Ian Leck

Incidence of Malformations following Influenza Epidemics

It is uncertain whether maternal influenza is a cause of human malformations, although defects of the nervous system and axial skeleton have been observed following the administration of the virus to chick embryos and pregnant mice (Hamburger and Habel, 1947; Shear, Heath, Imagawa, Jones and Adams, 1955; Adams, Heath, Imagawa, Jones and Shear, 1956; Williamson, Simonsen and Blattner, 1956). Several attempts have been made to determine whether malformations are commoner in children whose mothers had influenza in pregnancy than in other children, but the results of these inquiries are difficult to interpret. The published series (Table 1) include four in which births after influenza were not classified according to the stage in pregnancy at which infection occurred, and nine in which children born after influenza in the first trimester were considered separately. In seven of the nine series in the second group the incidence of malformations in births following first trimester influenza was higher than in other births. In three of the four series in which the time when infection occurred was not recorded, on the other hand, the malformation rate was not increased in births after overt influenza, but this finding cannot be taken to indicate that the rate was uninfluenced by infection: the mothers of most of the controls in two of these three series showed serological evidence of influenza although their histories were negative, and the incidence of malformations among their offspring was higher than in any other control group shown in Table I (opposite). Although these findings are suggestive, there are two reasons for doubting whether they indicate that influenza causes malformations:

Incidence of neoplasms in children born after influenza epidemics.

Following a recent report that neoplasia of the lymphatic and haematopoietic tissues is commoner than average in children whose mothers have had influenza in pregnancy, the incidence of neoplasms in 1954-68 in children of the Manchester Hospital Region was examined in relation to date of birth. There were no significant differences between cohorts born in different quinquennia. Incidence among children born after six influenza epidemics in 1951-68 was no higher than among other children born in these years. It is concluded that if there is an association between maternal influenza and childhood neoplasia it is probably due to factors such as immunological deficiencies which may predispose independently to both conditions.

Institutional Care of the Mentally Subnormal

The trend of progressive opinion concerning the hospital care of the mentally subnormal is well expressed in a Ministry of Health Memorandum [(65)104] on Improving the Effectiveness of the Hospital Service for the Mentally Subnormal. It states: In the absence of complicating conditions, such as severe physical disability or disturbed behaviour, the severely subnormal patient who has been adequately investigated and treated ought not to be primarily the responsibility of the hospital services for long-term care. Ultimately, when facilities outside hospitals are fully developed, continued hospital care will be necessary only for patients who require special or continuous nursing and for those who, because of unstable behaviour, need the kind of supervision and control provided by a hospital. Our object in this paper is to estimate the proportion of patients now in hospital who, according to these criteria, require hospital care and to consider the future organization of institutional care of the mentally subnormal in the light of the findings. In 1965 an investigation was made of the needs of all (1,652) Birmingham patients (874 male and 778 female) in 13 hospitals for the subnormal in the Birmingham area. Each patients requirements were assessed by a hospital doctor and nurse in charge of the ward. A previous report (Leck, Gordon, and McKeown, 1967) showed that in most respects Birmingham patients were similar to the subnormal in all hospitals in England and Wales. The exceptions were the lower proportion of young patients in Birmingham hospitals (accommodation for them in the area is deficient) and the higher proportion classified as severely subnormal.

EXAMINATION OF THE INCIDENCE OF MALFORMATIONS FOR EVIDENCE OF DRUG TERATOGENESIS.

The discovery that thalidomide can cause human malformations has been followed in recent years by a large number of reports of malformations in the offspring of women who have taken other drugs in pregnancy. But it has remained uncertain whether any of these drugs are teratogenic, since those reporting on them have not been in a position to relate their findings to the distribution of malformations in the general population. There are two reasons why population data are needed for the interpretation of associations between drugs and malformations. Firstly, the relative frequencies of the different types of defects in the general population need to be compared with those in affected children born after exposure to the drug in question; if teratogenic, it is likely to cause only a few specific types of defects, which will therefore be present in an abnormally high proportion of the exposed group. Secondly, comparisons between the population incidence of malformations at different times are needed to detect or exclude the changes that are likely to occur if any drug which is being used increasingly has teratogenic properties. These changes may be either prolonged trends or shortterm fluctuations. If a drug is used to treat endemic conditions such as anxiety or morning sickness, its output is likely to rise gradually as it becomes more widely known, and consequently any related increase in the malformation rate is also likely to be prolonged. Short-term fluctuations in incidence may occur if a teratogen is being used in the treatment of epidemic diseases (of which the commonest in pregnancy is influenza). In three previous reports (Leek and Millar, 1962, 1963; Leek, 1963) we examined the incidence of certain malformations in Birmingham for shortterm fluctuations between 1957 and 1961, and found

Dorothy Maud Record (nee Tidmas).

When Dorothy entered medical school in 1940, she had recently qualified as a nurse, and the gutsiness she needed to switch professions at that time never left her. After graduation …