The relative opportunity cost of birth of individual operators is more concentrated in the range of 50%–80%. The results show that the development of labor OEM industry is significantly influenced by the fertility willingness of rural families. This paper concludes that differentiated policies and measures should be taken according to the type of industrial promotion.At present, China is facing problems such as the decline of fertility rate, gender imbalance, serious aging, and the reduction of youth and working population, which will have an adverse impact on the long-term development of social economy. Based on the literature review, combined with China's financial family data, combined with the innovative calculation model of the correlation between rural family fertility willingness and labor original equipment manufacturing (OEM) industrial development, through the empirical analysis of rural families, this paper investigates the relationship between fertility willingness and the development and endogeneity of labor OEM industry and finds that female labor participation has a significant negative impact on the number of children in rural families. Spouse labor participation has a negative effect on the number of children in rural families. The regression coefficient of women's willingness to have two children for career development is significant and negative ( The introduction of the comprehensive three-child policy has greatly reformed the family planning policy that has been implemented for more than 30 years, which has attracted the attention of academia and the public. Some scholars worry that if the policy is liberalized, the pressure of fertility rate will still be great, and there will be another “population explosion.” Some scholars have high hopes for the two-child policy, which will significantly increase the fertility rate. The aging population will aggravate the decline of labor supply . The worAs the main body of reproductive behavior, women bear the dual roles of work and family, which is not only an important part of the labor market, but also an indispensable human resource for China's economic development and is responsible for the future labor supply and human resources. Fatima and others believe that the fertility rate depends on the balance between the income effect and the substitution effect of reproductive demand . Devaro Child support, fertility willingness, support, and other factors all play a role in the decision-making process for family fertility in rural areas. This paper adds to the explanation for the discrepancy between them, which is primarily due to women's reproductive choices in the labor market. The goal of this paper is to use the model in conjunction with data on female employment and fertility in China to better understand the impact of rural families' desire for children on the development of China's original equipment manufacturing industry, as well as to theoretically support the practical importance of family economic theory. Exploring how to eliminate the negative impact of women's employment on fertility through policy measures is useful for providing a theoretical foundation and decision-making reference for the government's employment policy direction and focus in the context of the current human dividend's disappearance.A possible innovation of this paper is to link the influence of rural families' fertility willingness on the development of China's labor OEM industry with the demographic dividend, which is the growth source of the demographic dividend itself.According to the research object, this paper adopts a variety of research methods, using probit and logit analysis methods as explanatory variables of children's binary variables, and the number of children is an ordinal variable analyzed by OLS. For different research objects, adopt more scientific analysis methods.Possible innovations of this paper are as follows:Fertility desire is people's desire and pursuit for fertility, and it is also the individual's desire and requirement for fertility, which is reflected in the expectation of the quantity, time, gender, and quality of fertility. Because there is a strong correlation between fertility behavior and fertility willingness, the three-dimensional thinking of fertility behavior is applied, in which fertility willingness, number of children, and gender of willing children are the main components.In a high fertility environment, unexpected births often occur, and the actual number of children born is larger than the expected number. They think that the level of fertility willingness is much higher than the actual fertility rate. Yakita believes that the deviation degree of fertility will and behavior is influenced by the life cycle of women . Tian etOEM industry, as its name implies, is an agent processing industry, also known as outsourcing industry, which is composed of many companies engaged in OEM industry. Its main business is to share the processing and assembly defects in other enterprises' industrial chains, and the main types are processing with incoming materials, processing with imported materials and processing with incoming samples. Labor cost is the main component of production cost. If the level of labor cost or labor wage rises, the production cost of enterprises will also rise. Industrial transfer is a process in which the market continuously allocates resources. Maximizing the allocation of resources through industrial transfer can promote the industrial structure of a country or region, improve efficiency, and ultimately promote economic development.Harrison and others studied many companies and multinational corporations on the basis of empirical analysis and thought that, in the highly industrialized open economy, labor-intensive industries were easier to transfer than before . ThroughAnalyzing the factors affecting fertility will help systematically understand the three child policy support needs of people of childbearing age. Through the analysis of the “three-child” policy and the wishes of children of childbearing age groups, it can be seen that the “three-child” policy is an important measure to solve the problems of China's population structure and population aging. The three-child policy is facing the dilemma of low fertility willingness, which is not conducive to the healthy development of China's society and economy .The main economic factors are high economic pressure and high cost of raising three children.Social factors, including raising children to prevent old age, giving birth to elders, happy and complete family, unattended children, affecting the development of work and career, etc.Cultural factors, such as the hope of both children and children to satisfy parent-child feelings.I can divide the influencing factors into the following:Due to the needs of China's actual national conditions, the family planning policy is China's basic national policy, and the influence of policy factors on fertility willingness of fertility families is also worth investigating. Therefore, this study divides the influencing factors of childbearing families into four dimensions: policy factors, economic factors, social factorsm and cultural factors. The theoretical framework of this paper is shown in In order to observe the influence of rural families' fertility desire on the development of China's labor OEM industry, it is assumed that women decide both the employment situation and the childbearing time and that she has not changed her employment situation after giving birth to her first child, and she decides whether to work at the same time as giving birth to her child. Assume that the number of children and women employed in a given period is the result of this decision-making process.Yth, t is the time variable, and h is the family variable. The expectation of Yth based on the exogenous feature zth is represented by E and θ. According to the above model and iterative expectation law, the conditional expectation of Yth can be obtained as follows:Wth represents the situation of women's employment . IYth > 0), the comparison between bivariate linear and multinomial logarithmic models is complicated, and there is no direct connection between the parameter estimates obtained from the two models. When children enter rural families, their conditional expectations areFor the existence of the second child, this setting always has an expected value greater than 1, which is limited by the existence of the child.First, we examine the variables related to the number of children in rural families. The variable described in this paper is the fertility rate, which is a binary dummy variable with a value of 1 when a child is born. The model of logit, probit regression, isThe variables in the model are explained in There is a causal relationship between rural family fertility willingness and the development of Chinese labor OEM industry. The choice of female reproductive behavior mainly includes the choice of reproductive age and the choice of the number of children, which is also a process of mutual decision and influence. Based on this, this paper constructs the following simultaneous equations to evaluate the influence of women's labor participation behavior on the childbearing age and the number of children.it,Ageit—Representing the number and age of women's childbearing respectively is the main index of reproductive behavior choice. Numberit—Variables reflecting women's labor participation, in this study, we will mainly consider whether women participate in labor and the nature of labor as variable indicators. LaborXit—Personal characteristics affecting the number of births. Yit—Personal characteristics that affect the reproductive age. Uit—Other controlled variables, mainly including the characteristics of family and community. Pit—Virtual variable of family planning policy. Among them:It can provide nonagricultural employment opportunities for surrounding women as a leader in economic development, and because of its proximity, it can also promote rural women's participation in nonagricultural work, which is beneficial to local rural women's participation in nonagricultural work. It is a problem that women should not consider when making reproductive decisions, just as it is a problem that women should not consider when making transportation facilities such as bus stops, development zones, and special economic zones. It only has to do with labor participation in decision-making and has nothing to do with reproductive choices.A and the company are located in the middle, and the company has three optional operations: requirement and default, A. The government adopts two selective measures to increase the preferential margin and maintain the status quo.We constructed a dynamic two-person and three-level game with complete information . The comA to provide more preferential treatment, otherwise, it will move to Zhengzhou. Government A learns that government B has also implemented preferential policies for attracting investment. At this time, the economic aggregate of the enterprise is (R+E3), the economic aggregate of government A changes to (G1 − E3), and the economic aggregate of government A does not change to G2, with zero change.If the enterprise fails to ask government R+E2 − C), the economic aggregate of government A is (G1 − R), and that of government B is (G2+R − E2).In the third stage, the enterprise's strategies are migration, default, and requirements. At the time of migration, the economic aggregate of enterprises is (R+E1), the economic aggregate of government A is (G1 − E1) at this time, and the economic aggregate of government B remains unchanged. This cycle continues until a certain local government withdraws from the game process. The whole game process is shown in If the enterprise chooses the default at this time, the economic aggregate of the enterprise is , there isAccording to , if π0=σSubstituting  into 6)6) resultπ0=π is substituted into formula  algorithm is an ensemble learning algorithm based on decision tree. Decision tree is a single learning method, called “Basic Learner,” which combines multiple decision trees into a “Forest.” By forming a strong learner in the integrated learning method, the predictive ability of the algorithm can be effectively improved. Create RF model:xi, ti are the characteristic variable and the corresponding splitting critical value of each decision tree when splitting at the i-layer in RF algorithm according to the principle of “minimizing the sum of squares of residuals.”λ—The punishment intensity of complexity T obtained by cross-validation method; n—Core characteristic variables; x—Other characteristic variables; B—Number of decision trees contained in RF. Among them, xi, ti, T, λ through algorithm training and verification, the relative opportunity cost of childbearing can be combined with the level of living burden to measure the degree that the opportunity cost of childbearing can be borne.After obtaining the results of parameters such as The data used in this paper is the panel data of CFPS 2015–2021. In this study, the variables used in the equivalence scale method include income satisfaction, total family income, family size, and number of children. This paper chooses income satisfaction as the explanatory variable. We need to filter data and delete missing items and outliers of families with children under 20 years old. Because the answer of income satisfaction is set to 1 to 5, 1 means “unsatisfied,” and 5 means “very satisfied,” and the variable is discrete.Compared with cross-sectional data, panel data has certain advantages: first, it can use the difference between groups to multiply the time trend, so as to eliminate the possible deviation caused by small samples; secondly, the endogenous problem can be overcome by using lag data. Among the basic elements of social support, this paper takes into account the respondents' maternity insurance status, peer reproductive pressure, and local infant community service facilities. From Increasing the female labor force participation rate can revitalize the current economy, but it will significantly reduce the female fertility rate, further affect the national fertility rate, and affect the future labor supply and economic development. Therefore, it is the goal of all countries to maintain a high female labor force participation rate without affecting the fertility rate. Asian countries, especially some East Asian countries and Southeast Asian countries, should constantly improve policies to encourage women to bear children, such as parental leave and flexible working system.The regression results in c1=−0.181, P=−0.003 < 0.01), indicating that the better the career development, the lower the probability that women intend to have two children. The regression coefficient between women's family status and the willingness to have two children is significant and negative , indicating that the higher the family status, the lower the probability that women intend to have two children. This means that the impact of a woman's professional advancement on her desire to have two children is at least partially realized through the parameters of her family status. The improvement of women's family status is one of the negative effects of their career advancement on their willingness to have a second child. We made a comparison by age in The regression coefficient between women's career development and their willingness to have two children is significant and negative , indicating that the better the career development, the lower the probability that women intend to have two children. The regression coefficient between women's family status and the willingness to have two children is significant and negative , indicating that the higher the family status, the lower the probability that women intend to have two children.The regression coefficient between women's career development and their willingness to have two children is significant and negative (The relative opportunity cost of unit female fertility rate is more obviously concentrated in the range of 0–10%, while that of private ownership is concentrated in the range of 10%–20%. The relative opportunity cost of female fertility rate in local governments and social organizations is concentrated in the range of 0∼10%, and distributed symmetrically around 0, but the relative opportunity cost of self-employed fertility rate is in the range of 50%–80%.The research of this paper mainly focuses on the measurement of the correlation degree between rural families' fertility willingness and the development of China's labor OEM industry and investigates the main influencing factors of different children in rural families. The main findings are as follows:


The HTLV-1 prevalence in China varies geographically, while HTLV-2 infection has rarely been found so far. Proviral load is one of the determining factors of pathogenesis and progression of HTLV-1 related diseases. However, neither molecular assays nor commercial kits are available for HTLV-1 diagnosis in China. The objective of the present study was to develop and validate a TaqMan qPCR assay for HTLV-1 proviral load quantification.8 copies/reaction ~ 25 copies/reaction) and sensitive to 1 copy for HTLV-1 and RPPH1. The limit of detection for Hut102 cell concentration was 0.0218% . The assay gave coefficient of variation (CV) for both the HTLV-1 and RPPH1 Ct values. All of the HTLV-1 sero-negative samples and MOT cell line (infected with HTLV-2) amplified only the RPPH1 gene by our method, presenting 100% specificity. 85 Samples confirmed positive or indeterminate by LIA were performed by established qPCR assay and WB. 90.0% (27/30) of LIA-HTLV-1-positive, 33% (2/6) of LIA-untypeable and 2% (1/49) of LIA-indeterminate samples were defined as qPCR-positive. The median PVL of LIA-positive samples  was much higher than that of LIA-untypeable and  indeterminate samples . Additionally, compared to WB, the duplex qPCR verified more positive samples, demonstrating a better sensitivity.A plasmid containing both the HTLV-1 of interest and a fragment of the RNase P (RPPH1) gene was constructed and used to establish the standard curves. The assay has a wide dynamic range (2.5 × 10The duplex qPCR developed here with high sensitivity, good specificity and reproducibility could accurately and quantitatively detect the HTLV-1 PVLs, which can be used to confirm the initial reactive samples for an improved cost/benefit ratio as well as to monitor the clinical progression and efficacy of therapy in patients with HTLV-1 related disease.The online version contains supplementary material available at 10.1186/s12985-023-01970-y. HTLV-1 is the first RNA retrovirus found to be mainly transmitted by mother-to-child, sexual contact and injecting drug users . It alsoAccording to the report of a statewide multicenter large-scale survey on the seroprevalence of HTLV infection among Chinese blood donors, the majority of mainland China is classified as an HTLV non-endemic area . The NatPVL quantification was initially performed using semiquantitative PCR and southern blots, however neither method was able to determine the precise copy number. In recent years, qPCR has been performed for HTLV-1 or/and HTLV-2 viral quantification. However, the published qPCR techniques had a few shortcomings. (1) the preparation of quantitative standards, which typically involved sequential reference DNA diluents derived from HTLV-1-infected cell lines, was a labor-intensive technique that made it challenging to replicate the findings , 10. (2)pol region and tax region) and the internal reference RPPH1 gene. A plasmid carrying both the HTLV-1 of interest and a fragment of the RPPH1 gene was used to establish the standard curves. The sensitivity, specificity, reproducibility and accuracy of this assay were analyzed and preliminary results on its use for specimens with LIA-indeterminate and positive results from blood donors were reported.Due to this, we decided to develop a single-tube qPCR assay to quantify HTLV-1 PVLs in PBMCs, which was normalized by means of the quantitation of a cellular gene RNase P (RPPH1). Multiple pairs of primers and probes were designed and screened based on the HTLV-1 conserved region . Hut102 is a HTLV-1-infected cell line and MOT is a HTLV-2-infected cell line. All of these cells were cultured in RPMI-1640 medium (Gibco), without addition of antibiotics and extra growth factors but supplemented with 10% FBS (Gibco) in a humidified atmosphere with 5% CO2. gDNA was extracted using a Tiangen Magnetic Blood Genomic DNA Kit .pol and tax region were amplified using gDNA from Hut102 cells and consecutively cloned into pcDNA3.1(-)-Rluc-Fluc vector (conserved in our lab). The HTLV-1 pol and tax region were separately cut with SpeI endonucleases and cloned into the vector that contains RPPH1 gene (pcDNA3.1(-)-RPPH1) previously generated by replace with the Fluc and Rluc gene cutting with BamHI endonucleases  were prepared immediately before use. All the dilutions and individual samples were run in duplicate.To construct the pcDNA3.1(-)-HTLV-1-RPPH1 plasmid, the human RPPH1 gene and the HTLV-1 pol and tax regions of the HTLV-1 and RPPH1 sequences. Primers were screened by efficiency of amplification using SYBR Premix Ex Taq™ II kit , and primers with significant dimerization were removed. Probes were further screened using Hyperstart Premix-UNG  in accordance with the manufacturer’s instructions. Probes with lower count (Ct) values were chosen for further experiments (data not shown). pcDNA3.1(-)-H1-pol-tax-RPPH1 was used as template for primers and probes screening. The primers and probes we finally selected for using were listed in Table Primers and probes were designed by Primer 5 to target the conserved sequences of the pol and RPPH1 were optimized from 0.2 to 1.0 μΜ, while the probes were optimized from 0.2 to 1.0 μM. The annealing temperature for qPCR were optimized from 60 to 68 °C. The operate concentration of primers and probes, as well as the annealing temperature selected for the following experiments were based on the high efficiency (between 95 and 105%) and the lowest Ct values at the same concentration of the template. Finally, the optimized amplification was performed using the following cycling conditions: initial step of 2 min/50 °C, denaturation of 5 min/95 °C, 40 cycles of 20 s/95 °C, annealing step of 30 s/60 °C and elongation step of 20 s/72 °C. The final volume of the reaction was 25 μL, the optimized primer concentrations for HTLV-1pol and RPPH1 genes were 800 nM, and the optimized probe concentrations for the two genes were 300 nM. The probes were labeled by FAM (HTLV-1 pol)/VIC (RPPH1). All reactions were carried out using Hyperstart Premix-UNG  in a concentration specified by the manufacturer. Standard curves for HTLV-1 and RPPH1 were accepted when the slopes were between − 3.44 and − 3.21 (corresponding to PCR efficiencies of between 95 and 105%) and the coefficients of correlation, r2, were > 0.98.Real-time qPCRs were conducted using a 7500 ABI (Applied Biosystems). The final concentrations of primers of HTLV-1 pol and RPPH1, pcDNA3.1(-)-H1-pol-tax-RPPH1 plasmid was serially diluted at the concentrations from 5 × 109 to 0.2 copies/μL and each of them was tested in replicate.To evaluate the dynamic range of the HTLV-1 7 copies/μL, 103 copies/μL, 5 copies/μL) 6 times per day for 3 consecutive days. Three different cell concentrations of Hut102 with known proviral loads  were prepared and each of them were extracted independently for six times. Their gDNA were carried out in the same TaqMan assay to evaluate the accuracy.To evaluate the intra- and inter-assay reproducibility, our method quantified three plasmid dilutions  and the MOT cell line (infected with HTLV-2) were tested by the assay. Hut102 containing HTLV-1 genome was used as a positive control.To evaluate the limit of detection (LOD), genomic DNA extracted from a serial dilution of Hut102 cells with Jurkat cells was used as the template, each of which was tested by the duplex qPCR for 20 times. Probit analysis was used to determine the LOD of the assay.pol-tax-RPPH1 plasmid were digested with KpnI  was added to digital PCR master mix v2  with a final concentration of 500 nM forward and reverse primers, and 150 nM of FAM and VIC-labeled probes. The PCR mixture was loaded on the digital PCR chip, and PCR was performed with a LifePro thermal cycler (Bio-Rad) using primers and probes for HTLV-1 and RPPH1 described above and detected with a QX200 droplet reader (Bio-Rad).For QuantiStudio 3D digital PCR analysis, 5 ng of genomic DNA from Hut102 cells and 10 ng of pcDNA3.1(-)-H1-A total of 85 samples from blood donors were included in this study. All of these samples were confirmed as LIA-positive or indeterminate by INNO-LIA HTLV I/II score kit  and simultaneously tested by WB  and qPCR. DNA was extracted from the whole blood of each blood sample described as above and HTLV-1 proviral DNA was detected and quantified. The normalized HTLV-1 PVL was calculated as the ratio of (HTLV-1 DNA average copy number/RPPH1 average copy number) × 2 × 100 leukocytes, expressed as the number of HTLV-1 copies per 100 cells.pol-tax-RPPH1 that contained one copy of the RPPH1 gene and HTLV-1 target region was constructed. To verify the capacity of the plasmid as a standard for quantification of HTLV-1 proviral DNA, serial dilutions from 5 × 109 copies/μL–0.2 copies/μL were tested by the duplex qPCR. Both HTLV-1 pol and RPPH1 showed excellent amplification result  when the plasmid dilutions from 5 × 107 copies/μL to 5 copies/μL -H1-pol gene but presented amplification of the reference gene RPPH1. Hut102 was amplified for both HTLV-1 pol and RPPH1 gene. Therefore, the duplex qPCR assay showed 100% specificity.24 HTLV-negative samples and the MOT cells with HTLV-2 genome were not amplified for the HTLV-1 pol-tax-RPPH1 and Hut102 were subjected to ddPCR. As shown in Table pol gene to RPPH1 for pcDNA3.1(-)-H1-pol-tax-RPPH1 was 1.001, indicating that the ddPCR results were credible and accurate. The mean ratio of the pol gene to RPPH1 for gDNA of Hut102 cells was 0.5735, that means each Hut102 cell contains 1.146 copies of HTLV-1. Consequently, gDNAs extracted from a serial dilution of Hut102 cells with Jurkat cells were subjected to our method and each gDNA was tested for 20 replicates. According to the results of probit regression, the limit of detection (LOD) by using our method for Hut102 cell concentration was 0.0218% , which means the LOD for the HTLV-1 pol region was estimated to be 2.5 copies per 10,000 host leukocytes with a 95% hit-rate -H1-pol-tax-RPPH1 plasmid . The intra- and inter-assay variations (CVs) for HTLV-1 Ct values were 0.36–2.81% and 0.64–3.19%, respectively. And for RPPH1 were 0.27–0.84% and 0.83–2.55%, respectively -H1-To evaluated the accuracy of the duplex qPCR, three standard Hut102 dilutions with accurate HTLV-1 proviral loads (quantitated by ddPCR) were tested by our method. Each sample’s gDNA was extracted independently by six times and then were carried out in the same TaqMan assay. The CV values of the standard cells were ranged from 2.9% ~ 33.45%, and for Hut102 cells, the detected copy number (1.22 ± 0.035 copies/cell) was very close to the theoretical values  was higher than that of the untypeable  and indeterminate samples , but there were no significant differences among them as the sample size were too small Fig. . Most ofThe qPCR is one of the most important molecular confirmatory tools for HTLV-1/2 diagnosis. Serological confirmatory assays for HTLV-1/2 (WB and LIA) are expensive and tend to provide indeterminate and untyped results. In China, no molecular assays for HTLV-1/2 diagnosis are available. The purpose of the present study was to develop and validate a duplex qPCR HTLV-1 assay to simultaneously detect the presence of HTLV-1 and the RPPH1 reference gene, so as to solve the problems related to time constraints, cost, and data absent about PVLs in HTLV-1 infected patients in China.LTR, pol, gag, tax and rex genes are the regions used most frequently for HTLV-1 DNA quantitation. But deletions or mutations in the rex region have been reported in HAM/TSP cases and defection of 5’LTR frequently occurred in ATL cases [pol and tax gene, which are relatively conservative in HTLV-1. In our study, a set of primer–probe with the best specificity for pol gene was finally used for our later work. It should be emphasized that we also screened specific primers and probes for internal reference RPPH1 gene, rather than using commercial kits described in previous studies [The TL cases –17. Ther studies , 18, whipol-tax-RPPH1 that contained one copy of the RPPH1 gene and HTLV-1 target region was constructed and used to establish the standard curves, which was simple to prepare, highly reproducible and stable over time.Previous research identified HTLV-1 PVLs using successive dilutions of reference extracted DNA from cell lines with known HTLV-1 virus copy numbers . This pr5 cells and 2.5 copies of HTLV-2 per 105 cells, using 5 specific target primer-probes sets and RPPH1 as reference gene [tax region shared by HTLV-1 and HTLV-2, and simultaneously detect the HLA-DQ alpha to normalize the amount of cellular DNA in another single qPCR tube; all of them based on SYBR Green dye. Although they displayed excellent sensitivity (1 copy per reaction), the duplex qPCR could not able to distinguish HTLV-1 from HTLV-2 and two tubes were required for each sample [In fact, the duplex qPCR established in our study demonstrated a broad linear dynamic range, presented acceptable efficiency and was capable of detecting low-level proviral load (1 copy/reaction). To evaluate the detection limit of the method for the real sample, Huh102 cells were serially diluted with Jurkat cells and then were detected by our duplex qPCR for 20 times. Our method was sensitive enough to detect 2.5 copies per 10,000 cells. Although earlier research using mqPCRs revealed greater sensitivity for detecting and quantifying HTLV-1 than the current study, those earlier studies detected the reference gene independently to estimate the number of cells. For instance, Moens et al. developed a triplex qPCR for simultaneous detections of 4 copies of HTLV-1 per 10nce gene . Howeverh sample .As for tIn order to verify the feasibility of this method, LIA-positive and indeterminate samples with blood cells available were performed with WB and our duplex qPCR simultaneously. As shown in the results, 90.0% of LIA-positive, 33% of LIA-untypeable and 2% of LIA-indeterminate samples were confirmed as qPCR-positive, indicating that our qPCR method could successfully detect HTLV-1 in the majority of seropositive samples and was able to distinguish partial untypeable and indeterminate samples. The median PVL value of the qPCR-positive samples in our study was 1.621 copies/100 cells, which was either higher or lower or similar to previous reports , 23. In In addition, 87% of LIA-positive, 17% of LIA-untypeable and none of the LIA-indeterminate samples were confirmed WB-positive in this investigation, demonstrating the duplex qPCR was more sensitive than WB. Actually, in our study, HTLV-1 provirus was found in 96.7% 27/28) of WB-positive blood donors, exceeding the detection rates of the qPCRs created by Moens et al. and Waters et al. for the seropositive blood donors (91% and 90%), and being close to the rate of a multiplex qPCR created by Gonçalves et al. (97.4%) , 26. How/28 of WBIn conclusion, the simplicity, applicable, reproducible and low-cost characteristics of the present assay for PVL quantification make it potentially an effective tool to instead of WB as the first-line test in confirming the ELISA reactive samples. It also offers a way for better compare of the PVLs obtained from different laboratories, and the results obtained support its use for monitoring infection and stratifying the risk for HTLV-1-associated disease.Additional file 1. Details of results by LIA, WB, qPCR, Murex-ELISA and Roche-ECLIA.