Plankton Imagery Data Inform Satellite-Based Estimates of Diatom Carbon.

Estimating the biomass of phytoplankton communities via remote sensing is a key requirement for understanding global ocean ecosystems. Of particular interest is the carbon associated with diatoms given their unequivocal ecological and biogeochemical roles. Satellite-based algorithms often rely on accessory pigment proxies to define diatom biomass, despite a lack of validation against independent diatom biomass measurements. We used imaging-in-flow cytometry to quantify diatom carbon in the western North Atlantic, and compared results to those obtained from accessory pigment-based approximations. Based on this analysis, we offer a new empirical formula to estimate diatom carbon concentrations from chlorophyll a. Additionally, we developed a neural network model in which we integrated chlorophyll a and environmental information to estimate diatom carbon distributions in the western North Atlantic. The potential for improving satellite-based diatom carbon estimates by integrating environmental information into a model, compared to models that are based solely on chlorophyll a, is discussed.

Dietary intake, body mass index, exercise, and alcohol: are college women following the dietary guidelines for Americans?

Study findings suggest that college women practice diet and health behaviors that contradict the 1995 Dietary Guidelines for Americans. To confirm this hypothesis, the authors surveyed the diet, exercise, and health habits of 60 female students enrolled in three university aerobics courses. They measured height and weight to calculate body mass index (BMI) and assessed physical activity, using the Self-Reported Physical Activity scale. To estimate food and nutrient intake, they used 3-day food records. Participants reported diets that were nutritionally adequate but exceeded national recommendations for fat, sugar, and sodium, and their reports of exercise habits suggested that the lifestyles of 66% of the respondents were sedentary. Although the students' mean BMIs suggested healthy weights, 25% of the women were classified as overweight. A majority of the participants were following at least 1 of the 7 dietary guidelines; however, no participant was adhering to all proposed behaviors.

The public health surveillance of asthma.

Asthma is a highly prevalent disease that affects the quality of life of many people in the United States. Yet there is limited descriptive epidemiological understanding of the disease, particularly at the state and local levels. Minimal surveillance of asthma is occurring across the country. Surveillance of a disease requires that public health workers have the ability to accurately identify cases, have access to needed data, and have adequate resources so that they can collect, assess, report, and use the data-all considerable challenges in the case of asthma. We consider four groups of questions that asthma surveillance should address: (1) How much asthma is there and what are the trends in asthma occurrence over time? (2) How severe is the asthma and what are the trends in asthma severity over time? (3) How well is asthma controlled and what are the trends in asthma management over time? (4) What is the cost of asthma? Because wise decision making in public health depends on the availability of appropriate data for program planning, implementation, and evaluation, we encourage increased surveillance of asthma in jurisdictions across the country.

Assessments of mortality, morbidity, and nutritional status in Somalia during the 1991-1992 famine. Recommendations for standardization of methods.

OBJECTIVES: To evaluate the various survey methods used in Somalia between 1991 and early 1993 while assessing documentation of mortality and malnutrition rates and common causes of morbidity and mortality. DATA SOURCES: Twenty-three population surveys were identified from the Center for Public Health Surveillance for Somalia, the United Nations Children's Fund, and other humanitarian organizations. STUDY SELECTION: Only surveys with defined populations and apparently systematic methodology that focused on mortality, morbidity, and/or nutritional status were included. RESULTS: Extensive methodological differences were found among the 23 surveys. Target populations and sampling strategies varied widely. Twelve studies were considered not reproducible. Of the 16 studies assessing mortality, only eight assessed cause of death. Use of units of measurement and inclusion of denominators in rate calculations were inconsistent. None of the studies provided confidence intervals around the point estimates of the rates. Of the 11 studies providing information on morbidity, none provided case definitions. And in the 16 studies reporting nutritional status, a variety of measurement methods and definitions of malnutrition were used. Three studies presented information based on mid-upper-arm circumference measurements, and 10 presented weight-for-height data below 70% and 80% of the reference median; only four studies presented z scores. CONCLUSIONS: While the results of some studies may have influenced policy and program management decisions, their effects may have been limited by failure to adequately document results and by differences among studies in objectives, design, parameters measured, methods of measurement, definitions, and analysis methods. We recommend that agencies conducting population studies in emergency situations define clear study objectives, use standard sampling and data collection methods, and ensure precise written documentation of study objectives, methods, and results.

Survey of state health agencies' staff who practice the epidemiology of noninfectious diseases and conditions.

The primary causes of mortality in the United States are noninfectious diseases and conditions. Epidemiologic and intervention activities related to most of these diseases and conditions have increased in most State health agencies over the past decade. Because little was known of the practice of noninfectious disease epidemiology in State health agencies, a mail survey was undertaken in 1991. Persons working in State health agencies who responded to the survey had a graduate degree in epidemiology, biostatistics, or related fields and actively participated in the epidemiology of noninfectious diseases or conditions. Respondents were from 48 States, predominantly male (56 percent) and white (92 percent). On an average, respondents spent roughly half of their time actually doing epidemiology. The focus of noninfectious disease epidemiology has been categorized by risk factors (environment, occupation, nutrition, tobacco, and substance abuse), diseases (diabetes, cancer, and cardiovascular disease), and health conditions (injury, birth defects, and other reproductive conditions). The percentage of respondents who reported epidemiologic activity in any risk factor, disease, or condition varied from 55 percent for environmental epidemiology to 9 percent in nutritional epidemiology. Respondents from 41 States reported activity in environmental epidemiology, those from 18 States reported activity in substance-abuse epidemiology, and those from 13 States reported activity in nutritional epidemiology. Although the practice of noninfectious disease epidemiology appears to be considered important in the majority of States, the extent of practice varies markedly. Those risk factors, diseases, and conditions that are most frequently associated with morbidity and mortality are the least addressed epidemiologically in State health agencies. In addition,when events such as environmental disasters occur, appropriate surveillance systems frequently are not in place to monitor the most important health outcomes. As a result, public health planning and intervention programs may not be driven by solid epidemiologic data.

Medicaid coverage of screening tests for breast and cervical cancer.

Although most women receive periodic Papanicolaou smear (Pap) those who do not are more likely to be of lower socioeconomic status. Similarly, for the many women who do not receive periodic mammography for early diagnosis of breast cancer, cost has often been cited as a reason. Medicaid provides health benefits to roughly 9.4 million women of the appropriate ages for Pap tests and roughly 3.3 million women of the appropriate ages for mammography. The decision to provide such coverage is made on the state level. Of the 50 states and the District of Columbia, 49 provide some level of coverage for Pap smears, 39 for screening mammography. Knowing the extent of coverage allows public health professionals to take advantage of this funding source to provide services for lower-income women and may help initiate coverage in those states where it is not currently available.

Uses of data to plan cancer prevention and control programs.

Seven State health departments, those in Illinois, Nebraska, New Jersey, New York, North Carolina, Texas, and Wisconsin, have participated in an effort to utilize a variety of State-specific cancer-related data to describe the cancer burden in their State's population. The data were then used to develop a statewide cancer plan or supplement an existing plan to address the defined problems. Cancer data have not been well utilized in the planning of intervention programs in the past, and the efforts in these States can serve as models for data use in programs to prevent and control cancer and other chronic diseases. State-specific data can be used to rank needs and make a clear case that can influence decision makers regarding resource allocation. The purpose of this report is to describe the data sources and additional statistics that were used to provide a broad picture of the cancer burden that will aid in targeting and defining intervention needs. Mortality, incidence, risk factor prevalence, and hospital discharge data appear to be the most accessible and potentially useful of the data sources examined, whereas insurance claims data, sources of treatment data, and environmental data bases were less useful in planning intervention strategies.

Breast cancer screening legislation in the United States.

We discuss some of the issues emerging from a powerful legislative movement for preventive services over the past three years. During this time an increasing number of states passed, considered, or are currently developing breast cancer screening legislation. Most of these laws require some form of third party payment for mammography or establish breast cancer screening programs. The legislation varies markedly with regard to periodicity of examinations, ages covered, type and extent of third party coverage, dosage regulation, and radiographic equipment standards. This shows a need for common standards. Legislation provides an essential incentive for a public health response to a serious problem, but more than laws are needed. Health care providers and the general public need to be aware and take advantage of the coverage provided as a result of legislation. Moreover, public health officials need to be aware that such legislation may lead to a demand for services that exceeds present capacity to deliver them.

A survey of physicians' breast cancer early detection practices.

Early detection of breast cancer through the use of mammography reduces long-term mortality from this disease, yet relatively little is known about its acceptance by the medical community. As part of a state health department cancer control program planning effort, we contacted 1,004 primary-care physicians in Pennsylvania to ascertain current breast cancer early detection practices. While 92% of the 557 eligible respondents reported conducting breast physical examinations at least annually in asymptomatic women age 50 or older, annual mammograms for this age group were ordered by only 42% of physicians. Obstetrician-gynecologists, as well as female and younger physicians, were more likely to obtain nondiagnostic mammograms regularly. Factors reported by physicians as affecting their practice of obtaining mammograms varied by patient age and, among patients 50 years and older, included the claim that their mammography practices represented optimal care (57% of the physicians), how often the patient visited their office (23%), patient refusal (16%), and cost of the examination (16%). Fear of radiation and expense were cited as the primary reasons for patient refusal. Public and physician education, as well as third-party payment changes, was viewed by the physicians as the most effective means to increase the level of breast cancer early detection in their geographic areas. This survey shows that the use of nondiagnostic mammography is still less than optimal, and identifies impediments to screening that need to be addressed in cancer control planning efforts.

Infant mortality and childhood nutritional status among Afghan refugees in Pakistan.

In 1984 and again in 1985, systematic surveys were undertaken to evaluate infant mortality and childhood nutritional status among the Afghan refugee population in Pakistan. The entire Afghan refugee population under the administration of the United Nations High Commissioner for Refugees was sampled. Infant mortality rates were estimated to be 156 per 1000 for 1984 and 119 per 1000 for 1985. A decline was also suggested in neonatal mortality rates from 61 per 1000 for 1984 to 46 per 1000 for 1985. For neither infant nor neonatal mortality was the difference statistically significant. Improvements were seen in the percentage of children who died before their fifth birthday (22.5% in 1984 and 18.8% in 1985), in the percentage of children who were malnourished (3.5% in 1984 and 2.3% in 1985), and an increase in the percentage of children above the WHO/NCHS/CDC weight-for-height reference median (26% in 1984 and 35% in 1985). Diarrhoea was the most frequently reported cause of death for both years and was a particularly important cause of death among one-year-old children. In 1985, measles was related to 24% of the deaths and neonatal tetanus to 9% of the deaths, an increase from 8% for measles and 6% for tetanus in 1984.

PIP: Female health visitors interviewed 1512 families in 1984 and 1566 families in 1985 dispersed among Afghan refugee camps in the provinces of the Northwest Frontier Province (NWFP), Baluchistan, and Punjab in Pakistan in Pashto, the language of most of the refugees. The refugees came to Pakistan as a result of civil war in Afghanistan. Infant mortality fell from 156-119/1000, but the difference was insignificant. The researchers believed the consistent direction of the differences to be real, however. A 3.7% increase in the percentage of children who lived to age 5 and a 9% increase in children above the standard weight for height median occurred between 1984-1985. Further 1.2% fewer children were malnourished in 1985 than 1984. Moreover no children in either year were 70% of the median. These improvements coincided with a shift from tents to permanent dwellings; more livestock, vegetable gardens, enclosed water supplies, and, in near urban camps, electricity. Despite these improvements and readily available oral rehydration salts, diarrhea still was the major cause of death, especially for 1 year old children. In addition, no change occurred in the percentage of children who had diarrhea 1 week before the interview between the 2 years. Vaccine preventable deaths increased between 1984-1985. Specifically, neonatal deaths from tetanus rose from 22-28%. Further 10 children died from measles in 1984 whereas 27 did in 1985. 24% of children in 1985 had measles. In 1985, researchers estimated previous access to immunizations by the presence of a BCG vaccine scar. 45% in NWFP and Punjab had the scar while only 26% in Baluchistan had a scar. Moreover infant mortality in Baluchistan was 2 times that of the other 2 provinces. In conclusion, relief workers should implement control measures in Afghan refugee camps that reduce neonatal and infant mortality.

A cluster of young patients with Burkitt's lymphoma and nasopharyngeal carcinoma in central Texas.

During a five-month period in 1982, diagnoses were made of Burkitt's lymphoma in three children and nasopharyngeal carcinoma in three teenagers who were residents of a small geographic area of central Texas. The observed number of these two Epstein-Barr virus-related cancers was significantly greater than the number expected in young patients based on Surveillance, Epidemiology, and End Results incidence rates. No epidemiologic associations were found linking any of the patients. Environmental studies including serological assays to determine a specific viral etiology were unrevealing. A search for new agents and the preservation of materials for future studies should continue to be a high priority in the evaluation of cancer clusters.

Serologic tests for diagnosis and post-treatment evaluation of patients with alveolar hydatid disease (Echinococcus multilocularis).

The indirect hemagglutination (IHA) and immunoelectrophoresis (IEP) tests were used for diagnosis and follow-up evaluation of 17 patients with alveolar hydatid disease caused by Echinococcus multilocularis. Follow-up periods ranged from 2 to 22 years. At the time of diagnosis 16 (94%) patients' sera gave IHA titers greater than or equal to 1:128. Serum specimens from 13 patients were examined by IEP; nine (69%) revealed the arc 5, and three of the four arc 5-negative sera revealed one or more non-characterized bands. Titers declined markedly during the first year following radical surgical resection of the larval lesions; in three cases clinical evidence of recurrence was preceded by rising serologic titers. Antibody has persisted at high levels in non-resected patients treated continuously with high doses of mebendazole.

Cancers of the gallbladder and biliary tract in Alaskan natives: 1970--79.

The records of Alaskan Native patients with gallbladder and extrahepatic bile duct cancers diagnosed during 1970--79 were reviewed. Of 34 cases identified, the primary cancer was in the gallbladder in 29, resulting in age-adjusted incidence rates for gallbladder cancer of 4.4 for males and 17.6 for females. On the basis of calculations applying cancer incidence rates for U.S. whites to the Alaska Native population, a greater than expected number of both Eskimo and Indian patients were diagnosed. A 5-year review of cholecystectomies indicated that nonmalignant gallbladder disease was also elevated in both Indians and Eskimos.

Hepatitis B testing in the families and villages of five young eskimos with primary hepatocellular carcinoma.

A 15-year-old female Eskimo and a 22-year-old male Eskimo from a southwestern Alaskan village (population 540) were diagnosed as having primary hepatocellular carcinoma (PHC) in December, 1977. The fathers of both patients also died of PHC. Three additional cases of PHC affecting young Alaskan Eskimos had been diagnosed since 1972, all from neighboring villages. Four of the five young patients were positive for hepatitis B surface antigen (HBsAg), and the family members of three patients were all positive for HBsAg or antibody to this antigen (anti-HBs). The other two families had no members positive for HBsAg. The prevalence of HBsAg in the villages of these patients ranged from 0--5%, and the prevalence of anti-HBs ranged from 3--25%. This part of Alaska has a high rate of infection with hepatitis B virus and an increased incidence of PHC. However, other Alaskan villages of similar ethnic background have considerably higher rates of hepatitis B infection than the four villages described and to date they have no PHC. This suggests that genetic and/or environmental factors in addition to hepatitis B infection may have a role in the etiology of PHC in Alaska.