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Biomedical subjects

B Christenson

Publications and source records attributed to B Christenson.

At least 73 records · Page 4Linked to original sources
PubMed1989

Immunity and immunization of children against diphtheria in Sweden.

The level of immunity to diphtheria and the effect of vaccination with different doses of diphtheria toxoid was investigated. The 457 study children, 6, 10 and 16 years of age, had as infants received routine primary vaccination with three doses of diphtheria-tetanus-toxoid or diphtheria-tetanus-pertussis vaccine, and the 16 year-olds also had received a booster dose of tetanus with a small dose of diphtheria at the age of ten. Prior to the study booster, 15% of the 6-year-olds had antitoxin levels against diphtheria less than 0.01 IU/ml, the given minimum level for protection. Of the 10-year-olds, 48% had titres less than 0.01 IU/ml, while the corresponding figure for the 16-year-olds was 24%. After a booster injection of 0.1, 0.25 or 0.5 ml of diphtheria-tetanus vaccine, more than 97% of the children showed titre levels greater than or equal to 0.1 IU/ml, while levels of greater than or equal to 1 IU/ml, indicating titres sufficient for long-term protection, were attained by 23-96%. Systemic reactions were few and moderate. Local reactions were of little clinical significance. In a group of 5-years-olds given diphtheria-tetanus primary vaccinations over wider intervals, only 1.4% had antitoxin titres less than 0.01 IU/ml. The results show a need for serologic monitoring of vaccination programmes.

Adolescent↗
PubMed1989

Diphtheria in Stockholm, with a theory concerning transmission.

Since 1984, diphtheria has been diagnosed in Sweden, mainly among men abusing alcohol. During the first half of 1986, eight cases of diphtheria were discovered in the city of Stockholm. The first three were among men abusing alcohol. The following five cases had no connection with them. These five persons were employed in two companies housed in the same building. The only connection between them was that they ate their lunch at the same restaurant. One alcohol-abusing man had worked temporarily in the kitchen of this restaurant during the week before the five cases of diphtheria arose. He knew one of the first three patients well. A throat swab taken from him a month after the five cases had been diagnosed was negative. It was suspected however, that this man might have been a carrier of Corynebacterium diphtheriae during the week that he worked in the kitchen. Tests for C. diphtheriae antitoxin revealed that the kitchen staff had high antitoxin titres although they lacked a history of basic immunisation. Even so, C. diphtheriae could not be isolated from their throats and it has not been possible to establish the mode of transmission. The most reasonable theory of transmission is that the organism was introduced into the kitchen by the man employed there temporarily and that it was spread by food served in the restaurant. This theory has not been proved but is discussed in order to facilitate future investigations of a similar outbreak.

Adult↗
PubMed1988

Heparin and fibrinolysis--comparison of subcutaneous administration of unfractionated and low molecular weight heparin.

The effects on the fibrinolytic system after a single s.c. bolus injection (at 9 a.m.) of either 5000 IU conventional heparin or 5000 anti-Xa U of a fractionated low molecular weight heparin (Fragmin, KabiVitrum, Sweden) were investigated in 9 healthy volunteers. The effects were compared to those of an injection of normal saline in 6 volunteers. Samples for biochemical analyses were taken regularily during 6 hours after drug or placebo administration. In the coagulation system the following parameters were measured: Activated partial thromboplastin time (APTT), anti-Xa activity, thrombin time and fibrinogen. The fibrinolytic system was monitored by analysing: plasminogen, alpha 2-antiplasmin, fibrin(ogen) degradation products (FDP), euglobulin clot lysis time (ECLT), tissue plasminogen activator (t-PA) activity, t-PA antigen and plasminogen activator inhibitor (PAI) activity. Injection of the 2 drugs was followed by elevations in APTT and anti-Xa activity, and were more pronounced for Fragmin than heparin. The fibrinolytic system exhibited a diurnal variation with decreasing PAI activity and increasing t-PA activity during the day. Volunteers receiving normal saline (placebo) showed a similar pattern. The results were unrelated to heparin. It is concluded from this study that neither heparin nor Fragmin had any significant effect on the fibrinolytic parameters when measured after a single s.c. bolus injection since the observed variations were within the diurnal range.

Adult↗
PubMed1987

Swedish experience of two dose vaccination programme aiming at eliminating measles, mumps, and rubella.

In 1982 a two dose regimen was introduced in Sweden for the combined vaccination against measles, mumps, and rubella of children aged 18 months and 12 years. Since 1977 about half of the preschool children were vaccinated against measles annually, and since 1974 about 80% of 12 year old girls were vaccinated against rubella. During the period 1982 to 1985 90-93% of the eligible age cohorts of 18 month old children and 88-91% of the 12 year old children were immunised with the new combined vaccine. A study in 1982 of about 140 18 month old children who were nearly all seronegative before vaccination showed that 96%, 92%, and 99% seroconverted against measles, mumps, and rubella, respectively. A second study was carried out in 1983 of 247 12 year old children, of whom 11% lacked antibodies to measles, 27% to mumps, and 45% to rubella. This showed seroconversion in 82% and 80% against measles and mumps, respectively, and all children seroconverted against rubella. In the latest study in 1985 of 496 12 year olds 9% and 13% were seronegative against measles and mumps before vaccination, and 41% against rubella. Of these, 88% seroconverted to measles and 80% to mumps, and all converted to rubella when sera were tested by the haemolysis in gel method. After a neutralisation test against measles as well all children showed immunity to the disease. A low incidence of measles and declining figures for mumps and rubella were reported in 1984 to 1986. An outbreak of rubella during 1985 affected mainly boys in age cohorts in which only the girls had been vaccinated during the 1970s.

Child↗
PubMed1987

Epidemiology of hepatitis B in Sweden.

All the cases of clinical hepatitis B reported in Sweden since 1969 have been studied. The 10-year period 1976-1985 has been analysed intensively. For comparative purposes, the study also includes the hepatitis cases reported in 1962 and 1967. Serum hepatitis first affected young adults aged 15-24 years at the beginning of the 1960s. Cyclical outbreaks of hepatitis B due to transmission among drug abusers have been recognised since 1969. The disease was first observed in urban areas but later in rural parts of Sweden also. After 1976, a year in which outbreaks arose in various parts of Sweden, the numbers of hepatitis B cases decreased. In 1969, more than 50% of the cases reported as serum hepatitis concerned drug abusers. During the period 1976-1985, the main risk factor was drug abuse for between 20 and 52% of cases and sexual activity for between 8 and 28% of cases. Since 1969, 2-3% of cases annually have been related to blood-transfusion. In the last 5-year period, a total of 129 cases was reported among persons employed in the medical and dental fields. Of these, 59 had non-occupational exposure. During the same period, 33 patients reported contacts with infected persons, mostly household contacts. Seventy five persons had been travelling abroad.

Disease Outbreaks↗
PubMed1987

Outbreak of respiratory illness on board a ship cruising to ports in southern Europe and northern Africa.

A large outbreak of influenza-like and diarrhoeal illness took place over a period of 21 days in April 1984 on board a ship cruising to ports in southern Europe and northern Africa. A cohort study of the 418 passengers was made by postal questionnaire and personal interview. Of the 391 passengers who were interviewed or who returned a questionnaire, 335 (86%) were affected. Of the ill passengers, 295 (88%) had an influenza-like illness. These included 20 with signs of lower respiratory tract infection. In 24 passengers, a viral infection was diagnosed. Influenza B virus infection was identified in 14 cases; other diagnoses were influenza A, para-influenza, respiratory syncytial virus and Epstein-Barr virus infections. In two of the 81 patients tested for Legionella antibodies, a titre of 128 was found; in 16 and 44 patients, titres of 64 and 32 respectively. The outbreak was thus evidently caused by multiple pathogens mainly affecting the respiratory tract. Although most of the passengers acquired their infections on board the ship, a common source was not discovered. A steep rise in the epidemic curve the day after the air-conditioning was switched on, however, is worth noting. If and when similar instances of the 'Sick Boat Syndrome' recur, a search for environmental sources of infection is to be recommended.

Adolescent↗
PubMed1987

Epidemiology and immunity to tetanus in Sweden.

An investigation of tetanus antitoxin titres in the Swedish population was carried out in 1985. In Sweden, primary vaccination against tetanus has consisted of 3 doses at intervals of 4-6 weeks, beginning in the 2nd or 3rd month of life. A booster dose is offered to school children at 8-10 years of age. Three levels of antitoxin concentration (0.01, 0.05 and 0.1 U/ml) are used to demonstrate different titre levels. The interpretation is based on the premise that a serum level of 0.01 U/ml is sufficient to protect the subject against clinical tetanus. A protective titre level (greater than 0.01 U/ml) was found in 98-99% of children and young adults. A rapid decrease in the number of children with high titres (0.05-0.1 U/ml) was observed after the age of 1 and was very low in the 4-5-year-old children. An increase in the number with titres of 0.05 and 0.1 U/ml was seen after the booster dose given at school. A protective level was detected in all 21-30-year-old men and in 94% of the women, in 94% of 31-50-year-old men and in 73% of the women in the same age group. 70% of 31-40-year-old men reached antitoxin concentrations of 0.1 U/ml, and 38% of the 41-50-year-olds. The corresponding figures for women were 22% and 16% respectively. In people over 60 years, 80% of the men and 56% of the women reached protective levels of antibodies.

Adolescent↗
PubMed1986

Epidemiological aspects of the transmission of hepatitis B by HBsAg-positive adopted children.

96 HBsAg-positive, adopted, foreign children were followed up in an epidemiological survey aimed at evaluating the risk of spreading hepatitis B in family settings. Each year 1 400-1 900 foreign children are adopted by Swedish families, 65% of them from countries in South East Asia with a high prevalence of HBsAg-positive carriers. 92% of the HBsAg-positive children came from South East Asia and 2% from Latin America. 36/96 adopted children (37.5%) transmitted hepatitis B to 54 family members. There was a considerably greater risk of transmission by younger children. 33 children less than 3 years gave rise to hepatitis in 50 family members. The greatest risk of transmitting acute hepatitis B was during the first year after the arrival of the child when 22/33 cases of acute hepatitis B (67%) occurred. 65/70 children tested for HBeAg (93%) were positive. Five had anti-e antibodies and 5 converted to anti-e during follow-up.

Adoption↗
PubMed1986

Serological immunity to diphtheria in Sweden in 1978 and 1984.

Antibody levels in relation to diphtheria toxin were studied in 2409 serum specimens collected from different age-groups in Sweden in 1977-78 and 1983-84. Among children and young adults less than 20 years of age, 46% showed antibody levels considered to be protective (greater than or equal to 0.1 IU/ml). The corresponding percentage among adults was 21%. In the child population, 35% showed a relative degree of protection (less than 0.1-greater than or equal to 0.01 IU/ml), while 19% lacked immunity (less than 0.01 IU/ml). After 40 years of age, only 15% showed protective levels. No difference between males and females was seen in the younger population, while women had a lower prevalence of immunity than men among the adult population. Thus, more than 70% of the adult women lacked immunity, while the figure for the men was 50%.

Adolescent↗
PubMed1986

Antitoxin antibody levels and the outcome of illness during an outbreak of diphtheria among alcoholics.

During an outbreak of diphtheria among alcoholics in Göteborg, Sweden, a study was made of the diphtheria-antitoxin antibodies in serum samples from 8 clinical cases and 36 carriers of toxin-producing Corynebacterium diphtheriae. 33/36 carriers were antibody-positive and had antitoxin titres greater than 0.01 IU/ml, a level which is regarded as relative protective, while only 1/8 clinical cases had such a titre. This patient presented a mild illness with no complications. The results of the study of this outbreak stress the importance of maintaining adequate antibody levels against diphtheria in highly developed societies.

Alcoholism↗
PubMed1986

Epidemiology of hepatitis A in children in Sweden 1979-1983.

The incidence and transmission of hepatitis A in the Swedish child population was investigated for the period 1979-83. 47% (152/323) of the hepatitis A cases in children reported in Sweden 1979-83 occurred in children born to parents of foreign extraction. The annual incidence in Swedish children was extremely low (2/100,000) during this period, whereas the incidence was between 103 and 20 in children born to immigrants of Turkish, Yugoslavian, Asian or African extraction. A known transmission of hepatitis A to Swedish children occurred mainly from 3 sources; in 60 cases (35%) by exposure within the families; in 18 of these cases a family member had been abroad, visiting a country where hepatitis A is endemic; in 34 cases (20%) by exposure in a pre-school setting; and in 29 cases (17%) by exposure when travelling abroad. In 48 cases (28%) the exposure was unknown.

Adolescent↗
PubMed1986

Vaccination with a combined vaccine against measles, mumps and rubella aiming at elimination of the three diseases.

General vaccination with a combined measles, mumps and rubella vaccine was introduced in Sweden in 1982. The vaccination is performed at the age of 18 months and 12 years. The coverage in the former age was about 90% and in the latter between 80 and 90%. Seroconversion against measles was 96% in 18 months old and 82% in the 12 year old. The corresponding figures concerning mumps were 93 and 80% and concerning rubella 99 and 100%. Before this vaccination was introduced preschool children were partly vaccinated against measles and teen-age girls against rubella. The measles morbidity is low since the beginning of the 1980's, the morbidity of mumps is unchanged while rubella was epidemic in 1985. Mainly unvaccinated age groups were affected.

Child↗