Evidence for Specific Suppression of Gametocytemia by Plasmodium Falciparum in Residents of Hyperendemic Irian Jaya

Baird, J. Kevin; Jones, Trevor R.; Purnomo, Purnomo; Masbar, S; Ratiwayanto, Sutanti; Leksana, Budhi

doi:10.4269/ajtmh.1991.44.183

Cited by 41 publications

(40 citation statements)

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“…It has been reported that P. vivax gametocytes are killed by pyrogenic cytokines and complementary factors in the paroxysm plasma of nonimmune patients, but that these factors and their effects are suppressed with the development of clinical immunity (Karunaweera et al, 1992). For P. falciparum, it has been reported that specific immune suppression of gametocytes develops with repeated exposure (Baird et al, 1991), but that seasonal fluctuations in gametocyte prevalence are greater among adults than children (Rosenberg et al, 1990). Detailed longitudinal studies should investigate the conjunction of parasitological, immunological, and clinical characteristics associated with gametocytemia.…”

Section: Discussionmentioning

confidence: 99%

Gametocytemia in Plasmodium Vivax and Plasmodium Falciparum Infections

McKenzie

Wongsrichanalai

Magill

et al. 2006

Journal of Parasitology

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Two expert research microscopists, each blinded to the other's reports, diagnosed single-species malaria infections in 2,141 adults presenting at outpatient malaria clinics in Tak Province, Thailand, and Iquitos, Peru, in May-August 1998, May-July 1999, and May-June 2001. Plasmodium vivax patients with gametocytemia had higher fever and higher parasitemia than those without gametocytemia; temperature correlated with parasitemia in the patients with gametocytemia. Plasmodium falciparum patients with gametocytemia had lower fever than those without gametocytemia, but similar parasitemia; temperature correlated with parasitemia in the patients without gametocytemia. Hematologic data in Thailand in 2001 showed lower platelet counts in P. vivax patients with gametocytemia than in the P. vivax patients without gametocytemia, whereas P. falciparum patients with gametocytemia had similar platelet counts but lower red blood cell counts, hemoglobin levels, hematocrit levels, and higher lymphocyte counts than patients without gametocytemia. NIH Public AccessAuthor Manuscript J Parasitol. Author manuscript; available in PMC 2008 August 7. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptGametocytes are the sexual, nonreplicating blood-stage forms of Plasmodium spp. that are transmission agents to mosquitoes. They are products of the asexual, replicating, nontransmissible forms with which the pathology of malaria is associated. Gametocytes themselves are clinically benign, but their production represents a diversion of parasites from the geometric growth of asexual forms; each asexual form that becomes a gametocyte might instead become millions of asexual forms (Carter and Graves, 1988;McKenzie and Bossert, 1998;Talman et al., 2004). Thus, the higher the rate of gametocyte production earlier in an infection, the longer it is until parasitemia reaches a pyrogenic level or any other given density.Gametocytes attract relatively little research attention, although classic studies of adult malaria cases reported positive relationships between gametocytemia, mildness of symptoms, leukocyte proliferation, and age (Thomson, 1911), and higher gametocyte-to-asexual form ratios in patients who cleared infections without treatment than in those requiring drugs (Kitchen and Putnam, 1942). Recent work has focused on children in sub-Saharan Africa infected with P. falciparum in whom gametocytemia is associated with an absence of fever (von Seidlein et al., 2001;Sowunmi et al., 2004), low (von Seidlein et al., 2001Sowunmi et al., 2004) or high (Githeko et al., 1992;Drakeley et al., 1999;Bousema et al., 2004) asexual parasitemia, and either anemia (Drakeley et al., 1999;von Seidlein et al., 2001) or its absence (Sowunmi et al., 2004).Few previous studies have examined characteristics associated with gametocytemia in adults, or in endemic regions other than Africa, or in species other than P. falciparum. Here, we report on gametocytemia in adults visiting local outpatient malaria clinics in western Thailand an...

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Section: Discussionmentioning

confidence: 99%

Gametocytemia in Plasmodium Vivax and Plasmodium Falciparum Infections

McKenzie

Wongsrichanalai

Magill

et al. 2006

Journal of Parasitology

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“…This implies that the kinetics of sexual stage immunity are different to the kinetics of asexual stage immunity. A study by Baird and others 30 found evidence for the specific suppression of P. falciparum gametocytemia in semi-immune natives of Irian Jaya. This suppresion was independent of immune control of asexual parasitemia.…”

Section: Discussionmentioning

confidence: 99%

Dynamics of P. falciparum gametocytemia in symptomatic patients in an area of intense perennial transmission in Tanzania.

Akim

Drakeley²,

Kingo³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

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Abstract. We investigated the dynamics of Plasmodium falciparum gametocytemia in symptomatic patients attending a local dispensary in the Kilombero district, Tanzania. Consenting individuals aged one and above, with varying asexual and sexual parasitemias were treated appropriately and asked to return weekly for 28 days. Gametocyte prevalence was highest on Day 7 of follow-up in all age groups (overall 30.5%). Multifactorial analysis showed that young age ( 2 ϭ 18.4; P ϭ 0.004), high asexual parasitemia on presentation ( 2 ϭ 19.4; P ϭ 0.0007) and gametocyte positivity on presentation ( 2 ϭ 29.4; P ϭ 0.001) were all significantly associated with the presence of gametocytes on Days 7 and 14 of follow-up. High presentation of asexual parasitemia alone was positively correlated with higher gametocyte densities on both days of follow-up (F 4, 297 ϭ 2.0; P ϭ 0.049). Gametocyte incidence rates decreased significantly with age ( 2 ϭ 7.6, P Ͻ 0.005). In summary, in this group of chloroquine-treated individuals, gametocyte prevalence and incidence rates decreased with age, while densities remained relatively constant.

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“…The prolonged and continuous contact with malaria parasite, as happened in Orinoco villages, has been considered as necessary to build up an effective immunity to malaria (Nielsen et al 2002). Antimalarial immunity can suppress gametocytemia (Baird et al 1991), and therefore reduce malaria transmission, and control parasitemia (Bull & Marsh 2002), leading to a reduction in malaria morbidity. It can be assumed that the relative isolation of Yanomami villagers (Laserson et al 1999) restricted the variety of circulating isolates of malaria parasites (Maitland et al 2000) and contributed to the efficacy of immunity.…”

Section: Discussionmentioning

confidence: 99%