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Neafsey DE, Juraska M, Bedford T, Benkeser D, Valim C, Griggs A, Lievens M, Abdulla S, Adjei S, Agbenyega T, Agnandji ST, Aide P, Anderson S, Ansong D, Aponte JJ, Asante KP, Bejon P, Birkett AJ, Bruls M, Connolly KM, D'Alessandro U, Dobaño C, Gesase S, Greenwood B, Grimsby J, Tinto H, Hamel MJ, Hoffman I, Kamthunzi P, Kariuki S, Kremsner PG, Leach A, Lell B, Lennon NJ, Lusingu J, Marsh K, Martinson F, Molel JT, Moss EL, Njuguna P, Ockenhouse CF, Ogutu BR, Otieno W, Otieno L, Otieno K, Owusu-Agyei S, Park DJ, Pellé K, Robbins D, Russ C, Ryan EM, Sacarlal J, Sogoloff B, Sorgho H, Tanner M, Theander T, Valea I, Volkman SK, Yu Q, Lapierre D, Birren BW, Gilbert PB, Wirth DF. Genetic Diversity and Protective Efficacy of the RTS,S/AS01 Malaria Vaccine. N Engl J Med 2015; 373:2025-2037. [PMID: 26488565 PMCID: PMC4762279 DOI: 10.1056/nejmoa1505819] [Citation(s) in RCA: 264] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND The RTS,S/AS01 vaccine targets the circumsporozoite protein of Plasmodium falciparum and has partial protective efficacy against clinical and severe malaria disease in infants and children. We investigated whether the vaccine efficacy was specific to certain parasite genotypes at the circumsporozoite protein locus. METHODS We used polymerase chain reaction-based next-generation sequencing of DNA extracted from samples from 4985 participants to survey circumsporozoite protein polymorphisms. We evaluated the effect that polymorphic positions and haplotypic regions within the circumsporozoite protein had on vaccine efficacy against first episodes of clinical malaria within 1 year after vaccination. RESULTS In the per-protocol group of 4577 RTS,S/AS01-vaccinated participants and 2335 control-vaccinated participants who were 5 to 17 months of age, the 1-year cumulative vaccine efficacy was 50.3% (95% confidence interval [CI], 34.6 to 62.3) against clinical malaria in which parasites matched the vaccine in the entire circumsporozoite protein C-terminal (139 infections), as compared with 33.4% (95% CI, 29.3 to 37.2) against mismatched malaria (1951 infections) (P=0.04 for differential vaccine efficacy). The vaccine efficacy based on the hazard ratio was 62.7% (95% CI, 51.6 to 71.3) against matched infections versus 54.2% (95% CI, 49.9 to 58.1) against mismatched infections (P=0.06). In the group of infants 6 to 12 weeks of age, there was no evidence of differential allele-specific vaccine efficacy. CONCLUSIONS These results suggest that among children 5 to 17 months of age, the RTS,S vaccine has greater activity against malaria parasites with the matched circumsporozoite protein allele than against mismatched malaria. The overall vaccine efficacy in this age category will depend on the proportion of matched alleles in the local parasite population; in this trial, less than 10% of parasites had matched alleles. (Funded by the National Institutes of Health and others.).
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González R, Munguambe K, Aponte JJ, Bavo C, Nhalungo D, Macete E, Alonso PL, Menéndez C, Naniche D. High HIV prevalence in a southern semi-rural area of Mozambique: a community-based survey. HIV Med 2012; 13:581-8. [DOI: 10.1111/j.1468-1293.2012.01018.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2012] [Indexed: 11/26/2022]
Affiliation(s)
| | - K Munguambe
- Manhiça Health Research Center (CISM); Maputo; Mozambique
| | | | - C Bavo
- Manhiça Health Research Center (CISM); Maputo; Mozambique
| | - D Nhalungo
- Manhiça Health Research Center (CISM); Maputo; Mozambique
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Perez-Hoyos S, Naniche D, Macete E, Aponte JJ, Sacarlal J, Sigauque B, Bardaji A, Moraleda C, de Deus N, Alonso PL, Menéndez C. Stabilization of HIV incidence in women of reproductive age in southern Mozambique. HIV Med 2011; 12:500-5. [DOI: 10.1111/j.1468-1293.2010.00908.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Macete E, Aponte JJ, Guinovart C, Sacarlal J, Ofori-Anyinam O, Mandomando I, Espasa M, Bevilacqua C, Leach A, Dubois MC, Heppner DG, Tello L, Milman J, Cohen J, Dubovsky F, Tornieporth N, Thompson R, Alonso PL. Safety and immunogenicity of the RTS,S/AS02A candidate malaria vaccine in children aged 1-4 in Mozambique. Trop Med Int Health 2007; 12:37-46. [PMID: 17207146 DOI: 10.1111/j.1365-3156.2006.01754.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The development of a malaria vaccine remains a public health priority for sub-Saharan Africa. RTS,S/AS02A candidate malaria vaccine has been shown to be safe and immunogenic in previous studies in adults and staggered dose-escalation studies in children in The Gambia. However, genetic features and the intensity of malaria transmission may modify the safety and immune response of a vaccine. OBJECTIVE We carried out a phase I, double-blind randomized controlled trial in 60 children aged 1-4 in Mozambique to evaluate the safety, reactogenicity and immunogenicity of the paediatric vaccine dose (fixed 25 microg RTS,S in 0.25 ml) of RTS,S/AS02A, prior to undertaking a planned larger phase IIb proof-of-concept of efficacy study in the same population. METHOD Children were randomized to receive either RTS,S/AS02A or Engerix-B vaccine. Monitoring of safety and reactogenicity included detailed clinical and laboratory analyses and assessment of adverse events (AEs). RESULTS The RTS,S/AS02A was found to be safe and well tolerated. Serious adverse events were balanced between both groups and none was related to vaccination. The frequency of adverse events reported with RTS, S/AS02A was comparable to previous studies in children. Grade 3 AEs were infrequent (one case of pain, one of fever in each group and some swelling greater than 20 mm in diameter), transient and resolved without sequelae. RTS,S/AS02A was highly immunogenic for anti-circumsporozoite protein antibody response and induced a strong anti-hepatitis-B surface antigen response.
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Affiliation(s)
- E Macete
- Centro de Investigação em Saúde da Manhiça (CISM), Manhiça, Mozambique
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Roca A, Quintó L, Saúte F, Thompson R, Aponte JJ, Alonso PL. Community incidences of respiratory infections in an actively followed cohort of children <1 year of age in Manhiça, a rural area of southern Mozambique. Trop Med Int Health 2006; 11:373-80. [PMID: 16553918 DOI: 10.1111/j.1365-3156.2006.01566.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To estimate the community incidence-rates of respiratory infections among infants in Manhiça, southern Mozambique, and to determine risk factors associated with these infections. METHODS A cohort of children <1 year of age were visited at home every week until they turned one. During the visits, field workers recorded signs/symptoms of respiratory infections and tested the children for malaria parasites when they had fever. RESULTS Between 1 July 1998 and 30 June 1999, 1,044 children contributed with 23,726 weeks at risk. Children met the criteria for acute respiratory infection in 19.2% of the visits, for lower respiratory infection in 0.9% and for severe lower respiratory infection in 0.2%. The crude incidence rate measured for acute respiratory infections was 23.0, that for lower respiratory infection was 0.9 and that for severe lower respiratory infection was 0.2 per 100-person-week-at-risk. The risk of acute and lower respiratory infection was inversely related to age. Females were at significantly lower risk for all three conditions than males. A trend of increased risk of severe lower respiratory infection was noted among children born during the rainy season (adjusted rate ratio = 1.95, P = 0.122 in only 47 episodes). Malaria was strongly associated with an increased risk of all three respiratory infections [rate ratio of 2.35, 10.90 and 13.82 (P < 0.001) in the adjusted analysis, respectively]. Thirty-five children died during the follow-up period; 20% of them from lower respiratory infection. Conclusions Respiratory infections are a major cause of morbidity and mortality among infants in rural Mozambique. Our study provides a better understanding of the associated determinants.
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Affiliation(s)
- A Roca
- Centre de Salut Internacional-Hospital Clínic/IDIBAPS, Barcelona, Spain.
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Schellenberg DM, Aponte JJ, Kahigwa EA, Mshinda H, Tanner M, Menendez C, Alonso PL. The incidence of clinical malaria detected by active case detection in children in Ifakara, southern Tanzania. Trans R Soc Trop Med Hyg 2006; 97:647-54. [PMID: 16117956 DOI: 10.1016/s0035-9203(03)80096-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2002] [Revised: 05/30/2003] [Accepted: 06/05/2003] [Indexed: 11/30/2022] Open
Abstract
Between July 2000 and June 2001, we used weekly active case detection (ACD) of clinical malaria episodes in 618 children aged < 5 years to describe the epidemiology of malaria in Ifakara, southern Tanzania. Plasmodium falciparum-positive blood slides prepared from children with axillary temperature 37.5 degrees C were used to define clinical malaria and a rolling cross-sectional survey documented the prevalences of parasitaemia and anaemia. A random subsample of children was visited daily for 1 month at the end of the study to assess the effect of more frequent visits on estimated incidence rates. Only 50 (8%) children had 1 or more episodes of clinical malaria during the year, an overall incidence of 0.275 episodes/100 child-weeks-at-risk, with no age dependence. The maximum parasite prevalence of 25% was reached in children aged 4 years. The incidence of illness was significantly lower in children visited daily than in those visited weekly, suggesting a marked effect of frequent visits on estimated incidence rates. We conclude that the age pattern of malaria detected through ACD is a more robust epidemiological indicator than absolute incidence rate estimates and that, in contrast to the surrounding area, Ifakara town is subject to only moderate perennial malaria transmission.
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Affiliation(s)
- D M Schellenberg
- Centro de Salud International, Institut d'Investigacions Biomedicas August Pi i Sunyer (IDIBAPS), Hospital Clinic, Villarroel 170, 08036 Barcelona, Spain.
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Aranda C, Aponte JJ, Saute F, Casimiro S, Pinto J, Sousa C, Rosario VD, Petrarca V, Dgedge M, Alonso P. Entomological characteristics of malaria transmission in Manhiça, a rural area in southern Mozambique. J Med Entomol 2005; 42:180-186. [PMID: 15799528 DOI: 10.1093/jmedent/42.2.180] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
From October 1997 to September 1998, an entomological survey was carried out in Manhiça, Mozambique, to describe the anopheline population and intensity of malaria transmission. Ten different huts were randomly selected for entomological surveillance throughout the year. CDC light trap collections were conducted during three nights each month. Additional knockdown spraying catches were carried out in the morning, after the last catch. A total of 17,245 Culicinae and 1,251 Anophelinae were collected during the study. There was substantial house to house variation and seasonality in the distribution of Anophelinae population, with a peak in April towards the end of the warm and rainy season. Four species of genus Anopheles (Diptera: Culicidae) were described: Anopheles funestus Giles, Anopheles tenebrosus Dönitz, Anopheles arabiensis Patton, and Anopheles merus Dönitz. An. funestus constitutes 72.3% of the anopheline population. The estimated sporozoite rate was 1.2% and the average entomological inoculation rate for the area was 15 infective bites per person per year.
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Affiliation(s)
- C Aranda
- Centro de Investigação em Saúde da Manhiça, Instituto Nacional de Saúde, Ministerio de Saúde, Manhiça, Mozambique
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Abacassamo F, Enosse S, Aponte JJ, Gómez-Olivé FX, Quintó L, Mabunda S, Barreto A, Magnussen P, Rønn AM, Thompson R, Alonso PL. Efficacy of chloroquine, amodiaquine, sulphadoxine-pyrimethamine and combination therapy with artesunate in Mozambican children with non-complicated malaria. Trop Med Int Health 2004; 9:200-8. [PMID: 15040556 DOI: 10.1046/j.1365-3156.2003.01182.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This paper reports a two-phase study in Manhiça district, Mozambique: first we assessed the clinical efficacy and parasitological response of Plasmodium falciparum to chloroquine (CQ), sulphadoxine-pyrimethamine (SP) and amodiaquine (AQ), then we tested the safety and efficacy in the treatment of uncomplicated malaria, of three combinations: AQ + SP, artesunate (AR) + SP and AQ + AR. Based on the WHO (1996, WHO/MAL/96.1077) in vivo protocol, we conducted two open, randomized, clinical trials. Children aged 6-59 months with axillary body temperature > or = 37.5 degrees C and non-complicated malaria were randomly allocated to treatment groups and followed up for 21 days (first and second trial) and 28 days (first trial). The therapeutic efficacy of AQ (91.6%) was better than that of SP (82.7%) and CQ (47.1%). After 14 days, 69% of the strains were parasitologically resistant to CQ, 21.4% to SP and 26% to AQ. Co-administration of AQ + SP, AR + SP and AQ + AR was safe and had 100% clinical efficacy at 14-day follow-up. The combination therapies affected rapid fever clearance time and reduced the incidence of gametocytaemia during follow-up.
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Affiliation(s)
- F Abacassamo
- Centro de Investigação em Saúde da Manhiça, Manhiça, Mozambique.
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Kahigwa E, Schellenberg D, Schellenberg JA, Aponte JJ, Alonso PL, Menendez C. Inter-observer variation in the assessment of clinical signs in sick Tanzanian children. Trans R Soc Trop Med Hyg 2002; 96:162-6. [PMID: 12055806 DOI: 10.1016/s0035-9203(02)90290-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
We assessed the inter-observer agreement in identification of a range of 24 clinical signs associated with disease presentation in 327 children aged < 5 years admitted to hospital in January-June 1999 in Ifakara, southern Tanzania. Children with diagnoses of malaria, pneumonia, diarrhoea, anaemia and malnutrition were examined independently by 2 clinical officers. Findings were recorded on a standard proforma. The Kappa-statistic was used to assess inter-observer agreement for each sign. Physical signs were more likely to be agreed upon by clinicians if they involved inspection than if they involved auscultation. The signs included in the Integrated Management of Childhood Illness (IMCI) algorithm were found to be largely appropriate (Kappa-scores > 0.41) although there was only fair agreement (Kappa-score 0.21-0.40) in the detection of neck stiffness and chest indrawing and slight agreement in the detection of dehydration (Kappa-score 0.199). All objective neurological signs were less reliably assessed in infants than in older children. The difficulties surrounding the diagnosis of impaired consciousness in young children should increase vigilance in the diagnosis and management of neurological complications of illnesses in infancy.
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Affiliation(s)
- E Kahigwa
- Ifakara Health Research and Development Centre, P.O. Box 53, Ifakara, Tanzania
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Llovet JM, Mas X, Aponte JJ, Fuster J, Navasa M, Christensen E, Rodés J, Bruix J. Cost effectiveness of adjuvant therapy for hepatocellular carcinoma during the waiting list for liver transplantation. Gut 2002; 50:123-8. [PMID: 11772979 PMCID: PMC1773063 DOI: 10.1136/gut.50.1.123] [Citation(s) in RCA: 224] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Survival after liver transplantation for early hepatocellular carcinoma (HCC) is worsened by the increasing dropout rate while waiting for a donor. AIMS To assess the cost effectiveness of adjuvant therapy while waiting for liver transplantation in HCC patients. METHOD Using a Markov model, a hypothetical cohort of cirrhotic patients with early HCC was considered for: (1) adjuvant treatment-resection was limited to Child-Pugh's A patients with single tumours, and percutaneous treatment was considered for Child-Pugh's A and B patients with single tumours unsuitable for resection or with up to three nodules < 3 cm; and (2) standard management. Length of waiting time ranged from six to 24 months. RESULTS Surgical resection increased the transplantation rate (>10%) and provided gains in life expectancy of 4.8-6.1 months with an acceptable cost ($40,000/ year of life gained) for waiting lists > or = 1 year whereas it was not cost effective ($74,000/life of year gained) for shorter waiting times or high dropout rate scenarios. Percutaneous treatment increased life expectancy by 5.2-6.7 months with a marginal cost of approximately $20,000/year of life gained in all cases, remaining cost effective for all waiting times. CONCLUSIONS Adjuvant therapies for HCC while waiting for liver transplantation provide moderate gains in life expectancy and are cost effective for waiting lists of one year or more. For shorter waiting times, only percutaneous treatment confers a relevant survival advantage.
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Affiliation(s)
- J M Llovet
- Barcelona-Clínic Liver Cancer Group, Liver Unit, Institut d'Investigacions Biomédiques August Pi I Sunyer (IDIBAPS), Hospital Clínic, University of Barcelona, Catalonia, Spain.
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Bauer TM, Steinbrückner B, Brinkmann FE, Ditzen AK, Schwacha H, Aponte JJ, Pelz K, Kist M, Blum HE. Small intestinal bacterial overgrowth in patients with cirrhosis: prevalence and relation with spontaneous bacterial peritonitis. Am J Gastroenterol 2001; 96:2962-7. [PMID: 11693333 DOI: 10.1111/j.1572-0241.2001.04668.x] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The significance of small intestinal bacterial overgrowth in patients with cirrhosis is not fully understood and its diagnostic criteria are not uniform. We examined the association of small intestinal bacterial overgrowth with spontaneous bacterial peritonitis and compared various microbiological criteria. METHODS Jejunal secretions from 70 patients with cirrhosis were cultivated quantitatively and classified according to various definitions. Clinical characteristics of patients were evaluated and the incidence of spontaneous bacterial peritonitis was monitored during a 1-yr follow-up. RESULTS Small intestinal bacterial overgrowth, defined as > or = 10(5) total colony-forming units/ml jejunal secretions, was present in 61% of patients. Small intestinal bacterial overgrowth was associated with acid-suppressive therapy (p = 0.01) and hypochlorhydria (p < 0.001). Twenty-nine patients with persistent ascites were observed. Six episodes of spontaneous bacterial peritonitis occurred after an average 12.8 wk. Occurence of spontaneous bacterial peritonitis correlated with ascitic fluid protein concentration (p = 0.01) and serum bilirubin (p = 0.04) but not with small intestinal bacterial overgrowth (p = 0.39). Its association with acid-suppressive therapy was of borderline significance (hazard ratio = 7.0, p = 0.08). CONCLUSIONS Small intestinal bacterial overgrowth in cirrhotic patients is associated with acid-suppressive therapy and hypochlorhydria, but not with spontaneous bacterial peritonitis. The potential role of acid-suppressive therapy in the pathogenesis of spontaneous bacterial peritonitis merits further studies.
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Affiliation(s)
- T M Bauer
- Department of Medicine II and Institute of Medical Microbiology and Hygiene, University Hospital, Freiburg, Germany
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Menendez C, Quinto LL, Kahigwa E, Alvarez L, Fernandez R, Gimenez N, Schellenberg D, Aponte JJ, Tanner M, Alonso PL. Effect of malaria on soluble transferrin receptor levels in Tanzanian infants. Am J Trop Med Hyg 2001; 65:138-42. [PMID: 11508389 DOI: 10.4269/ajtmh.2001.65.138] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The diagnosis of iron deficiency anemia in malaria endemic areas is complicated by the influence of the infection on the laboratory tests conventionally used to assess iron status. Determination of soluble transferrin receptor (sTfR) levels has been shown to be a sensitive indicator of iron deficiency in adults and is not affected by a range of infectious and inflammatory conditions. The utility of sTfR levels in the diagnosis of iron deficiency in malaria endemic areas remains unresolved. Three hundred and fourteen infants in a rural area of southern Tanzania living under conditions of intense and perennial malaria transmission were studied to determine the utility of sTfR plasma levels in the assessment of iron deficiency anemia. Independent of the presence of anemia, malaria parasitemia was associated with a significant increase in sTfR plasma levels that were even higher than those found in iron deficiency anemia. We conclude that the measurement of sTfR levels does not have a role in the diagnosis of iron deficiency anemia in young children exposed to malaria infection.
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Affiliation(s)
- C Menendez
- Departamento de Bioquimica Clínica, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic, Barcelona, Spain
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Mayor AG, Gómez-Olivé X, Aponte JJ, Casimiro S, Mabunda S, Dgedge M, Barreto A, Alonso PL. Prevalence of the K76T mutation in the putative Plasmodium falciparum chloroquine resistance transporter (pfcrt) gene and its relation to chloroquine resistance in Mozambique. J Infect Dis 2001; 183:1413-6. [PMID: 11294676 DOI: 10.1086/319856] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2000] [Revised: 02/05/2001] [Indexed: 11/03/2022] Open
Abstract
K76T, a mutation in the Plasmodium falciparum chloroquine (CQ) resistance transporter protein, has been implicated in resistance to CQ. A modified 14-day in vivo test to estimate the CQ resistance level was done in southern Mozambique: 21 (42%) of 50 subjects who completed the follow-up were CQ susceptible. Use of msa2-restriction fragment length polymorphism (RFLP) genotyping to differentiate new from recrudescent infections made little difference in the estimated prevalence of resistance. The K76T mutation prevalence was estimated by RFLP-polymerase chain reaction and sequencing, and its relation to parasitological CQ resistance was explored on day 0 samples: 51 of 56 pretreatment samples presented the T76 codon, and it was present in 100% of children with parasitological resistance. T76 also was present in 18 of 23 subjects in whom the infection resolved after CQ treatment. These findings show a high prevalence of the K76T mutation among wild isolates but also suggest additional factors responsible for CQ resistance.
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Affiliation(s)
- A G Mayor
- Centro de Investigaçao em Saúde da Manhiça, Dirección Nacional de Saúde, Ministerio de Saúde, Maputo, Mozambique.
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Sunyer J, Mendendez C, Ventura PJ, Aponte JJ, Schellenberg D, Kahigwa E, Acosta C, Antó JM, Alonso PL. Prenatal risk factors of wheezing at the age of four years in Tanzania. Thorax 2001; 56:290-5. [PMID: 11254820 PMCID: PMC1746018 DOI: 10.1136/thorax.56.4.290] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND A study was undertaken to assess the interactions between prenatal exposures, early life infections, atopic predisposition, and allergen exposures in the development of wheezing up to the age of 4 years in a tropical region of Africa. METHODS The study subjects comprised children born at the district hospital in Ifakara, Tanzania during a 1 year period who were participating in a trial of iron supplementation and malaria chemoprophylaxis during the first year of life and followed for up to 4 years. From this group of subjects, 658 (79%) participated in the interview at 18 months and 528 (64%) in a second interview at 4 years. Wheezing was measured with the ISAAC questionnaire. A hospital based inpatient and outpatient surveillance system was set up to document all attendance by study children for any cause, including episodes of clinical malaria and lower respiratory tract infections. Total IgE levels and malaria parasites were measured in maternal and cord blood. Total IgE was also measured at 18 months of age. Indoor environmental levels of Der p I and Fel d I were determined using an enzyme linked immunosorbent assay at the same time as the interview at the age of 18 months. RESULTS The prevalence of wheezing at 4 years is common in Ifakara (14%, range 13-15%). The presence of malaria parasites in cord blood (odds ratio, OR = 6.84, 95% CI 1.84 to 24.0) and maternal asthma (OR = 8.47, 95% CI 2.72 to 26.2) were positively associated with wheezing at the age of 4 years, and cord blood total IgE was negatively associated (OR = 0.24, 95% CI 0.07 to 0.85) (all p<0.05). Parasitaemia at birth was not related to total IgE levels in cord blood (p=0.6). Clinical episodes of malaria during infancy were not associated with wheezing, and nor were levels of indoor aeroallergens. CONCLUSION These findings suggest that events occurring during pregnancy may play a role in the future appearance of wheezing, although the results must be interpreted with caution because of the small numbers studied.
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Affiliation(s)
- J Sunyer
- Unitat de Recerca Respiratòria I Ambiental, Institut Municipal d'Investigació Mèdica (IMIM), Doctor Aiguader 80, E-08003 Barcelona, Spain.
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Bauer TM, Lalvani A, Fehrenbach J, Steffen I, Aponte JJ, Segovia R, Vila J, Philippczik G, Steinbrückner B, Frei R, Bowler I, Kist M. Derivation and validation of guidelines for stool cultures for enteropathogenic bacteria other than Clostridium difficile in hospitalized adults. JAMA 2001; 285:313-9. [PMID: 11176841 DOI: 10.1001/jama.285.3.313] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT The yield of in-hospital stool cultures performed more than 72 hours after admission is low, and a commonly used policy dictates that laboratories reject these cultures to save costs. However, enteropathogenic bacteria other than Clostridium difficile (EPB) may cause nosocomial illness that would be missed by use of such a "3-day rule." OBJECTIVE To develop guidelines for hospital use of stool cultures that are sensitive to clinically relevant cases of sporadic and epidemic nosocomial diarrhea. DESIGN Five-part study that incorporated a derivation sample based on retrospective chart review and a prospective cohort study (including cost savings analysis), and a validation sample based on retrospective chart review. SETTING Four European academic health care centers. PATIENTS Derivation sample: 1735 adult inpatients from whom 3416 stool cultures were obtained during a 19-month period (1995-1997) and 68 adult inpatients for whom EPB were grown from stool cultures during a 10-year period (1988-1998); validation sample: 65 patients with sporadic isolation of EPB (1993-1998), 56 patients involved in 2 nosocomial Salmonella outbreaks (1992 and 1997), and 330 patients who had stool cultures performed (1998). MAIN OUTCOME MEASURE Performance of derived criteria in detecting pathogenic bacteria and outbreaks and reducing total number of stool cultures performed. RESULTS Stool cultures grew EPB in 3.3% of samples obtained </=72 hours after admission and 0.5% of samples obtained thereafter (P<.001). Isolation of EPB >72 hours after admission was not associated with clinical symptoms or signs but was associated with community-acquired diarrhea (24%), age 65 years or older with preexisting comorbid disease (25%), neutropenia (13%), HIV infection (10%), and nondiarrheal manifestations of enteric infections (16%). Twelve percent were asymptomatic carriers. These characteristics were used to create criteria for selecting patients for whom stool cultures would be indicated. These criteria were applied post hoc to a series of 1025 stool cultures; the number of stool cultures would have been reduced by 52% and no clinically significant cases would have been missed. Annual savings to a 355-bed institution would be approximately $7800 for reagent costs and 75 hours of technician time. In the validation samples, only 2 patients of 65 who had EPB would not have been identified, and neither required treatment. If the 3-day rule had been applied, 52 cases would not have been identified, 28 of which required antibiotic treatment. CONCLUSION Our modified 3-day rule for use in selecting cases for stool culture is sensitive to sporadic and epidemic cases of nosocomial diarrhea in hospitalized adults.
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Affiliation(s)
- T M Bauer
- Department of Internal Medicine II, University Hospital Freiburg, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
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16
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Gascón J, Vargas M, Schellenberg D, Urassa H, Casals C, Kahigwa E, Aponte JJ, Mshinda H, Vila J. Diarrhea in children under 5 years of age from Ifakara, Tanzania: a case-control study. J Clin Microbiol 2000; 38:4459-62. [PMID: 11101580 PMCID: PMC87621 DOI: 10.1128/jcm.38.12.4459-4462.2000] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A matched case-control study was conducted in the Maternal and Child Health Clinic (MCH) in Ifakara, Tanzania, during the rainy season in order to elucidate the risk factors for and etiology of diarrheal diseases in children under 5 years of age. Cases (103) and controls (206) were matched for sex and age group. Precoded questionnaires with demographic details, clinical history, and physical signs were completed. Stools samples were collected for bacterial, parasitological, and viral studies. A high number of siblings (odds ratio [OR], 0.86; P = 0.027), the number of siblings surviving (OR, 0.82; P = 0.007), the birth order (OR, 0.85; P = 0.018) and the distance from the house to the water source (OR, 0.33; P = 0.011) were associated with the risk of diarrhea. There were high rates of enteropathogen isolates in stool samples from children without diarrhea (52.23%). Shigella species were the only enteropathogen statistically related with diarrhea (OR, 2.90; P < 0.029). Enterotoxigenic, enteropathogenic, and enteroaggregative strains of Escherichia coli were not related with diarrhea, and neither were Giardia lamblia or Salmonella species.
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Affiliation(s)
- J Gascón
- Tropical Section, Hospital Clínic Barcelona, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain.
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17
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Galindo CM, Acosta CJ, Schellenberg D, Aponte JJ, Roca A, Oettli A, Urassa H, Armstrong Schellenberg J, Kahigwa E, Ascaso C, Mshinda H, Lwilla F, Vidal J, Menendez C, Tanner M, Alonso PL. Humoral immune responses during a malaria vaccine trial in Tanzanian infants. Parasite Immunol 2000; 22:437-43. [PMID: 10972850 DOI: 10.1046/j.1365-3024.2000.00322.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The development of a malaria vaccine is a priority for improved and sustained malaria control. Optimal use of a vaccine in Africa will only be achieved if it can be delivered through the Expanded Programme of Immunization (EPI). We have completed a trial of the peptide vaccine SPf66 in Tanzanian infants, given alongside the EPI vaccines. This paper describes the humoral responses to SPf66 and the EPI vaccines. A total of 1207 infants were recruited into a two-arm, double-blind, individually randomized placebo-controlled trial of SPf66. The objectives of the trial were to determine the safety, immunogenicity and efficacy of SPf66 and to assess interactions with EPI vaccines when three doses of SPf66 were delivered alongside the EPI vaccines. Cross-sectional surveys were carried out to asses seroconversion rates to the EPI vaccines and the antibody response to SPf66 (NANP)50 and Plasmodium falciparum lysates. Seroconversion rates to EPI vaccines were high and no statistically significant differences in prevalence or titres were found between SPf66 and placebo recipients. IgG antibodies against SPf66 (NANP)50 and whole P. falciparum lysate were present in high titres in mothers of recruited children at the time of birth. Vaccination with SPf66 stimulated a good anti-SPf66 IgG response which declined to preimmunization levels by 2 years of age and which was not associated with protection against clinical malaria. The vaccine induced no IgG antibodies against (NANP)50 or P. falciparum lysates. SPf66 stimulated a humoral immune response when given to very young infants and did not interfere with seroconversion to EPI vaccines. The response to SPf66 was qualitatively different from that seen in older children, in whom SPf66 has been shown to be moderately efficacious. This difference raises concerns about the difficulties of immunizing very young infants who need to be targeted by antimalarial vaccination programs.
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Affiliation(s)
- C M Galindo
- Unidad de Epidemiología y Bioestadística and Department of Microbiology, Hospital Clinic/IDIBAPS, Universidad de Barcelona, Barcelona, Spain
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18
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Menendez C, Ordi J, Ismail MR, Ventura PJ, Aponte JJ, Kahigwa E, Font F, Alonso PL. The impact of placental malaria on gestational age and birth weight. J Infect Dis 2000; 181:1740-5. [PMID: 10823776 DOI: 10.1086/315449] [Citation(s) in RCA: 301] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/1999] [Revised: 01/21/2000] [Indexed: 11/03/2022] Open
Abstract
Maternal malaria is associated with reduced birth weight, which is thought to be effected through placental insufficiency, which leads to intrauterine growth retardation (IUGR). The impact of malaria on preterm delivery is unclear. The effects of placental malaria-related changes on birth weight and gestational age were studied in 1177 mothers (and their newborns) from Tanzania. Evidence of malaria infection was found in 75.5% of placental samples. Only massive mononuclear intervillous inflammatory infiltration (MMI) was associated with increased risk of low birth weight (odds ratio ¿OR, 4.0). Maternal parasitized red blood cells and perivillous fibrin deposition both were associated independently with increased risk of premature delivery (OR, 3.2; OR, 2.1, respectively). MMI is an important mechanism in the pathogenesis of IUGR in malaria-infected placentas. This study also shows that placental malaria causes prematurity even in high-transmission areas. The impact of maternal malaria on infant mortality may be greater than was thought previously.
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Affiliation(s)
- C Menendez
- Unidad de Epidemiologia y Bioestadistica, Hospital Clinic, E-08036, Barcelona, Spain.
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19
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Ismail MR, Ordi J, Menendez C, Ventura PJ, Aponte JJ, Kahigwa E, Hirt R, Cardesa A, Alonso PL. Placental pathology in malaria: a histological, immunohistochemical, and quantitative study. Hum Pathol 2000; 31:85-93. [PMID: 10665918 DOI: 10.1016/s0046-8177(00)80203-8] [Citation(s) in RCA: 197] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
To characterize the histological changes in malarial placentas and their relationship with parity and maternal and cord parasitemias, we conducted a histological study on 1,179 placentas from Ifakara, Tanzania, an area with intense and perennial malaria transmission. Immunohistochemical and quantitative studies for CD45, fibrin, and villous area were performed in 60 cases. Four hundred fifteen placentas (35.2%) showed parasites (active infections); in 303 of them, parasites co-existed with pigment covered by fibrin (chronic infections), and in 112 only parasites were detected (acute infections). Four hundred seventy-five cases (40.3%) showed hemozoin deposition without parasites (past infections). Of women with parasitized placentas, 46.3% did not show parasites in the peripheral blood. Basal membrane thickening (P = .002), fibrinoid necrosis (P = .004), and prominence of syncytial knots (P = .031) were associated with active malarial infection. No quantitative differences for perivillous fibrin deposition or villous area were found. The most significant association with active malarial infection was intervillous infiltration by mononuclear inflammatory cells (P < .001). Chronic infections were associated with the most severe changes, particularly intervillous mononuclear inflammation (OR, 28.7; 95% CI = 16.0 to 51.5, P< .001). Past infections showed only minimal differences with noninfected placentas. Primiparas showed chronic infections more frequently than multiparas (52% v 15%, P < .001). They also showed significantly higher placental parasitemias and intervillous inflammatory infiltrate. In conclusion, placental histology is more sensitive than peripheral blood examination in detecting malarial infection during pregnancy. Most malarial infections recover during pregnancy, leaving few residual changes in the placenta. Intervillous inflammation is the most frequent finding associated with malaria and is especially severe in primiparas, suggesting that mechanisms other than immunosuppression are responsible for the high susceptibility in this group.
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Affiliation(s)
- M R Ismail
- Instituto Nacional de Salud, Universidade Eduardo Mondlane, Maputo, Moçambique
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20
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Schellenberg D, Menendez C, Kahigwa E, Font F, Galindo C, Acosta C, Schellenberg JA, Aponte JJ, Kimario J, Urassa H, Mshinda H, Tanner M, Alonso P. African children with malaria in an area of intense Plasmodium falciparum transmission: features on admission to the hospital and risk factors for death. Am J Trop Med Hyg 1999; 61:431-8. [PMID: 10497986 DOI: 10.4269/ajtmh.1999.61.431] [Citation(s) in RCA: 139] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Malaria remains the most important parasitic cause of mortality in humans. Its presentation is thought to vary according to the intensity of Plasmodium falciparum transmission. However, detailed descriptions of presenting features and risk factors for death are only available from moderate transmission settings. Such descriptions help to improve case management and identify priority research areas. Standardized systematic procedures were used to collect clinical and laboratory data on 6,624 children admitted to hospital over a 1-year period in an intensely malarious part of Tanzania. Frequencies of signs and symptoms were calculated and their association with a fatal outcome was assessed using multivariate logistic regression. There were 72 deaths among 2,432 malaria cases (case fatality rate [CFR] = 3.0%); 44% of the cases and 54% of the deaths were in individuals less than 1 year of age. There was no association between level of parasitemia and CFR. Increased risk of dying was independently found in all children with hypoglycemia (odds ratio [OR] = 6.7, 95% confidence interval [CI] = 3.9-11.7), in children 1-7 months of age with tachypnea (OR = 8.8, 95% CI = 2.6-30.5) and dehydration (OR = 5.0, 95% CI = 1.9-14.2), and in children 8 months to 4 years of age with chest indrawing (OR = 4.7, 95% CI = 2.0-11.2) and inability to localize a painful stimulus (OR = 6.9, 95% CI = 2.9-16.5). Children in the bottom quartile of weight-for-age were more likely to die (OR = 2.1, 95% CI = 1.3-3.5). Eight percent of the malaria cases had severe anemia (packed cell volume < 15%) but 24% received a blood transfusion. The epidemiology of malaria disease may be more complex than previously thought. Improved case management in a wide variety of health facilities may result from adequate identification and treatment of dehydration and hypoglycemia. Transfusion-requiring anemia is a major problem and sustainable, effective preventive measures are urgently needed.
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Affiliation(s)
- D Schellenberg
- Unidad de Epidemiologia y Bioestadistica, Hospital Clinic/Institut d'Investigaciones Biomèdiques August Pi I Sunyer, Villarroel, Barcelona, Spain
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21
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Menéndez C, Sánchez-Tapias JM, Alonso PL, Giménez-Barcons M, Kahigwa E, Aponte JJ, Mshinda H, Navia MM, Jiménez de Anta MT, Rodés J, Saiz JC. Molecular evidence of mother-to-infant transmission of hepatitis G virus among women without known risk factors for parenteral infections. J Clin Microbiol 1999; 37:2333-6. [PMID: 10364608 PMCID: PMC85152 DOI: 10.1128/jcm.37.7.2333-2336.1999] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/1998] [Accepted: 03/15/1999] [Indexed: 11/20/2022] Open
Abstract
Hepatitis G virus (HGV) RNA was detected in 18 of 133 pregnant women from Tanzania without known risk factors for HGV infection and in 7 of 18 children born to HGV RNA-positive mothers. Molecular evidence of mother-to-infant transmission was obtained only for three of seven children. HGV RNA was also detected in 4 of 42 children born to non-HGV-infected women. Thus, mechanisms other than materno-filial may play an important role in HGV transmission during early childhood.
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Affiliation(s)
- C Menéndez
- Liver Unit, Department of Medicine, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clinic, Barcelona, Spain
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22
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Acosta CJ, Galindo CM, Schellenberg D, Aponte JJ, Kahigwa E, Urassa H, Schellenberg JR, Masanja H, Hayes R, Kitua AY, Lwilla F, Mshinda H, Menendez C, Tanner M, Alonso PL. Evaluation of the SPf66 vaccine for malaria control when delivered through the EPI scheme in Tanzania. Trop Med Int Health 1999; 4:368-76. [PMID: 10402973 DOI: 10.1046/j.1365-3156.1999.00406.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Malaria control programmes need to protect young children, who bear the brunt of malaria disease and death in Africa. The development of a vaccine is a priority if improved and sustained malaria control is to be achieved. The best use of a vaccine in Africa will be achieved if it can be delivered through the expanded programme of immunization (EPI). We conducted a trial designed to evaluate the efficacy of SPf66 vaccine for malaria control when delivered through the EPI scheme in Tanzania. METHODS The study was a two-arm, double blind, individually randomized placebo controlled trial involving 1207 infants. The primary objective of the trial was to estimate the efficacy of three doses of SPf66 given at 1, 2 and 7 months of age in preventing clinical episodes of malaria. These were documented through a health facility-based passive case detection system. RESULTS Among 1207 randomized children, overall compliance for third dose was 91%. SPf66 was safe, immunogenic and did not interfere with the humoral immune responses to EPI vaccines. There were 294 children among SPf66 recipients and 288 among placebo recipients with at least one malaria episode, yielding a vaccine efficacy estimate of 2% (95% CI: -16, 16; P = 0.84). CONCLUSION This has been the first trial of a malaria vaccine among very young infants. It provides information on the safety of peptide vaccines administered at this early age as well as their capacity to induce immune responses without negatively interacting with EPI vaccines. Given the modest protection previously documented in older age groups and the lack of efficacy in younger infants, this vaccine in its current alum-based formulation does not appear to have a role in malaria control in sub-Saharan Africa. The lack of efficacy found in this trial also raises concerns about potential difficulties of inducing protective immune responses against malaria through immunization in infants.
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Affiliation(s)
- C J Acosta
- Unidad de Epidemiologia y Bioestadistica, Hospital Clinic/IDIBAPS, Barcelona, Spain
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23
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Schellenberg DM, Acosta CJ, Galindo CM, Kahigwa E, Urassa H, Masanja H, Aponte JJ, Schellenberg JR, Fraser-Hurt N, Lwilla F, Menendez C, Mshinda H, Tanner M, Alonso PL. Safety in infants of SPf66, a synthetic malaria vaccine, delivered alongside the EPI. Trop Med Int Health 1999; 4:377-82. [PMID: 10402974 DOI: 10.1046/j.1365-3156.1999.00424.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The most likely mechanism to deliver a malaria vaccine in African countries is through the Expanded Program of Immunization (EPI). So far only SPf66, a multistage synthetic peptide, has shown any evidence of protection in Phase III field trials. In Tanzania, SPf66 reduced the risk of clinical malaria by 31% in children aged 1-5 years. In order to progress in the critical path of vaccine development and testing towards the implementation of a new vaccine in malaria control programs, we carried out a randomized double-blind placebo controlled efficacy trial of SPf66 when given alongside the EPI scheme. Monitoring of safety and reactogenicity during this trial included detailed clinical and laboratory assessments on 98 infants and assessment of adverse effects within 1 h of vaccination for all 1207 children vaccinated. Surveillance systems monitored attendances as outpatients, admissions to hospital and fatal events in the community. No serious adverse effects were detected more frequently amongst SPf66 recipients compared to placebo. This first assessment in very young infants of a synthetic vaccine provides evidence of a good safety profile.
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Affiliation(s)
- D M Schellenberg
- Unidad de Epidemiologia y Bioestadistica, Hospital Clinic/IDIBAPS, Barcelona, Spain
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24
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Alonso PL, Lopez MC, Bordmann G, Smith TA, Aponte JJ, Weiss NA, Urassa H, Armstrong-Schellenberg JR, Kitua AY, Masanja H, Thomas MC, Oettli A, Hurt N, Hayes R, Kilama WL, Tanner M. Immune responses to Plasmodium falciparum antigens during a malaria vaccine trial in Tanzanian children. Parasite Immunol 1998; 20:63-71. [PMID: 9572049 DOI: 10.1046/j.1365-3024.1998.00125.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Among Tanzanian children living in an area of intense and perennial malaria transmission, prevalence of naturally acquired IgG antibodies that recognize SPf66, NANP, p190 and a 19 kDa fragment of the merozoite surface protein-1 (MSP-1) is high and increases with age. This possibly reflects the high level of natural exposure of the children to P. falciparum. The prevalences of IgG antibodies that recognize the three putative merozoite derived sequences contained in the malaria vaccine SPf66 (83.1, 55.1 and 35.1) is low but also show some age dependence. Three doses of the SPf66 vaccine induce a strong IgG antibody response against both the SPf66 construct, NANP and the three individual peptides. Vaccination with SPf66 did not result in an increase of anti19 kDa fragment antibodies. This reflects the specificity of the humoral immune response induced by the SPf66 construct. Among vaccinated children, antibody titres against SPf66 decreased over time following the third dose. However, 18 months after the third dose, SPf66 recipients still had significantly higher IgG titres and stimulation indices of peripheral blood mononuclear cells (PBMC) than placebo recipients. Within the vaccine group, there is a trend for increasing anti-SPf66 IgG titre to be associated with decreasing risk of clinical malaria but this was not statistically significant. Results also show the difficulties of establishing whether antibody responses are related to protection in field trials in endemic areas.
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Affiliation(s)
- P L Alonso
- Unidad de Epidemiologia y Bioestadistica, Hospital Clinic, Barcelona, Spain
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25
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Menendez C, Kahigwa E, Hirt R, Vounatsou P, Aponte JJ, Font F, Acosta CJ, Schellenberg DM, Galindo CM, Kimario J, Urassa H, Brabin B, Smith TA, Kitua AY, Tanner M, Alonso PL. Randomised placebo-controlled trial of iron supplementation and malaria chemoprophylaxis for prevention of severe anaemia and malaria in Tanzanian infants. Lancet 1997; 350:844-50. [PMID: 9310602 DOI: 10.1016/s0140-6736(97)04229-3] [Citation(s) in RCA: 242] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Malaria and anaemia, especially that due to iron deficiency, are two leading causes of morbidity worldwide. Little is known about the relative contribution of Plasmodium falciparum infection and iron deficiency to the aetiology of anaemia in malaria-endemic areas. We undertook a randomised comparison of different strategies for control of anaemia and malaria in infants, including an assessment of the effect of iron supplementation on malaria susceptibility. METHODS 832 infants born at one hospital in a malaria-hyperendemic area of Tanzania between January and October, 1995, were randomly assigned to group DI, receiving daily oral iron (2 mg/kg daily) plus weekly Deltaprim (3.125 mg pyrimethamine plus 25 mg dapsone); group IP, receiving iron plus weekly placebo; group DP, receiving daily placebo plus weekly Deltaprim; or group PP. supplementation was given from 8 to 24 weeks of age, and the weekly chemoprophylaxis from 8 to 48 weeks. The frequency of severe anaemia (packed-cell volume < 25%) and malaria episodes was assessed through a combination of passive case detection and cross-sectional surveys. FINDINGS The groups that received iron supplementation had a lower frequency of severe anaemia than those that did not receive iron (0.62 vs 0.87 cases per person-year; protective efficacy 28.8% [95% CI 6.3-45.8). Iron supplementation had no effect on the frequency of malaria (0.87 vs 1.00 cases per person-year; protective efficacy 12.8% [-12.8 to 32.5]). The groups that received malaria prophylaxis had lower frequencies of both severe anaemia (0.45 vs 1.04 episodes per person-year; protective efficacy 57.3% [43.0-67.9]) and malaria (0.53 vs 1.34 episodes per person-year; protective efficacy 60.5% [48.2-69.9]) than the groups that did not receive prophylaxis. After the end of the intervention period, children who had received malaria chemoprophylaxis had higher rates of severe anaemia and malaria than non-chemoprophylaxis groups (relative risks 2.2 [1.3-3.7] and 1.8 [1.3-2.6]). INTERPRETATION Malaria chemoprophylaxis during the first year of life was effective in prevention of malaria and anaemia but apparently impaired the development of natural immunity. Iron supplementation was effective in preventing severe anaemia without increasing susceptibility to malaria. Our findings support iron supplementation of infants to prevent iron-deficiency anaemia, even in malaria-endemic areas.
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Affiliation(s)
- C Menendez
- Unidad de Epidemiologia y Bioestadistica, Hospital Clinic, Barcelona, Spain.
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26
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Valero MV, Amador R, Aponte JJ, Narvaez A, Galindo C, Silva Y, Rosas J, Guzman F, Patarroyo ME. Evaluation of SPf66 malaria vaccine during a 22-month follow-up field trial in the Pacific coast of Colombia. Vaccine 1996; 14:1466-70. [PMID: 8994323 DOI: 10.1016/s0264-410x(96)00070-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A double-blind randomized placebo-controlled field trial with the SPf66 malaria vaccine was carried out in an endemic area consisting of 14 small villages with exclusive fluvial access, in a rain forest area along the Rosario River, Colombia. A total of 1257 subjects completed the full three dose vaccination schedule on days 0, 30 and 180 (643 vaccinated group/623 placebo group) and were followed-up by passive and active surveillance over a period of 22 months. One hundred and thirty-four Plasmodium falciparum malaria episodes were detected (53 in vaccinated group/81 in placebo group), yielding an attack rate of 5.47 cases/100 person years of follow-up (pyears) in the vaccine group and 8.44/100 pyears in the placebo group. The estimated vaccine protective efficacy was 35.2% (95% CI 8.4-54.2%, P = 0.01). This result supports earlier findings that the SPf66 malaria vaccine diminishes the risk of infection by P. falciparum in endemic areas of South America.
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Affiliation(s)
- M V Valero
- Instituto de Inmunologia, Hospital San Juan de Dios, Universidad Nacional de Colombia, Santafé de Bogotá, Colombia
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