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Biomedical subjects

J P Koplan

Publications and source records attributed to J P Koplan.

18 recordsLinked to original sources

Treatment of chloroquine-resistant malaria in African children: a cost-effectiveness analysis.

Because chloroquine (Cq)-resistant Plasmodium falciparum (CRPF) has now spread throughout most of Africa, the efficacy and practicability of other drugs such as amodiaquine (Aq), and pyrimethamine-sulfadoxine (PS), for the treatment of fever needs to be assessed. We used a decision-analysis model to compare the cost and effectiveness of Cq, Aq, and PS. The variables considered were the probability of P. falciparum infection, drug compliance, minor and lethal side effects of the drug, the level of drug resistance in the community, and case-fatality rates associated with treatment. The measures of effectiveness were the number of malaria-related fever episodes cured parasitologically with each treatment and the number of malaria deaths prevented in children 6-59 months old. Cost-effectiveness comparisons were made for cases cured and deaths prevented. For treating 100,000 febrile episodes, Cq, PS, and Aq cost US$1812, US$2622, and US$3044, respectively. Cost of the drug, compliance, and the level of CRPF had the greatest effect on the cost-effectiveness ratio. The prevalence of high-level drug resistance (RIII) was the most important determinant of the cost-effectiveness. In a scenario with high-level CRPF, treatment with Cq costs US$0.47 to cure one patient and US$2.29 to prevent one death compared with US$0.05 and US$1.52 for treatment with PS. When the prevalence of RIII-level CRPF is greater than 14-31% (depending on the level of compliance), the most cost-effective treatment is PS, despite its 45% greater cost. Decision analysis models will be useful for malaria control planners as strategies are reconsidered in the 1990s.

Africa

Cardiovascular deaths while running.

When a person dies of cardiovascular causes during recreational running, the public frequently assumes the exercise caused the death. For a statistical perspective, the number of cardiovascular deaths while running that occurs by chance alone is estimated. If white male runners resemble marathoners, being nonsmokers and at lowest lean weight, four deaths from cardiovascular disease would occur per year while running 20 minutes, three times per week and 30 deaths per year if the two hours after running are considered as a running-associated period. However, if runners resemble the white male population, then 15 deaths would occur from cardiovascular disease per year while running and 104 during the associated period. Thus, four to 104 cardiovascular deaths per year are predicted on a purely temporal basis in white men while running.

Adult

Pertussis vaccine--an analysis of benefits, risks and costs.

Using decision analysis, we estimated the benefits, risks and costs of routine childhood immunization against pertussis. Without an immunization program, we predict that there would be a 71-fold increase in cases and an almost fourfold increase in deaths (2.0 to 7.6) per cohort of one million children. With a vaccination program, we predict 0.1 case of encephalitis associated with pertussis and five cases of post-vaccination encephalitis; without a program, there would be only 2.3 cases of encephalitis associated with pertussis. Community vaccination would reduce by 61 per cent the costs related to pertussis. Our analysis supports continuation of vaccination in routine childhood immunization programs, but suggests the need for more reliable data on complications from the vaccine, further study of the epidemiology of pertussis and development of a less toxic vaccine.

Child

High-density lipoprotein cholesterol concentration and other serum lipids in an isolated island community free of coronary heart disease.

Fasting serum high-density lipoprotein (HDL) cholesterol, other lipid concentrations and related characteristics have been measured in 87% of 261 residents aged over 5 years on the small isolated island of Salt Cay, Turks and Caicos Isles. Only one subject, a hypertensive woman, had a major electrocardiographic Q wave abnormality, and none of the islanders had clinical coronary heart disease. These findings, together with local clinical experience indicated a low incidence of coronary heart disease in this community. Adult mean concentrations of HDL cholesterol (1.6 mmol/l) and serum total triglyceride (0.81 mmol/l) were relatively high and low respectively compared with those of men and women in North American communities. Unlike findings in North America, there was no significant sex difference in HDL cholesterol concentration apparent in adulthood and this was not explained by sex differences in alcohol consumption (positively correlated with HDL cholesterol in both sexes) or adiposity (negatively correlated with HDL cholesterol in men only). Residents who were recovering from an epidemic of mild upper respiratory infection had on average a 9% reduction in HDL cholesterol concentration compared with the remainder of the community. The lipoprotein lipid pattern in these people is consistent with a low cardiovascular risk status, and might account for the apparent absence of coronary heart disease on the island.

Adolescent

Contaminated roof-collected rainwater as a possible cause of an outbreak of salmonellosis.

Roof-collected rainwater is a common water source in subtropical regions and has not been associated with human illness. In Trinidad, the West Indies, a church group, attending a rural camp, developed gastrointestinal illness, caused by Salmonella arechevalata. This rare serotype was isolated from stool specimens of campers, foods eaten at the camp, and a water tap, which was supplied by a storage tank of roof-collected rainwater. The surface of the roof, used as water catchment, was covered with bird faeces. It is postulated that rainwater, falling on the roof, washed off animal excrement which contained S. arechevalata and led to the outbreak of salmonellosis through camper ingestion of contaminated food and water.

Adolescent

Histoplasmosis in Belize, Central America.

After two small outbreaks of histoplasmosis in Belize, an epidemiologic survey was carried out. Forty percent of 141 persons in two groups tested demonstrated a positive histoplasmin reaction. In one study group there was a significant association between visiting caves and histoplasmin positivity. Histoplasma capsulatum was not isolated in 20 soil specimens collected from outbreak-associated caves, but was isolated from 1 of 26 bats collected from the same caves. The presence of histoplasmosis in Belize, C.A. is documented, and this disease should be considered in differential diagnosis in patients, both residents and visitors in Belize, with compatible clinical presentations.

Adolescent

Urban hospital and rural village smallpox in Bangladesh.

Smallpox mortality at Dacca, Bangladesh Infectious Diseases Hospital during 1972 and 1973 was 46 per cent. To determine if this was the actual rate within the population, data were compared to those collected from village populations in Noakhali District. Age/sex adjusted smallpox mortality for the rural population was 23 per 100 cases as compared to 52 per 100 for the hospital population. Analysis of the difference identified a selection bias of the hospital for severe disease.

Adolescent

Lead Absorption in a community of potters in Barbados.

In a community of potters in Barbados where lead glazes traditionally have been used, a survey of 12 potters, 19 of their family members, and 24 controls revealed elevated blood lead levels in the potters, their family members, and the neighbours who used pottery for culinary purposes. Dust from the potters' homes and work areas contained lead in concentrations up to 320,000 ppm. Pottery was found to have lead release levels up to 3,125 microgram/ml. Six people had upper extremity tremor associated with elevated blood lead levels. This survey demonstrates the risk of using lead glazes in pottery production to family members of potters as well as the potters themselves and emphasizes the need for surveillance of occupational hazards in developing countries.

Adolescent

Epidemic diarrhea at Crater Lake from enterotoxigenic Escherichia coli. A large waterborne outbreak.

In June and July 1975, Gastrointestinal illness occurred in more than 200 staff members and 2000 visitors to an American national park. In was characterized by prolonged diarrhea, cramps, nausea, and vomiting, lasted a median duration of 8 days, and was significantly associated with consumption of park water (P less than 0.001), which had been contaminated by raw sewage. Enterotoxigenic Escherichia coli serotype 06:K15:H16 was isolated from 20 of 49 ill park residents and from the park's water supply, but not from 71 residents who had never been ill or had been well for at least 4 days. No other bacterial, viral, or parasitic pathogens were isolated from ill or well persons. This outbreak is the first waterborne epidemic of diarrheal illness shown to be due to enterotoxigenic. E. coli, and this study documents one mode of transmission of this pathogen. This investigation also suggests the relative insensitivity of current methods for identifying persons infected with this organism, either by the culturing of randomly selected isolates or by measuring serologic responses.

Diarrhea

Nosocomial vaccinia infection.

Although hospital-associated spread of vaccinia has been reported in the past, there have been no recent reports. This paper describes hospital-associated spread of vaccinia virus infection, supplies data on the environmental survival of vaccinia virus and offers recommendations for the management of patients with vaccinia that may minimize the hazard of infection in other high-risk patients.

Adult

Treatment of variola major with adenine arabinoside.

A double-blind study of the efficacy of adenine arabinoside in the treatment of patients with variola major was conducted. Adenine arabinoside (20 mg/kg of body weight) was given to patients intravenously every 24 hr for seven days in a 8-hr infusion. Five of the nine patients receiving adinine arabinoside died, and four of 11 patients receiving placebo died. Mortality was related to the severity of illness for both groups of patients. No difference was found between the drug and control groups in number of febrile days after initiation of therapy or in the period during which it was possible to isolate virus from skin lisions, throat swabs, and sources of clotted blood. Formation of scabs on skin lesions was complete 8.3 days after the initiation of therapy for the drug group and after 11.3 days for the control group. The findings suggest that adenine arabinoside is not effective in the chemotherapy of smallpox.

Adenine

Detection by radioimmunoassay of antibodies in human smallpox patients and vaccinees.

A radioimmunoassay procedure was developed for determining smallpox and vaccinia antibodies in human sera. The test detected and measured both primary and secondary immune responses in persons infected with variola virus or vaccinia virus. The antibody titers obtained by complement fixation, hemagglutination inhibition, plaque reduction neutralization, and radioimmunoassay methods were compared. In sequential serum specimens, the radioimmunoassay test indicated fourfold or greater increases in all of the smallpox patients and in six of eight vaccinated persons. Both the complement fixation and the hemagglutination inhibition tests were less effective. In persons who had been vaccinated, radioimmunoassay and plaque reduction neutralization tests appeared to measure the same immune response. However, in smallpox patients the immune response was readily detected by radioimmunoassay, whereas an immune response was not detected by the plaque reduction neutralization test when vaccinia virus was the antigen in the test system. Radioimmunoassay is an operationally simple procedure which provides objective and quantitative end-point titers in serological determinations.

Antibodies, Viral

Smallpox vaccination revisited. Some observations on the biology of vaccinia.

Sixty-two volunteers were studied to determine their local cutaneous, serologic, and virologic reactions to smallpox revaccination. Of 55 subjects available for examination, 45 (82%) had major cutaneous reactions. Subjects over 30 years old were more likely to have a major reaction. An increase in complement-fixing antibody titer was found in 74% of revaccinees with a major reaction. An increase in complement-fixing antibody titer was found in 74% of revaccinees with a major cutaneous reaction and is felt to be the best serologic indicator revaccination did not yield vaccinia virus. Cultures of the vaccination site demonstrated the virus to be present for a mean of 7.8 days (range 0--18 days) which coincided with separation correlate with antibody response. However, subjects vaccinated more than 3 years previously and subjects with major skin reactions shed vaccinia virus for longer periods than those vaccinated less than 3 years previously or who had equivocal reactions.

Adolescent

Smallpox vaccination reactions, prophylaxis, and therapy of complications.

Smallpox vaccination in the United States is a routine public health measure which has been under intensive review during the last decade. The most frequently occurring adverse reactions to vaccination are benign and require little or no systemic therapy. These reactions include accidental infection, erythematous and urticarial rash, and generalized vaccinia. Chickenpox occurring concurrently with vaccination presents no problem unless vaccinia has widely superinfected the chickenpox lesions. There is no risk to the pregnant woman who is vaccinated, but there is a slight risk that the fetus will develop fetal vaccinia. The vaccinia does not cause congenital malformations. Vaccinia hyperimmune globulin (VIG) in prophylactic dosage may be given to a pregnant woman who is traveling to a smallpox infected or endemic area in order to prevent fetal vaccinia. Vaccinia necrosum and eczema vaccinatum require vigorous systemic therapy with VIG, and often thiosemicarbazone. Post-vaccinial encephalitis, while frequently serious, has not been shown to be ameliorated by VIG therapy, although there are data which suggest VIG has some value in prophylaxis for encephalitis. Prophylaxis, prompt recognition, and proper therapy may reduce the fatality rates of these complications. Revaccination of patients who have suffered a complication is a frequent clinical problem. Revaccination of an individual who has had post-vaccinial encephalitis or vaccinia necrosum is contraindicated unless the risk of contracting smallpox outweighs the risk of the above two diseases. Revaccination of children who have had eczema vaccinatum is not contraindicated. Revaccination of children with a history of accidental infection or erythematous or urticarial rash presents no known or theoretically increased risk.

Eczema