Evaluation of Malaria Diagnoses Using a Handheld Light Microscope in a Community-Based Setting in Rural Côte d'Ivoire

Abstract

Abstract. Portable microscopy may facilitate quality diagnostic care in resource-constrained settings. We compared a handheld light microscope (Newton Nm1) with a mobile phone attachment to conventional light microscopy for the detection of Plasmodium falciparum in a cross-sectional study in rural Côte d'Ivoire. Single Giemsa-stained thick blood film from 223 individuals were prepared and read by local laboratory technicians on both microscopes under 1,000× magnification with oil. Of the 223 samples, 162 (72.6%) were P. falciparum positive, and the overall mean parasite count was 1,392/μL of blood. Sensitivity and specificity of the handheld microscope was 80.2% (95% confidence interval [CI]: 73.1-85.9%) and 100.0% (95% CI: 92.6-100.0%), respectively, with a positive and negative predictive value of 100.0% (95% CI: 96.4-100.0%) and 65.6% (95% CI: 54.9-74.9%), respectively. If sensitivity can be improved, handheld light microscopy may become a valuable public health tool for P. falciparum diagnosis.

“Smart Diagnosis” of Parasitic Diseases by Use of Smartphones

“…For instance, a bright-field microscope was constructed using objective and wide-field eyepiece lenses to produce 28ϫ magnification onto a smartphone camera sensor for the identification of P. falciparum in blood smears (17). In another field study, P. falciparum was identified in Giemsa-stained blood films using a handheld Newton Nm1 light microscope attached to a smartphone (18). The system achieved a moderate sensitivity and a high specificity (see Table 1), suggesting that this could be invaluable in large-scale malaria screening programs.…”

Evaluation of a Mobile Phone-Based Microscope for Screening of Schistosoma haematobium Infection in Rural Ghana

“…Mobile phone microscopy has the potential to bring quality diagnostics to settings without access to standard laboratory facilities and may have applications in both clinical and public health settings. [8][9][10] Here, we demonstrated a modest sensitivity and excellent specificity of a novel mobile phone microscope design for the diagnosis of schistosomiasis in a school-based survey.…”

“…Given the paucity of skilled microscopists, machine learning technology could enable better access to care, as many health-care technicians would conceivably require training for sample processing, rather than training on both sample processing and microscopy analysis. Other future directions include integrating these novel diagnostic devices into routine public health practice, as has been recently studied with schistosomiasis, 9 malaria, 10 and Loa loa control efforts. 20 Mobile phone-enabled imaging, sensing, and diagnostics technologies have the potential to bring diagnostic testing to areas most in need, and to support clinical and public health practice in underserviced locations.…”

“…Recent studies have evaluated handheld and mobile phone-based microscopes designed to diagnose pathogens of global health concern, with field testing conducted in resource-constrained public health settings. 9,10 Here we describe the diagnostic operating char-acteristics of a novel mobile phone-based microscope for S. haematobium infection in a rural Ghanaian school.…”

Mobile phone and handheld microscopes for public health applications

“…5 Global positioning system coordinates can be linked to diagnostic results to map disease burden in real time. Cases in which mobile phone microscopes have been successfully used include for detection of malaria, 6 Loa loa, 7 schistosomiasis, and soil-transmitted helminths, 8 a set of diseases that disproportionately afflict those living in settings with limited access to conventional diagnostics. Also, initial results on applications related to diagnostics of non-communicable diseases show promise and can address the paucity of experts in lowresource settings through remote diagnostic support.…”