Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi
Background: Plasmodium knowlesi, a malaria parasite of Southeast Asian macaques, infects humans and can cause fatal malaria. It is difficult to diagnose by microscopy because of morphological similarity to Plasmodium malariae. Nested PCR assay is the most accurate method to distinguish P. knowlesi...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BioMed Central Ltd.
2014
|
| Subjects: | |
| Online Access: | http://ir.unimas.my/id/eprint/15787/ http://ir.unimas.my/id/eprint/15787/1/Evaluation%20of%20three%20rapid%20diagnostic%20tests%20%28abstract%29.pdf |
| _version_ | 1848837926394265600 |
|---|---|
| author | Foster, Deshka Cox-Singh, J. Dayang SA, Mohamad Krishna, Sanjeev Pek, P Chin Balbir, Singh |
| author_facet | Foster, Deshka Cox-Singh, J. Dayang SA, Mohamad Krishna, Sanjeev Pek, P Chin Balbir, Singh |
| author_sort | Foster, Deshka |
| building | UNIMAS Institutional Repository |
| collection | Online Access |
| description | Background: Plasmodium knowlesi, a malaria parasite of Southeast Asian macaques, infects humans and can cause
fatal malaria. It is difficult to diagnose by microscopy because of morphological similarity to Plasmodium malariae.
Nested PCR assay is the most accurate method to distinguish P. knowlesi from other Plasmodium species but is not
cost effective in resource-poor settings. Rapid diagnostic tests (RDTs) are recommended for settings where malaria
is prevalent. In this study, the effectiveness of three RDTs in detecting P. knowlesi from fresh and frozen patient
blood samples was evaluated.
Methods: Forty malaria patients (28 P. knowlesi, ten P. vivax and two P. falciparum) diagnosed by microscopy were
recruited in Sarawak, Malaysian Borneo during a 16-month period. Patient blood samples were used to determine
parasitaemia by microscopy, confirm the Plasmodium species present by PCR and evaluate three RDTs: OptiMAL-IT,
BinaxNOW® Malaria and Paramax-3. The RDTs were also evaluated using frozen blood samples from 41 knowlesi
malaria patients.
Results: OptiMAL-IT was the most sensitive RDT, with a sensitivity of 71% (20/28; 95% CI = 54-88%) for fresh and
73% (30/41; 95% CI = 59-87%) for frozen knowlesi samples. However, it yielded predominantly falciparum-positive
results due to cross-reactivity of the P. falciparum test reagent with P. knowlesi. BinaxNOW® Malaria correctly detected
non-P. falciparum malaria in P. knowlesi samples but was the least sensitive, detecting only 29% (8/28; 95% CI = 12-46%)
of fresh and 24% (10/41; 95% CI = 11-37%) of frozen samples. The Paramax-3 RDT tested positive for P. vivax with
PCR-confirmed P. knowlesi samples with sensitivities of 40% (10/25; 95% CI = 21-59%) with fresh and 32% (13/41;
95% CI = 17-46%) with frozen samples. All RDTs correctly identified P. falciparum- and P. vivax-positive controls
with parasitaemias above 2,000 parasites/μl blood.
Conclusions: The RDTs detected Plasmodium in P. knowlesi-infected blood samples with poor sensitivity and
specificity. Patients with P. knowlesi could be misdiagnosed as P. falciparum with OptiMAL-IT, P. vivax with
Paramax-3 and more correctly as non-P. vivax/non-P. falciparum with BinaxNOW® Malaria. There is a need for a sensitive
and specific RDT for malaria diagnosis in settings where P. knowlesi infections predominate. |
| first_indexed | 2025-11-15T06:47:25Z |
| format | Article |
| id | unimas-15787 |
| institution | Universiti Malaysia Sarawak |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T06:47:25Z |
| publishDate | 2014 |
| publisher | BioMed Central Ltd. |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | unimas-157872017-04-03T06:53:49Z http://ir.unimas.my/id/eprint/15787/ Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi Foster, Deshka Cox-Singh, J. Dayang SA, Mohamad Krishna, Sanjeev Pek, P Chin Balbir, Singh R Medicine (General) Background: Plasmodium knowlesi, a malaria parasite of Southeast Asian macaques, infects humans and can cause fatal malaria. It is difficult to diagnose by microscopy because of morphological similarity to Plasmodium malariae. Nested PCR assay is the most accurate method to distinguish P. knowlesi from other Plasmodium species but is not cost effective in resource-poor settings. Rapid diagnostic tests (RDTs) are recommended for settings where malaria is prevalent. In this study, the effectiveness of three RDTs in detecting P. knowlesi from fresh and frozen patient blood samples was evaluated. Methods: Forty malaria patients (28 P. knowlesi, ten P. vivax and two P. falciparum) diagnosed by microscopy were recruited in Sarawak, Malaysian Borneo during a 16-month period. Patient blood samples were used to determine parasitaemia by microscopy, confirm the Plasmodium species present by PCR and evaluate three RDTs: OptiMAL-IT, BinaxNOW® Malaria and Paramax-3. The RDTs were also evaluated using frozen blood samples from 41 knowlesi malaria patients. Results: OptiMAL-IT was the most sensitive RDT, with a sensitivity of 71% (20/28; 95% CI = 54-88%) for fresh and 73% (30/41; 95% CI = 59-87%) for frozen knowlesi samples. However, it yielded predominantly falciparum-positive results due to cross-reactivity of the P. falciparum test reagent with P. knowlesi. BinaxNOW® Malaria correctly detected non-P. falciparum malaria in P. knowlesi samples but was the least sensitive, detecting only 29% (8/28; 95% CI = 12-46%) of fresh and 24% (10/41; 95% CI = 11-37%) of frozen samples. The Paramax-3 RDT tested positive for P. vivax with PCR-confirmed P. knowlesi samples with sensitivities of 40% (10/25; 95% CI = 21-59%) with fresh and 32% (13/41; 95% CI = 17-46%) with frozen samples. All RDTs correctly identified P. falciparum- and P. vivax-positive controls with parasitaemias above 2,000 parasites/μl blood. Conclusions: The RDTs detected Plasmodium in P. knowlesi-infected blood samples with poor sensitivity and specificity. Patients with P. knowlesi could be misdiagnosed as P. falciparum with OptiMAL-IT, P. vivax with Paramax-3 and more correctly as non-P. vivax/non-P. falciparum with BinaxNOW® Malaria. There is a need for a sensitive and specific RDT for malaria diagnosis in settings where P. knowlesi infections predominate. BioMed Central Ltd. 2014 Article PeerReviewed text en http://ir.unimas.my/id/eprint/15787/1/Evaluation%20of%20three%20rapid%20diagnostic%20tests%20%28abstract%29.pdf Foster, Deshka and Cox-Singh, J. and Dayang SA, Mohamad and Krishna, Sanjeev and Pek, P Chin and Balbir, Singh (2014) Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi. Malaria Journal, 13 (60). ISSN 14752875 https://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-13-60 DOI: 10.1186/1475-2875-13-60 |
| spellingShingle | R Medicine (General) Foster, Deshka Cox-Singh, J. Dayang SA, Mohamad Krishna, Sanjeev Pek, P Chin Balbir, Singh Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi |
| title | Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi |
| title_full | Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi |
| title_fullStr | Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi |
| title_full_unstemmed | Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi |
| title_short | Evaluation of three rapid diagnostic tests for the detection of human infections with Plasmodium knowlesi |
| title_sort | evaluation of three rapid diagnostic tests for the detection of human infections with plasmodium knowlesi |
| topic | R Medicine (General) |
| url | http://ir.unimas.my/id/eprint/15787/ http://ir.unimas.my/id/eprint/15787/ http://ir.unimas.my/id/eprint/15787/ http://ir.unimas.my/id/eprint/15787/1/Evaluation%20of%20three%20rapid%20diagnostic%20tests%20%28abstract%29.pdf |