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Tropical Animal Health and Production Sep 2023Bovine leukemia virus (BLV) causes enzootic bovine leukosis, a persistent infection and the most important neoplastic disease in cattle. It is spread primarily by...
Bovine leukemia virus (BLV) causes enzootic bovine leukosis, a persistent infection and the most important neoplastic disease in cattle. It is spread primarily by transferring infected lymphocytes through blood from carriers to healthy animals. The present study is aimed at determining the seropositivity of BLV in breeding bulls from Costa Rica and at detecting for the first time in the country BLV DNA in bull semen. Between May 2011 and August 2018, 379 blood and 133 semen samples were collected from bulls distributed in 118 farms. The serum was analyzed by an enzymatic immunoassay and the semen by polymerase chain reaction and sequencing. BLV seropositivity was 43.5% (165/379), while 64.4% (76/118) of the farms had positive reactors. Holstein (75.7%) and Jersey (73.0%) breeds showed the highest seropositivity. In addition, Bos taurus bulls (68.1%), older than seven years (50.0%), and those belonging to dairy farms (75.5%) had higher seropositivity compared to Bos indicus (17.7%), younger than seven years (42.2%), and those from beef farms (15.5%), respectively. Moreover, Bos taurus bulls had a higher risk of being seropositive than Bos indicus (OR = 3.4; 95% CI: 1.7-6.8). BLV DNA was found in one semen sample (2.5%; 1/40) from a seropositive bull. The importance of serum and molecular BLV screening in semen samples and the potential role of some risk factors associated with the disease, such as the bull's age, genotype, and type of livestock productive system, is argued in the present report.
Topics: Cattle; Animals; Male; Semen; Enzootic Bovine Leukosis; Leukemia Virus, Bovine; Costa Rica; Seroepidemiologic Studies; Cattle Diseases
PubMed: 37777681
DOI: 10.1007/s11250-023-03763-5 -
PLoS Neglected Tropical Diseases Sep 2023Familial clustering of HTLV-1 and related diseases has been reported in Brazil. However, intrafamilial transmission of HTLV-1 based on molecular analysis has been...
Epidemiological and molecular evidence of intrafamilial transmission through sexual and vertical routes in Bahia, the state with the highest prevalence of HTLV-1 in Brazil.
INTRODUCTION
Familial clustering of HTLV-1 and related diseases has been reported in Brazil. However, intrafamilial transmission of HTLV-1 based on molecular analysis has been studied only in a few communities of Japanese immigrants and African-Brazilians.
OBJECTIVE
To investigate the familial clustering of HTLV-1 infection and to determine the likely routes of transmission through epidemiological and genetic analyzes.
METHODS
Medical records of 1,759 HTLV-1+ patients from de the Center for HTLV in Salvador, Brazil, were evaluated to identify first-degree relatives previously tested for HTLV-1. Familial clustering was assumed if more than one member of the same family was HTLV-1+. LTR regions of HTLV-1 sequences were analyzed for the presence of intrafamilial polymorphisms. Family pedigrees were constructed and analyzed to infer the likely transmission routes of HTLV-1.
RESULTS
In 154 patients at least one other family member had tested positive for HTLV-1 (a total of 182 first-degree relatives). Of the 91 couples (182 individuals), 51.6% were breastfed, and 67.4% reported never using a condom. Of the 42 mother-child pairs, 23.8% had a child aged 13 years or younger; all mothers reported breastfeeding their babies. Pedigrees of families with 4 or more members suggests that vertical transmission is a likely mode of transmission in three families. Three families may have had both vertical and sexual transmission routes for HTLV-1. The genetic signatures of the LTR region of 8 families revealed 3 families with evidence of vertical transmission, another 3 families (spouses) with sexual transmission, and one family with both transmission routes. HTLV-1 sequences belonged to Cosmopolitan subtype HTLV-1a Transcontinental subgroup A.
CONCLUSION
Sexual and vertical transmission routes contribute to the intrafamilial spread of HTLV-1 in the state of Bahia.
Topics: Infant; Female; Humans; Human T-lymphotropic virus 1; Brazil; Prevalence; HTLV-I Infections; Infectious Disease Transmission, Vertical; Mothers
PubMed: 37769013
DOI: 10.1371/journal.pntd.0011005 -
Epidemiologia E Servicos de Saude :... Sep 2023
Topics: Humans; Female; Brazil; Breast Feeding; Deltaretrovirus Infections
PubMed: 37729266
DOI: 10.1590/S2237-96222023000200025 -
Journal of Dairy Science Jan 2024The objective was to evaluate the effects of bovine leukemia virus (BLV) infection, as determined by BLV seropositivity and proviral load, on 305-d milk, fat, and...
The objective was to evaluate the effects of bovine leukemia virus (BLV) infection, as determined by BLV seropositivity and proviral load, on 305-d milk, fat, and protein production of dairy cows. A cross-sectional study was conducted among 1,712 cows from 9 dairy herds in Alberta, Canada. The BLV status was assessed using an antibody ELISA, whereas BLV proviral load in BLV-seropositive cattle was determined with quantitative PCR. Dairy Herd Improvement 305-d milk, fat, and protein production data were obtained for all enrolled cattle. Differences in these milk end points were assessed in 2 ways: first, by categorizing cows based on BLV serostatus (i.e., BLV positive or negative), and second, by categorizing based on BLV proviral load (i.e., BLV negative, low proviral load [LPL] BLV positive, and high proviral load [HPL] BLV positive). A mixed-effect multivariable linear regression model was used to assess differences in milk parameters. We found that BLV positivity, adjusted for parity and natural log-transformed somatic cell count (SCC), was not associated with reduction in 305-d milk, fat, or protein production. However, significant reductions in 305-d milk, fat, and protein yield occurred in HPL cows, but not in LPL cows, compared with BLV-negative cows, when adjusted for parity number and natural log-transformed SCC. In summary, BLV proviral load may predict effects of BLV infection on milk, fat, and protein production.
Topics: Pregnancy; Female; Cattle; Animals; Milk; Leukemia Virus, Bovine; Enzootic Bovine Leukosis; Proviruses; Cross-Sectional Studies; Antibodies, Viral; Alberta; Cattle Diseases
PubMed: 37709045
DOI: 10.3168/jds.2023-23695 -
Open Veterinary Journal Aug 2023Enzootic bovine leukosis (EBL) is a lymphoproliferative disorder caused by the bovine leukemia virus (BLV), a virus of the Retroviridae family. The infection is...
BACKGROUND
Enzootic bovine leukosis (EBL) is a lymphoproliferative disorder caused by the bovine leukemia virus (BLV), a virus of the Retroviridae family. The infection is distributed worldwide, and a high percentage of animals infected by the BLV are asymptomatic and act as carriers of the virus in many cattle populations.
AIM
To identify the risk factors associated with EBL in the municipalities of Boyacá and Cundinamarca (Colombia).
METHODS
A simple descriptive cross-sectional study with random sampling was conducted. A total of 1,140 blood samples were taken from cattle (females and males) from the municipalities of Chiquinquirá, Ubaté, and San Miguel de Sema of different breeds and age groups. The samples were processed using the commercial ELISA SERELISA® BLV Ab Mono Blocking kit (sensitivity 97%, specificity 98%). The data were processed with the statistical programs WinEpi and Epi Info® version 7.2.4.0, estimating the prevalence ratio, implementing the chi-square test ( ≤ 0.05) and logistic regression.
RESULTS
A true prevalence (TP) and apparent prevalence (AP) of 23.61% and 22.7% in Ubaté, 19.22% and 18.1% in Chiquinquirá, and 15.61% and 14.3% in San Miguel de Sema, respectively, were established. Bovines 2-4 years old were the most prevalent in Ubaté and Chiquinquirá (37.5% and 21.21%, respectively), while in San Miguel de Sema individuals >4 years had the highest percentage of antibodies (18.3%). The Holstein breed had a higher prevalence in Ubaté and San Miguel de Sema (26.02% and 19.67%), and crossbreeds were more BLV-seroprevalence in Chiquinquirá (20.20%). In Ubaté, re-use of needles was identified as a risk factor, contaminated blood in needles is considered one of the main routes of transmission. On the other hand, manual milking was identified as a risk factor in San Miguel de Sema.
CONCLUSION
The non-implementation of an individual needle per animal in Ubaté; the Holstein breed and manual milking in San Miguel de Sema were identified as risk factors for the presence of antibodies against the disease. EBL prevention and control plans should be established that focus on the implementation of management and sanitary practices based on herd biosecurity.
Topics: Animals; Cattle; Female; Male; Colombia; Cities; Cross-Sectional Studies; Enzootic Bovine Leukosis; Seroepidemiologic Studies; Risk Factors; Leukemia Virus, Bovine; Cattle Diseases
PubMed: 37701663
DOI: 10.5455/OVJ.2023.v13.i8.7 -
International Journal of Molecular... Aug 2023HTLV-1 is an oncogenic human retrovirus and the etiologic agent of the highly aggressive ATL malignancy. Two viral genes, and , are individually linked to oncogenic...
HTLV-1 is an oncogenic human retrovirus and the etiologic agent of the highly aggressive ATL malignancy. Two viral genes, and , are individually linked to oncogenic transformation and play an important role in the pathogenic process. Consequently, regulation of HTLV-1 gene expression is a central feature in the viral lifecycle and directly contributes to its pathogenic potential. Herein, we identified the cellular transcription factor YBX1 as a binding partner for HBZ. We found YBX1 activated transcription and enhanced Tax-mediated transcription from the viral 5' LTR promoter. Interestingly, YBX1 also interacted with Tax. shRNA-mediated loss of YBX1 decreased transcript and protein abundance of both Tax and HBZ in HTLV-1-transformed T-cell lines, as well as Tax association with the 5' LTR. Conversely, YBX1 transcriptional activation of the 5' LTR promoter was increased in the absence of HBZ. YBX1 was found to be associated with both the 5' and 3' LTRs in HTLV-1-transformed and ATL-derived T-cell lines. Together, these data suggest that YBX1 positively influences transcription from both the 5' and 3' promoter elements. YBX1 is able to interact with Tax and help recruit Tax to the 5' LTR. However, through interactions with HBZ, YBX1 transcriptional activation of the 5' LTR is repressed.
Topics: Humans; Genes, Viral; Human T-lymphotropic virus 1; Promoter Regions, Genetic; RNA, Small Interfering; Terminal Repeat Sequences; Y-Box-Binding Protein 1
PubMed: 37685922
DOI: 10.3390/ijms241713119 -
Scientific Reports Sep 2023Human T-lymphotropic virus (HTLV) infection has a worldwide distribution and currently, more than 2.5 million individuals have been infected in Brazil. The study aimed...
Human T-lymphotropic virus (HTLV) infection has a worldwide distribution and currently, more than 2.5 million individuals have been infected in Brazil. The study aimed to investigate HTLV infection prevalence among blood donors in Mato Grosso do Sul, characterizing seroepidemiological profiles of HTLV-1/2 positive individuals and evaluating the blood bank's HTLV screening system. A cross-sectional survey was conducted among blood donors from Mato Grosso do Sul state (MS)-Central Brazil, between January to December 2021. The information was obtained from databases, samples from the collection of HEMOSUL, and active searching, with the completion of laboratory analyses. 35,278 blood donors were screened for anti-HTLV-1/2 by chemiluminescence immunoassay (CMIA). Among them, 78 were initially reactive for anti-HTLV-1/2 (2.21/1000). Out of 78, 67 returned to the blood center to collect a second sample for retesting with a second screening with CMIA. After confirmation, 8 samples were indeterminate, and 8 were confirmed as positive for HTLV antibodies. New tests were performed for the 8 positive samples, and 6 were confirmed as HTLV-1 infection (0.17/1,000), one as negative, and one as indeterminate. The present study describes the low prevalence of HTLV infection in blood donors from MS and contributes to the definition of the regional infection profile. The prevalence found in this study (0.017%-0.17/1000) shows to be a much lower value than the rates reported in other states in Brazil. We highlight the need for confirmatory testing for those seropositive donors in screening assays and the need for adequate counseling and patient management for those confirmed HTLV individuals.
Topics: Humans; Brazil; Blood Banks; Blood Donors; Cross-Sectional Studies; Deltaretrovirus; Deltaretrovirus Infections; Human T-lymphotropic virus 1
PubMed: 37667056
DOI: 10.1038/s41598-023-41875-y -
Internal Medicine (Tokyo, Japan) Apr 2024Human T-cell lymphotropic virus type-1 (HTLV-1)-associated bronchioloalveolar disorder (HABA) is a pulmonary disorder characterized by lymphocytic infiltration of the... (Review)
Review
Human T-cell lymphotropic virus type-1 (HTLV-1)-associated bronchioloalveolar disorder (HABA) is a pulmonary disorder characterized by lymphocytic infiltration of the peribronchiolar space and interstitium in HTLV-1 carriers and in adult T-cell leukemia/lymphoma (ATLL). We herein report an 85-year-old woman carrying HTLV-1 with HABA who presented with a miliary pattern of micronodules in both lungs on high-resolution computed tomography and a lymphocytic infiltrate with non-necrotizing granulomas on pathology. This rare case of HABA should be differentiated from sarcoidosis, hypersensitivity pneumonitis, or miliary tuberculosis.
Topics: Adult; Female; Humans; Aged, 80 and over; Human T-lymphotropic virus 1; Leukemia-Lymphoma, Adult T-Cell; Granuloma; T-Lymphocytes; HTLV-I Infections; Azo Compounds
PubMed: 37661452
DOI: 10.2169/internalmedicine.2201-23 -
Tropical Animal Health and Production Sep 2023Enzootic bovine leukosis (EBL) is a chronic infectious disease caused by the bovine leukosis virus (BLV), a Deltaretrovirus. Bovine viral diarrhea (BVD) is an infectious...
Enzootic bovine leukosis (EBL) is a chronic infectious disease caused by the bovine leukosis virus (BLV), a Deltaretrovirus. Bovine viral diarrhea (BVD) is an infectious disease caused by a pestivirus. Bovine neosporosis is caused by the obligate intracellular parasite Neospora caninum (Nc). These pathogens can have horizontal (postnatal) or vertical (transplacental) transmissions and affect the productive and reproductive performance of infected bovines. This work aimed to detect BLV, BVD, and Nc seroprevalence in specialized dairy cattle from the north, east, and Aburrá Valley regions of the Department of Antioquia, the highest in milk production regions in Antioquia. A total of 599 blood samples, obtained from 53 specialized dairy cattle herds, were evaluated by the ELISA test. The results revealed a seroprevalence of 41.13% for BLV (242/599), 28.48% (163/599) for Nc, and 22.7% (132/599) for BVD. Regarding the regional seroprevalence evaluation, BLV was found in 47.02% of the samples from the east, 36.87% from the north, and 46.02% from the Aburrá Valley. Nc was found in 31.03% of the samples from the east, 24.26% from the north, and 36.63% from Aburrá Valley. BVD was found in 21.62% of the samples from the east, 25.03% from the north region, and 10.39% of the samples from the Aburrá Valley. It is highlighted by these results that the north region, with the highest milk production in Antioquia, had the lowest BLV and Nc seroprevalences but the highest seroprevalence of BVD. BLV has increased in Antioquia in recent years, and as an immunosuppressive infection, opportunities for other pathogens are created by it. A significant statistical difference was found in the average prevalence of the pathogens according to the municipality, cattle breed, and region of origin of the sample. The seroprevalence of these pathogens in specialized dairy herds in Antioquia can be classified as medium-low. However, it is recommended that biosecurity practices should be maximized to avoid the spread of these pathogens due to the variability detected in the region, municipality, breed group, and herd age. The rapid and efficient diagnosis of these three pathogens through reliable methodologies will allow for the control of dissemination in dairy herds.
Topics: Animals; Cattle; Colombia; Enzootic Bovine Leukosis; Leukemia Virus, Bovine; Seroepidemiologic Studies; Neospora; Communicable Diseases; Diarrhea; Cattle Diseases
PubMed: 37656253
DOI: 10.1007/s11250-023-03685-2 -
Journal of Dairy Science Dec 2023Bovine leukemia virus (BLV) has spread worldwide and causes serious problems in the cattle industry owing to the lack of effective treatments and vaccines. Bovine...
Effectiveness of integrated bovine leukemia virus eradication strategies utilizing cattle carrying resistant and susceptible major histocompatibility complex class II DRB3 alleles.
Bovine leukemia virus (BLV) has spread worldwide and causes serious problems in the cattle industry owing to the lack of effective treatments and vaccines. Bovine leukemia virus is transmitted via horizontal and vertical infection, and cattle with high BLV proviral load (PVL), which is a useful index for estimating disease progression and transmission risk, are considered major infectious sources within herds. The PVL strongly correlates with highly polymorphic bovine lymphocyte antigen (BoLA)-DRB3 alleles. The BoLA-DRB3*015:01 and *012:01 alleles are known susceptibility-associated markers related to high PVL, and cattle with susceptible alleles may be at a high risk of BLV transmission via direct contact with healthy cows. In contrast, the BoLA-DRB3*009:02 and *014:01:01 alleles comprise resistant markers associated with the development of low PVL, and cattle with resistant alleles may be low-risk spreaders for BLV transmission and disrupt the BLV transmission chain. However, whether polymorphisms in BoLA-DRB3 are useful for BLV eradication in farms remains unknown. Here, we conducted a validation trial of the integrated BLV eradication strategy to prevent new infection by resistant cattle and actively eliminate susceptible cattle in addition to conventional BLV eradication strategies to maximally reduce the BLV prevalence and PVL using a total of 342 cattle at 4 stall-barn farms in Japan from 2017 to 2019. First, we placed the resistant milking cattle between the BLV-positive and BLV-negative milking cattle in a stall barn for 3 yr. Interestingly, the resistant cattle proved to be an effective biological barrier to successfully block the new BLV infections in the stall-barn system among all 4 farms. Concomitantly, we actively eliminated cattle with high PVL, especially susceptible cattle. Indeed, 39 of the 60 susceptible cattle (65%), 76 of the 140 neutral cattle (54%), and 20 of the 41 resistant cattle (48.8%) were culled on 4 farms for 3 years. Consequently, BLV prevalence and mean PVL decreased in all 4 farms. In particular, one farm achieved BLV-free status in May 2020. By decreasing the number of BLV-positive animals, the revenue-enhancing effect was estimated to be ¥5,839,262 ($39,292.39) for the 4 farms over 3 yr. Our results suggest that an integrated BLV eradication program utilization of resistant cattle as a biological barrier and the preferential elimination of susceptible cattle are useful for BLV infection control.
Topics: Animals; Cattle; Female; Alleles; Cattle Diseases; Disease Susceptibility; Enzootic Bovine Leukosis; Histocompatibility Antigens Class II; Leukemia Virus, Bovine; Major Histocompatibility Complex
PubMed: 37641252
DOI: 10.3168/jds.2023-23524