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Biomedical subjects

R W Steketee

Publications and source records attributed to R W Steketee.

At least 73 records · Page 4Linked to original sources
PubMed1994

Malaria and childbearing women in Malawi: knowledge, attitudes and practices.

Information on women's use of antenatal clinic (ANC) service, including malaria prevention and treatment during pregnancy, was collected during a national malaria knowledge, attitudes, and practices survey in Malawi. Among 1531 households, 809 (53%) included a woman who had carried a pregnancy past the second trimester within the past 5 years. Of these, 756 (93%) women reported at least one ANC visit during pregnancy (median = 4); 336 (42%) attended 5 or more times. Approximately half (51%) reported delivering in a hospital; 5% delivered in a clinic; 13% delivered at home with a trained birth attendant; and 28% delivered at home with only family attending. Women at increased risk for delivery complications (e.g. primigravidas and grand multigravidas) were no more likely to attend ANC or deliver in hospital than women without increased risk. The woman's level of education was the only significant predictor of initiating ANC care, continued ANC attendance, and delivery in hospital. In a setting where 43% of women pregnant within the past 5 years had received no formal education and 70% had completed less than 5 years, this survey identified a critical need for targeting health messages towards poorly educated women to ensure proper utilization of antenatal care services, including coverage with malaria prevention throughout pregnancy.

Adult↗
PubMed1993

Immunoglobulin complex deposits in Plasmodium falciparum-infected placentas from Malawi and Papua New Guinea.

Term placentas from 35 patients infected with Plasmodium falciparum were obtained in Malawi in southeast Africa and six term placentas from patients infected with P. falciparum were obtained in Wewak, Papua New Guinea, Melanesia. The placental tissues were examined by light microscopy and by an immunohistologic method to compare the pathologic changes of placentas in the two malaria-endemic countries. Using the number of parasitized red blood cells (PRBC) in intervillous spaces, pregnant women from Malawi with placental parasitemia were categorized into three groups. In the high PRBC group (> 20%, group I), there was no deposition of IgE in fetal blood vessels. In contrast, IgE was observed in fetal blood vessels of the intermediate PRBC group (1-10%, group II) and low PRBC group (< 1%, group III). In all six placentas from Papua New Guinean women, deposition of immune complexes, including IgE, was observed in the fetal blood vessels. All placentas with deposition of IgE in fetal blood vessels showed no sequestration of malaria parasites in intervillous spaces. Our data indicate that the amount of deposition of IgE in the placenta from women infected with P. falciparum is inversely correlated with the degree of parasitemia at that site.

Animals↗
PubMed1992

Effect of blood transfusion on survival among children in a Kenyan hospital.

In Africa, blood transfusions are frequently given to treat severe paediatric anaemia. Because of the risk of HIV transmission, identification of when transfusion will reduce the risk of death for severely anaemic children has become increasingly important. For all children admitted to a Kenyan hospital from October, 1989, to October, 1990, we collected data on clinical presentation, haemoglobin (Hb), receipt of transfusion, and in-hospital survival. Of 2433 admissions, 29% (684) had severe anaemia (Hb less than 5.0 g/dl), and 20% (483) received blood transfusions. Based on laboratory criteria only, children with Hb less than 3.9 g/dl who were transfused had lower mortality than those with Hb less than 3.9 g/dl who were not transfused, but this finding applied only to children transfused on the day of admission (odds ratio [OR] 0.30; 95% Cl 0.14, 0.61) or the day after admission (OR 0.37; 95% Cl 0.14, 1.00). Based on a combination of laboratory and clinical criteria, children with clinical signs of respiratory distress and Hb less than 4.7 g/dl who were transfused had lower morality than those who were not (OR 0.19; 95% Cl 0.09, 0.41). Among children without respiratory distress, there was no association between receipt of transfusion and mortality, irrespective of admission Hb. The frequency of blood transfusion can be reduced and survival enhanced by targeting blood to those children with severe anaemia and clinical signs of respiratory distress, and by using transfusion early in the course of hospitalisation.

Anemia↗
PubMed1990

Mefloquine therapy for Plasmodium falciparum malaria in children under 5 years of age in Malawi: in vivo/in vitro efficacy and correlation of drug concentration with parasitological outcome.

The in vivo and in vitro response of Plasmodium falciparum to a single oral dose of mefloquine (25 mg/kg body weight (M25) or 15 mg/kg (M15] was studied in children under 5 years of age in Malawi. Of the children who received mefloquine, 35% vomited at least once, and 10% did not tolerate the drug because of vomiting. The therapy failure rates for the M25 group on day 7, 14, and 28 were 15%, 18%, and 42%, respectively, and these did not differ significantly from those for the M15 group (4%, 18%, and 59%). In contrast, 34 in vitro microtests (17 per group) showed schizont inhibition at less than or equal to 32 pmol mefloquine per test well. On day 7, the concentration of mefloquine in samples of blood was significantly lower in both the M25 and M15 groups for children who were parasitaemic on day 7 than in samples from those who were aparasitaemic. A positive blood smear on day 7 was strongly associated with a mefloquine concentration of less than 500 ng/ml blood on day 2 or day 7 (P less than 0.0003). Vomiting was associated with a low mefloquine concentration on day 2 but not day 7. These results suggest that mefloquine is effective against P. falciparum in Malawi but that for young children the therapy appears to be complicated by frequent vomiting.

Animals↗
PubMed1989

Recurrent outbreaks of giardiasis in a child day care center, Wisconsin.

In the 19-month period September 1983-March 1985, three outbreaks of giardiasis occurred in one large child day care center. Control measures instituted during each outbreak included case finding; pharmacologic treatment and follow-up testing of stool specimens for cases of giardia infection in day care children and staff, and their household contacts; facilitating and stressing personal and environmental hygiene, including altering diapering practices and teaching appropriate hand washing techniques. In the first, second, and third outbreaks, overall attack rates (stool analysis positive for Giardia lamblia) were determined for those persons with greater than or equal to 2 stool specimens submitted; attack rates in children were 47, 17, and 37 per cent, respectively; for tested staff, the rates were 35, 13, and 9 per cent; and for tested household contacts were 18, 9, and 5 per cent. Attack rates were highest for ambulatory diapered children, children attending the day care center greater than or equal to 40 hours per week, and children who were infected with G. lamblia in the most recent previous outbreak. Despite extensive efforts to identify cases, a cure rate of greater than 90 per cent in treated cases, and improvements in personal and environmental hygiene practices, G. lamblia infections recurred in outbreak proportions.

Child Day Care Centers↗
PubMed1989

Measles prevention and control in emergency settings.

Outbreaks of measles continue to be a common occurrence among refugee and famine-affected children in emergency relief camps. Extremely high measles-associated mortality rates have been reported from refugee camps--where undernutrition is common--in several countries over the past 10 years. Mortality from measles is, however, preventable, and immunization against the disease is a high priority in emergency relief programmes, second only in importance to the provision of adequate food rations. All children aged 6 months to 5 years should be immunized with measles vaccine as soon as they enter an organized camp or settlement. Should supplies of measles vaccine be inadequate, children in feeding centres, or those otherwise identified as undernourished, are the top priority for immunization. The occurrence of measles in a camp is not a contraindication to conducting an immunization campaign. Strong coordination by a designated lead agency is needed if such campaigns are to be successful; however, cooperation with the local expanded programme on immunization is essential to ensure that existing cold chain equipment, training protocols, and management manuals are used. If additional equipment is necessary, a complete immunization kit developed by the Office of the United Nations High Commissioner for Refugees, the World Health Organization, and Oxfam can be procured from Oxfam headquarters in the United Kingdom. Vitamin A supplements should be given routinely at the time of measles immunization in situations where malnutrition is severe. Mortality and morbidity in children with clinical measles can be reduced by administering high doses of vitamin A.

Child, Preschool↗
PubMed1988

Response of children with Plasmodium falciparum to chloroquine and development of a national malaria treatment policy in Zaire.

In vivo sensitivity of Plasmodium falciparum to chloroquine was evaluated in 4 of 9 regions of Zaire in 1985 to develop a national strategy for treatment of malaria. Children less than 5 years of age were treated with either a single dose of chloroquine base, 10 mg/kg, or a dose of 25 mg/kg given over 3 d. A modified 7-day World Health Organization in vivo test was used with follow-up 2, 3 and 7 d after the start of treatment. 339 children were studied. In Bwamanda 92% of children were aparasitaemic 7 days after chloroquine, 10 mg/kg, but in Kinshasa only 44% were free of parasites after 25 mg/kg chloroquine. The mean drop in parasite density among those who did not clear parasites by day 7 was greater than 98% of the initial value. Although the parasite density decreased markedly, the failure of most subjects to become aparasitaemic indicated a marked decrease in parasite sensitivity since 1983. Only one child of 51 who were initially febrile remained febrile, although 14 (28%) of these had resistant parasites. The decrease in parasitaemia and temperature, even among children with resistant strains, led the Ministry of Health to recommend 25 mg/kg chloroquine as first line treatment for fever/malaria in their national malaria control plan. The plan includes drug sensitivity surveillance and a referral system for patients who do not respond to chloroquine treatment.

Animals↗
PubMed1988

Efficacy of chemoprophylaxis in preventing Plasmodium falciparum parasitaemia and placental infection in pregnant women in Malawi.

73 pregnant women in Malawi were given weekly antimalarial chemoprophylaxis under observation and were monitored for Plasmodium falciparum parasitaemia and placental infection. 3 of 19 women (16%) who were parasitaemic at the time they began chemoprophylaxis were infected with chloroquine-resistant P. falciparum. After clearance of initial infections, 25% of the 73 women became parasitaemic while taking prophylaxis and 56% had evidence of active or past placental infection at the time of delivery. None of the women who were parasitaemic at the time of enrollment, and only 11% of those who had breakthrough parasitaemias while taking prophylaxis, had a history of fever and signs or symptoms that they recognized as malaria. Although the density of P. falciparum infection and rates of placental infection appeared to be lower among women taking regular chloroquine prophylaxis, this drug did not prevent P. falciparum infection among pregnant women.

Amodiaquine↗
PubMed1988

Malaria infection in pregnant women in Zaire: the effects and the potential for intervention.

In five maternity centres in urban and rural Zaire we evaluated the maternal prevalence of Plasmodium falciparum parasitaemia and recorded fever, the frequency of abortions and stillbirths, newborn birth weights and the feasibility of delivering antimalarial chemoprophylaxis. Women in their first and second pregnancy, compared to others (greater than or equal to third pregnancies), had a higher frequency of parasitaemia (38 v. 15%, respectively, P less than 0.001), higher parasite densities (geometric mean densities 927 per mm3 v. 277 per mm3, respectively, P = 0.01), higher rates of stillbirths and low birth weight babies (24% v. 6.4%, P less than 0.001). On average, pregnant women first attended prenatal clinics in the sixth to seventh month of gestation and made three to four visits before delivery. In these areas of Zaire, antimalarial interventions during pregnancy would have the largest impact if they were targeted to women in their first and second pregnancy. In the study areas, maternal attitudes and prenatal care-seeking behaviours do not appear to be barriers to providing an antimalarial intervention.

Abortion, Spontaneous↗
PubMed1988

Evidence for a high attack rate and efficacy of erythromycin prophylaxis in a pertussis outbreak in a facility for the developmentally disabled.

During an outbreak of pertussis in residents and staff of a facility for the developmentally disabled, 149 persons had laboratory evidence of Bordetella pertussis infection; 130 (87%) reported respiratory illness. Infection rates (IR) in affected wards ranged from 6% to 91%. Most residents were adolescents and adults and had received a full course of diphtheria-tetanus toxoids-pertussis (DTP) vaccine; IRs increased with increasing time after the last DTP dose in fully vaccinated residents. The IR was lower in residents on wards where erythromycin treatment/prophylaxis was started two or fewer weeks after the onset of illness in the first case on the ward (IR, 16%), compared with four or more weeks after onset (IR, 75%; P less than 10(-6)). Respiratory symptoms were milder in ill residents treated within seven days of onset of illness. Although B. pertussis transmission was substantial, erythromycin treatment of patients and prophylaxis of exposed persons was effective in decreasing transmission and disease severity. Carbamazepine toxicity occurred in seven (19%) of 37 residents when carbamazepine was administered with erythromycin.

Adolescent↗
PubMed1988

A comparison of laboratory and clinical methods for diagnosing pertussis in an outbreak in a facility for the developmentally disabled.

During a pertussis outbreak in a facility for the developmentally disabled, culture- or direct fluorescent-antibody-confirmed cases were identified in 24 residents and 17 staff members; 38 (93%) were culture positive for Bordetella pertussis. An enzyme-linked immunosorbent assay (ELISA) was used to detect serum IgG and IgA to the filamentous hemagglutinin and lymphocytosis-promoting factor of B. pertussis. Using criteria from ELISA values, we identified an additional 83 residents and 28 staff members as seropositive. Among seropositive persons, antibody levels were elevated by the time of onset of respiratory symptoms and, in three of the four assays, remained elevated for 14 mo. In 44 seropositive persons tested within two weeks of onset of symptoms, 80% were culture positive, compared with 33% of 15 tested two to four weeks after onset (P = .003) and none of 15 tested more than four weeks after onset. The most specific (94%) clinical case definition identified only 41% of seropositive persons. Thus, ELISAs are important tools for individual diagnosis and epidemiological studies of pertussis.

Antibodies, Bacterial↗
PubMed1988

Seroresponse to hepatitis B vaccine in patients and staff of renal dialysis centers, Wisconsin.

Since June 1982, the Wisconsin Chronic Renal Disease Program has provided reimbursement for hepatitis B virus vaccine and pre- and postvaccine serologic testing for patients and staff in all Wisconsin renal dialysis centers. Between July 1, 1982 and June 30, 1984, 444 dialysis patients in 22 renal dialysis centers and 128 staff from nine renal dialysis centers each received three doses of hepatitis B virus vaccine and were tested more than 14 days after the third dose. Antibody response (antibody to hepatitis B surface antigen) occurred in 208 (47%) patients and was age-dependent; the rate of antibody response ranged from 86% (for those aged less than 30 years) to 32% (for those aged over 70 years). Among staff, the rate of antibody response ranged from 96% (for those aged less than 35 years) to 71% (for those aged over 45 years). Results of a multiple logistic regression analysis showed that within age groups, antibody response in dialysis patients was positively associated with length of time on dialysis prior to receipt of vaccine (p = 0.014) and negatively associated with the time interval between the third dose and postvaccine testing (p = 0.0003). Variables that did not enter the regression equation were dialysis mode and frequency, transplant status, concurrent medication use, and injection site. Given the low rates of post-hepatitis B virus vaccine antibody response observed in renal dialysis center patients reported here, the authors recommend that hepatitis B virus vaccine plus alternative hepatitis B virus preventive methods be used. Consideration should be given to a schedule for testing of all vaccinated patients and staff aged over 40 years to ascertain postvaccine susceptibility to hepatitis B virus infection.

Adolescent↗
PubMed1988

Field application of a colorimetric method of assaying chloroquine and desethylchloroquine in urine.

In a study in western Kenya of malaria-infected adult women who had been treated with chloroquine, we compared the level of chloroquine and its principal metabolite, desethylchloroquine, in urine, measured using a newly developed modified Haskins test, with the level of chloroquine in whole blood, determined by high-performance liquid chromatography. Over a 28-day follow-up period, 277 matched urine and blood samples from 81 women were evaluated. A high correlation was observed between the level of chloroquine in whole blood (in mug/l) and that of chloroquine + desethylchloroquine in urine (in mg/l). The test was easily performed and may be useful for monitoring use of chloroquine in a community and determining pre-study or post-treatment ingestion or absorption of the drug in in vivo studies of parasite sensitivity.

Adolescent↗
PubMed1988

Outbreaks of pertussis in the United States: the Wisconsin experience.

To identify risk factors for pertussis in older age groups and to examine the effectiveness of erythromycin therapy and prophylaxis in reducing secondary spread, epidemiologic investigations of two outbreaks involving teenagers and adults were conducted. The first outbreak occurred in 1984 among residents of a facility for developmentally disabled persons (median age 17 years). Rates of culture-and/or serologically confirmed infection ranged from 6% to 91% in exposed wards (42% overall), with transmission continuing over a five-month period. Although residents age 10-19 years experienced the highest rates of infection, they were also more likely to be exposed compared with residents in other age groups. Infection rates were significantly lower on wards where erythromycin treatment and prophylaxis were initiated less than 2 weeks after onset of illness in the index case (overall attack rate = 16% vs. 75% in wards where more than 4 weeks had elapsed; p less than .0001). Early treatment with erythromycin was also effective in reducing pertussis severity. The second outbreak occurred over a six-month period among residents of a 3-county area in central Wisconsin in 1985, with adults accounting for 38% of 161 culture-positive cases. Exposure outside the home was the most important predictor of community-acquired infection (p less than .001), with adolescents being at higher risk than persons in other age groups (odds ratio 3.2; p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

In vivo response of Plasmodium falciparum to chloroquine in pregnant and non-pregnant women in Siaya District, Kenya.

Chemoprophylaxis using chloroquine (CQ) in suppressive doses has been recommended to protect pregnant women in malarious areas from the adverse effects of malaria during pregnancy. In a malaria-endemic area of western Kenya with CQ-resistant Plasmodium falciparum, we determined the prevalence and density of falciparum infection in gravid and nulligravid women and compared the in-vivo parasite response to CQ using two regimens: 25 mg/kg body weight (CQ25) divided over a period of three days (for high-density parasitaemias) and 5 mg/kg body weight (CQ5) weekly for 4 weeks (for low-density parasitaemias). P. falciparum infections were present in 102 (42%) of 244 pregnant women. A greater proportion of primigravidae were parasitaemic (68%) than nulligravidae (50%, P=0.02) or multigravidae (33%, P <10(-6)). Primigravidae showed a higher geometric mean parasite density. In the CQ25 treatment group, failure to clear parasites by day 7 was more common in primigravidae than nulligravidae (P=0.008) or multigravidae (P=0.15). In the CQ5 treatment group, primigravidae were more likely to show increasing parasite density than nulligravidae or multigravidae.In this area of Kenya, virtually all women in their first pregnancy are exposed to malaria and are at greatest risk for malaria infection; compared with other women, they show higher parasite densities and are least likely to respond to chloroquine treatment in areas of chloroquine resistance. Malaria control strategies might be targeted to this group of women, but we are pessimistic about the efficacy of weekly CQ5 where there is chloroquine resistance.

Animals↗
PubMed1985

Babesiosis in Wisconsin. A new focus of disease transmission.

A confirmed case of human babesiosis was identified in August 1983 in a 54-year-old asplenic Wisconsin resident. Babesia microti was identified as the causative agent by blood smear morphology and hamster inoculation techniques. The patient's wife had clinically confirmed Lyme disease in 1981 and had serologic evidence (immunofluorescent antibody to a B microti titer of 1:1,024) of recent Babesia infection in August 1983. Mice (Peromyscus species) trapped on the patients' property and elsewhere in their Wisconsin county of residence were infected with B microti. Lyme disease and babesiosis have the same tick vector and animal reservoir; serum samples from 116 Wisconsin and Minnesota residents with clinically confirmed Lyme disease between 1980 and 1983 were tested, and none were found to have concurrent Babesia infection. This area of Wisconsin is identified as a new focus for babesiosis transmission, but the risk of transmission seems to be low.

Animals↗
PubMedDate not supplied

Serological reactivity to the ring-infected erythrocyte surface antigen and circumsporozoite protein in gravid and nulligravid women infected with Plasmodium falciparum.

To investigate potential mechanisms for pregnancy-associated alterations in the immune response to malaria, we tested plasma samples from Plasmodium falciparum-infected nulligravida (42), primigravida (23) and multigravida (38) Kenyan women for reactivity to the ring-infected erythrocyte surface antigen (RESA) by a modified indirect fluorescent antibody assay and to synthetic peptides derived from amino acid sequences of RESA and the circumsporozoite (CS) protein of P. falciparum by an enzyme-linked immunosorbent assay. Reactivity to RESA showed the lowest titres in primigravid women, intermediate titres in nulligravid women and the highest titres in multigravid women (loge mean antibody = 3.28, 4.64, and 5.28, respectively, P less than 0.03), but was not associated with initial parasite density or response to chloroquine treatment. No relationship in antibody reactivity to the 3 synthetic peptides of the RESA molecule was observed by gravidity (0, 1, or greater than or equal to 2), age, initial parasite density or response to treatment. Levels of antibody to the synthetic peptides of the CS protein increased with age and were higher in gravid than in nulligravid women in the 15-19 year age group. The increased malaria prevalence and parasite density and the decreased response to antimalarial treatment in pregnant women is not explained by lower levels of antibody to RESA or CS protein during pregnancy.

Adolescent↗