Shigellosis in Kentucky, 1986 through 1989

A marked increase in the number of cases of shigellosis was reported in Kentucky in 1988. To examine reasons for this increase, we reviewed the 389 cases of shigellosis reported from 1986 through 1989. Ninety-three percent (285/305) of cases due to known species were due to Shigella sonnei. Sixty-two percent (243/389) of cases occurred in children less than 10 years of age. The annual incidence for blacks (6.8 cases per 100,000) was nearly four times that for whites (1.8 per 100,000). The increased number of cases in 1988 was due to outbreaks in five areas of the state, which accounted for 85% (200/234) of the cases. Three of the five outbreaks involved day-care centers. The primary mode of transmission appeared to be person-to-person; there was no evidence of a common source of infection from food or water. To prevent future outbreaks, cases of shigellosis need to be reported promptly to ensure appropriate investigation and control by local health departments.

Epidemiology of infant deaths due to congenital malformations: Italy 1958-1981

The spatial and temporal distribution of infant death rates attributed to the single cause of congenital malformation (DCM) in Italy was studied for the period 1958-1981. Variation of DCM rates in this period was investigated for the whole country, for the three main geographical areas of the North, Center, and South, and for each of the 18 Italian regions (there are 20 administrative regions, but in this study Abruzzo were pooled with Molise and the Aosta Valley with neighbouring Piedmont). It was found that DCM decreases significantly with time. The decrease is considerable in the North and the Center of the country, whereas in the South temporal variation is minimal. There is a marked decrease of the variance of the DCM rates between regions with later years, possibly indicating a tendency to equalization of environmental effects in a large part of the peninsula.

Epidemiological evidence for the 'two-disease hypothesis' in Hodgkin's disease

This study relates to 1803 newly diagnosed cases of Hodgkin's Disease (HD) registered between 1984 and 1988 by a specialist leukaemia-lymphoma registry covering approximately half of England and Wales. In addition to registration data the analyses use routine census data. Rye classification is available for the majority of cases with only 7% being unclassified. The data confirm that the young adult peak in HD occurrence is attributable to the nodular sclerosing subtype (NS), and there is some evidence that NS has a different geographical distribution by county to the other Rye subtypes. Because of possible geographical biases in the classification, subsequent spatial analyses are disaggregated by age at diagnosis with particular emphasis being placed on the two age groups 0-34 and 50-79 years. For these, trends of risk by areal socioeconomic status are in opposite directions and the effects of urban-rural status while in the same direction also differ significantly. Allowance for these does not, however, explain the significant difference between the county distributions of the two groups. Patterns of spatial clustering are quite distinct with evidence for local spatial aggregation amongst younger cases.

Estimating maternal mortality in Djibouti: an application of the sisterhood method

In many developing countries even crude estimates of the level of maternal mortality are lacking and the prospects of fulfilling this need using conventional sources of vital registration and health service statistics are not encouraging. The constraint this imposes on the effective planning, management and evaluation of the programmes now being launched to reduce these neglected deaths is self-evident. It is less obvious how the majority of developing countries can be expected to meet the call for reliable estimates of maternal mortality by 1995. The sisterhood method provides a means of obtaining population-based estimates using household surveys for data collection. This paper describes the application of the method in Djibouti in the context of a rapid multi-purpose household survey in difficult field circumstances. In recent years the reduction of the level of maternal mortality in developing countries has become a priority for both national governments and international agencies. Attention has been drawn to the wide range of levels within and between countries and to the huge discrepancies in the lifetime risk of maternal death for women in the developed compared with the developing world. This risk has been estimated to range from 1 in 19 in West Africa to almost 1 in 10,000 in Northern Europe.

Cluster survey for poliomyelitis and neonatal tetanus in Ilorin, Nigeria

The incidence of poliomyelitis and neonatal tetanus in Ilorin Local Government Area was estimated using a 40-cluster, retrospective survey of neonatal tetanus deaths and lameness from poliomyelitis in March and April 1988. The survey identified 19 neonatal tetanus deaths among 1601 livebirths, giving an incidence rate of 14.9/1000 livebirths. Some 31 residual paralytic polio cases were identified among 4576 children aged five to nine years, giving a prevalence rate of 6.8/1000 children in this age group and an annual incidence rate of 38.3/100,000 general population. Immunization of pregnant women with tetanus toxoid, had a greater impact on mortality from neonatal tetanus than delivery in hospital or birth at home attended by a traditional birth attendant. Antenatal coverage with two doses of tetanus toxoid was 62.6%. Poliomyelitis and neonatal tetanus still constitute important causes of childhood morbidity and mortality in Ilorin and antenatal tetanus immunization coverage is not yet sufficient to control neonatal tetanus in this population. The target age for immunization with tetanus toxoid should be extended to include all women of childbearing age. Further retrospective surveys from other Nigerian states are needed to determine the magnitude of the neonatal tetanus problem throughout the country.

A cancer mortality study in Bombay-based atomic energy community: 1975-1987

Cancer deaths recorded by the centralised health services of the Department of Atomic Energy (DAE) among its employees and their families stationed in Bombay during 1975-1987 have been analysed. Expected number of deaths due to cancer in the study group has been estimated by using the age-sex-specific cancer death rates reported for Bombay resident population for the year 1983. The size of the database for the entire DAE community is about 702,000 person years and the number of cancer deaths observed in 154. Analysis has been done separately for employees and their families, individually for important groups of cancer sites such as respiratory organs, digestive organs, breast, genito-urinary organs and lymphatic and haematopoietic systems. The standardised mortality ratios are generally lower than 100, which may partly be due to the 'healthy worker effect' in the DAE community and partly because of its differences in the social class distribution and the concomitant differences in lifestyle with respect to the comparison group of Bombay city.

Hospital outbreaks with yeasts

Five previous outbreaks of disseminated candidosis due to Candida albicans are reviewed and a new outbreak on a neonatal unit in Belfast presented. This involved four disseminated cases. The control and definition of outbreaks by morpho-, immunoblot- and DNA-typing is discussed. An outbreak of Torulopsis glabrata infection involving 23 patients is described. This was defined by DNA fingerprinting with the enzyme Xba. There were five deaths attributable either completely or in part to the yeast infection.

Household clustering and intra-household transmission patterns of hepatitis B virus infection in South Africa

The objective of this study was to investigate household clustering of hepatitis B virus (HBV) infection in South Africa in order to understand intra-household patterns of virus transmission that would provide information on potential risk factors of HBV infection. Subjects were the household contacts of 28 hepatitis B surface antigen (HBsAg) positive children (index-carrier), 22 hepatitis B surface antibody positive children (index-past-infection) and 35 children with no serological evidence of HBV infection (index-negative). Evidence of HBV infection (at least one positive HBV marker) was present in 73.7%, 48.7% and 38.2% and HBsAg was present in 19.9%, 8.7% and 2.9% of household contacts of index-carrier (N = 186), index-past-infection (N = 150) and index-negative (N = 207) children respectively. The clustering of HBV infection and HBsAg was present in all subgroups of household contacts regardless of the degree of relatedness to the index child. As age increased, the cumulative prevalence of HBV infection increased while the likelihood of being HBsAg positive decreased. Regardless of age, males were more likely (p less than 0.01) than females to be HBsAg positive. We conclude that HBV infection clusters in households; that there is an increased susceptibility, which is probably not genetically mediated, of becoming an HBV carrier in certain households and that males are at greater risk of being HBV carriers. Intra-household horizontal person-to-person transmission, the precise mechanisms of which are not known, is important in South African blacks.

Adolescent suicide and suicide attempts--Santa Fe County, New Mexico, January 1985-May 1990

In February 1990, a physician notified the Office of Epidemiology, New Mexico Department of Health (NMDH), of a possible cluster of suicides among high school students in Santa Fe County, New Mexico, after two male high school students committed suicide within a 4-day period. Because of concerns by school officials that the number of students attempting suicide in 1990 had increased, the NMDH began an epidemiologic investigation.

Survival of classic cholera in Bangladesh

During the present cholera pandemic the El Tor biotype of Vibrio cholerae has completely displaced the classic biotype, except in Bangladesh. We studied the distribution of these two biotypes in twenty-four rural districts during epidemics in 1988-89; there was clustering of the classic biotype in the southern region and of the El Tor biotype in all other regions. These findings suggest that the southern coastal region is now (and may always have been) the habitat of classic cholera. The selective distribution of V cholerae O1 biotypes in Bangladesh may have been affected by ecological changes occurring in the country.

Clustering of features of von Hippel-Lindau syndrome: evidence for a complex genetic locus

von Hippel-Lindau syndrome (HLS), an autosomal-dominant inherited disease, was studied in 92 affected subjects from 29 kindreds. In an initial survey to identify HLS gene carriers, all patients treated at the University of Freiburg for angiomatosis retinae (22), haemangioblastoma of the central nervous system (CNS) (63), and phaeochromocytoma (54) were examined as potential HLS gene carriers. HLS was diagnosed in 86% of the patients with angiomatosis retinae, 19% of the patients with haemangioblastoma of the CNS, and 19% of the patients with phaeochromocytoma. Based on these and on an additional 49 newly diagnosed cases (24 by clinical examination and 25 by pedigree analysis), the calculated prevalence of the disease in the district of Freiburg, Germany, with a population of 1.909 million is 1/38 951. There was a striking tendency for familial clustering of HLS features in affected kindreds. Both angiomatosis retinae and haemangioblastoma of the CNS occurred in most families, whereas renal lesions and/or pancreatic cysts and phaeochromatocytoma were mutually exclusive. This finding suggests that HLS is caused by different mutations within a complex genetic locus, or additional genetic lesions, which cooperate with the HLS gene on chromosome 3p. The data point to a linear sequence of features as follows: phaeochromocytoma, angiomatosis retinae, haemangioblastoma of the CNS, renal lesions, pancreatic cysts, and epididymal cystadenoma.

Clustering of residence of multiple sclerosis patients at age 13 to 20 years in Hordaland, Norway

Geographic and temporal variation and migration studies point to an exogenous agent in the etiology of multiple sclerosis. If infectious etiology is involved, space-time clustering would also be expected. The authors analyzed 381 patients with a clinical onset of multiple sclerosis between 1953 and 1987 in the county of Hordaland, Norway. Patients within the same birth cohort had lived significantly closer to each other than would be expected during ages 13-20 years, with peak clustering at age 18 years (p = 0.002). Clustering was also shown between patients in pairs comprised of one individual with initial remittent disease and the other with chronic progressive course of disease, suggesting a similar etiology for both clinical patterns. Clustering between cases with widely divergent dates of clinical onset provides evidence of marked variation in latency. No similar clustering was observed in age-, sex-, and area-matched hospital controls without multiple sclerosis, and no clustering was found among the cases when using fixed number of years before onset. These results are compatible with a common infectious agent, such as the Epstein-Barr virus, acquired in adolescence in genetically vulnerable persons who are also not protected by an infection acquired before this age of susceptibility. Susceptibility could be related to the route of transmission or to other age-related covariates or it may be hormonally mediated.

Maternal filarial infection as risk factor for infection in children

Familial clustering of filarial infection was investigated through random house-to-house surveys of 643 individuals in Leogane, Haiti, an area with endemic Bancroftian filariasis. Children of infected mothers were 2.4 to 2.9 times more likely to be infected than were those of amicrofilaraemic mothers. Filarial-specific cellular responsiveness in amicrofilaraemic children born to infected mothers was lower than that in amicrofilaraemic children born to amicrofilaraemic mothers. No effect of paternal infection status was seen. The findings show that maternal infection is a risk factor for filarial infection in children and is associated with altered parasite-specific immune reactivity.

Leukaemia and paternal radiation exposure

OBJECTIVE

Recently, Gardner and colleagues inferred, from a case-control study of leukaemia incidence in young people near the Sellafield nuclear facility in West Cumbria, that an increase near Sellafield was real, and was probably caused by occupational exposure of the father to ionising radiation at the Sellafield plant. The intent of this paper is to dispute that attribution, and to suggest that confirmation of such an alarming and prejudicial conclusion should precede its dissemination. MATERIAL CONSIDERED: Critical comment is limited to the paper by the Gardner group presenting their results, the accompanying paper outlining their methods, a review from Mathews that provides some support for the Gardner proposal by suggesting a pathogenetic mechanism, and some observations on inherited tumours by Nomura that are quoted by Gardner et al. and Mathews in support of their beliefs. Other material quoted is from the general medical literature of the past 20 years relating to radiation biology, mutagenesis and carcinogenesis with some relevance to the Gardner contention; it is not exhaustive.

MAIN RESULTS

Statistical arguments suggest that it is almost impossible to be sure that a specific leukaemia "cluster", such as that near Sellafield, is not a chance finding. The study by Gardner et al. provides only weak statistical evidence for an association between leukaemia in children and parental occupational radiation exposure at Sellafield. The postulate of a causal relation between parental exposure at Sellafield and leukaemia in progeny is incompatible with what is known of the role of genetic mechanisms in leukaemia, with current views on the quantitative relation between radiation dose and mutagenetic effect, and with observations on the children of people exposed to radiation by the nuclear bombs used in Japan in 1945.

CONCLUSIONS

The suggestion that occupational exposure to ionising radiation of a father may be responsible for an increased risk of leukaemia in his children cannot be substantiated. It would be proper to seek confirmation from other groups of occupationally exposed persons before undertaking precipitous, and inevitably disturbing, action to remedy the supposed problem.

An appraisal of the epidemiology of Trypanosoma cruzi serology in Brazil

A large bibliographic survey provided data on Trypanosoma cruzi serology covering the period 1948-1984. Epidemiological-demographic methods provided an estimate of 11% for the prevalence of positive serology in Brazil, by 1984. Significant temporal trends were observed for most of the Brazilian geographical regions as well as for Brazil, as a whole. The parabolic curve that fit best for the entire country, indicates that by 1991, the incidence of new positive serology would be close to zero. This conclusion needs further fine-adjustment, since the forecast point is somewhat distant from the measured period.

[Family outbreak of hepatitis B]

Hepatitis B virus (HBV) causes one of the most widespread infections worldwide. We report a family outbreak where a male with Down's syndrome attending an open institution for mentally retarded individuals probably was the source of the infection. We consider the prevention as the only means to attack the infection with intervention on the transmission mechanisms and immuniprophylaxis. We emphasize eh need of a perfect communication between the several institutions involved in epidemiological surveillance. This might have prevented the present outbreak. Finally, we insist on the importance that the primary care physician could have in the prescription and indication of immunoprophylaxis. To this end, the disappearance of the administrative barriers established by the Secretaría General de Asistencia Sanitaria from the Health Ministry would be needed.

Massive sero-epidemiological survey of hepatitis C virus: clustering of carriers on the southwest coast of Tsushima, Japan

We conducted a mass screening survey for anti-hepatitis C virus antibody (anti-HCV-Ab) among 1,009 inhabitants, 341 males and 668 females, older than 40 years, in south Tsushima in 1989. The overall positive rate for anti-HCV-Ab was 2.3% (2.9% in males and 1.9% in females). The positive rate for anti-HCV-Ab among people with histories of blood transfusions was 14.8% (8/54), which was higher than than (1.6%, 15/955) in people without blood transfusions (P less 0.001). The positive rate (15.1%, 8/53) in people with an elevated level of glutamic oxalacetic transaminase (GOT, greater than or equal to 41 U/liter) or glutamic pyruvic transaminase (GPT, greater than or equal to 36 U/liter) was significantly higher than that (1.6%, 15/956) for people with normal values of GOT and GPT (P less than 0.001). The most interesting finding was that the anti-HCV-Ab positives without histories of blood transfusions were clustered in a few villages located in the southwestern coastal areas of Tsushima, where the positive rate of 3.7% (13/355) was significantly higher (P less than 0.001) than that of 0.3% (2/600) in other villages.

Parental occupation and intracranial neoplasms of childhood: anecdotal evidence from a unique occupational cancer cluster

Near the end of the data-collection phase of a case-control interview study of environmental factors and childhood brain tumors, an unusual space-time cluster was revealed. Not only had six genetically unrelated children been diagnosed with a primary intracranial tumor in a recent 2.4 year period in a rural county in Ohio, but each child had one parent employed by the same company (two mothers, four fathers). This represents an observed/expected ratio greater than 70 (p much less than 0.001). All tumors were microscopically confirmed, and all case parents worked at the facility in question for at least 1 year prior to conception, during the index pregnancy, and for at least 6 months after birth. The place of parental employment was an electronics firm (Standard Industrial Classification [SIC] group number 367, electronic components and accessories), where more than 100 chemical compounds are used by the company in a manufacturing process. Results of the cluster investigation are described, including a description of the case series. This cancer cluster is unique in that the index case series is composed of the offspring of workers, not the workers themselves.

Community lifestyle characteristics and risk of acute lymphoblastic leukaemia in children

High rates of leukaemia in children and young people have been associated with features of community isolation and population growth. Incidence data collected by two specialist registries were used to compare incidence rates at ward level with relevant ward characteristics derived from routine census and Ordnance Survey data for England and Wales. An excess risk of childhood acute lymphoblastic leukaemia (ALL) was found for wards which are farthest from large urban centres. The excess was greatest for wards of higher socioeconomic status and for children aged 1-7 years (the childhood peak), for which a two-fold excess was seen. These findings in general support the hypothesis that childhood leukaemia has an infectious aetiology.