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.

Changing epidemiology of group A streptococcal infection in the USA

To see whether changes in the epidemiology of group A streptococcal disease in the USA have been accompanied by a corresponding change in serotype distribution, epidemiological and M-typing and T-typing data for 5193 strains sent to the Centers for Disease Control, Atlanta, between 1972 and 1988 were analysed. The proportions of M-types 1, 3, and 18 increased significantly during the study period. These M-types were more likely to be invasive, to cause fatal infection, and to occur in a cluster of infections than were other types. By contrast, the proportions of M-types 4 and 12 decreased; they were less invasive and were less likely to be found in clusters than were other types. These data suggest that changes in the epidemiology of group A streptococcal disease may be related to changes in the distribution of M-types causing infection.

Risk factors for transmission of hepatitis B virus to Gambian children

Risk factors for hepatitis B virus transmission were examined in 973 Gambian children aged 6 months to 5 years. 33% had evidence of infection with hepatitis B virus and a third of these were carriers. A significant association was found between infection and tropical ulcer scars, and between e antigenaemia and the presence of bedbugs in each child's bed. There was no association between infection and traditional scarring, circumcision, or injections. Skin disease and arthropods are the two most likely modes of transmission of hepatitis B virus between children in West Africa.

Clinical Q fever in Northern Ireland 1962-1989

Q fever was diagnosed in 443 patients in Northern Ireland between 1962 and 1989. From 1986 onwards there was an increase, which peaked in 1989 with 107 cases of whom 47 were infected in Ballycastle, Co Antrim. There were three outbreaks and 21 clusters of patients with Q fever. Most cases were in April and May which correlated with the peak lambing and calving season. Q fever mainly affected males in the 40-49 year old age group. County Antrim had the highest prevalence rate of 40/100,000 population and also had the most sheep. The number of sheep in Northern Ireland has doubled in the past ten years. Q fever was strongly associated with occupation and animal contact. Eighty-seven patients (19.6%) drank unpasteurized milk. The commonest presenting illnesses were pneumonia (62.8%), influenza-like illness (24.6%), involvement of the heart (9.0%) and hepatitis (1.6%). Thirty-two patients (7.2%) had endocarditis, 20 of whom had prosthetic valves and three of whom died. Coxiella burnetii was present on valves removed from seven patients.

[The epidemiology of meningitis caused by Streptococcus pneumoniae in a metropolitan area, Brazil, 1960-1977]

The epidemiology of meningitis caused by S. pneumoniae in the city of S. Paulo, Brazil, during the period 1960-77 is analysed. Data were obtained directly from the patients' records and registered on a pre-coded form. Cases of S. pneumoniae meningitis were confirmed by gram stain and/or culture of the cerebrospinal fluid (CSF). During the period 1960-77, there was confirmation of 1,965 cases of S. pneumoniae meningitis, giving an average rate of 1.9 per 100,000 inhabitants. Children of less than 5 years of age accounted for 52% of cases and 39% were less than 1 year old. The average rates for children below 1 year of age were 37 and 30 per 100,000 inhabitants, respectively, for the periods 1960-69 and 1970-77. The rate of incidence for the peripheral zone--2.2 per 100,000 inhabitants--was practically double the rate for the central area--1.2 per 100,000 inhabitants--in the 1960's. The age standardized rates were 1.6, 1.5 and 2.0 for central, intermediate, and peripheral zones, respectively. In the 1970's these rates were 1.4, 1.5 and 2.0. The average case fatality rate for the period was 47% which was inversely proportional to the number of CSF leucocytes at first examination. For children less than year old, the case fatality rate was 60% for the same period.

Geographic patterns of parkinsonism-dementia complex on Guam. 1956 through 1985

Average annual age-adjusted incidence rates of parkinsonism-dementia complex were obtained for the 19 election districts of Guam from 1956 through 1985. The highest rates were found in the southern and central districts, and the lowest rates were found in the northern and western districts. Geographic and temporal patterns of incidence were associated with socioeconomic status but not with geochemical factors. The risk of parkinsonism-dementia complex in susceptible sibships was much higher than that in the general population--even in districts with the highest incidence rates, but especially in districts with the lowest incidence rates. Our evidence tends to support the hypothesis that multiple factors linked to cycad use play an important role in the cause of PDC. Hypotheses related to metal exposure and simple genetic factors were unsatisfactory explanations for the epidemiologic patterns observed.

Tartrate resistant acid phosphatase positive splenic lymphoma: a relatively benign condition occurring in a time-space cluster?

Conventional light and electron microscopic studies, together with cytochemical and immunocytochemical staining procedures, were carried out to ascertain whether the lymphomata of four elderly female patients living within 10 kilometers of each other, who presented within a short space of time with massive splenomegaly and varying cytopenia, belonged to any particular subgroup of lymphoma. In each case the lymphoma had a diffuse pattern and mature B cell phenotype. The malignant cells were of uniform cell type, slightly larger than admixed polymorphonuclear leucocytes, and showed minimal nuclear irregularity and positivity for tartrate resistant acid phosphatase (TRAP) staining. Their clinical and morphological features were compared with those of other lymphoproliferative disorders, but while sharing some features in common with each condition, this small group of patients seemed to have a unique combination of findings. The cytopenias of all four responded well after removal of the spleen and their disease has not been aggressive. It is concluded that these patients have a distinct subgroup of lymphoma, which it is important to recognise so that inappropriate use of aggressive cytotoxic drugs can be avoided.

A waterborne outbreak of leptospirosis among United States military personnel in Okinawa, Japan

A waterborne outbreak of leptospirosis occurred among US military personnel during September 1987, on the island of Okinawa, Japan. Micro-agglutination titres for leptospiral antigen of greater than or equal to 200 were detected in hospitalized adult males averaging 22.5 years of age with symptoms compatible with leptospirosis. Epidemiological findings revealed two case clusters distinguished by time and place of exposure. The overall attack rates among recreational swimmers and combat skills training participants were 467/1000 (7/15) and 183/1000 (15/82), respectively. Swallowing of water differentiated individuals with laboratory-confirmed infection from those with no infection, while water immersion alone did not appear to result in leptospiral infection. Additionally, subnormal rainfall may have contributed to the risk of exposure associated with this outbreak.

Considerations on a group of 13 patients with Creutzfeldt-Jakob disease in the region of Parma (Italy)

We report a group of 13 cases of Creutzfeldt-Jakob disease treated in the region of Parma (Italy) between 1975 and 1984. An extensive study did not point to any common source of infection. The clinical stereotypy and distinctive neuropathology in this temporo-spatially confined group of patients might be stressed, but the possibility of infection by a single strain of the CJD agent remains speculative.

Parallelism in the mortality clustering of the most frequent cancer sites in Italy and in the Marche region

Clusters of selected cancer sites mortality, regarding Italy and the Marche region, were compared. Very similar associations were found both in males and in females, in particular between the alcohol-tobacco-related sites. Many clusters agree with the international literature, while others could constitute a starting point for formulating new hypotheses.

Familial clustering of neural tube defects and gastric cancer

A retrospective cohort study was conducted to determine whether producing an offspring with a neural tube defect (NTD) is associated with the development of unusual patterns of cancer among the parents in subsequent years. Mothers and fathers who had a child with an NTD in Upstate New York from 1945 to 1955 were followed through 1979 and compared to a control group of parents with normal offspring. Overall mortality and site-specific cancer incidence were not significantly different for case parents versus control parents, with the exception of gastric cancer, which occurred significantly more frequently in case parents. The finding of a familial association between NTDs and gastric cancer, coupled with a parallel decline in rates of these two diseases, suggests a common aetiology, perhaps related to dietary factors.

Amyotrophic lateral sclerosis in Lancashire and South Cumbria, England, 1976-1986. A geographical study

An attempt was made to identify all patients presenting with amyotrophic lateral sclerosis (ALS) during a 10-year period in Lancashire and South Cumbria, England. An analysis of their place of residence was made using the postal code. This was used to allocate each patient to an electoral ward. Using such small areal units, it was found that more cases of ALS had arisen than would have been expected by chance in several wards during the study period. Although the actual number of wards showing this effect was probably not increased, the significance levels suggest that the disease may not show a random geographical distribution. No evidence of clustering of year of birth was found. These findings indicate the need for further work seeking geographical clusters of ALS and are discussed in relation to current etiological hypotheses of the disease.

The epidemiology of thyrotoxicosis in New Zealand: incidence and geographical distribution in north Canterbury, 1983-1985

In a 3-year (1983-1985) epidemiological study of thyrotoxicosis in North Canterbury, New Zealand, the annual incidence was 25.8 per 100,000 (female 40.7, male 10.5). Thyroid scintiscanning showed that 64% had diffuse hyperplasia (DH), 27% toxic multinodular goitre (TMG), 7% toxic uninodular goitre (TUG), and 2% zero uptake. The calculated annual incidence of toxic diffuse goitre (DH) was 15 per 100,000, and for toxic nodular goitre (TMG and TUG combined) was 8 per 100,000. The age-related incidence for toxic diffuse goitre peaked in middle life whereas toxic nodular goitre showed an increasing incidence with age. There was no significant seasonal variation or rural/urban difference in incidence. Analysis of geocoded addresses did not identify areas of high incidence. The variable duration of symptoms prior to diagnosis limits the search for possible environmental trigger factors. North Canterbury was an endemic goitre area prior to the introduction of iodized salt 50 years ago, and the incidence of toxic nodular goitre is likely to fall in future.

[Familial microepidemics of tuberculosis]

We report a microepidemic of tuberculosis (TBC) in a family of 12 members, 4 of which were parenteral drug abusers and 3 had anti-human immunodeficiency virus (HIV) antibodies. Four new cases were simultaneously diagnosed in the investigation of the contacts of a patient with extrapulmonary tuberculosis and acquired immunodeficiency syndrome. We review the requirements for the development of these epidemic outbreaks, both in noninfected communities and in the family contacts, where positive anti-HIV antibodies may increase the risk. We emphasize the importance of a systematic study of contacts in these families and the indication of chemoprophylaxis in all those sharing the same household, without age limit.