Age dependent characteristics of protection v. susceptibility to Plasmodium falciparum

Jk, Baird

doi:10.1080/00034989859366

Cited by 192 publications

(162 citation statements)

References 98 publications

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“…21,22 Age-associated variations in the pharmacokinetics of CQ does not appear to affect treatment outcome because CQ is well absorbed both in children and adults. 23 This study underscores the vulnerability of children in the clinical and treatment response and the importance of including them in efficacy evaluations.…”

Section: Discussionmentioning

confidence: 99%

Assessment of therapeutic response of Plasmodium falciparum to chloroquine and sulfadoxine-pyrimethamine in an area of low malaria transmission in Colombia.

Osório¹,

Giraldo²,

Grajales³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

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Abstract. Although chloroquine (CQ) resistance was first reported in Colombia in 1961 and sulfadoxine-pyrimethamine (SP) resistance in 1981, the frequency of treatment failures to these drugs in Colombia is unclear. A modified World Health Organization 14-day in vivo drug efficacy test for uncomplicated Plasmodium falciparum malaria in areas with intense malaria transmission was adapted to reflect the clinical and epidemiologic features of a low-intensity malaria transmission area in the Pacific Coast Region of Colombia. Patients Ն1 year of age with a parasite density Ն1,000 asexual parasites per microliter were enrolled in this study. Forty-four percent (24 of 54) of the CQ-treated patients were therapeutic failures, including 7 early treatment failures (ETFs) and 17 late treatment failures (LTFs). Four (6%) of 67 SP-treated patients were therapeutic failures (2 ETFs and 2 LTFs). Therapeutic failure in the CQ-treated group was associated with an age Ͻ15 years old (P Ͻ 0.01), but was not associated with initial parasite density, the presence of CQ or sulfa-containing drugs in urine, or a history of malaria. The high level of therapeutic failures to CQ detected in this study underscores the need and importance of drug efficacy evaluation in the development of a rational national antimalarial drug policy. The relatively low level of therapeutic failures to SP compared with other South American countries raises further questions regarding factors that might have prevented the rapid development of in vivo resistance to this drug combination.Despite attempts at eradication, malaria remains a major public health problem in Colombia. During 1997, 180,910 malaria cases were reported to the Ministry of Health, of which 36% were caused by Plasmodium falciparum. The administrative departments of Chocó, Valle, Cauca, and Nariño on the Pacific coast accounted for 45% of the P. falciparum malaria cases diagnosed in 1997 in Colombia.Since 1961, when chloroquine (CQ) resistance was first reported in Colombia, 1 several studies have confirmed CQ and sulfadoxine-pyrimethamine (SP) resistance both in vivo and in vitro. [2][3][4] In 1986, the National Malaria Control Program recommended a combination of CQ plus SP with a single-dose of primaquine (as a gametocidal agent) for the treatment of uncomplicated P. falciparum infection in areas without CQ resistance, and amodiaquine plus SP and primaquine for areas with CQ resistance. Although the national treatment policy differentiates areas with and without resistance to CQ, few studies have attempted to elucidate the distribution and magnitude of CQ resistance in Colombia.The objective of our study was to determine the frequency of therapeutic failures to CQ and SP in patients with uncomplicated P. falciparum infection, using a 14-day in vivo test in an area of low intensity transmission in the northern Pacific coast of Colombia. At the same time, the study was used to train personnel from the Ministry of Health and regional malaria control programs from 3 Departments of Colombia in t...

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Section: Discussionmentioning

confidence: 99%

Assessment of therapeutic response of Plasmodium falciparum to chloroquine and sulfadoxine-pyrimethamine in an area of low malaria transmission in Colombia.

Osório¹,

Giraldo²,

Grajales³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

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“…5 and 4 infections/person-year [32][33][34][35]. Cross-sectional studies in similar villages revealed relatively uniform prevalence of parasitemia across age groups during the first year of exposure [20]. In a recent study in a similar setting we followed 243 migrants to their first infection by P. falciparum or P. vivax and found no difference in the attack rates between adults and children [36].…”

Section: Study Sitementioning

confidence: 99%

“…The relative susceptibility of children in heavily endemic areas may be driven primarily by intrinsic factors rather than by insufficient exposure to infection. We previously conducted epidemiological studies of Javanese migrants to hyperendemic Indonesian Papua that supported this view [19,20]. Defining the cellular and molecular basis of agedependent clinical immunity may guide approaches to inducing adult-like protection from P. falciparum in children [21,22].…”

Section: Introductionmentioning

confidence: 97%

Adult Javanese migrants to Indonesian Papua at high risk of severe disease caused by malaria

Baird¹,

Basri

Weina³

et al. 2003

Epidemiol. Infect.

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Migrants from Java arrive in hyperendemic Papua, Indonesia lacking exposure to endemic malaria. We evaluated records of evacuation to hospital with a diagnosis of severe malaria from a transmigration village in northeastern Papua. During the first 30 months, 198 residents with severe disease were evacuated (7·5 evacuations/100 person-years). During this period the risk of evacuation for adults (>15 years of age) was 2·8. (95% CI=2·1–3·8; P<0·0001) relative to children, despite apparently equal exposure to risk of infection. Relative risk (RR) for adults was greatest during the first 6 months (RR>16; 95% CI[ges ]2·0–129; P=0·0009), and diminished during the second 6 months (RR=9·4; 95% CI=2·7–32·8; P<0·0001) and the third 6 months (RR=3·7; 95% CI=1·7–7·9; P=0·0004). During the next two 6-month intervals, the RR for adults was 1·6 and 1·5 (95% CI range 0·8–2·6; P<0·18). Adults lacking chronic exposure were far more likely to progress to severe disease compared to children during initial exposure, but not after chronic exposure to infection.

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“…24,25 Duly, this entails cumulative exposure to multiple variants of a particular species which generally requires the first twenty years of life to develop completely. 24,26 Infections are more severe in children, in which most malaria-related mortality occurs. 4,27 In endemic areas, P. falciparum infection in children of under 5 years of age can lead to severe disease and is the cause a quarter of juvenile deaths in Africa.…”

Section: Correlation With Exposurementioning

confidence: 99%

Advancement Towards an Approved Vaccine to Target Plasmodium Falciparum Malaria

Taylor‐Robinson

2014

IJI

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Abstract:Plasmodium falciparum causes the severest form of malaria which kills well over one million persons each year, chiefly children, and results in significant debilitation in hundreds of millions more. This disease has a dramatic socioeconomic impact in endemic countries and thus it is a recurring target for global health enterprises. Increased investment in existing control measures, including insecticide-impregnated bed nets, has been paired with revitalized efforts to develop an efficacious vaccine. Sequencing of the genome of P. falciparum has provided insights into the malaria parasite's complex lifecycle, which, combined with a deeper understanding of the human immune response to infection, has yielded many novel candidate vaccines during the past two decades. Most notable of these is RTS,S which has shown great promise over a long development process, becoming the first candidate vaccine against human malaria to advance to phase III clinical trials. Hence, there is optimism that in the near future RTS,S may become the first ever licensed vaccine against a parasitic disease in humans. However, this is qualified by the need for a better knowledge of its mechanism of protection and questions raised over its long-term therapeutic capacity. While the availability of RTS,S as a validated commercial product is not guaranteed, it is likely to contribute to the continuing campaign against malaria, if only as a forerunner to a fine-tuned second generation vaccine.

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Age dependent characteristics of protection v. susceptibility to Plasmodium falciparum

Cited by 192 publications

References 98 publications

Assessment of therapeutic response of Plasmodium falciparum to chloroquine and sulfadoxine-pyrimethamine in an area of low malaria transmission in Colombia.

Assessment of therapeutic response of Plasmodium falciparum to chloroquine and sulfadoxine-pyrimethamine in an area of low malaria transmission in Colombia.

Adult Javanese migrants to Indonesian Papua at high risk of severe disease caused by malaria

Advancement Towards an Approved Vaccine to Target Plasmodium Falciparum Malaria

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