Browsing by Author "Baird, J.K."
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Item Incidence of symptomatic and asymptomatic plasmodium falciparum infection following curative therapy in adult residents of northern Ghana.(American Journal of Tropical Medicine and Hygiene, 2001) Owusu-Agyei, S.; Koram, K.A.; Baird, J.K.; Utz, G.C.; Binka, F.N.; Nkrumah, F.K.; Fryauff, D.J.; Hoffman, S.L.Adult residents of holoendemic malaria regions in Africa have a naturally acquired immunity (NAI) to malaria that renders them more resistant to new infections, limits parasitemia, and reduces the frequency and severity of illness. Given such attributes, it is not clear how one might evaluate drug or vaccine efficacy in adults without serious confounding. To determine symptomatic and asymptomatic malaria attack rates in adults of northern Ghana, 197 men and women underwent curative therapy for any pre-existing malaria infections at the start of the high transmission (wet) season. They were monitored for first parasitemia and first clinical episode of infection by Plasmodium falciparum over a 20-week period (May-October 1996). The cumulative incidence of primary infection by P. falciparum was 0.98 and incidence density of infection was calculated to be 7.0 cases/person-year. Symptoms were reported by 19.5% of the individuals at the time of first recurrent parasitemia. Incidence of infection, parasite density, and the frequency of symptoms were comparable in males and females. The results suggest that NAI did not provide these adults with significant defense against rapid re-infection and suggest that this population-infection design could serve to demonstrate the efficacy of a drug or vaccine in preventing parasitemia.Item Mefloquine (MQ) single dose 20 mg/kg treatment of falciparum malaria was evaluated in 186 children of 6-24 months of age in northern Ghana(American Journal of Tropical Medicine and Hygiene 76(2): 224-31, 2007) Fryauff, D.J.; Owusu-Agyei, S.; Utz, G.; Baird, J.K.; Koram, K.A.; Binka, F.; Nkrumah, F.; Hoffman, S.L.There were 15 RII/RIII-type parasitologic failures, all with Day 2 MQ blood levels significantly lower than children whose parasitemias cleared before Day 7 and remained clear through 28 days. Predictors of RII/RIII parasitologic response were vomiting after MQ dosing, Day 2 MQ levels < 500 ng/mL, and undetectable Day 2 levels of the carboxymefloquine metabolite. There were 50 cases of delayed RI parasitologic failure, but 71% of these cases had undetectable Day 28 blood levels of MQ and drug levels in the remaining 29% ranged below the 620 ng/mL level that suppresses MQ sensitive strains of P. falciparum. Drug levels among infants that tolerated MQ well were not associated with age, weight, hemoglobin, parasitemia, and pre-existing symptoms of vomiting or diarrhea. An observed recurrent parasitemia of 34,400 trophozoites/microL against a MQ blood concentration of 550 ng/mL was taken as indication of tolerance to suppressive levels of the drug at this location.Item A randomized, double-blind, placebo-controlled, dose-ranging trial of tafenoquine for weekly prophylaxis against Plasmodium falciparum(Clinical Infectious Diseases, 2003-03) Hale, B.R.; Owusu-Agyei, S.; Fryauff, D.J.; Koram, K.A.; Adjuik, M.; Oduro, A.R.; Prescott, W.R.; Baird, J.K.; Nkrumah, F.; Ritchie, T.L.; Franke, E.D.; Binka, F.N.; Horton, J.; Hoffman, S.L.Tafenoquine is a promising new 8-aminoquinoline drug that may be useful for malaria prophylaxis in non-pregnant persons with normal glucose-6-phosphate dehydrogenase (G6PD) function. A randomized, double-blind, placebo-controlled chemoprophylaxis trial was conducted with adult residents of northern Ghana to determine the minimum effective weekly dose of tafenoquine for the prevention of infection by Plasmodium falciparum. The primary end point was a positive malaria blood smear result during the 13 weeks of study drug coverage. Relative to the placebo, all 4 tafenoquine dosages demonstrated significant protection against P. falciparum infection: for 25 mg/week, protective efficacy was 32% (95% confidence interval [CI], 20%-43%); for 50 mg/week, 84% (95% CI, 75%-91%); for 100 mg/week, 87% (95% CI, 78%-93%); and for 200 mg/week, 86% (95% CI, 76%-92%). The mefloquine dosage of 250 mg/week also demonstrated significant protection against P. falciparum infection (protective efficacy, 86%; 95% CI, 72%-93%). There was little difference between study groups in the adverse events reported, and there was no evidence of a relationship between tafenoquine dosage and reports of physical complaints or the occurrence of abnormal laboratory parameters. Tafenoquine dosages of 50, 100, and 200 mg/week were safe, well tolerated, and effective against P. falciparum infection in this study population.Item Seasonal malaria attack rates in infants and young children in northern Ghana.(Journal of Tropical Medicine and Hygiene, 2002) Baird, J.K.; Agyei, S.O.; Utz, G.C.; Koram, K.A.; Barcus, M.J.; Jones, T.R.; Nkrumah, F.N.The incidence density of infection and disease caused by Plasmodium falciparum in children aged six to 24 months living in the holoendemic Sahel of northern Ghana was measured during the wet and dry seasons of 1996 and 1997. At the beginning of each season, a cohort composed of 259 and 277 randomly selected children received supervised curative therapy with quinine and Fansidar® and primaquine for those with normal glucose-6-phosphate dehydrogenase activity. The 20 weeks of post-therapy follow-up consisted of three home visits weekly and examination of Giemsa-stained blood films once every two weeks. Blood films were also taken from children brought to clinic with illness. The incidence density of parasitemia after radical cure was 4.7 infections/person-year during the dry season and 7.1 during the wet season (relative risk = 1.51, 95% confidence interval [CI] = 1.25-1.81; P = 0.00001). Although the mean parasitemia count at time of reinfection in the dry season (3,310/μl) roughly equaled that in the wet season (3,056/μl; P = 0.737), the risk ratio for parasitemia > 20,000/μl during the wet season was 1.71 (95% CI = 1.2-2.4; P = 0.0025). The risk ratio for parasitemia > 20,000/μl with fever during the wet season was 2.45 (95% CI = 1.5-4.1; P = 0.0002). The risk ratio for anemia (hemoglobin < 8 g/dl) at first post-radical cure parasitemia showed no difference between seasons (1.0; 95 % CI = 0.73-1.4; P = 0.9915). We did not see seasonal differences in anemia known to exist in this region, probably because the longitudinal cohort design using first parasitemia as an end point prevented the subjects from developing the repeated or chronic infections required for anemia induction. These findings bear upon the design of malaria drug and vaccine trials in holoendemic areas.Item Severe anemia in young children after high and low malaria transmission seasons in the Kassena-Nankana district of northern Ghana.(American Journal of Tropical Medicine and Hygiene, 2000) Koram, K.A.; Owusu-Agyei, S.; Utz, G.; Binka, F.N.; Baird, J.K.; Hoffman, S.L.; Nkrumah, F.K.Malaria and anemia accounted for 41% and 18% respectively of hospital deaths in the Kassena-Nankana district of northern Ghana during 1996. We measured hemoglobin (Hb), malaria prevalence, and anthropometric indices of 6—24-month-old infants and young children randomly selected from this community at the end of the high (May–October, n 347) and low (November–April, n 286) malaria transmission seasons. High transmission season is characterized by rainfall (the equivalent of 800–900 mm/yr.), while the remaining months receive less than 50 mm/yr. Severe anemia, defined as Hb 6.0 g/dL, was 22.1% at the end of the high transmission season compared to 1.4% at the end of the low transmission season (Odds Ratio [OR] 20.1; 95% CI: 7.1–55.3). Parasitemia was 71% and 54.3% at these time points (OR 2.1; 95% CI: 1.5–2.9). Nutritional anemia appeared to have little impact upon this seasonal difference since anthropometric indices were comparable. Although the relative contributions of other causes of severe anemia were not assessed, repeated malaria infections may be a primary determinant of severe anemia among infants and young children during the high transmission season.Item Stakeholders Identification– Targeted list of stakeholders’ for the In-depth interview. Research Institutions/ Universities - UCC, UDS, UMat, Atomic Energy, GAEC, School of Nuclear and Allied Sciences. Ministries Departments and Agencies (MDA’s)– EPA, Ministry of Health, Ministry of Environment and Science, CSIR, Ministry of Mines and Energy, Ministry of Roads and Transport, AMA, Zoomlion, Ministry of Food and Agriculture Industries – Tullow Oil, Anglogold Ashanti, Newmont Ghana, Gold Fields, TOR, Bulk Oil Storage and Transportation, Ghana Ports and Harbours, Ghana Standards Authority. Civil Societies and NGO’s – WHO, UNICEF, UNDP, Traditional Leaders, CONIWAS, Association of Environment and Health. Contact key persons or experts in Occupational and Environmental Health field. Questionnaires should include a checklist. The meeting went ahead to include in the framework the levels of stakeholders, specifics, Contact Persons, Timelines and the Expected Output to aid in the categorization of the framework. The meeting agreed that all members should take a look at Edith’s report and provide comments, however, this questionnaires must be sent to all the stakeholders. Timelines- 26th June, 2013 Point-person: – Dr. Stephens, Julius, Hannah, with Strong Input from Edith and Prof. Quakyi to Contact Key Persons. 3.2 Priority Research for Capacity Building- Extractive Industry mainly Mining, Oil and Gas, Agriculture and Disease Control Activiites Eg. Indoor residual spraying versus burden on chronic diseases.(2003-03) Hale, B. R.; Owusu-Agyei, S.; Fryauff, D. J.; Koram, K.A.; Adjuik, M.; Oduro, A.R.; Prescott, W.R.; Baird, J.K.; Nkrumah, F.; Ritchie, T.L.; Franke, E.D.; Binka, F.N.; Horton, J.; Hoffman, S.L.Tafenoquine is a promising new 8-aminoquinoline drug that may be useful for malaria prophylaxis in non-pregnant persons with normal glucose-6-phosphate dehydrogenase (G6PD) function. A randomized, double-blind, placebo-controlled chemoprophylaxis trial was conducted with adult residents of northern Ghana to determine the minimum effective weekly dose of tafenoquine for the prevention of infection by Plasmodium falciparum. The primary end point was a positive malaria blood smear result during the 13 weeks of study drug coverage. Relative to the placebo, all 4 tafenoquine dosages demonstrated significant protection against P. falciparum infection: for 25 mg/week, protective efficacy was 32% (95% confidence interval [CI], 20%-43%); for 50 mg/week, 84% (95% CI, 75%-91%); for 100 mg/week, 87% (95% CI, 78%-93%); and for 200 mg/week, 86% (95% CI, 76%-92%). The mefloquine dosage of 250 mg/week also demonstrated significant protection against P. falciparum infection (protective efficacy, 86%; 95% CI, 72%-93%). There was little difference between study groups in the adverse events reported, and there was no evidence of a relationship between tafenoquine dosage and reports of physical complaints or the occurrence of abnormal laboratory parameters. Tafenoquine dosages of 50, 100, and 200 mg/week were safe, well tolerated, and effective against P. falciparum infection in this study population.