Instrument-free, visual and direct detection of porcine reproductive and respiratory syndrome viruses in resource-limited settings.

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) is one of the most complicated and dangerous diseases in pigs with high mortality since it modulates the immune system of the lungs and has been closely associated with secondary infection of other lethal bacteria and viruses. The gold standard of molecular diagnosis for PRRSV, reverse transcription (RT)-PCR, is time-consuming, expensive and requires transportation of samples to a specialized laboratory. In this study, a direct colorimetric RT-loop-mediated isothermal amplification (RT-LAMP) method was developed to specifically and rapidly detect PRRSV. The RT-LAMP outcomes can be visualized by the naked eye after 45 min of incubation at 65˚C without any cross-reactivity recorded with the bacteria and other viruses tested. In particular, the mobile, non-instrumented, commercial pocket hand warmers were demonstrated to su-ccessfully provide constant temperature for consistent nucleic acid amplification throughout the RT-LAMP reactions. The limit of detection of the assay was defined as the genomic RNA concentration extracted from a known viral titer of 10-2.5 TCID50/ml. The direct use of clinical serum samples required a simple dilution to maintain the performance of the colorimetric RT-LAMP assay. Therefore, the direct colorimetric RT-LAMP assay developed is well-qualified for producing a ready-to-use kit for PRRSV diagnosis in the field. Keywords: porcine reproductive and respiratory syndrome; rapid testing; RT-LAMP; colorimetric; direct detection; instrument-free.

Reuse of waste sludge from water treatment plants and fly ash for manufacturing of adobe bricks.

Reuse of sludge from a water treatment plant and fly ash for the manufacturing of adobe brick is a feasible approach for practical applications due to the numerous benefits from the cost savings of construction materials and the reduction of environmental pollution. In this study, sludge from a groundwater treatment plant and fly ash from a thermal power plant were used as alternative aggregates to replace clay, a traditional component for brick making. The main objective of this study is to produce adobe bricks by using hydraulic press technology. The optimum aggregate composition was investigated by determining the compressive strength according to Vietnam national standard TCVN 6355:1-2009. Other supplementary materials, including cement, liquid glass, and polypropylene fibers, were used as additives and adhesives. Results showed that a 2-hole brick product (8 × 4 × 8 cm) with strength M 4.0 satisfied the national quality standard, TCVN 6477-2016. In addition, the aggregate composition (wt%) as sludge: cement: fly ash: polypropylene fibers of 50 : 35: 15 : 0.5%/m3 aggregates was found to be the optimum ratio. This product shows a medium compressive strength that is appropriate in the construction of walls or fences in industrial factories or households. The results obtained in this study show a promising approach for the brick-making industry in Vietnam. A large amount of sludge can be reused as an alternative material to reduce the product price and achieve natural resource conservation.

Reasons for Increased Caesarean Section Rate in Vietnam: A Qualitative Study among Vietnamese Mothers and Health Care Professionals.

The Caesarean section rate in urban Vietnam is 43% in 2014, which is more than twice the recommended rate (10%-15%) by the World Health Organization. This qualitative study aims to identify the perceptions of pregnant mothers and health care professionals on the medical and social factors related to the increased Caesarean section rate in Vietnam. A qualitative descriptive study was conducted among pregnant mothers and healthcare professionals at two public hospitals in Nha Trang city. A content analysis was adopted in order to identify social and medical factors. As a result, 29 pregnant women and 19 health care professionals were invited to participate in the qualitative interviews. Private interviews were conducted with 10 women who wished to have a Caesarean section, and the others participated in focus group interviews. The main themes of the social factors were 'request for Caesarean section,' 'mental strain of obstetricians,' and 'decision-making process.' To conclude, this qualitative study suggests that there were unnecessary caesarean sections without a clear medical indication, which were requested by women and family members. Psychological fear occurred among women and family, and doctors were the main determinants for driving the requests for Caesarean section, which implies that education and emotional encouragement is necessary by midwives. In addition, a multi-faced approach including a mandatory reporting system in clinical fields and involving family members in antenatal education is important.

Recent Advances of Vaccine Adjuvants for Infectious Diseases

Vaccines are the most effective and cost-efficient method for preventing diseases caused by infectious pathogens. Despite the great success of vaccines, development of safe and strong vaccines is still required for emerging new pathogens, re-emerging old pathogens, and in order to improve the inadequate protection conferred by existing vaccines. One of the most important strategies for the development of effective new vaccines is the selection and usage of a suitable adjuvant. Immunologic adjuvants are essential for enhancing vaccine potency by improvement of the humoral and/or cell-mediated immune response to vaccine antigens. Thus, formulation of vaccines with appropriate adjuvants is an attractive approach towards eliciting protective and long-lasting immunity in humans. However, only a limited number of adjuvants is licensed for human vaccines due to concerns about safety and toxicity. We summarize current knowledge about the potential benefits of adjuvants, the characteristics of adjuvants and the mechanisms of adjuvants in human vaccines. Adjuvants have diverse modes of action and should be selected for use on the basis of the type of immune response that is desired for a particular vaccine. Better understanding of current adjuvants will help exploring new adjuvant formulations and facilitate rational design of vaccines against infectious diseases.