Nanophotonics: An Emerging and Promising Approach for COVID-19 Diagnostic Technology

The public health crisis initiated by the emergence of the COVID-19 pandemic emphasizes the need for rapid and accurate diagnostic tests to monitor large populations through community mass testing. Many testing techniques have been implemented to prevent disease spread, critical to pandemic control. Polymerase chain reaction (PCR) tests for detecting viral RNA and immunoassay tests for detecting SARS-CoV-2 antibodies are currently used to diagnose COVID-19. PCR tests are time-consuming, with a 24–48 hours turnaround time. Samples undergoing PCR detection must also be sent to a laboratory to be processed by highly specialized workers, preventing a point-of-care diagnosis from being provided. Popular immunoassay tests have drawbacks as well. Enzyme-linked immunosorbent assays (ELISAs) are extremely labor-intensive and expensive, whereas lateral flow assays (LFAs) are primarily used for antigen detection. In this work, we propose a photonic SARS-CoV-2 detection method based on a ring resonator. We calculate the sensor performance using the finite-difference eigenmode (FDE) method. The sensor sensitivity in ring resonator resonance frequency is 29 nm/RIU, with an intrinsic detection level (iLOD) of 6.89 × 10-5 RIU. We envision ring resonator-based lab-on-chip devices being widely used for applications such as early diagnosis, with the added benefit of being ultra-compact and easily handled by non-specialists.

How to Effectively Identify Patients With Rifampin-Resistant Tuberculosis in China: Perspectives of Stakeholders Among Service Providers

To evaluate China's current rifampin-resistant tuberculosis (RR-TB) screening strategy from stakeholders' perspectives, the perceptions, attitudes, and interests of 245 stakeholders from three eastern, central, and western China provinces on RR-TB screening strategies, were investigated through stakeholder survey and interview. The attitudes toward three RR-TB screening strategies were statistically different: inclination to choose who to screen (Z = 98.477; P < 0.001), funding for rapid diagnostic technology screening either by reimbursed health insurance or directly subsidized financial assistance (Z = 4.142, P < 0.001), and respondents' attitude during RR-TB screening implementation levels (Z = 2.380, P = 0.017). In conclusion, RR-TB screening scope could be expanded by applying rapid diagnostic technologies. Provinces with different economic status could adjust their screening policies accordingly.

New and emerging technologies for the diagnosis of urinary tract infections

Urinary tract infections affect 150 million people worldwide, yet the diagnosis of this common infection is not straightforward. Misdiagnoses and incorrect prescriptions are frequent in the treatment of urinary tract infections; this also contributes to the increase in antibiotic resistance among pathogens. Present diagnostic practices take 2–3 days for pathogen identification and antibiotic susceptibility testing. New technologies are urgently needed for improved patient care as well as to promote antibiotic stewardship. An ideal new diagnostic technology will test clinical urine samples directly and identify the pathogen and determine its antibiotic susceptibilities within a few hours such that the patient can be prescribed the appropriate antibiotic treatment the same day. Screening tools, such as flow cytometers and new dipstick assays, can help with rapidly identifying negative samples and improving workflow and reducing costs. Several groups have made progress in optimizing mass spectrometry methods for direct urine processing, and there are also new multiplex PCR panels that are specific for UTI pathogens and antibiotic resistance. We also discuss several emerging technologies – microfluidics, biosensors, real-time microscopy systems, and sequence-based diagnostics – that show huge potential in delivering rapid results.

Update on the management of a newborn with a suspected difference of sex development

Differences or disorders of sex development are a group of heterogeneous conditions, which most commonly present in the newborn period, with the appearance of atypical genitalia on newborn examination. Over recent years, the improvement in our knowledge of these conditions has been accompanied by advances in diagnostic technology and therapeutic options, as well as societal shifts in attitudes and expectations. These factors have placed an even greater emphasis than before on the need for early expert input through a multidisciplinary service that can support the patient and the family; perform and interpret the investigations required to reach a diagnosis; and formulate a management plan that lays down the foundation for optimal long-term outcome. While providing a regional service, the expert team should also be committed to research and quality improvement through participation in national and international networks.

Feasibility of Rapid Diagnostic Technology for SARS-CoV-2 Virus Using a Trace Amount of Saliva

Containment of SARS-CoV-2 has become an urgent global issue. To overcome the problems of conventional quantitative polymerase chain reaction (qPCR) tests, we verified the usefulness of a mobile qPCR device that utilizes mouthwash to obtain a saliva sample with the aim of developing a rapid diagnostic method for SARS-CoV-2. First, we examined whether anyone could easily operate this device. Then, we examined whether RNA in the mouthwash could be detected in a short time. In addition, we investigated whether it was possible to diagnose SARS-CoV-2 infection using mouthwash obtained from COVID-19 patients undergoing hospitalization. The results revealed that all subjects were able to complete the operation properly without error. In addition, RNase P was detected in the mouthwash without pretreatment. The average detection time was 18 min, which is significantly shorter than conventional qPCR devices. Furthermore, this device detected SARS-CoV-2 in the mouthwash of a COVID-19 patient undergoing hospitalization. The above findings verified the efficacy of this diagnostic method, which had a low risk of infection, was technically simple, and provided stable results. Therefore, this method is useful for the rapid detection of SARS-CoV-2.

Hepatic echinococcosis: difficulties in diagnosis at the early stages of progression and with complications (literature review)

To demonstrate the possible difficulties in the diagnosis of hepatic echinococcosis, that a specialist in ultrasound diagnostics and a radiologist may encounter in everyday practice, russian and foreign literature as well as our own experience have been reviewed. With high accuracy and specificity of ultrasonography in the differential diagnosis of echinococcal cysts, incorrect interpretation is possible in the presence of mural hemorrhages and (or) hemorrhagic clots in a nonparasitic cyst, which aren’t also visible in ultrasonography and can imitate elements of the chitinous membrane. The degree of prevalence of the process, the exclusion of damage to the lungs and other organs of the abdominal cavity are important. In such cases CT scan is the most convenient and accurate diagnostic method due to its high spatial and temporal resolution, standardization and availability. In the most difficult cases the capabilities of MRI are used in the comparison of diffusion-weighted images and apparent diffusion coefficient, which also makes it possible to diagnose cystic neoplasms. Ultrasonography is a diagnostic technology that is still the most commonly used to differentiate cavity structures; however, all dubious clinical observations should be further examined by using CT or MRI.

The value of single-molecule real-time technology in the diagnosis of rare thalassemia variants and analysis of phenotype–genotype correlation

To compare single-molecule real-time technology (SMRT) and conventional genetic diagnostic technology of rare types of thalassemia mutations, and to analyze the molecular characteristics and phenotypes of rare thalassemia gene variants, we used 434 cases with positive hematology screening as the cohort, then used SMRT technology and conventional gene diagnosis technology [(Gap-PCR, multiple ligation probe amplification technology (MLPA), PCR-reverse dot blot (RDB)] for thalassemia gene screening. Among the 434 enrolled cases, conventional technology identified 318 patients with variants (73.27%) and 116 patients without variants (26.73%), SMRT identified 361 patients with variants (83.18%), and 73 patients without variants (16.82%). The positive detection rate of SMRT was 9.91% higher than conventional technology. Combination of the two methods identified 485 positive alleles among 49 types of variant. The genotypes of 354 cases were concordant between the two methods, while 80 cases were discordant. Among the 80 cases, 76 cases had variants only identified in SMRT method, 3 cases had variants only identified in conventional method, and 1 false positive result by the traditional PCR detection technology. Except the three variants in HS40 and HBG1-HBG2 loci, which was beyond the design of SMRT method in this study, all the other discordant variants identified by SMRT were validated by further Sanger sequencing or MLPA. The hematological phenotypic parameters of 80 discordant cases were also analyzed. SMRT technology increased the positive detection rate of thalassemia genes, and detected rare thalassemia cases with variable phenotypes, which had great significance for clinical thalassemia gene screening.

Eradication of Malaria: Present Situations and New Strategies

Malaria is a serious disease caused by the protozoon parasite Plasmodium and transmitted by the female Anopheles mosquito as a vector. P. falciparum is the gravest infection for all other species P. ovale, P. vivax, P. Malariae and P. knowlesi in terms of morbidity or mortality, which is why most research focused on P. falciparum. The disease affects about 300-500 million people, mostly in the tropics. In regions with a weak economic downturn in tropical and subtropical capital, morbidity and mortality have elevated. Malaria remains a persistent threat in recent research. At the beginning of the 20th century, scientists tried to describe a successful way of eradicating malaria. However, the presence of drug resistance and social and environmental problems, no acceptable and positive future solution has been pointed out. Several studies have highlighted the need to establish advanced nano-biotechnology treatment, novel anti-malarial drug targets, an efficient malaria vaccine technique, and Anopheles gene editing, which opened the door to a healthy, environmentally friendly malaria treatment method over the last two decades. In recent years, the use of mosquito microbiota has shown great potential for cutting down the transmission of mosquito-borne pathogens. This review aims to cover important issues in malarial eradication as rapid diagnostic technology, novel anti-malarial drug targets, Anopheles gene editing, use of mosquito microbiota, and recent vaccines.