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Gametocyte prevalence
GAMEa & PRa observations GAMEa & PRa observations SARa observations
a) b) c)
Fig.: (a) Frequency distribution of annual averaged sexual and asexual parasite ratios (in %), (b) scatter plot of annual averaged sexual and asexual parasite ratios (in %), and (c) annual averaged ratio between asexual and sexual parasite prevalence (in %) observed by parasitological malaria studies. The straight line in (b) displays the angle bisector.
                     

Asexual and sexual parasite ratios

Sexual parasite ratios (gametocytaemia) are generally lower than asexual parasite ratios (Fig. a and b). Only one annual averaged gametocytaemia is found to be higher than 40%. By standard microscopy mostly less than 15% of the population were detected as gametocyte carriers. By contrast most of the studies reveal more than 30% asexual parasite ratios. The ratio between asexual and sexual parasite prevalence mainly ranges between 10 and 35% (Fig. b).

Enumeration of gametocytes

There is a problem of enumerating gametocytes patterns, gametocytes are prone to be missed by microscopy examination (Nedelman 1989; Drakeley et al. 2006). For example, reverse transcriptase polymerase chain reaction reveals partially more than 40% higher gametocyte prevalence compared with microscopy (Ali et al. 2006). Ouédraogo et al. (2007) recently found that the Pfs25 mRNA quantitative-nucleic acid sequence-based amplification (QT-NASBA) technique provided about 3.3 fold higher estimates of gametocyte prevalence than microscopy. This clearly demonstrates that studies based on the detection of gametocytes by microscopy are rather insensitive and inaccurate in the quantification of gametocytes in blood smears.

Age dependence & circulation times

Sexual and asexual parasite ratios are generally higher in children than in adults (Fig. b and c). That is due to the fact that adults better control asexual and sexual parasite densities, and are therefore more likely to carry gametocytes at the borderline level of detection (Drakeley et al. 2006). Young children are least likely to be able to control malaria infections, and likely more parasites are committed to the sexual pathway. Children also show a longer sexual carriage of parasites than adults. Bousema et al. (2004) finds in Kenya for asymptomatic children a decrease in the mean duration of gametocyte carriage with increasing age. The expected circulation time of gametocytes ranges between 3.4 and 7.4 days (Smalley and Sinden 1977; Eichner et al. 2001).

Duration of gametocytogenesis

The duration until mature gametocytes appear in the blood is much longer than the period until asexual parasites are detectable. The production of the sexual form of the parasites starts when a successful merozoite invades a red blood cell and either goes into another round of multiplication or develops into a single gametocyte. Newly invaded red blood cells circulate for a day as ring-infected parasitised red blood cells, then sequester to the vascular endothelium of deep tissues. On the one hand new merozoites are released in the peripheral circulation after a day (Carter and Miller 1979). But, on the other hand maturing gametocytes are preferentially sequestered in the bone marrow and spleen (Thomson and Robertson 1935; Smalley et al. 1980). The so called sequestration time lasts until gametocytes appear in the peripheral circulation, where they can be detected by microscopy.
Sequestration time is derived in vitro or from the delay in vivo between the onset of fever or the detection of asexual parasites and the detection of gametocytes (Eichner et al. 2001). The values reported in the literature generally range between 7 and 15 days (Shute and Maryon 1951: about 10 days for non-immune subjects; Miller 1958: about 12 days for immune adults; Hawking et al. 1971: 9-12 days; Day et al. 1998: 7-15 days). Diebner et al. (2000) and Eichner et al. (2001) more recently estimated the sequestration time from fitting a model to malaria therapy data. According to their studies the time needed for the transition of asexual blood stages of Plasmodium falciparum to mature gametocytes amounts to 4 to 12 days (mean 7.4 days). It is also shown that sequestration time depends on presence of the geographical parasite strain (geometric mean: 4.9 days for SanteeCooper strain (South Caroline, 1946); 6.2 days for ElLimon strain (Panama, 1948); 8.7 days for McLendon strain (South Carolina, 1940)). Eichner et al. (2001) state that in the former literature, the time for sequestration, is probably overestimated by the time needed to reach a certain level of gametocytaemia that can be detected by microscopy.
However, gametocytes of Plasmodium falciparum do not infect mosquitoes when the mature forms first appear in the blood. They become capacitated after a period of one to four days (Macdonald 1957; Sinden 1983; Nedelman 1989). The time needed for the final maturation of gametocytes is not considered in the estimation of the sequestration time by Eichner et al. (2001). Since there might be a delay in the former studies those might have indirectly accounted for the period of maturation.

Other gametocyte characteristics

For Plasmodium falciparum the temporal pattern of trophozoite and gametocyte density in the peripheral blood has frequently been described as wavelike (Hawking et al. 1971; Nedelman 1989; Diebner et al. 2000). Competition with large numbers of asexual parasites could reduce the success rate of maturing gametocytes. It is plausible that a higher supply of gametocytes (gametocytogenesis) is stimulated by immune stress. The parasite appears to have the ability to modulate the proportion of the parasite population within an infection that undergoes sexual development (Eichner et al. 2001).
  • Raw data: colon separated values (ASCII file)

    • country place long [°E] lat [°N] M1 YYY1 M2 YYY2 GAMEa GAMEmin,a GAMEmax,a SARa SARmin,a SARmax,a Ub Ua Up note Refs
    Burkina Faso Bobo-Dioulasso, Colma-Nord quarter -4.30 11.21b 01 1985 12 1985 10.5 5.6 21.1 36.1 26.7 44.3 children (0-15 years) U/R R1 R Gazin et al. 1987
    Burkina Faso Bobo-Dioulasso, Diaradougou quarter -4.29 11.18b 01 1985 12 1985 2.3 0.6 4.7 33.3 12.5 45.5 children (0-15 years) U R1 U Gazin et al. 1987
    Burkina Faso Bobo-Dioulasso, Dioulassoba quarter -4.30 11.19b 01 1985 12 1985 3.1 2.6 3.4 28.0 19.0 57.1 children (0-15 years) U R1 U Gazin et al. 1987
    Burkina Faso Bouloy, Kolel, Bella and Peul Djelgobé camps -999.00 -99.00 06 1985 03 1986 1.7 0.0 5.0 12.9 0.0 16.7 NA NA R adults Gazin et al. 1988a
    Burkina Faso Bouloy, Kolel, Bella and Peul Djelgobé camps -999.00 -99.00 06 1985 03 1986 8.6 7.5 9.1 17.0 12.0 24.1 NA NA R children between 0.5 and 15 years Gazin et al. 1988a
    Burkina Faso Karangasso -4.63 11.22b 02 1985 02 1986 21.3 4.5 30.0 38.3 6.0 52.7 R R2 R Plasmodium falciparum, children (5-9 years) Boudin et al. 1991b, Boudin et al. 1992
    Burkina Faso Karangasso -4.63 11.22b 02 1985 02 1986 25.5 9.2 37.3 40.8 24.2 63.9 R R2 R Plasmodium falciparum, children (0-4 years) Boudin et al. 1991b, Boudin et al. 1992
    Burkina Faso Karangasso -4.63 11.22b 02 1985 02 1986 29.4 8.5 39.7 47.8 11.8 65.1 R R2 R Plasmodium falciparum, children (10-14 years) Boudin et al. 1991b, Boudin et al. 1992
    Burkina Faso near Bobo-Dioulasso -999.00 -99.00 NA 1985 NA 1987 10.9 NA NA NA NA NA R R2 R all ages Boudin et al. 1991a
    Burkina Faso Ouagadougou -999.00 -99.00 08 1984 09 1984 NA NA 7.6 25.9 NA NA NA NA U children between 0 and 5 years; more detailed information is available Sabatinelli et al. 1986
    Burkina Faso Oursi and Déou -999.00 -99.00 06 1985 03 1986 4.4 0.0 15.2 16.5 0.0 33.3 NA NA R children between 0.5 and 15 years Gazin et al. 1988a
    Burkina Faso six villages north of Ouagadougou -999.00 -99.00 12 2003 12 2003 NA 21.4 NA NA 28.5 NA NA NA R all ages; microscope detection Ouédraogo et al. 2007
    Burkina Faso six villages north of Ouagadougou -999.00 -99.00 12 2003 12 2003 NA 70.1 NA NA 73.6 NA NA NA R all ages;QT-NASBA detection Ouédraogo et al. 2007
    Burkina Faso Tin Edjar -0.68 14.69m 06 1985 03 1986 0.0 0.0 0.0 0.0 0.0 0.0 NA NA R adults Gazin et al. 1988a
    Burkina Faso Tin Edjar -0.68 14.69m 06 1985 03 1986 4.2 2.6 5.4 12.5 8.0 26.7 NA NA R children between 0.5 and 15 years Gazin et al. 1988a
    Burkina Faso VK4 -4.42 11.37b 01 1985 02 1986 12.0 3.2 16.2 37.2 18.0 56.7 I R2 I Plasmodium falciparum, children (0-4 years) Boudin et al. 1992
    Burkina Faso VK4 -4.42 11.37b 01 1985 02 1986 13.9 7.2 23.8 32.2 22.6 48.4 I R2 I Plasmodium falciparum, children (5-9 years) Boudin et al. 1992
    Burkina Faso VK4 -4.42 11.37b 01 1985 02 1986 6.2 0.0 19.1 17.0 0.0 56.2 I R2 I Plasmodium falciparum, children (10-14 years) Boudin et al. 1992
    Cameroon Bondi 12.19 3.86m NA 1998 NA 2000 11.8 8.7 15.0 23.7 17.2 30.3 NA NA R Plasmodium falciparum, ages from 0.8-77 years; area: degraded forest; position derived from Meunier et al. 1999 Bonnet et al. 2003
    Cameroon Ebolakounou 12.13 3.93a 05 1996 05 1998 4.7 NA NA 13.7 NA NA NA R2 R GAME: Plasmodium falciparum prevalences for adults (>15 years); forest area Bonnet et al. 2002
    Cameroon Ebolakounou 12.13 3.93a 05 1996 05 1998 9.1 NA NA 14.7 NA NA NA R2 R GAME: Plasmodium falciparum prevalences for children between 0 and 15 years; forest area Bonnet et al. 2002
    Cameroon Koundou 12.12 3.90a 05 1996 05 1998 10.3 NA NA 14.8 NA NA NA R2 R Plasmodium falciparum prevalences for children between 0 and 15 years; degraded forest area Bonnet et al. 2002
    Cameroon Koundou 12.12 3.90a 05 1996 05 1998 3.8 NA NA 9.6 NA NA NA R2 R Plasmodium falciparum prevalences for adults (>15 years); degraded forest area Bonnet et al. 2002
    Cameroon Mengang 12.05 3.88i NA 1998 NA 2000 23.6 12.9 34.3 33.7 22.1 42.0 NA NA R Plasmodium falciparum, ages from 0.8-77 years; area: degraded forest Bonnet et al. 2003
    Cameroon Mengang and Yaounde -999.00 -99.00 NA NA NA NA 10.4 NA NA 15.6 NA NA NA NA R and U children between 0 and 14 years Boudin et al. 2005
    Cameroon Mengang and Yaounde -999.00 -99.00 NA NA NA NA 4.8 NA NA 11.5 NA NA NA NA R and U adults (>14 years) Boudin et al. 2005
    Cameroon Mengang district, two villages -999.00 -99.00 NA NA NA NA 15.7 NA NA 27.7 NA NA NA NA R - Paul et al. 2007
    Cameroon Yaound&eacue; Messa quarter -999.00 -99.00 10 1990 01 1993 5.4 NA NA 14.6 NA NA NA NA U GAME: children and adults (4-60 years) Tchuinkam et al. 1993
    Cameroon Yaoundé and Mengang -999.00 -99.00 NA NA NA NA 19.1 NA NA 40.2 NA NA NA NA NA detected by quantitative buffy coat tests; patients presenting clinical malaria and children (3-15 years), respectively Mulder et al. 1998
    Cameroon Yaoundé and Mengang -999.00 -99.00 NA NA NA NA 20.0 NA NA 39.8 NA NA NA NA NA detected by thick blood films and quantitative buffy coat tests; patients presenting clinical malaria and children (3-15 years), respectively Mulder et al. 1998
    Cameroon Yaoundé and Mengang -999.00 -99.00 NA NA NA NA 4.6 NA NA 10.1 NA NA NA NA NA detected by thick blood films; patients presenting clinical malaria and children (3-15 years), respectively Mulder et al. 1998
    Cameroon Yaoundé, Dakar quarter 11.52 3.87i 07 1999 05 2000 4.3 0.0 7.0 12.6 0.0 21.9 NA NA U all ages; microscope; drug influenced van der Kolk et al. 2003
    Cameroon Yaoundé, Essos 11.00 3.00b 06 1989 02 1990 3.2 2.4 7.4 8.5 0.0 16.7 NA NA U PR: children (0-15 years) Manga et al. 1993b
    Cameroon Yaoundé, Obili district 11.52 3.87i 10 1989 07 1990 1.1 0.0 3.0 4.0 0.0 7.7 NA U U PR: children (0-15 years) Manga et al. 1993b
    Côte d'Ivoire Katiola district, 8 villages (no rice cultivation) -999.00 -99.00 03 1997 01 1998 13.0 11.0 14.0 14.9 13.3 15.6 NA NA R PR: children (0-9 years); the villages are Angolokaha, Doussoulokaha, Folofonkaha, Kabolo, Ounadiékaha, Petionara, Sérigobokaha and Timorokaha (located between 8.18 and 8.90°??N and 4.98 and 5.22°??W) Henry et al. 2003
    Côte d'Ivoire Katiola district, 8 villages (no rice cultivation) -999.00 -99.00 03 1997 01 1998 4.0 3.0 5.0 6.5 5.4 7.6 NA NA R PR: children (&ge??10 years); the villages are Angolokaha, Doussoulokaha, Folofonkaha, Kabolo, Ounadiékaha, Petionara, Sérigobokaha and Timorokaha (located between 8.18 and 8.90°??N and 4.98 and 5.22°??W) Henry et al. 2003
    Côte d'Ivoire Korhogo district, 8 villages (rice cultivation during the dry season) -999.00 -99.00 03 1997 01 1998 11.0 10.0 11.0 13.9 13.3 13.6 NA NA I GAME: children (0-9 years); the villages are Gbahaouakaha, Kohotieri, Koumbolikaha, Lamékaha, Nambékaha, Nombolo, Nongotchénékaha and Zémongokaha) Henry et al. 2003
    Côte d'Ivoire Korhogo district, 8 villages (rice cultivation during the dry season) -999.00 -99.00 03 1997 01 1998 4.0 4.0 5.0 9.2 10.0 10.3 NA NA I GAME: subjects (&ge??10 years); the villages are Gbahaouakaha, Kohotieri, Koumbolikaha, Lamékaha, Nambékaha, Nombolo, Nongotchénékaha and Zémongokaha) Henry et al. 2003
    Côte d'Ivoire Korhogo district, 8 villages (rice cultivation during the rainy season) -999.00 -99.00 03 1997 01 1998 12.0 12.0 12.0 14.3 14.0 15.0 NA NA R PR: children (0-9 years); the villages are Binguebougou, Fapaha, Kombolokoura, Kaforo, Karakpo, Kassoumbarga, Katiorkpo, and Tioro) Henry et al. 2003
    Côte d'Ivoire Korhogo district, 8 villages (rice cultivation during the rainy season) -999.00 -99.00 03 1997 01 1998 4.0 3.0 5.0 6.1 4.9 7.2 NA NA R PR: children (&ge?? 10 years); the villages are Binguebougou, Fapaha, Kombolokoura, Kaforo, Karakpo, Kassoumbarga, Katiorkpo, and Tioro) Henry et al. 2003
    Congo Linzolo 15.11 -4.41b 11 1981 05 1985 22.5 21.8 27.7 28.5 27.6 34.2 R R1 R children (0-14 years); microscope Trape 1987b
    Congo six villages near Brazzaville -999.00 -99.00 11 1981 05 1985 28.4 NA NA 34.0 NA NA NA NA R school children (5-15 years); microscope Trape 1987b
    Gambia four villages west of Farafenni -999.00 -99.00 05 2001 06 2001 NA 13.5 NA NA 24.9 NA NA NA R children(0.5-15 years) Dunyo et al. 2006
    Gambia, The 5 villages around Farafenni -16.57 13.47p 04 2003 05 2003 NA NA 3.1 NA NA 15.3 NA NA R 950 subjects from 5-45 years; detected by microscopy Nwakanma et al. 2006
    Gambia, The 5 villages around Farafenni -16.57 13.47p 04 2003 05 2003 NA NA 3.1 NA NA 15.3 NA NA R 950 subjects from 5-45 years; detected by microscopy Nwakanma et al. 2006
    Gambia, The 5 villages around Farafenni -16.57 13.47p 05 2003 10 2003 24.2 NA NA 44.9 NA NA NA NA R 31 subjects from 5-45 years; detected by microscopy Nwakanma et al. 2006
    Gambia, The 5 villages around Farafenni -16.57 13.47p 05 2003 10 2003 51.6 NA NA 62.7 NA NA NA NA R 31 subjects from 5-45 years; detected by polymerase chain reaction and reverse transcriptase polymerase chain reaction Nwakanma et al. 2006
    Gambia, The near Farafenni, north bank villages -999.00 -99.00 06/11 1990 1991 06/11 1990 1991 12.3 NA NA NA NA NA NA NA NA children (1-19 years) Drakeley et al. 2000
    Gambia, The near Farafenni, north bank villages -999.00 -99.00 06/11 1990 1991 06/11 1990 1991 6.1 NA NA NA NA NA NA NA NA adults (>20 years) Drakeley et al. 2000
    Gambia, The near Farafenni, north bank villages -999.00 -99.00 NA NA NA NA NA NA NA NA 11.7 31.0 NA NA NA adults (>14 years); graphically derived Drakeley et al. 2006
    Gambia, The near Farafenni, north bank villages -999.00 -99.00 NA NA NA NA NA NA NA NA 18.8 43.5 NA NA NA children (0-14 years); graphically derived Drakeley et al. 2006
    Gambia, The near Farafenni, south bank villages -999.00 -99.00 NA NA NA NA NA NA NA NA 15.3 26.0 NA NA NA adults (>14 years); graphically derived Drakeley et al. 2006
    Gambia, The near Farafenni, south bank villages -999.00 -99.00 NA NA NA NA NA NA NA NA 16.5 27.0 NA NA NA children (0-14 years); graphically derived Drakeley et al. 2006
    Ghana ? -999.00 -99.00 01 1952 10 1952 20.0 ? ? ? ? ? NA NA ? children (0-14 years) Muirhead-Thomson 1954
    Ghana ? -999.00 -99.00 01 1952 10 1952 6.0 ? ? ? ? ? NA NA ? adults (>14 years) Muirhead-Thomson 1954
    Ghana Weija -99.00 -999.00 01 1952 10 1952 20.0 NA NA 22.9 NA NA NA NA R children (0.8-10 years) Muirhead-Thomson 1954
    Kenya Ahero -999.00 -99.00 NA 1935 NA 1936 51.6 NA NA 61.5 NA NA NA NA NA children (0-4 years); microscope detection Garnham 1949
    Kenya Chonyi -999.00 -99.00 NA NA NA NA NA NA NA 17.3 NA NA NA NA NA children (0-14 years); graphically derived Drakeley et al. 2006
    Kenya Chonyi -999.00 -99.00 NA NA NA NA NA NA NA 3.7 NA NA NA NA NA adults (>14 years); graphically derived Drakeley et al. 2006
    Kenya Kanyamedha -999.00 -99.00 NA 1935 NA 1936 24.2 NA NA 29.1 NA NA NA NA NA children (0-4 years); microscope detection Garnham 1949
    Kenya Kasagam -999.00 -99.00 NA 1935 NA 1936 9.3 NA NA 10.7 NA NA NA NA NA children (0-4 years); microscope detection Garnham 1949
    Kenya Kisumu -999.00 -99.00 NA 1935 NA 1936 17.9 NA NA 25.2 NA NA NA NA NA children (0-4 years); microscope detection Garnham 1949
    Kenya Ngerenya -999.00 -99.00 NA NA NA NA NA NA NA 23.8 NA NA NA NA NA children (0-14 years); graphically derived Drakeley et al. 2006
    Kenya Ngerenya -999.00 -99.00 NA NA NA NA NA NA NA 7.3 NA NA NA NA NA adults (>14 years); graphically derived Drakeley et al. 2006
    Kenya Nyakatch -999.00 -99.00 NA 1935 NA 1936 37.7 NA NA 49.1 NA NA NA NA NA children (0-4 years); microscope detection Garnham 1949
    Liberia ? -999.00 -99.00 ? ? ? ? 15.6 ? ? ? ? ? NA NA ? children (0-14 years) Muirhead-Thomson 1957
    Liberia ? -999.00 -99.00 ? ? ? ? 5.5 ? ? ? ? ? NA NA ? adults (>14 years) Muirhead-Thomson 1957
    Liberia Marshall Territory -999.00 -99.00 01 195? 12 195? 6.0 NA NA 31.4% NA NA NA NA NA - Miller 1958
    Nigeria Garki, village 154 -999.00 -99.00 ? ? ? ? 36.5 NA NA NA NA NA NA NA ? children (1NA years) Nedelman 1989
    Nigeria Garki, village 154 -999.00 -99.00 ? ? ? ? 9.8 NA NA NA NA NA NA NA ? children/adults (>9 years) Nedelman 1989
    Nigeria Garki, village 202 -999.00 -99.00 ? ? ? ? 27.0 NA NA NA NA NA NA NA NA children (1NA years) Nedelman 1989
    Nigeria Garki, village 202 -999.00 -99.00 ? ? ? ? 5.5 NA NA NA NA NA NA NA NA children/adults (>9 years) Nedelman 1989
    Nigeria Garki, village 218 -999.00 -99.00 ? ? ? ? 30.0 NA NA NA NA NA NA NA NA children (1NA years) Nedelman 1989
    Nigeria Garki, village 218 -999.00 -99.00 ? ? ? ? 7.8 NA NA NA NA NA NA NA NA children/adults (>9 years) Nedelman 1989
    Nigeria Garki, village 304 -999.00 -99.00 ? ? ? ? 22.5 NA NA NA NA NA NA NA NA children (1NA years) Nedelman 1989
    Nigeria Garki, village 304 -999.00 -99.00 ? ? ? ? 7.3 NA NA NA NA NA NA NA NA children/adults (>9 years) Nedelman 1989
    Nigeria Garki, village 408 -999.00 -99.00 ? ? ? ? 30.5 NA NA NA NA NA NA NA NA children (1NA years) Nedelman 1989
    Nigeria Garki, village 408 -999.00 -99.00 ? ? ? ? 6.3 NA NA NA NA NA NA NA NA children/adults (>9 years) Nedelman 1989
    Nigeria Garki, village 553 -999.00 -99.00 ? ? ? ? 26.0 NA NA NA NA NA NA NA NA children (1NA years) Nedelman 1989
    Nigeria Garki, village 553 -999.00 -99.00 ? ? ? ? 4.5 NA NA NA NA NA NA NA NA children/adults (>9 years) Nedelman 1989
    Nigeria Garki, village 55 -999.00 -99.00 ? ? ? ? 29.5 NA NA NA NA NA NA NA NA children (1NA years) Nedelman 1989
    Nigeria Garki, village 55 -999.00 -99.00 ? ? ? ? 8.8 NA NA NA NA NA NA NA NA children/adults (>9 years) Nedelman 1989
    Nigeria Garki, village 802 -999.00 -99.00 ? ? ? ? 27.5 NA NA NA NA NA NA NA NA children (1NA years) Nedelman 1989
    Nigeria Garki, village 802 -999.00 -99.00 ? ? ? ? 8.3 NA NA NA NA NA NA NA NA children/adults (>9 years) Nedelman 1989
    Nigeria Kaduna area -999.00 -99.00 05 1963 08 1963 26.5 NA NA NA NA 8.0 NA NA R - Service 1965
    Nigeria Lagos 3.40 6.45i NA 1949 NA 1949 11.8 NA NA 44.8 NA NA NA NA U children (0-1 years) Bruce-Chwatt 1951
    Nigeria Lagos 3.40 6.45i NA NA NA NA 30.2 NA NA 38.8 NA NA NA NA U children (1-2 years) Bruce-Chwatt 1951
    Nigeria village in Yoruba country -999.00 -99.00 11 1951 12 1951 NA NA 9.8 NA NA 14.3 NA NA R children (0-15 years); microscope detection Draper 1953
    Papua New Guinea 72 villages around Madang -99.00 -999.00 07 1981 01 1983 6.3 5.5 7.0 15.3 14.6 16.0 NA NA R Plasmodium falciparum;children (0-14 years) Cattani et al. 1986
    Papua New Guinea Butelgut 145.75 -5.15i 06 1983 09 1985 14.7 NA NA 23.3 NA NA NA NA R children (0-20 years) Graves et al. 1988
    Papua New Guinea Mebat 145.78 -5.083 06 1983 09 1985 14.3 NA NA 25.6 NA NA NA NA R children (0-20 years) Graves et al. 1988
    Papua New Guinea Mebat 145.78 -5.083 06 1983 09 1985 7.9 NA NA 15.9 NA NA NA NA R children (0-20 years) Graves et al. 1988
    Senegal Aéré Lao and Boké Diallobé -14.30 16.40b 05 1982 08 1983 NA 0.0 4.8 NA 0.0 28.2 R R2 R - Vercruysse 1985
    Senegal Dakar, Grande Niaye Mrash -17.42 14.75p 05 1987 09 1988 1.3 NA NA 34.4 NA NA NA U U all ages Trape et al. 1992
    Senegal Diohine -16.51 14.48a 10 1996 11 1996 16.7 NA NA 25.8 NA NA NA R1 R adults between 19 and 66 years Sokhna et al. 2001
    Senegal Diohine, Kotiokh and Ngayokhème -999.00 -99.00 02 1995 11 1995 26.0 15.0 45.0 45.9 36.6 54.9 R R1 R children 0-9 years Robert et al. 1998
    Senegal Diohine, Kotiokh and Ngayokhème -999.00 -99.00 02 1995 11 1995 9.0 3.0 20.0 26.8 18.2 30.8 R R1 R adults Robert et al. 1998
    Senegal Thies -16.93 14.80i NA NA NA NA 4.8 NA NA 53.2 NA NA NA NA R adults (>14 years) Boudin et al. 2005
    Senegal Thies -16.93 14.80i NA NA NA NA 7.5 NA NA 42.9 NA NA NA NA R children between 0 and 14 years Boudin et al. 2005
    Sierra Leone eight villages near Bo -999.00 -99.00 03 1990 12 1990 10.9 NA NA 17.9 NA NA NA NA R Plasmodium falciparum; children between four months and 7 years Barnish et al. 1993
    Sudan Asar 13.75 35.25a 10 1998 08 1999 29.8 12.2 52.3 NA NA NA NA R2 R all ages; RT-PCR detection Abdel-Wahab et al. 2002
    Sudan Asar 13.75 35.25a 10 1998 08 1999 3.5 0.0 6.2 13.2 0.0 NA NA R2 R all ages; microscope detection Abdel-Wahab et al. 2002
    Sudan Asar -999.00 -99.00 10 1999 10 1999 NA NA NA 6.5 NA 62.0 NA R2 R all ages (6-50 years); detection by reverse transcriptase polymerase chain reaction Ali et al. 2006
    Sudan Asar -999.00 -99.00 10 1999 10 1999 NA NA NA NA NA 6.5 NA R2 R all ages (6-50 years); detection by microscopy Ali et al. 2006
    Tanzania 40 miles west of Tanga -999.00 -99.00 09 1952 12 1952 7.7 NA NA 14.0 NA NA NA NA S all ages Davidson and Draper 1953
    Tanzania Kisegese -999.00?? -99.00 NA 1992 NA 1994 11.6 NA NA NA NA NA NA NA NA children (1-19 years) Drakeley et al. 2000
    Tanzania Kisegese -999.00?? -99.00 NA 1992 NA 1994 7.0 NA NA NA NA NA NA NA NA adults (>19 years) Drakeley et al. 2000
    Tanzania Northeastern Tanzania -999.00 -99.00 NA NA NA NA 13.5 NA NA 28.0 NA NA NA NA NA children (0-14 years); graphically derived Drakeley et al. 2006
    Tanzania Northeastern Tanzania -999.00 -99.00 NA NA NA NA 3.7 NA NA 11.2 NA NA NA NA NA adults (>14 years); graphically derived Drakeley et al. 2006
    Thailand Ban Phluang -999.00?? -99.00 06 1983 05 1985 4.6 1.1 7.7 NA NA NA NA NA R adults (&ge??14 years) Rosenberg et al. 1990
    Thailand Ban Phluang -999.00?? -99.00 06 1983 05 1985 6.4 3.2 9.4 NA NA NA NA NA R children (1-14 years) Rosenberg et al. 1990
    Uganda Lira -999.00 -99.00 09 1953 12 1953 16.9 NA NA 28.6 NA NA NA NA S all ages; East African plateau Davidson 1955

    Abbreviations

    countrycountry of the study site
    placename of the location of the study site
    longlongitude [°E]; -999.00: position unknown
    latlatitude [°N]; -99.00: position unknown; sources of latitude/longitude: a: Hay et al. 2005a, b: Hay et al. 2000b, p: taken from the paper, m: published map, i: http://www.heavens-above.com/countries.aspx
    M1month of the study start
    YYY1year of the study start
    M2month of the study end
    YYY2year of the study end
    GAMEaannual averaged gametocyte prevalence [%]
    GAMEmin,aannual minimum gametocyte prevalence [%]
    GAMEmax,aannual maximum gametocyte prevalence [%]
    SARaannual averaged ratio between asexual and sexual parasite prevalence, i.e. the proportion gametocytaemic [%]
    SARmin,aannual minimum ratio between asexual and sexual parasite prevalence [%]
    SARmax,aannual maximum ratio between asexual and sexual parasite prevalence [%]
    UbR=rural, I=irrigated rice, U= urban area; source: Hay et al. (2000b)
    Uaas definded by Hay et al. (2005a): PU=peri-urban (population densities of 250-1,000 persons per km2), R1=rural 1 (population densities of 100-250 persons per km2), R2=rural 2 (population densities of < 100 persons per km2), U=urban (population densities of > 1,000 persons per km
    UpR=rural area, I=irrigation/permanent stream or river, U= urban area; derived from information of the reference
    notenotes
    Refsreferences
    NArefers to data that was not available in the reference
    ?the question mark refers to references that were not checked, since they were not available