Loop-Mediated Isothermal Amplification (LAMP) for the Diagnosis of Zika Virus: A Review

Abstract

The recent outbreak of Zika virus (ZIKV) in the Americas and its devastating developmental and neurological manifestations has prompted the development of field-based diagnostics that are rapid, reliable, handheld, specific, sensitive, and inexpensive. The gold standard molecular method for lab-based diagnosis of ZIKV, from either patient samples or insect vectors, is reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The method, however, is costly and requires lab-based equipment and expertise, which severely limits its use as a point-of-care (POC) tool in resource-poor settings. Moreover, given the lack of antivirals or approved vaccines for ZIKV infection, a POC diagnostic test is urgently needed for the early detection of new outbreaks and to adequately manage patients. Loop-mediated isothermal amplification (LAMP) is a compelling alternative to RT-qPCR for ZIKV and other arboviruses. This low-cost molecular system can be freeze-dried for distribution and exhibits high specificity, sensitivity, and efficiency. A growing body of evidence suggests that LAMP assays can provide greater accessibility to much-needed diagnostics for ZIKV infections, especially in developing countries where the ZIKV is now endemic. This review summarizes the different LAMP methods that have been developed for the virus and summarizes their features, advantages, and limitations.Viruses 2020, 12, 19 2 of 20 raising concerns about the neurological tropism of the virus [12]. In May 2015, the first case of ZIKV infection was reported in Brazil [13] and the virus rapidly spread throughout the country and much of Latin America, causing the largest recorded epidemic of the virus to date [14]. The Brazilian epidemic raised great international concern because of severe birth defects, including microcephaly, in neonates born to mothers infected by ZIKV during pregnancy [3,15,16].ZIKV is transmitted mainly through the bite of infected mosquitoes from the genus Aedes, although other vectors may also be involved in the transmission [17][18][19][20][21]. Additionally, other routes of ZIKV transmission have been identified, including blood transfusions, transplacental, perinatal, and sexual intercourse [22][23][24]. ZIKV infection usually causes a self-limiting and a mild illness, where the majority of cases are asymptomatic and, when present, symptoms include fever, headache, rash, conjunctivitis, and arthralgia [25]. In regions where there is a circulation of other arboviruses, such as DENV and chikungunya (CHIKV), the clinical diagnosis of ZIKV infection becomes extremely difficult because of common symptoms. Therefore, laboratory-based molecular diagnosis is of fundamental importance to correctly identify the etiologic agent [3,26].Given the lack of approved vaccines and antivirals against ZIKV, a rapid and reliable point-of-care (POC) diagnostic test for detection of ZIKV is urgently required for control and prevention measures and to increase the diagnostic capacity of ZIKV-affected, mainly in low-resource areas [27,28]. Z...

Navigating the Pandemic Response Life Cycle: Molecular Diagnostics and Immunoassays in the Context of COVID-19 Management

“…In isothermal amplification reactions, several versions of strand displacement enzymes are available to amplify from both RNA and DNA [149] [150]. These enzymes have been demonstrated to achieve more rapid sample to result turnaround time, certain levels of tolerance for complex matrices and dirty samples, while exhibiting higher sensitivity [151].…”

Clinical Validation of Two Recombinase-Based Isothermal Amplification Assays (RPA/RAA) for the Rapid Detection of African Swine Fever Virus

“…However, they are costly, time-consuming and inappropriate for wide application in resource-limited laboratories or even in the field. Isothermal amplification has recently been introduced for the detection of various viruses (Congdon et al, 2019;Hu et al, 2019;Silva et al, 2019). The detection of ASFV with loop-mediated isothermal amplification (LAMP), for instance, shows concordance with real-time PCR but requires four or more primers, and primer design is typically complex (James et al, 2010;Wozniakowski et al, 2018).…”

Detecting the Coronavirus (COVID-19)

“…These methods do not require any thermal cycler to perform the amplification and, therefore, can be carried out in a simple water bath at a constant temperature of 40–65 °C. 47 One promising isothermal nucleic acid amplification approach is reverse transcription loop mediated isothermal amplification (RT-LAMP). In this method, the RNA genome of SARS-CoV-2 is first reverse transcribed to cDNA and is then amplified using four to six target-specific primers.…”