TY - JOUR
T1 - Clustering of malaria in households in the Greater Mekong Subregion: operational implications for reactive case detection
AU - Mukaka, Mavuto
AU - Peerawaranun, Pimnara
AU - Parker, Daniel M.
AU - Kajeechiwa, Ladda
AU - Nosten, Francois H.
AU - Nguyen, Thuy-Nhien
AU - Hien, Tran Tinh
AU - Tripura, Rupam
AU - Peto, Thomas J.
AU - Phommasone, Koukeo
AU - Mayxay, Mayfong
AU - Newton, Paul N.
AU - Imwong, Mallika
AU - Day, Nicholas P. J.
AU - Dondorp, Arjen M.
AU - White, Nicholas J.
AU - von Seidlein, Lorenz
N1 - Funding Information: First and foremost, we thank the study communities that kindly agreed to participate in this project. Second, we want to thank the large number of people who made it possible to collect and process the data for the underlying malaria elimination study including Khin Maung Lwin, Lilly Keereecharoen, May Myo Thwin, Jacher Wiladphaingern, Suphak Nosten, Stephane Proux, Vincent Corbel, Julie A. Simpson, Dao Van Hue, Le Thanh Dong, Tam-Uyen Nguyen, Pham Nguyen Huong Thu, Ngo Trong Hung, Do Hung Son, Nguyen Thanh Tien. Nguyen Van Dung, Huynh Hong Quang, Chea Nguon, Chan Davoeung, Huy Rekol, Martin P. Grobusch, Bipin Adhikari, Gisela Henriques, Tiengkham Pongvongsa, Panom Phongmany, Frank Cobelens, Frank van Leth, Frank Smithuis, Sue J. Lee, Preyanan Suangkanarat, Atthanee Jeeyapant, Benchawan Vihokhern, Yoel Lubell, Lisa White, Ricardo Aguas, Mehul Dhorda, Cholrawee Promnarate, Pratap Singhasivanon, Pasathorn Sirithiranont, Jem Chalk, Olivo Miotto, Krittaya Patumrat, Jureeporn Duanguppama, Dominique Cerqueira, Sasithon Pukrittayakamee, Kesinee Chotivanich, Borimas Hanboonkunupakarn, Podjanee Jittmala, Phaek Yeong Chea, Chris Pell, Carl Onsj?, Benoit Malleret, Laurent R?nia, Georges Snounou, Nils Kaehler, David Lalloo, Decha Tangseefa, Mike Parker, Phan Kim Son, Ric Price, Sarah Walker, Amir Hossain, and Susanna J. Dunachie. Publisher Copyright: © 2021, The Author(s).
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Background: Malaria reactive case detection is the testing and, if positive, treatment of close contacts of index cases. It is included in national malaria control programmes of countries in the Greater Mekong Subregion to accelerate malaria elimination. Yet the value of reactive case detection in the control and elimination of malaria remains controversial because of the low yield, limited evidence for impact, and high demands on resources. Methods: Data from the epidemiological assessments of large mass drug administration (MDA) studies in Myanmar, Vietnam, Cambodia and Laos were analysed to explore malaria infection clustering in households. The proportion of malaria positive cases among contacts screened in a hypothetical reactive case detection programme was then determined. The parasite density thresholds for rapid diagnostic test (RDT) detection was assumed to be > 50/µL (50,000/mL), for dried-blood-spot (DBS) based PCR > 5/µL (5000/mL), and for ultrasensitive PCR (uPCR) with a validated limit of detection at 0.0022/µL (22/mL). Results: At baseline, before MDA, 1223 Plasmodium infections were detected by uPCR in 693 households. There was clustering of Plasmodium infections. In 637 households with asymptomatic infections 44% (278/637) had more than one member with Plasmodium infections. In the 132 households with symptomatic infections, 65% (86/132) had more than one member with Plasmodium infections. At baseline 4% of households had more than one Plasmodium falciparum infection, but three months after MDA no household had more than one P. falciparum infected member. Reactive case detection using DBS PCR would have detected ten additional cases in six households, and an RDT screen would have detected five additional cases in three households among the 169 households with at least one RDT positive case. This translates to 19 and 9 additional cases identified per 1000 people screened, respectively. Overall, assuming all febrile RDT positive patients would seek treatment and provoke reactive case detection using RDTs, then 1047 of 1052 (99.5%) Plasmodium infections in these communities would have remained undetected. Conclusion: Reactive case detection in the Greater Mekong subregion is predicted to have a negligible impact on the malaria burden, but it has substantial costs in terms of human and financial resources.
AB - Background: Malaria reactive case detection is the testing and, if positive, treatment of close contacts of index cases. It is included in national malaria control programmes of countries in the Greater Mekong Subregion to accelerate malaria elimination. Yet the value of reactive case detection in the control and elimination of malaria remains controversial because of the low yield, limited evidence for impact, and high demands on resources. Methods: Data from the epidemiological assessments of large mass drug administration (MDA) studies in Myanmar, Vietnam, Cambodia and Laos were analysed to explore malaria infection clustering in households. The proportion of malaria positive cases among contacts screened in a hypothetical reactive case detection programme was then determined. The parasite density thresholds for rapid diagnostic test (RDT) detection was assumed to be > 50/µL (50,000/mL), for dried-blood-spot (DBS) based PCR > 5/µL (5000/mL), and for ultrasensitive PCR (uPCR) with a validated limit of detection at 0.0022/µL (22/mL). Results: At baseline, before MDA, 1223 Plasmodium infections were detected by uPCR in 693 households. There was clustering of Plasmodium infections. In 637 households with asymptomatic infections 44% (278/637) had more than one member with Plasmodium infections. In the 132 households with symptomatic infections, 65% (86/132) had more than one member with Plasmodium infections. At baseline 4% of households had more than one Plasmodium falciparum infection, but three months after MDA no household had more than one P. falciparum infected member. Reactive case detection using DBS PCR would have detected ten additional cases in six households, and an RDT screen would have detected five additional cases in three households among the 169 households with at least one RDT positive case. This translates to 19 and 9 additional cases identified per 1000 people screened, respectively. Overall, assuming all febrile RDT positive patients would seek treatment and provoke reactive case detection using RDTs, then 1047 of 1052 (99.5%) Plasmodium infections in these communities would have remained undetected. Conclusion: Reactive case detection in the Greater Mekong subregion is predicted to have a negligible impact on the malaria burden, but it has substantial costs in terms of human and financial resources.
UR - http://www.scopus.com/inward/record.url?scp=85113496300&partnerID=8YFLogxK
U2 - https://doi.org/10.1186/s12936-021-03879-9
DO - https://doi.org/10.1186/s12936-021-03879-9
M3 - Article
C2 - 34446009
SN - 1475-2875
VL - 20
JO - Malaria journal
JF - Malaria journal
IS - 1
M1 - 351
ER -