TY - JOUR
T1 - Surveillance for malaria elimination in Swaziland
T2 - A national cross-sectional study using pooled PCR and serology
AU - Hsiang, Michelle S.
AU - Hwang, Jimee
AU - Kunene, Simon
AU - Drakeley, Chris
AU - Kandula, Deepika
AU - Novotny, Joseph
AU - Parizo, Justin
AU - Jensen, Trevor
AU - Tong, Marcus
AU - Kemere, Jordan
AU - Dlamini, Sabelo
AU - Moonen, Bruno
AU - Angov, Evelina
AU - Dutta, Sheetij
AU - Ockenhouse, Christian
AU - Dorsey, Grant
AU - Greenhouse, Bryan
PY - 2012/1/6
Y1 - 2012/1/6
N2 - Background: To guide malaria elimination efforts in Swaziland and other countries, accurate assessments of transmission are critical. Pooled-PCR has potential to efficiently improve sensitivity to detect infections; serology may clarify temporal and spatial trends in exposure. Methodology/Principal Findings: Using a stratified two-stage cluster, cross-sectional design, subjects were recruited from the malaria endemic region of Swaziland. Blood was collected for rapid diagnostic testing (RDT), pooled PCR, and ELISA detecting antibodies to Plasmodium falciparum surface antigens. Of 4330 participants tested, three were RDT-positive yet false positives by PCR. Pooled PCR led to the identification of one P. falciparum and one P. malariae infection among RDT-negative participants. The P. falciparum-infected participant reported recent travel to Mozambique. Compared to performing individual testing on thousands of samples, PCR pooling reduced labor and consumable costs by 95.5%. Seropositivity was associated with age ≥20 years (11·7% vs 1·9%, P<0.001), recent travel to Mozambique (OR 4.4 [95% CI 1.0-19.0]) and residence in southeast Swaziland (RR 3.78, P<0.001). Conclusions: The prevalence of malaria infection and recent exposure in Swaziland are extremely low, suggesting elimination is feasible. Future efforts should address imported malaria and target remaining foci of transmission. Pooled PCR and ELISA are valuable surveillance tools for guiding elimination efforts.
AB - Background: To guide malaria elimination efforts in Swaziland and other countries, accurate assessments of transmission are critical. Pooled-PCR has potential to efficiently improve sensitivity to detect infections; serology may clarify temporal and spatial trends in exposure. Methodology/Principal Findings: Using a stratified two-stage cluster, cross-sectional design, subjects were recruited from the malaria endemic region of Swaziland. Blood was collected for rapid diagnostic testing (RDT), pooled PCR, and ELISA detecting antibodies to Plasmodium falciparum surface antigens. Of 4330 participants tested, three were RDT-positive yet false positives by PCR. Pooled PCR led to the identification of one P. falciparum and one P. malariae infection among RDT-negative participants. The P. falciparum-infected participant reported recent travel to Mozambique. Compared to performing individual testing on thousands of samples, PCR pooling reduced labor and consumable costs by 95.5%. Seropositivity was associated with age ≥20 years (11·7% vs 1·9%, P<0.001), recent travel to Mozambique (OR 4.4 [95% CI 1.0-19.0]) and residence in southeast Swaziland (RR 3.78, P<0.001). Conclusions: The prevalence of malaria infection and recent exposure in Swaziland are extremely low, suggesting elimination is feasible. Future efforts should address imported malaria and target remaining foci of transmission. Pooled PCR and ELISA are valuable surveillance tools for guiding elimination efforts.
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U2 - 10.1371/journal.pone.0029550
DO - 10.1371/journal.pone.0029550
M3 - Article
C2 - 22238621
AN - SCOPUS:84855419670
SN - 1932-6203
VL - 7
JO - PloS one
JF - PloS one
IS - 1
M1 - e29550
ER -