing countries, immunization is an efficient use of limited health resources.

Adolescent↗
PubMed1983

Microtiter determination of measles hemagglutination inhibition antibody with filter papers.

Epidemiological studies of measles and measles immunization frequently require determination of measles antibody status. In developing countries, where venipuncture is frequently unacceptable and where refrigerated storage of serum specimens is often unavailable, microtiter techniques not requiring refrigeration are required. We developed a filter paper technique that measures measles hemagglutination inhibition antibody and meets these criteria. Comparison of separately collected venous blood and peripheral blood collected on filter paper demonstrated 97% agreement in terms of presence or absence of antibody. In 30 of 32 measles specimens, 94% of titers were the same or varied by less than 2 twofold dilutions.

Antibodies, Viral↗
PubMed1981

Immunofluorescence staining for detection of variola virus.

In September 1975 Bangladesh was the only country in the world with endemic variola major, and the eradication of the disease was imminent. A rapid and accurate laboratory diagnostic method was required to supplement immunodiffusion in agar gel and culture on chorioallantoic membrane of embryonated egg available at the Institute of Public Health in Dacca, Bangladesh. To determine its effectiveness, a new, improved immunofluorescence (IF) staining technique was introduced. Laboratory specimens (scabs or vesicular or pustular impressions) were collected from patients who had, or were suspected of having, smallpox. Seventy-eight of 144 specimens collected were found to be IF positive for smallpox. As the number of laboratory-positive cases far exceeded the number of clinically diagnosed smallpox cases, IF-positive cases were reinvestigated and subsamples of the IF-positive specimens were tested at a World Health Organization poxvirus reference laboratory at the Centers for Disease Control in Atlanta, Ga. The results indicated 100% sensitivity for the IF technique (no false-negative results) in diagnosing variola major but also showed a high rate of false-positive results. Consequently, IF could not be recommended as a routine screening test for smallpox.

Animals↗
PubMed1980

Smallpox surveillance in Bangladesh: I - Development of surveillance containment strategy.

A major epidemic of Variola major with an estimated 90 000 cases and 18 000 deaths occurred in Bangladesh in 1972. During a 3-year period methods of active surveillance (market search, outbreak investigation, and house-to-house search) were developed to supplement the passive reporting system. The percentage of smallpox cases detected increased from 11.8% in 1972 to 83% in 1975. Together with the implementation of improved methods of outbreak control, smallpox transmission was interrupted in October 1975.

Bangladesh↗
PubMed1980

Smallpox surveillance in Bangladesh: II - Smallpox facial scar survey assessment of surveillance effectiveness.

A smallpox facial scar survey of 465 892 persons aged 0-19 years was carried out in Bangladesh in 1976, covering approximately 1% of the 0-19 year old population. Of the 4 306 persons found with facial scarring consistent with previous smallpox infection, none had a history of smallpox with onset after the last reported case on October 16, 1975. Histories taken from persons with facial scars allowed smallpox incidence to be estimated for each year from 1972 to 1975. These estimates indicate that completeness of reporting increased steadily from 11.8% in 1972 to 83.0% in 1975, reflecting the increasing effectiveness of surveillance.

Adolescent↗
PubMed1980

Gastroenteritis due to rotavirus in an isolated Pacific island group: an epidemic of 3,439 cases.

In the spring of 1964, 3,439 cases of acute gastroenteritis were reported from Truk District, an island group in the mid-Pacific. The causative agent was not identified in laboratory studies performed in that year. Retrospective serologic studies 15 years later with the complement fixation test and the enzyme-linked immunosorbent assay provided serologic evidence that this outbreak was caused by the human rotavirus that was first isolated in 1973.

Adolescent↗
PubMed1979

Experimental smallpox in chimpanzees.

In an attempt to prepare highly specific antiserum to variola virus, a chimpanzee was inoculated with a virulent human strain of this virus. Three uninoculated chimpanzees were housed in the same room; two of these developed clinical disease with seroconversion, while the third developed no evidence of infection and no antibody. The three animals that became ill also developed antibody to vaccinia and monkeypox viruses. Human contacts during the study and following a break in containment showed no evidence of infection as determined by serological tests and lack of clinical disease.

Animals↗
PubMed1978

Simultaneous administration of live attenuated measles vaccine with DTP vaccine.

Live attenuated measles vaccine was administered to Cameroonian children 12 to 39 months of age alone or with either diphtheria-tetanus toxoids or diphtheria and tetanus toxoids and pertussis (DTP) vaccine. Among children who were initially seronegative for measles hemagglutination inhibition antibodies, seroconversion rates and postvaccination geometric mean titers were similar in all groups. Pertussis antigen in the DTP vaccine was judged to be potent by laboratory potency testing and serologic response in recipients of the vaccine. Thus, the two vaccines may be administered simultaneously without compromising their immunogenicity. These results allow greater flexibility in planning individual or mass immunization schedules.

Antibodies↗
PubMed1978

Urban hospital and rural village smallpox in Bangladesh.

Smallpox mortality at Dacca, Bangladesh Infectious Diseases Hospital during 1972 and 1973 was 46 per cent. To determine if this was the actual rate within the population, data were compared to those collected from village populations in Noakhali District. Age/sex adjusted smallpox mortality for the rural population was 23 per 100 cases as compared to 52 per 100 for the hospital population. Analysis of the difference identified a selection bias of the hospital for severe disease.

Adolescent↗
PubMed1976

Evaluation of a mass measles immunization campaign in Yaoundé, Cameroun.

A mass measles immunization campaign carried out in Yaoundé, Cameroun, has been evaluated. Sixty per cent of the children were immune to measles at the time of the campaign. Only 51% of the susceptible children received vaccine. This was caused by a lack of attendance at the vaccination centres and errors in the selection of children given vaccine. The vaccine administered was relatively ineffective: 40% seroconversion. Difficulties which probably contributed to the low seroconversion rate included sub-optimal vaccine titre, inadequate doses of vaccine, and the relatively long time of vaccine utilization under tropical temperatures. Overall, 83% of the vaccine given to the vaccinating team was wasted. Future immunization campaigns can be improved through better screening of the children, improved handling of the vaccine, the use of marker vaccines, and improved health education.

Cameroon↗
PubMed1976

Trial of a reduced dose of measles vaccine in Nigerian children.

To evaluate the effectiveness of measles vaccine in reduced dosage, Schwarz live, further attenuated measles virus vaccine was given in various doses by jet injector to 967 seronegative children aged 7-30 months in rural villages in the Northwest State of Nigeria. For children over 12 months of age, reducing vaccine virus dosage by 40%, 60%, or 80% led to progressive and statistically significant reductions in the seroconversion rates from 89% in children receiving the full dose to a minimum value of 46%. Reducing the volume of the inoculum below the standard of 0.5 ml resulted in a further reduction of seroconversion rates at each antigen dose level. Seroconversion rates in all dosage groups were lower for children below 12 months of age. These data suggest that dose reduction would not be a satisfactory economy measure in measles vaccination campaigns.

Antibodies, Viral↗
PubMed1975

Treatment of variola major with adenine arabinoside.

A double-blind study of the efficacy of adenine arabinoside in the treatment of patients with variola major was conducted. Adenine arabinoside (20 mg/kg of body weight) was given to patients intravenously every 24 hr for seven days in a 8-hr infusion. Five of the nine patients receiving adinine arabinoside died, and four of 11 patients receiving placebo died. Mortality was related to the severity of illness for both groups of patients. No difference was found between the drug and control groups in number of febrile days after initiation of therapy or in the period during which it was possible to isolate virus from skin lisions, throat swabs, and sources of clotted blood. Formation of scabs on skin lesions was complete 8.3 days after the initiation of therapy for the drug group and after 11.3 days for the control group. The findings suggest that adenine arabinoside is not effective in the chemotherapy of smallpox.

Adenine↗
PubMed1975

Evaluation of a measles-smallpox vaccination campaign by a sero-epidemiologic method.

An assessment technique has been devised whereby children from 30 randomly chosen sampling sites are visited within three days of measles-smallpox vaccination and one month later. Vaccination coverage is measured at house visits and immunologic status is determined by collection of early and late blood samples on filter papers from substratified children in priority age-groups, and by looking at vaccination scars. The methodology was employed in a rural area of the Ivory Coast during the maintenance phase of a measles-smallpox vaccination program; 1762 children from 0--72 months old were inspected. Children in the target age groups, 6--24 months, had a vaccination coverage of 53.6% whereas children outside of the target group had a 10.5% coverage. Of 571 target age children, 94.6% had a measles hemagglutination-inhibition antibody titer of less than 1:10 dilution at the first visit, and were presumed susceptible to measles or vaccine. Of 247 substratified children 6--8 months, 98.3% were susceptible to measles before vaccination; 84.3% of 127 vaccinated children in this age-group sero-converted when re-tested. Of 324 children 9--24 months, 91.7% were susceptible before the campaign; 94.7% of 170 vaccinated children in this age-group converted. A positive history of prior measles or prior measles-vaccination was not a good indicator of measles serologic status. The smallpox vaccination major reaction rate was 93.2%; 91.4% of children with a recent vaccination scar sero-converted to measles vaccine. Thus, the smallpox scar read at the second visit proved the best clinical marker for determining both coverage and immunologic effectiveness of the campaign.

Age Factors↗