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Subpatent malaria in a low transmission African setting: a cross-sectional study using rapid diagnostic testing (RDT) and loop-mediated isothermal amplification (LAMP) from Zambezi region, Namibia
- Source :
- Malaria Journal, Vol 17, Iss 1, Pp 1-11 (2018), Malaria journal, vol 17, iss 1, BASE-Bielefeld Academic Search Engine, Malaria Journal
- Publication Year :
- 2018
- Publisher :
- BMC, 2018.
-
Abstract
- Background Subpatent malaria infections, or low-density infections below the detection threshold of microscopy or standard rapid diagnostic testing (RDT), can perpetuate persistent transmission and, therefore, may be a barrier for countries like Namibia that are pursuing malaria elimination. This potential burden in Namibia has not been well characterized. Methods Using a two-stage cluster sampling, cross-sectional design, subjects of all age were enrolled during the end of the 2015 malaria transmission season in Zambezi region, located in northeast Namibia. Malaria RDTs were performed with subsequent gold standard testing by loop-mediated isothermal amplification (LAMP) using dried blood spots. Infection prevalence was measured and the diagnostic accuracy of RDT calculated. Relationships between recent fever, demographics, epidemiological factors, and infection were assessed. Results Prevalence of Plasmodium falciparum malaria infection was low: 0.8% (16/1919) by RDT and 2.2% (43/1919) by LAMP. All but one LAMP-positive infection was RDT-negative. Using LAMP as gold standard, the sensitivity and specificity of RDT were 2.3% and 99.2%, respectively. Compared to LAMP-negative infections, a higher portion LAMP-positive infections were associated with fever (45.2% vs. 30.4%, p = 0.04), though 55% of infections were not associated with fever. Agricultural occupations and cattle herding were significantly associated with LAMP-detectable infection (Adjusted ORs 5.02, 95% CI 1.77–14.23, and 11.82, 95% CI 1.06–131.81, respectively), while gender, travel, bed net use, and indoor residual spray coverage were not. Conclusions This study presents results from the first large-scale malaria cross-sectional survey from Namibia using molecular testing to characterize subpatent infections. Findings suggest that fever history and standard RDTs are not useful to address this burden. Achievement of malaria elimination may require active case detection using more sensitive point-of-care diagnostics or presumptive treatment and targeted to high-risk groups. Electronic supplementary material The online version of this article (10.1186/s12936-018-2626-5) contains supplementary material, which is available to authorized users.
- Subjects :
- Male
Subpatent
Rapid diagnostic test
law.invention
0302 clinical medicine
law
Risk Factors
Prevalence
80 and over
Medicine
030212 general & internal medicine
Malaria, Falciparum
Child
Subclinical infection
Aged, 80 and over
screening and diagnosis
biology
Middle Aged
Namibia
Asymptomatic
Detection
Transmission (mechanics)
Infectious Diseases
Medical Microbiology
Child, Preschool
Public Health and Health Services
Female
Infection
Nucleic Acid Amplification Techniques
4.2 Evaluation of markers and technologies
Falciparum
Adult
medicine.medical_specialty
lcsh:Arctic medicine. Tropical medicine
Adolescent
lcsh:RC955-962
030231 tropical medicine
Malaria elimination
Subclinical
Sensitivity and Specificity
Microbiology
lcsh:Infectious and parasitic diseases
03 medical and health sciences
Young Adult
Rare Diseases
Diagnostic Tests
Clinical Research
LAMP
Internal medicine
Tropical Medicine
parasitic diseases
Humans
Routine
lcsh:RC109-216
Preschool
RDT
Aged
Diagnostic Tests, Routine
business.industry
Research
Infant, Newborn
Infant
Plasmodium falciparum
Gold standard (test)
Submicroscopic
medicine.disease
biology.organism_classification
Newborn
Malaria
Vector-Borne Diseases
Good Health and Well Being
Cross-Sectional Studies
Parasitology
Tropical medicine
business
Subjects
Details
- Language :
- English
- ISSN :
- 14752875
- Volume :
- 17
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Malaria Journal
- Accession number :
- edsair.doi.dedup.....d8d8837410083df8e6d1ab9802c670ef