Detection of waterborne parasites using field-portable and cost-effective lensfree microscopy

Abstract

Protection of human health and well-being through water quality management is an important goal for both the developed and the developing parts of the world. In the meantime, insufficient disinfection techniques still fail to eliminate pathogenic contaminants in freshwater as well as recreational water resources. Therefore, there is a significant need for screening of water quality to prevent waterborne outbreaks and incidents of water-related diseases. Toward this end, here we investigate the use of a field-portable and cost-effective lensfree holographic microscope to image and detect pathogenic protozoan parasites such as Giardia Lamblia and Cryptosporidium Parvum at low concentration levels. This compact lensless microscope (O. Mudanyali et al., Lab Chip, 2010, 10, 1417-1428, weighing ~46 grams, achieves a numerical aperture of ~0.1-0.2 over an imaging field of view that is more than an order of magnitude larger than a typical 10X objective lens, and therefore may provide an important high-throughput analysis tool for combating waterborne diseases especially in resource limited settings.Water-associated diseases create major problems in the developing parts of the world where there is no reliable infrastructure for proper decontamination of water resources which also brings inadequate access to clean drinking water. The same danger also occurs during natural disasters and wars, where water treatment and sewage facilities lose their functionality. As a matter of fact, the occurrence of waterborne diseases has been dramatically increasing worldwide including in highly industrialized countries such as the United States. [2][3][4][5] Two widely spread examples of such diarrheal diseases include Giardiasis and Cryptosporidiosis which are caused by protozoan parasites, namely Giardia Lamblia and Cryptosporidium Parvum, respectively. 6 Unfortunately, these parasites can survive in cold water for several weeks and are resistant to most of the conventional water treatment methods such as chlorination. 7 Various approaches have been demonstrated so far for identification and quantification of pathogens in drinking and recreational water resources. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Traditional culture-based methods are time-consuming and have serious drawbacks due to lack of accurate enumeration methods as well as rapid transition of some of the species into non-culturable state after being released into freshwater. 11,12 To address the challenges of these laborious tools, culture-independent techniques have also been demonstrated, which utilize various technologies including polymerase chain reaction † Published as part of a special issue dedicated to To provide an alternative solution to this important problem, here we investigate the use of a field-portable lensfree holographic microscope (see Fig. 1) to image and automatically detect pathogenic protozoan parasites such as Giardia Lamblia and Cryptosporidium Parvum at low concentration levels of <400/mL without the use o...

Comparison of supervised machine learning algorithms for waterborne pathogen detection using mobile phone fluorescence microscopy

“…Traditional treatment methods such as chlorination are not as effective to remove the cysts of the parasite because the cyst's thick cell wall makes it moderately resistant to chlorine [1,2]. Therefore, timely detection of the presence of the cysts in water samples is extremely important to treat and prevent the spread of the disease, especially in field settings [4][5][6][7][8][9][10].…”

Lensfree color imaging on a nanostructured chip using compressive decoding

“…For this end, several lensfree onchip microscopy modalities have been introduced so far, covering both bright-field and fluorescent imaging. [5][6][7][8][9][10][11][12][13] Along the same lines, we have recently demonstrated lensfree incoherent imaging on a chip using nanostructured substrates.…”

Field-portable lensfree holographic color microscope for telemedicine applications

“…taking few intensity measurements (typically 3-5) at different heights, multi-height phase recovery can be implemented to reconstruct images of dense and confluent samples. It should be emphasized that the exact sample height for each lensfree hologram is calculated digitally by an autofocus algorithm [31]. As a result, the exact axial translation does not need to be known during the data acquisition process.…”