Incidence Of Notifications Research Articles

Primary hepatocellular carcinoma in an area of low incidence: evidence for a viral aetiology from routinely collected data.

In recent years a strong case has been made in support of a viral aetiology for at least some primary hepatocellular carcinoma (PHC) in areas of low incidence. By pooling routinely collected cancer registration and infection data, study of the relationship between hepatitis B virus (HBV) infection and the incidence of PHC in Scotland over the period 1972-1985 has confirmed this view. Over this period the incidence of PHC in men increased, there was a relationship between the incidence of notification of HBV infection and that of hepatocellular carcinoma in different parts of the country, and an increased risk attached to those chronically infected with the virus. Given the recent introduction of lower cost yeast derived vaccines, there may now be more scope for prevention both of primary liver cancer and of other liver disease.

Visual impairment in Danish children 1985.

In 1985 150 children aged 0-18 were reported to the Danish National Register for Visually Impaired Children. Cross tabulation of the ophthalmological diagnoses by site and type of affection was performed with respect to year of birth, aetiology, visual acuity and birth weight. Finally the relations between aetiology and the presence of additional handicaps are demonstrated. The 'incidence of notification' (IN) was calculated for each birth year as the number of notified children per 100,000 within each birth year group showing variations between 46 in the 1984 birth year group and 3 in the 1970 birth year group with a mean value of 14. The figures stress the impact of congenital and neonatal visual impairment. The significance of IN is discussed with respect to other concepts of incidence. It is concluded that the presented epidemiological method is useful as a tool of analysis in the planning of preventional strategies. From the tables the following main features may be highlighted: Nearly 90% of the blinding causes anatomically are located in the posterior segment of the eye, the optic pathways or in the brain. Isolated visual handicap was notified in 34% of the children, while another 48% presented central nervous system involvement. From an aetiological point of view it is noteworthy that no specific aetiology could be encircled in 38% of the material. In conclusion, it is proposed that future lines of ophthalmological work in the prevention of visual handicap in childhood should concentrate on a higher degree of specificity in diagnostic procedures and an intensified search for specific aetiologies in every single child with visual impairment.

Poliomyelitis in England and Wales, 1947-1950.

Poliomyelitis has been endemic in England and Wales since its notification was made compulsory in 1912, but prior to 1947 its incidence was, with the exception of three years, of the nature of a sporadic disease with a seasonal rise rather than that of an epidemic disease. This was in contrast to the experience of the United States and some continental countries, where large epidemics had occurred periodically. On the other hand, the vagaries of the disease in England and Wales between the two wars presented some interesting and puzzling features. The fatality rate, i.e. the proportion of deaths to notified cases, varied greatly from year to year; for example, the notifications in 1926 were three times the 1925 level but the fatality rate only half. On the whole, the yearly deaths from poliomyelitis varied only slightly in number, and the concomitant large variations in the notifications would (if they can be accepted as accurate) suggest that the severity of the disease was changing from year to year. Similarly, the incidence of notifications increased more than the mortality during the seasonal period of greater prevalence. This was possibly due to an increased recognition of milder cases at the times when the disease was known to be most likely to occur. The Registrar-General, discussing this possibility, wrote: There is evidence that milder cases of the disease are often overlooked, its characteristic after-effects being met with in persons in whom the early stages of the disease have never been recognized.