Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Activities: During the reporting period, final assays were completed and data completed. Analysis continues. Funding for the project ended during the previous reporting period; project outputs will be updated in final report during next reporting period. DISSEMINATION: CAEV & Coxiella epidemiologic findings form this project were included presented in infectious disease control and abortion seminars at 2 veterinary continuing education conferences and 1 producer conference during the reporting period. Peer and industry publications planned upon completion of analysis. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Current reporting period: Preliminary outcomes were reported in last reporting period. No additional outcomes for this unfunded reporting period, pending final analysis of multi-year follow-up and completion of final report.
Publications
- No publications reported this period
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: OUTPUTS: Activities: Data collection completed; serologic testing (CAEV and Coxiella burnetti (CB) and & PCR testing (CB)of vaginal (and and male samples) samples now complete for the study goat herds. Preliminary data analyzed for association between CAEV infection status and Coxiella infection was reported in prior progress report. Correlation between Coxiella Phase I and Phase II IFA tests and ELISA serologic tests are determined. Reproductive outcomes (subsequent kidding, abortion, conception, culling) data collection is complete and quantitative PCR analysis for lochia during the reporting period. Reproductive outcomes and CB shedding data for all enrolled animals/herds are now completed and data analyses are in progress. DISSEMINATION: Preliminary data were shared locally with participating producers and their personnel. Dr. Kreutzberg previously presented preliminary herd Coxiella data at 2009 US Army CHPPM Force Health Protection Conference and during the report period at 2010 U.C. Extension Goat Day. Future dissemination upon completion of analysis will be to goat producer groups (2012 U.C. Extension Goat Day) and veterinary practitioners (AASRP/ADGA/AABP) presentations. Peer and industry publications planned upon completion of analysis. PARTICIPANTS: Co-investigators are University of California, Davis veterinary faculty Joan Dean Rowe and Bruno Chomel. This project is proved laboratory training and clinical zoonosis management training for MPVM student/veterinarian Therese Kreutzberg. Karen VanHoosear provided technical support. California Animal Health and Food Safety Laboratory abortion necropsy results were used from participating herds. Lucy Whittier Molecular and Diagnostic Core Facility was a participant with Coxiella real-time PCR. TARGET AUDIENCES: Dairy goat producers, small ruminant veterinarians, public health veterinarians PROJECT MODIFICATIONS: None. Final report will follow completion of data analysis and manuscript preparation.
Impacts
As previously reported, CAEV infection does not appear to be a risk factor for Coxiella abortion. Caprine Coxiella infection can result in infertility, repeat abortion and increased culling. Current reporting period: As expected, not all seropositive animals were found to shed CB in their genital secretions. However, serology alone could not detect all infected (shedding) animals, as seronegative animals were found to shed CB in vaginal secretions. Bucks may also play a role in CB infection, as evidence of organism was found in preputial swabs of seropositive males which not in recent contact with does. Improved diagnostic tests are needed to provide rapid field screening to detect shedding animals in order to best management the disease by minimizing exposure of herd to potentially high-shedding animals. Change in action: Decision making for CAEV control program in goat herds should be independent of abortion risk consideration/control. Increased risk of repeat CB abortion favors culling of aborted animals. Best management practice is to minimize exposure of does to previously aborting females and males in infected herds. Management of placentas, birthing environment and herd replacement female policy are needed to maximize herd immunity.
Publications
- No publications reported this period
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Activities: Data collection & analysis: Enrolled 181 goats from herd with high abortion rate (39% abortions/abnormal kiddings) and human Coxiellosis. Caprine arthritis-encephalitis virus (CAEV, 9% seropositive) and Coxiella burnetti (CB) infection status was determined by serology (82% seropositive); vaginal swabs were taken for PCR for Coxiella shedding. Preliminary data analyzed for association between CAEV infection status and Coxiella infection. Correlation between Coxiella IFA and ELISA serologic tests determined. Reproductive outcomes (subsequent kidding, abortion, conception, culling) data collection will be determined and quantitative PCR analysis for lochia will be collected in spring 2010. Reproductive outcomes and CB shedding data for previously enrolled animals/herds are being completed. DISSEMINATION: Preliminary data has been shared locally with participating producers and their personnel. Dr. Kreutzberg presented preliminary herd Coxiella data at 2009 US Army CHPPM Force Health Protection Conference. Future dissemination upon completion of analysis will be to goat producer groups (2010 U.C. Extension Goat Day) and veterinary practitioners (AASRP/ADGA/AABP) presentations. Peer and industry publications planned upon completion of analysis. PARTICIPANTS: Co-investigators are University of California, Davis veterinary faculty Joan Dean Rowe and Bruno Chomel. This project is providing laboratory training and clinical zoonosis management training for MPVM student/veterinarian Therese Kreutzberg. Karen VanHoosear provides technical support. California Animal Health and Food Safety Laboratory abortion necropsy results are used from participating herds. Lucy Whittier Molecular and Diagnostic Core Facility is a participant with Coxiella real-time PCR. TARGET AUDIENCES: Dairy goat producers, small ruminant veterinarians, public health veterinarians PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Change in knowledge: CAEV infection does not appear to be a risk factor for Coxiella abortion. Caprine Coxiella infection can result in infertility, repeat abortion and increased culling. Best practices to manage caprine Coxiella infection are defined. Change in action: Decision making for CAEV control program in goat herds should be independent of abortion risk consideration/control. Increased risk of repeat CB abortion favors culling of aborted animals.
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Activities: Data collection & analysis: Caprine arthritis-encephalitis virus (CAEV) infection status was determined by serology for 350-goat (2008 = 19% seroprevalence) and smaller seronegative study herds, and aborted goats continued to be enrolled through 2008 kidding season, 48 aborted goats to date sampled (serum, WBC, lochia, milk if lactating) for Coxiella Phase I & II serology and PCR for Coxiella shedding. Preliminary data analyzed for association between CAEV infection status and Coxiella infection. Correlation between Coxiella IFA and ELISA serologic tests determined. Reproductive outcomes (subsequent kidding, abortion, conception, culling) data collection for 2008 and quantitative PCR analysis for lochia are in progress as follow up data/sample collection is completed. Dissemination/audience: Preliminary data was shared locally with participating producers and their personnel. One herd is a campus facility where preliminary results have been used in clinical instruction on professional and undergraduate students involved in parturient goat care. Future dissemination upon completion of analysis will be to goat producer groups (U.C. Extension Goat Day) and veterinary practitioners (AASRP/ADGA) presentations. PARTICIPANTS: Co-investigators are University of California, Davis veterinary faculty Joan Dean Rowe and Bruno Chomel. Karen VanHoosear provides technical support. California Animal Health and Food Safety Laboratory abortion necropsy results are used from participating herds. Lucy Whittier Molecular and Diagnostic Core Facility is a participant with Coxiella real-time. This project is providing laboratory training and clinical zoonosis management training for MPVM student/veterinarian Therese Kreutzberg. TARGET AUDIENCES: Dairy goat producers/breeders Small ruminant veterinarians PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Outcomes are pending data analysis. To date: Change in knowledge: CAEV infection does not apppear to be a risk factor for Coxiella abortion. Change in action: Decision making for CAEV control program in goat herds should be independent of abortion risk consideration/control.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Biological Use Authorization (BUA) for Coxiella burnetii was approved May 21, 2007. Upon approval of BUA # 0102-02, Samples were collected (limited by end of kidding season) goat samples (blood, lochia, and milk) from a client dairy herd and a research herd of goats. Samples from 28 aborted or stillborn cases have been collected and stored in a locked Revco -80 deg C. freezer until the samples can be processed. These samples are being processed and used to validate the laboratory protocols for the C. burnetii IFA and ELISA. Parafilm sections from Coxiella burnetii positive and negative placenta samples (Aborted/stillborn cases from the UCD Goat Facility) were obtained from CAHFS Histology Laboratory and used to develop and validated the Coxiella burnetii PCR protocol. To date, these diagnostic tests have been validated and are ready for the continuation of the Q Fever Study. The client dairy will be kidding from October 2007 through March 2008. A herd bleed and CAEV ELISA
testing was complete fall 2007 and does assigned to study groups. The research herd will have meat goats kidding in the Fall 2007/ Winter 2008 and dairy goats kiddding in the Spring 2008. A herd bleed of the meat goats and CAEV ELISA testing was completed 2007. Coxiella has been diagnosed in an additional client herd of 150 does with unmonitored CAEV status. We plan a pilot survey of that herd to determine suitability for inclusion in this project. Results of this study will be presented to veterinarians and producers at AASRP/ADGA meetings and at UCD Dairy Goat Day.
PARTICIPANTS: Bruno Chomel DVM, MS, MS, PhD
TARGET AUDIENCES: Additional focus of Coxiella abortion (a zoonosis) in CAEV studies expands target audience to include veterinarians, livestock producers and workers involved public health.
PROJECT MODIFICATIONS: We hypothesize that (a) CAEV-infected does are more susceptible to Coxiella infection than their uninfected herdmates and that postpartum CAEV-infected does would have higher prevalence and load of C. burnetti shedding in their milk and lochia; (b) CAEV-infected goats with C. burnetti infection are more likely to shed C. burnetti in biosecretions; and (c) C. burnetti infection is significantly associated with abortion and results in lower subsequent kidding rates in infected goats. The objective of this study is to test the above hypotheses by examining the relationships among CAEV infection (as previously determined by serology), C. burnetii infection and shedding status in both milk and lochia (as determined by serology and PCR, respectively), and reproductive performance (as determined by kidding rates) for a general population and for aborted and nonaborted goats.
Impacts
Preliminary data: CAEV ELISA (2/23 positive, 0/23 suspect, 21/23 negative) C burnetii IFA (Phase I: 19/22 positive, 1/22 suspect, 2/22 negative; Phase II: 16/22 positive, 4/22 suspect, 2/22 negative) C. burnetii ELISA (Phase I IgG: 18/23 positive, 2/23 suspect, 3/23 negative) C.burnetii PCR(Lochia: 9/18 positive, 9/18 negative) Samples from 2 animals were negative in all tests, they will be used as current negative controls. Coxiella PCR has been validated. Additional assays for 19 aborted goats are currently in progress.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
CAEV infection status in a dairy goat herd with >50% herd seroprevalence before implementing a pasteurized rearing scheme was followed serologically for CAEV infection. Age-specific seroprevalence over three years was examined in the present reporting period. In year 1, 8/160 yearling and two year old animals (5.0%) were seropositive. In year 2, 19 of 188 (10.1%) goats 1-3 years, and in Year 3, 19 of 194 (10.3%) goats of multiple ages were seropositive for CAEV. Results suggest that herd prevalence of 10% can be achieved through pasteurized rearing alone. This result exceeds the degree of overall herd reduction achieved in other studies, although further analysis of risk factors is pending. Investigators conclude that further reduction of seroprevalence would require segregation or culling procedures.
Impacts
Clinical CAEV infection results in reduced function and productivity. The efficacy of long term control programs of interest to producers. During this study period we examined change in herd prevalence over time under a pasteurized rearing program without segregation of infected goats. Results of this study examining the long term efficacy of pasteurized rearing alone as a herd CAEV control program suggest that reduction to 10% prevalence is achievable through rigorous pasteurized rearing, more successful result than previously reported. Economic decision-making relative to control measures needed to further reduce CAEV infection warrant further analysis.
Publications
- No publications reported this period
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Progress 01/01/05 to 12/31/05
Outputs
CAEV-infected does (n=51) without signs of joint enlargement (sign of clinical CAEV infection) and 181 CAEV-uninfected does (as determined by ELISA and/or PBMC PCR) were studied to determine the impact of subclinical CAEV infection on productivity and udder health. The 305 day Fat-Corrected Milk (FCM) was higher in CAEV-negative (mean=2888 lbs., 95% CI = 2796.6, 2980.9) goats than in CAEV-infected herdmates (mean=2728 lbs., 95% CI = 2542.6, 2728.8); significant difference in FCM was observed in older (3 or greater lactations) goats (mean =2671 lbs. for 33 CAEV-negative goats; mean= 2247 lbs. for 9 CAEV-positive goats; p<0.05), suggesting a cumulative effect on mammary gland function with chronic infection. Lactation mean somatic cell count scores (L2) was lower in CAEV-uninfected (mean = 5.36, 95% CI = 5.22, 5.51) than in CAEV-infected goats (mean = 5.68, 95% CI = 5.39, 5.98). When modeled including the effect FCM, CAEV infection resulted in average increase in SCS L2
score of 0.27 (p= .09). Further analysis of microbial infection status is continued.
Impacts
Clinical CAEV infection results in reduced function and productivity. The role of subclinical CAEV infection on productivity is less well understood. This study examined relationship between subclinical CAEV infection and milk yield, milk quality, milk composition and udder health. Results of this study examining the impact of subclinical CAEV infection on milk production will be used to assist producers in economic decision-making relative to control measures needed to prevent CAEV infection.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
Fifty-one CAEV-infected does without signs of joint enlargement (sign of clinical CAEV infection) and 181 uninfected does were studied to determine the impact of subclinical CAEV infection on productivity. Complete lactation mean Fat-Corrected Milk (FCM) tended to be higher in CAEV-negative (mean=2888 lbs.) goats than in CAEV-infected herdmates (mean=2728 lbs.); significant difference in FCM was observed in older (3 or greater lactations) goats (mean =2671 lbs. for 33 CAEV-negative goats; mean= 2247 lbs. for 9 CAEV-positive goats; p<0.05). This would suggest a cumulative effect on mammary gland function with chronic infection. Lactation mean somatic cell count scores (L2) was lower in CAEV-uninfected (5.36) than in CAEV-infected goats (5.68, p<0.05). Complete data analysis of lactation yield, composition and imtramammary infection status is in progress.
Impacts
The impact of clinical CAEV infection on productivity is well understood. The purpose of this study is to assess the impact of subclinical CAEV infection on milk yield, milk quality and milk composition. Results of this study examining the impact of subclinical CAEV infection on milk production will be used to assist producers in decision-making relative to the cost:benefit of CAEV control/eradication measures.
Publications
- No publications reported this period
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Progress 01/01/03 to 12/31/03
Outputs
Fifty CAEV-infected does, as determined by positive serum CAEV-ELISA and/or PBMC CAEV-PCR, without signs of joint enlargement (sign of clinical CAEV infection) and 75 CAEV-uninfected does, as determined by negative CAEV-ELISA and/or PBMC CAEV-PCR tests, have been enrolled in the study at time of freshening. Breed, parity, kidding group (month) and prior mastitis history were recorded at time of enrollment. DHIA records have been reviewed on a monthly basis for change in somatic cell counts (SCC) and to record 305-day milk yield and composition data. Goats with SCC exceeding 800,000/ml at any monthly test were milk cultured for bacterial intramammary infection (IMI). Data collection is ongoing for current lactations in progress.
Impacts
The impact of clinical CAEV infection on productivity is well understood. The purpose of this study is to assess the impact of subclinical CAEV infection on milk yield, milk quality and milk composition. Results of this study examining the impact of subclinical CAEV infection on milk production will be used to assist producers in decision-making relative to the cost:benefit of CAEV control/eradication measures.
Publications
- No publications reported this period
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Progress 01/01/02 to 12/31/02
Outputs
Our previous studies reported the time to return to seronegativity (for uninfected kids) of kids fed heat treated colostrum from infected does as well as time to PCR reactivity for CAEV-infected herd replacement kids. We also reported evidence of in-utero infection in the tissues of 2 of 19 kids born to infected does and sacrificed at birth. We suspected that in-utero infections and colostrum (despite heat-treated by conventional means) are sources of infrequent infection in herds where pasteurized rearing programs are employed (despite pasteurized rearing programs, kids born to infected does have an approximate 10% likelihood of becoming infected). In this progress report we found evidence for delayed seroconversion/PCR reactivity (near parturition, at 1 year of age) most likely from in-utero infection in an offspring of an infected doe (7 of her progeny have been followed, some up to 4 years). Of 42 kids born to CAEV infected does (but PCR negative at birth) and
receiving heat-treated colostrum from CAEV infected does, 10 of these kids became PCR positive for CAEV proviral DNA in PBMC at between 2 and 5 months of age, suggesting colostrum may have contributed to infection risk. To determine whether colostrum heat treated by the method conventionally used to prevent CAEV transmission (56 C for 1 hour) might still provide a source of CAEV or CAEV-infected cells, cells from the raw and heat-treated colostrum from infected and uninfected does were cocultured with goat synovial membrane (GSM) cells. We were able to infect GSM cells with the colostral cells (raw and heat-treated) from CAEV-infected goats. Findings of our studies suggest that (a) heat treated colostrum may still support transmission of CAEV; (b) PCR testing of kids receiving heat-treated colostrum may best provide early detection of perinatally infected kids (until decline of colostral antibody); (c) evidence for delayed detection of in-utero infection suggests that long term
monitoring may be needed to detect all perinatal CAEV infections.
Impacts
Our ongoing studies are aimed at identifying means of and preventing transmission of CAEV infection in young goats and predicting which kids might be at increased risk of perinatal CAEV transmisison. The results of our studies suggest that accepted means of heat treating colostrum may still allow for infection of a proportion of kids, and that screening of colostrum donors so that only CAEV negative heat treated colostrum is used may reduce risk of infection. Perinatal infections may be detectable by PCR within 2-5 months of birth. In contrast, some presumed in-utero infection may not be detected for up to 1 year, so continued monitoring of kids born to infected dams is warranted to minimize risk of infected animals remaining in the herd.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
We previously reported finding CAEV proviral DNA in genital secretions of infected does and the characterizing the rate of disappearance of colostral CAEV antibody in kids. During this reporting period, we examined time to PCR reactivity to detect CAEV-infected PBMC in 129 kids. The mean age at detection for kids apparently perinatally infected was 84 (44, 144) days; for those with an initial decline in colostral titer the mean age at detection was 134 days (58, 318) suggesting vairable times of postnatal exposure to virus. We detected evidence of in-utero infection by finding CAEV-infected cells in the tissues of 2 of 19 seronegative precolostral kids but did not to detect evidence of infection in the PBMC or sera of 43 live kids examined. We conclude that CAEV-PCR is variable in time to detection and may allow earlier detection, but not sufficient to suggest its use to replace serum antibody testing. We demonstrated the infrequent occurrence of in-utero CAEV
infection.
Impacts
Our ongoing studies are aimed at identifying means of preventing CAEV infection in young goats and predicting which kidsmight be a increased risk of perinatal CAEV transmission. The results of this research could impact breeding and culling decisions regarding both the doe and her kids. Herd owners are advised to use a combination of serum antibody testing and PCR detection on high risk kids (those born to infected does or receiving heat treated colostrum from infected does) and to begin testing at 3-4 months of age.
Publications
- Rowe, JD. CAEV Overview and Research Update. In: Proc. American Dairy Goat Association Annual Meeting/ American Association of Small Ruminant Practitioners CE Program. Portland Oregon, October 21-27, 2001.
- Rowe J, Van Hoosear K, East N, et al. Evidence of in-utero transmission of caprine arthritis-encephalitis virus in precolostral kids. (Abstract) In: Proc Reproduction in Small Ruminants, Sandnes, Norway, June 30 - July 2, 2000, p. 87.
- Rowe J, Van Hoosear K, East N, et al. Presence of caprine arthritis-encephalitis virus proviral DNA in estrus mucus of dairy goat does and preputial secretions of bucks. (Abstract) In: Proc Reproduction in Small Ruminants, Sandnes, Norway, June 30 - July 2, 2000, p. 88.
- Drake D. Duration of caprine arthritis-encephalitis virus colostral antibodies in dairy goats. (MPVM thesis) School of Veterinary Medicine, University of California, Davis, August 2000.
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Progress 01/01/00 to 12/31/00
Outputs
We recently completed studies demonstrating CAEV proviral DNA in prebreeding and postpartum genital secretions of infected does. Does with detectable cAEV-infected cells in genital secretions may post greater risk of in-utero or cervico-vaginal CAEV transmission to their kids. During the past year we achieved our goal of characterizing decline of colostral CAEV antibody. We found a mean disappearance of colostral antibodies by age 66 days and that antibodies to CAEV were not detected in 95% of kids by day 93. All kids were seronegative by 108 days, suggesting that serologic testing may begin at 3 to 3 1/2 months of age instead of the conventional 4 to 6 months. Our current work examining time to PCR reactivity to detect infected PBMC, which has not previously been described, is in progress. We have detected CAEV infection in 23% of study kids to date, with data collection in progress. We identified a cluster of seroconversion/PCR reactivity in kids delivered by the
investigators and determined to be PCR negative and seronegative at birth, despite receiving apparently properly processed heat-treated colostrum. We have detected CAEV-infected cells in the tissues of two seronegative precolostral kids and have other samples pending, but additional kids are needed to assess the likelihood of in-utero infection.
Impacts
Our ongoing studies are aimed at identifying means of preventing CAEV infection in young goats and predicting which kids might be a increased risk of perinatal CAEV transmission. The results of this research could impact breeding and culling decisions regarding both the doe and her kids.
Publications
- Rowe JD, VanHoosear KA, East NE, et al. 2000. Evidence of in-utero transmission of caprine arthritis-encephalitis virus in precolostral kids (Abstract). In: Proc Reproduction in Small Ruminants, Sandnes, Norway June 30-July 2, 2000, p.87.
- Rowe JD, VanHoosear KA, East NE, et al. 2000. Presence of caprine arthritis-encephalitis virus proviral DNA in estruc mucus of dairy goat does and preputial secretions of bucks (Abstract). In Proc Reproduction in Small Ruminants, Sandnes, Norway June 30-July 2, 2000, p.88.
- Drake D. 2000. Duration of caprine arthritis-encephalitis virus colostral antibodies in dairy goats. (MPVM thesis). School of Veterinary Medicine, University of California Davis. August 2000.
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Progress 01/01/99 to 12/31/99
Outputs
Our current studies of caprine arthritis-encephalitis virus infection in dairy goats are aimed at identifying potential risk of infection among parturient does and from doe to kid. While transmission from doe to kid via milk is the most efficient route of transmission, an approximate 10% of kids born to infected does have unexplained seroconversion by 6 months of age despite removal at birth and feeding of heat-treated colostrum pasteurized milk until weaning. Also, adult goats experience a low level of horizontal transmission, likely from contact with biosecretions of infected does containing CAEV-infected mononuclear cells. During the reporting period, we completed our study of lochia as a potential source of virus-infected cells and began the second phase of the project, examining the relationship of CAEV-infected cells in doe genital secretions with the likelihood of perinatal kid infection. Our first objective was to assess the pattern of detection of CAEV-
infected cells from the post-partum secretions of dairy goat does. During the reporting period, we completed this portion of the study and presented results at the World Veterinary Congress in Lyon, France. We determined that CAEV-infected cells could be detected in lochia from 48% (31/64), 70% (45/64), 78% (50/64) and 75% (48/64) of does at 1,2,3 and 4 weeks after kidding, respectively. The occurrence of CAEV-infected cells in lochia was higher than the 35% found in estrus mucus. These results suggest that the copious discharge found in does after kidding may be a significant source of CAEV-infected cells to susceptible herdmates. Testing of does before kidding to identify and remove infected does from kidding groups could reduce the risk of CAEV transmission among parturient does. This work also determined that waiting until week 2 post partum for doe lochia sampling would maximize the likelihood of detecting CAEV-infected cells in lochia for the continuing portions of our studies.
Our second objective (work still in progress) is to determine if kids born to does with CAEV pro-viral DNA in genital secretions during estrus and in post-partum lochia are at greater risk of becoming infected by in-utero or perinatal horizontal transmission. Estrous mucus samples have been obtained from >140 does, and those pregnant does confirmed pregnant to synchronized breedings have now started to kid. Precolostral sera and peripheral blood mononuclear cells have been harvested from 46 replacement kids and follow up sampling of does and kids as they freshen/are born is underway. Additional kids not available are being followed for decline of colostral antibody and evidence of CAEV-infection. Our objectives have expanded to include time to disappearance of colostral antibody for uninfected kids and time to detection of CAEV-infected cells in peripheral blood in infected kids born to the does in the study. We will also continue our studies of tissues of precolostral kids for
evidence of in-utero transmission. To date we have detected CAEV-infected cells in the tissues of two seronegative precolostral kids, but additional kids are needed to assess the likelihood of in-utero infection.
Impacts
The impact of our studies has been to modify recommendations for herd CAEV testing strategies and herd management based on our detection of virus-infected cells in genital secretions. Does may expose kids to virus-infected cells during the birth process; discharge (lochia)from does after kidding may serve as a significant source of CAEV-infected cells to susceptible herdmates. Strategic timing of serologic testing of does (before breeding and before kidding kidding) to identify and remove infected does from breeding/kidding groups should improve the success of CAEV control programs.
Publications
- Rowe JD, East NE. Risk factors for transmission and methods for control of caprine arthritis-encephalitis virus infection. Vet Clin No Am Food Anim Pract 1997; 13:35-53.
- Rowe JD. Epidemiology of CAEV: horizontal transmission of the virus. (Presentation) In: Proc. World Veterinary Congress, Lyon, France, September 23-26, 1999.
- Rowe JD, VanHoosear KA, East NE, deRock E. The presence of caprine arthritis-encephalitis virus proviral DNA in post partum genital secretions of dairy goat does. (Abstract) In: Proc World Veterinary Congress, Lyon, France, September 23-26, 1999.
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Progress 01/01/98 to 12/31/98
Outputs
During this reporting period, we have optimized the methods for separating mononuclear cells from lochia and cervical mucus for the PCR technique for proviral CAEV DNA. We were able to sample pre-partum secretions and/or post-partum lochia of 47 does from a larger group of does with synchronized kiddings. Consistent with our previous findings in estrous mucus, approximately 35% of infected does had evidence of CAEV proviral DNA in lochia following kidding. Given the high volume and persistent discharge of lochia in the post-parturn doe, lochia likely represents significant risk of transfer of CAEV-infected cells to susceptible herd mates. We have also identified a small group of seronegative does with known point source CAEV exposure. Some of these does have evidence of CAEV proviral DNA in peripheral blood mononuclear cells and have remained seronegative for the one year since known exposure. We propose verifying the presence of infectious virus in these does by
virus isolation form milk and in situ hybridization of CAE viral RNA in milk macrophages. We have recognized the need to increase the sensitivity of detection of virus-infected cells, and the need to establish presence of infective virus and determine virus load in tissues in order to assess biological importance and more clearly define infection status in naturally exposed animals.
Impacts
(N/A)
Publications
- Rowe JD, East NE, Thurmond MC, et al. Cohort study of natural transmission and two methods for control of caprine arthritis-encephalitis virus infection in goats on a California dairy. Am J Vet Res. 1992. 53:2386-2395.
- East, NE; Rowe JD, Dahlberg JD, et al. Modes of transmission of caprine arthritis-encephalitis virus infection. Res. 1993. 10:251-262.
- Rowe JD, East NE. Risk Factors for transmission and methods for control of caprine arthritis encephalitis virus infection. Vet ClinNo Am Food Anim Pract. 1997. 13:35-53.
- Rimstad, E; East, N.E.; Torten, M et al. Delayed seroconversion following naturally acquired caprine arthritis-encephalitis virus infection in goats. AmJVetRes. 1993. 54:1858-1862.
- Dandekar S, Beebe AM, BarloughJ, et al. Detection of feline immunodeficiency virus (FIV) nucleic acids inFIV-seronegative cats. JVirol. 1992. 4040-4049.
- Leroux C, Lerondelle C, Chastang J, et al. RT-PCR detection of lentiviruses in milk or mammary secretions of sheep or goats from infected
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Progress 01/01/97 to 12/31/97
Outputs
During this reporting period, we have optimized the methods for separating mononuclear cells from lochia and cervical mucus for the PCR technique for proviral CAEV DNA. We were able to sample pre-partum secretions and/or post-partum lochia of 47 does from a larger group of does with synchronized kiddings. Consistent with our previous findings in estrous mucus, approximately 35% of infected does had evidence of CAEV proviral DNA in lochia following kidding. Given the high volume and persistent discharge of lochia in the post-partum doe, lochia likely represents significant risk of transfer of CAEV-infected cells to susceptible herd mates. We have also identified a small group of seronegative does with known point source CAEV exposure. Some of these does have evidence of CAEV proviral DNA in peripheral blood mononuclear cells and have remained seronegative for the one year since known exposure. We propose verifying the presence of infectious virus in these does by virus
isolation form milk and in situ hybridization of CAE viral RNA in milk macrophages. We have recognized the need to increase the sensitivity of detection of virus-infected cells, and the need to establish presence of infective virus and determine virus load in tissues in order to assess biological importance and more clearly define infection status in naturally exposed animals.
Impacts
(N/A)
Publications
- 4. Rimstad E, East NE, Torten M, et al. Delayed seroconversion following naturally acquired caprine arthritis-encephalitis virus infection in goats. Am J Vet Res. 1993. 54:1858-1862.
- 5. Dandekar S, Beebe AM, Barlough J, et al. Detection of feline immunodeficiency virus (FIV) nucleic acids in FIV-seronegative cats. J Virol. 1992. 4040-4049.
- 6. Leroux C, Lerondelle C, Chastang J, et al. RT-PCR detection of lentiviruses in milk or mammary secretions of sheep or goats from infected flocks. Vet Res 1997. 1997. 28:115-121.
- 7. Storset AK, Teig A, Rimstad E. Detection of caprine arthritis-encephalitis virus RNA in macrophages by in situ hybridization using fluorescein-labeled single-stranded RNA probes.
- 1. Rowe JD, East NE, Thurmond MC, et al. Cohort study of natural transmission and two methods for control of caprine arthritis-encephalitis virus infection in goats on a California
- 2. East NE, Rowe JD, Dahlberg JD, et al. Modes of transmission of caprine arthritis-encephalitis virus infection. Small Rumin Res.
- 3. Rowe JD, East NE. Risk Factors for transmission and methods for control of caprine arthritis-encephalitis virus infection. Vet Clin No Am Food Anim Pract. 1997. 13:35-53.
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