Table 2.
Malaria prevalence, Plasmodium species, and parasite density in Nouakchott (2015–2020)
| Characteristicsa | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2015–2020 |
|---|---|---|---|---|---|---|---|
| N (%) | 459 (26.1) | 325 (18.5) | 103 (5.8) | 192 (11.0) | 402 (22.8) | 279 (15.8) | 1760 (100) |
| Malaria-positive | |||||||
| RDT | 166 (36.1) | 63 (19.3) | 5 (4.8) | 23 (11.9) | 17 (4.2) | 0 | 274 (15.5) |
| Microscopy | 131 (28.5) | 52 (16.0) | 5 (4.8) | 33 (17.1) | 34 (8.4) | 1 (0.3) | 256 (14.5) |
| PCR | 134 (29.2) | 64 (19.7) | 5 (4.8) | 29 (15.1) | 53 (13.2) | 6 (2.1) | 291 (16.5) |
| Plasmodium spp. | |||||||
| Pv | 107 (79.8) | 30 (46.9) | 5 (100) | 21 (72.4) | 49 (92.5) | 4 (66.6) | 216 (74.2) |
| Pf | 18 (13.4) | 15 (23.4) | 0 | 8 (27.6) | 4 (7.5) | 2 (33.3) | 47 (16.1) |
| Pf–Pv | 9 (6.7) | 19 (29.7) | 0 | 0 | 0 | 0 | 28 (9.6) |
| Parasite density | 1250 | 2540 | 3060 | 1100 | 1730 | 935 | 1480 |
aData are expressed as the number (N) and % in parentheses (the denominator is the total number of screened patients per year shown in the first row) for malaria prevalence determined by different diagnostic tools and Plasmodium species determined by PCR (Pv, P. vivax monoinfection; Pf, P. falciparum monoinfection; Pf-Pv, P. falciparum-P. vivax mixed infection). The last column (2015–2020) presents the total number (%) of malaria-positive patients with each diagnostic tool and distribution of Plasmodium species during the entire study period (2015–2020). PCR did not detect any P. ovale or P. malariae. Parasite density denotes the geometric mean parasite density, expressed as the number of asexual parasites per µL of blood. The parasite density in 2020 (935 asexual parasites/µL) is based on a single smear-positive sample