Tuberculosis Infection in Animal and Human Populations in Three Districts of Western Gojam,Ethiopia

Tuberculosis concurrent infection in cattle and their respective owners in North‐western Ethiopia had been investigated. Two hundred and ten cattle owners and 1220 heads of their cattle were included in the study to determine degree of tuberculosis infection in cattle owned by tuberculosis patients and tuberculosis patients. Comparative intradermal tuberculin test, bacteria culturing, acid fast staining and biochemical tests were used to conduct the study. The prevalence of tuberculosis was significantly (P < 0.001) higher in cattle owned by tuberculosis patients than in cattle owned by non‐tuberculosis owners, and infection with tuberculosis was threefold greater in cattle owned by tuberculosis‐positive owners. Further more, cattle owners who consumed raw milk were at higher risk (P < 0.001, OR = 3.23) for tuberculosis infection than those who consumed boiled milk. Mycobacterium tuberculosis (15.4%), Mycobacterium bovis (44.1%) and atypical mycobacteria (38.5%) were identified from milk collected from tuberculin‐positive cows using biochemical tests. Similarly M. tuberculosis (74.5%), M. bovis (14.9%) and atypical mycobacteria (8.5%) were identified from sputum and fine needle aspiration specimens of tuberculosis patient cattle owners. Mutual transmission of mycobacterium from animals to humans and vice versa has been signified.     

Prevalence of Mycobacterium bovis skin positivity and associated risk factors in cattle from Western Uganda

Purpose

A cross-sectional study was undertaken to determine the prevalence of Mycobacterium bovis skin positivity and associated risk factors in cattle in western Uganda.

Methods

Herds were selected using multi-stage cluster sampling. The comparative cervical intradermal tuberculin test (CCT) was used to determine cattle tuberculosis status using US Department of Agriculture protocols. Risk factor data were collected from cattle owners through questionnaires collected by in-person interviews. Multivariable logistic regression models were used to measure the association between risk factors and herd CCT reactor prevalence.

Results

A total of 525 cattle from 63 herds were screened for M. bovis infection. Of the 525 cattle tested, 2.1 % were CCT reactors and 15.43 % were CCT suspects. Of herds tested, 14.28 % had at least 1 CCT reactor. Using a private water source for cattle and not introducing new cattle into the farm were associated with lower prevalence of M. bovis skin positivity. The herd-level prevalence of M. bovis reactors in Kashaari County of Mbarara District was 14.5 %, and the individual cattle prevalence was low (2.1 %).

Conclusions

Using communal sources of drinking water for cattle and introducing new cattle on the farm were farm management practices associated with increased risk of M. bovis exposure in cattle. Despite the low prevalence of bovine tuberculosis (TB), there is a need to educate the populace on the possibility of human infection with zoonotic TB and for educating farmers on practices to reduce the risk of acquiring M. bovis in the Mbarara District.     

Prevalence of Mycobacterium bovis infection in traditionally managed cattle at the wildlife-livestock interface in South Africa in the absence of control measures

Cattle are the domestic animal reservoir for Mycobacterium bovis (M. bovis) which also affects other domestic animals, several wildlife species and humans leading to tuberculosis. The study area is in a resource-poor community that is surrounded by several game parks, where M. bovis infection has been previously diagnosed in wildlife. A cross-sectional study was carried out to determine the prevalence of M. bovis infection in 659 cattle from a total of 192 traditionally managed herds using the BOVIGAM® interferon gamma assay (IFN-γ). Infection was confirmed by post mortem examination and M. bovis isolation from three test-positive cattle. Genotyping of the M. bovis isolates was done using spoligotyping and VNTR (variable number of tandem repeats typing). The apparent M. bovis prevalence rate in cattle at animal level was 12% with a true population prevalence of 6% (95% Confidence interval (C.I) 3.8 to 8.1) and a herd prevalence of 28%. Spoligotyping analysis revealed that the M. bovis isolates belonged to spoligotype SB0130 and were shared with wildlife. Three VNTR profiles were identified among the SB0130 isolates from cattle, two of which had previously been detected in buffalo in a game reserve adjacent to the study area. The apparent widespread presence of M. bovis in the cattle population raises a serious public health concern and justifies further investigation into the risk factors for M. bovis transmission to cattle and humans. Moreover, there is an urgent need for effective bTB control measures to reduce infection in the communal cattle and prevent its spread to uninfected herds.

     

Prevalence and risk factors of mycobacterial infections in farm and trade cattle in southwestern Nigeria

We evaluated the prevalence of mycobacterial infections (i.e., Mycobacterium bovis and non-tuberculous mycobacteria [NTM]) and their associated risk factors among cattle herds and trade cattle in southwestern Nigeria. Through cross-sectional study design, cattle herds from three locations were screened using the single intradermal comparative cervical tuberculin test based on two diagnostic standards; more than 4 mm (? 4 mm) and more than 2 mm (? 2 mm) cut-off points. Abattoir study involved screening trade cattle for tuberculous lesions. Overall, 515 cattle from 45 herds were screened. Using >?4 mm, animal level and herd prevalence of 11.7 and 46.7% were recorded, respectively. Applying the ? 2 mm cut-off, animal level and herd prevalence increased to 31.1 and 60.0%, respectively. Significantly, using the ? 2 mm cut-off, cattle in medium size herds/extensive management system (OR?=?1.6; 95% CI 1.1–2.5) and Sokoto Gudali (OR?=?2.3; 95% CI 1.4–3.8) were more at risk of being positive reactors, while Rahaji (OR?=?0.3; 95% CI 0.1–0.7) breeds of cattle and cows in the peri-urban area (OR?=?0.4; 95% CI 0.2–0.9) were less at risk of being positive reactors. Again, M. avium reactor of 21.7% was observed. In the abattoir, 1797 cattle were examined with 126 lesions suggestive of tuberculosis (TB). Culture/molecular analyses confirmed 2.2% M. bovis and 0.9% NTM infections. Risk factors associated with bovine TB among trade cattle were sex (OR?=?4.0; 95% CI 1.2–13.5) and age (OR?=?0.3; 95% CI 0.1–0.9). We confirm 11.7% prevalence of mycobacterial infections among populations of cattle screened with breed and herd size being major risk factors.     

The use of the enzyme-linked immunosorbent assay (ELISA) in serological diagnosis of Mycoplasma bovis in dairy cattle

Between December 1985 and March 1987 an enzyme-linked immunosorbent assay (ELISA) was used with 3774 sera to estimate the prevalence of antibodies to Mycoplasma bovis in sera from three age groups of cattle in four dairies in California and to test for possible associations between the presence of M. bovis antibodies and the age or breed of the cattle and the farm. Unadjusted and adjusted associations were evaluated using the -square test for associations and multiple logistic regression analysis, respectively.There was a tendency for the proportion of cattle seropositive for M. bovis to increase steadily and approximately linearly with age (p<0.05). There was also a statistically significant relationship bbetween a M. bovis seropositive test and being from Farm IV (p<0.05). Farm IV was the largest of the four dairies and this association may be due to the effect of herd size.These findings confirm the ubiquitous distribution of antibodies to M. bovis in dairy cattle in California and also support previous reports of herd size as an important factor in mycoplasmal mastitis.     

A SURVEY OF MYCOBACTERIOSIS OF FERAL PIGS IN THE NORTHERN TERRITORY

Seven hundred and fifty-one feral pigs from the subcoastal plains of the Northern Territory were examined. The sample population consisted of 52.4% females and 47.6% males. They ranged in age from newborn piglets to mature animals of over 72 months. Of the pigs examined 47.7% had macroscopic abscesses and of these 80.2% were probably caused by mycobacteria. Tissues from 193 pigs were examined bacteriologically and 93 strains of mycobacteria were isolated. These were typed as M. bovis (37 strains); M. avium serotype 2 (1); M. intracellulare serotypes 6 (2), 7 (3), 9 (1) and 18 (1); M. intracellulare double serotypes 6 + 12 (1), 8 + 12 (1) and 11 + 25 (1); M. intracellulare unclassified serotype (4); M. scrofulaceum serotype 41 (1); M. scrofulaceum unclassified serotype (7); M. gordonae (2); M. kansasii (1); M. simiae (2); M. szulgai (2); M. vaccae (1); and M. xenopi (2). Additionally, 3 strains were unidentifiable members of the M. avium-M. intracellulare-M. scrofulaceum (MAIS) complex, one strain was a Runyon's group IV and 4 strains were typed as members of the genus Rhodococcus. Five strains were non-viable on subculture and 10 did not conform to any currently recognised species of mycobacteria. Of the 93 strains, 3 were isolated from tissue that did not contain macroscopic lesions, viz. M. simiae, Runyon's group IV and an unidentifiable member of the MAIS complex. It was concluded that the feral pig is probably an end host for both M. bovis and atypical mycobacteria and not a significant source of infection for cattle. M. bovis is not a significant cause of mortality in feral pigs but mycobacterioses are a significant cause of morbidity. With increasing age, the proportion of pigs having lesions increased whereas the proportion of lesions from which mycobacteria could be isolated decreased.     

Mycobacterium bovis prevalence affects the performance of a commercial serological assay for bovine tuberculosis in African buffaloes

The endemic presence of bovine tuberculosis (BTB) in African buffaloes in South Africa has severe consequences for BTB control in domestic cattle, buffalo ranching and wildlife conservation, and poses a potential risk to public health. This study determined the BTB prevalence in free-ranging buffaloes in two game reserves and assessed the influence of the prevalence of mycobacterial infections on the performance of a commercial cattle-specific serological assay for BTB (TB ELISA). Buffaloes (n = 997) were tested with the tuberculin skin test and TB ELISA; a subset (n = 119) was tested longitudinally. Culture, PCR and sequencing were used to confirm infection with M. bovis and/or non-tuberculous mycobacteria (NTM). Prevalence of BTB, but not NTM, influenced the TB ELISA performance. Multiple testing did not increase test confidence. The findings strongly illustrate the need for development of novel assays that can supplement existing assays for a more comprehensive testing scheme for BTB in African buffaloes.     

THE DISTRIBUTION OF MYCOBACTERIUM BOVIS IN QUEENSLAND CATTLE HERDS WITH OBSERVATIONS ON THE LABORATORY DIAGNOSIS OF TUBERCULOSIS

SUMMARY Of 1,791 tissues submitted from 1975 to 1978 for histological examination for tuberculosis, 78.5% were classified as tuberculosis, 8.1% as club-forming granulomas, 3.3% as hydatid cysts, 3.4% as other granulomas and 2.4% as squamous cell carcinomas. Cultural examination of 2,682 tissues for mycobacteria yielded Mycobacterium bovis from 42.88%, other mycobacteria from 7.64% and 0.89%Rhodococcus (Corynebacterium) equi. Of 1,478 tissues on which both examinations were performed, culture and histology results were in agreement on 94.1%. M. bovis was isolated on one or more occasions from 564 herds with the highest herd prevalence being recorded in western areas of the state. Culture of 1,024 tissues from no visible lesion (NVL) reactors yielded 0.59%M. bovis, 15.04% other mycobacteria and 0.19%R. equi. Of 120 isolates of other mycobacteria from tissues of NVL reactors, 39 were Runyon Group III (20 M. avium complex) and 61 Runyon Group IV. Approximately half of the herds from which NVL tissues were collected were confirmed M. bovis infected properties.     

Bovine tuberculosis is more prevalent in cattle owned by farmers with active tuberculosis in central Ethiopia

A case control study was conducted between October 2004 and April 2005 to determine the prevalence of bovine tuberculosis (BTB) in cattle in central Ethiopia relative to the tuberculosis status of their owners. A total of 174 farmers (87 with active tuberculosis and 87 with no active tuberculosis), and 1041 cattle (506 owned by farmers with active tuberculosis and 535 by farmers without active tuberculosis) were included. The comparative intradermal cervical tuberculin test was used in cattle while clinical symptoms, chest X-ray and Ziehl-Neelsen staining were used for the diagnosis of tuberculosis in the farmers. In addition, mycobacterial culture, biochemical tests, and drug susceptibility tests were performed for the identification Mycobacterium spp. from both humans and cattle. The prevalence of BTB was threefold higher (odds ratio [OR]=4.2, 95% confidence interval [CI]=2.79-6.2) in cattle owned by farmers with active tuberculosis (24.3%) than in those owned by farmers who did not have active tuberculosis (8.6%). Cattle owned by farmers with active tuberculosis were four times more likely to have tuberculosis than cattle owned by farmers with no active tuberculosis. Furthermore, cattle owners who consumed raw milk were at greater risk (chi2=14.1, P<0.001, OR=3.34) of having active tuberculosis than those who consumed boiled milk. Of the 42 human isolates, 31 (74%) were Mycobacterium tuberculosis, seven (16%) were Mycobacterium bovis while four (10%) were considered a typical mycobacteria on the basis of biochemical and drug sensitivity tests. Of the 11 cattle isolates, two (18%) were Mycobacterium tuberculosis, five (46%) Mycobacterium bovis, and four (36%) were atypical mycobacteria. The prevalence of tuberculosis was higher in cattle owned by farmers with active tuberculosis than in cattle owned by farmers who did not have active tuberculosis, which could suggest possible transmission of Mycobacterium spp. between cattle and their owners.     

Molecular fingerprinting confirms extensive cow-to-cow intra-herd transmission of a single Mycobacterium bovis strain

In this study we have characterized M. bovis isolates from a herd of cattle in Uvalde, Texas in which 52 of the 193 animals selected at random in 1994 from a herd of 331 were caudal fold skin-test positive. Thirty-two of 52 skin-test positive cattle had gross lesions at slaughter, and isolations of M. bovis were made from 29 animals. The herd was comprised of Red Devon cattle purchased between 1978 and 1980 (n = 26) and breeding bulls (n = 3) introduced at later times, and all were tuberculosis test negative at the time of purchase. Other animals were natural additions (offspring) of these cattle. One additional animal, a Holstein present on the ranch at the time of purchase in 1976, was retained to nurse orphaned and weak calves. Using several molecular fingerprinting techniques we have verified a clonal relationship among the M. bovis isolates consistent with infection originating with a single strain. The molecular fingerprint patterns demonstrate the stability of the profiles despite persistence and spread of the organism within the herd for two decades and confirms their use in epidemiological tracing.     

Isolation and molecular characterization of Mycobacterium bovis from Kafue lechwe (Kobus leche kafuensis) from Zambia

Bovine tuberculosis (BTB) is a chronic bacterial disease caused by Mycobacterium bovis. Infections due to M. bovis, which serves as a stable reservoir, can pose serious challenge to control and eradicate in both wildlife and livestock at the interface. This study aimed at isolating and characterizing M. bovis from Kafue lechwe (Kobus leche kafuensis) and black lechwe (Kobus leche smithemani) at the animal/human interface in Zambia. The samples with lesions compatible with BTB collected during the hunting seasons of 2009 and 2010 were cultured for isolation of mycobacteria using Stonebrink with pyruvate (BD Diagnostics, MD, USA) and Middlebrook 7H10 (BD Diagnostics) slants. Isolated mycobacteria were identified using IS6110 polymerase chain reaction and deletion analysis. Molecular characterization of the isolates was performed using spoligotyping and mycobacteria interspersed repetitive unit–variable number tandem repeat (MIRU–VNTR) with nine loci. Data was analyzed using BioNumerics software 6.1. Out of the 39 samples, acid fast bacilli were detected in 27 (69.2 %) based on smear microscopy. Seven isolates were found to belong to Mycobacterium tuberculosis complex, and all were identified as M. bovis based on deletion analysis. All seven isolates were identical on spoligotyping as belonging to the SB0120 (SIT 482). MIRU–VNTR differentiated the isolates into five different patterns. This study has confirmed that M. bovis circulates in the Kafue lechwe, and non-tuberculous mycobacteria were detected in the black lechwe in Zambia which represents a wildlife reservoir, with a potential to spillover to cattle and humans. Isolates of M. bovis from lechwe antelopes are much conserved as only one spoligotype was detected. The study has shown that three loci differentiated fairly well. This option is cheap and less laborious, and hence a better option in resource-strained country like Zambia. The study further showed that some of the loci recommended by the European Reference Laboratory are not suitable for typing M. bovis in Zambia.     

Bovine tuberculosis in South Darfur State, Sudan: an abattoir study based on microscopy and molecular detection methods

Bovine tuberculosis (BTB) is a widespread zoonosis in developing countries but has received little attention in many sub-Saharan African countries including Sudan and particularly in some parts such as Darfur states. This study aimed to detect bovine tuberculosis among caseous materials of cattle slaughtered in abattoirs in South Darfur State, Sudan by using microscopic and PCR-based methods. The study was a cross-sectional abattoir-based study which examined a total of 6,680 bovine carcasses for caseous lesions in South Darfur State between 2007 and 2009. Collected specimens were examined for the presence of acid-fast bacilli (AFB) by using microscopic and culture techniques. Isolated mycobacteria were identified by selected conventional cultural and biochemical tests in comparison to a single tube multiplex PCR (m-PCR) assay which detect Mycobacterium bovis-specific 168-bp amplicons. Of the total 6,680 slaughtered cattle examined in South Darfur, 400 (6 %) showed caseations restricted to lymph nodes (86.8 %) or generalized (13.2 %). Bovine tuberculosis was diagnosed in 12 (0.18 %), bovine farcy in 59 (0.88 %), unidentified mycobacteria in 6 (0.09 %), and missed or contaminated cultures in 7 (0.1 %). Out of 18 cultures with nonbranching acid-fast rods, 12 amplified unique 168-bp sequence specific for M. bovis and subsequently confirmed as M. bovis. With the exception of the reference M. tuberculosis strains, none of the remaining AFB amplified the 337-bp amplicon specific for M. tuberculosis. It could be concluded that bovine tuberculosis is prevalent among cattle in South Darfur representing 4.5 % from all slaughtered cattle with caseous lesions. The study sustains microscopy as a useful and accessible technique for detecting AFB. m-PCR assay proved to be valuable for confirmation of BTB and its differentiation from other related mycobacteriosis, notably bovine farcy.     

Risk factors of bovine tuberculosis in cattle in rural livestock production systems of Ethiopia

This study shows a representative stratified cluster sample survey of the prevalence of comparative intradermal tuberculin test in cattle from four regions in Ethiopia. Using a cut-off for positivity of 2 mm, it assesses possible risk factors for tuberculin-positive reaction in cattle. Seventy-three villages in 24 kebeles (administrative units) were randomly selected, from which 2216 cattle from 780 owners were tested. In addition, 450 of these cattle owners were interviewed for risk factor assessment. Ninety-nine percent of the tested cattle in this rural livestock production system were traditional zebus. The individual overall prevalence of cattle bovine tuberculosis (BTB)e was 3%, with the highest found in Meskan Mareko, in Central Ethiopia (7.9%) and the lowest in Woldia, in the North East edge of the Rift Valley (1.2%). Generalised Linear Mixed Models (GLMM) with random effect on kebeles was used to analyse risk factors of cattle reactors and human tuberculosis (TB) infection. Purchase of cattle and presence of other livestock in the herd were statistically significant, with OR: 1.7, p-values of 0.03 and OR: 2, p = 0.05, respectively. Family members diagnosed with TB or showing clinical signs of extra-pulmonary TB (EPTB) were reported in 86 households (19%). None of the assessed potential risk factors of disease transmission between cattle and human (food consumption, livestock husbandry and presence of BTB-positive cattle) were statistically significant.     

Risk factors associated with bovine tuberculosis in traditional cattle of the livestock/wildlife interface areas in the Kafue basin of Zambia

We conducted a cross-sectional study from August 2003 to February 2004 to identify risk factors for bovine tuberculosis (BTB) in the Kafue basin of Zambia. We investigated a total of 106 herds of cattle for presence of BTB using the comparative intradermal tuberculin test (CITT) while an interviewer-administered questionnaire was used to gather epidemiological data on herd structure, management and grazing strategies. BTB prevalence at herd level was estimated and possible risk factors were investigated using the multiple logistic regression model. The true herd level prevalence of BTB was estimated at 49.8% (95% CI: 37.9, 61.7%). The logistic regression model showed that cattle herd BTB status was highly associated with area and husbandry practices. When compared to Kazungula, cattle herds in Blue Lagoon were more likely to test positive for BTB when other factors such as management practices were controlled (OR=10.5). In terms of grazing strategies, transhumant herds (TH) had higher odds (OR=3.0) of being positive compared to sedentary herds (OR=1.0). The results in this study provide preliminary information about potential risk factors that were found to be associated with BTB status in cattle.     

Recombinant <Emphasis Type="Italic">Moraxella bovoculi</Emphasis> cytotoxin-ISCOM matrix adjuvanted vaccine to prevent naturally occurring infectious bovine keratoconjunctivitis

A randomized, blinded, controlled field trial was conducted during summer 2006 in a northern California, USA, herd of beef cattle to evaluate the efficacy of a recombinant Moraxella bovoculi cytotoxin subunit vaccine to prevent naturally occurring infectious bovine keratoconjunctivitis (IBK; pinkeye). A convenience sample comprised of 127 steers were administered a subcutaneous dose of either adjuvant alone (ISCOM matrices; control group) or recombinant M. bovoculi cytotoxin carboxy terminus adjuvanted with ISCOM matrices (MbvA group) and were boostered 21 days later. The steers were examined once weekly for 15 weeks for evidence of IBK. No significant difference in the cumulative proportion of corneal ulcerations was detected between groups. Compared to the control calves, the MbvA vaccinates had significantly higher increases in serum neutralizing titers to M. bovoculi hemolysin between week 0 and week 6. The prevalence of M. bovis isolations was higher from ulcerated eyes of calves vaccinated with MbvA as compared to control calves. Vaccination of calves against the carboxy terminus of M. bovoculi RTX toxin resulted in significant increases in serum hemolysin neutralizing titers and may modulate organism type cultured from ulcerated eyes of calves in herds where both M. bovis and M. bovoculi exist. Use of M. bovoculi antigens alone in vaccines to prevent IBK may not be beneficial in herds where IBK is associated with both M. bovoculi and M. bovis.     

Extent of Mycobacterium bovis infection in dairy cattle herds subject to partial culling as determined by an interferon-gamma assay

The interferon-gamma (IFN-γ) assay is employed as a complementary diagnostic test for bovine tuberculosis (BTB) in many countries. To simplify this assay, we established a 96-well plate format using the ESAT-6 and CFP-10 antigens and then employed it to determine the extent of Mycobacterium (M.) bovis infection in dairy herds with a history of BTB outbreaks in a country where only selective culling is practiced. The sensitivity and specificity of this IFN-γ assay were 85.9% and 100%, respectively, based on comparison with the conventional single intradermal tuberculin test (SIDT). The IFN-γ assay was also positive in 30.4% and 36.8% of SIDT-negative animals from herds with recent and remote BTB outbreaks, respectively. Of 14 SIDT-negative, IFN-γ positive cattle, five (35.7%) were culture positive and an additional six were positive based on a polymerase chain reaction-based test for M. bovis. Therefore, the IFN-γ assay has the potential to serve as a specific and sensitive test for M. bovis infection in dairy cattle. Further, the results indicated that a substantial portion of SIDT-negative animals in herds with previous BTB outbreaks were actually infected with M. bovis. Accordingly, the present selective-culling strategy may require modifications to include this more sensitive assay.     

Experimental Mycobacterium bovis infection of cattle: Effect of dose of M. bovis and pregnancy on immune responses and distribution of lesions

Groups of l8-month-old cattle were inoculated intratracheally with 5 X 10⁵ colony forming units (high dose) or 500 colony forming units (low dose) of Mycobacterium bovis to determine an appropriate dose to induce lesions similar to those seen in the natural disease. An additional group of 21–28 weeks pregnant cattle were inoculated with the high dose of M. bovis to determine if pregnancy increased the susceptibility of cattle to M. bovis infection. By 23–24 weeks after challenge, the high dose of M. bovis had induced extensive lung lesions, and tuberculous lesions were observed in the lymph nodes of the head, neck, and thoracic and abdominal cavities. In contrast, the low dose of M. bovis induced predominantly small lesions (< 1 cm diameter) which were localised to the lungs and pulmonary lymph nodes. The lesions induced by the low dose were similar to those seen in the natural disease in cattle. The majority of the high dose group cattle produced strong antibody responses to M. bovis culture filtrate, while only one low dose animal produced a detectable response. All of the M. bovis-inoculated cattle produced strong cellular immune responses to bovine PPD (skin test and interferon-γ responses). Pregnancy did not appear to affect the susceptibility to M. bovis infection, and immune responses of the cattle in this group at the end of the study were similar to those in the high dose non-pregnant group. However, from the first test after calving, the interferon-y responses of peripheral blood cultures to bovine PPD were low compared with the responses prior to calving.     

Seroprevalence estimation and management factors associated with high herd seropositivity for <Emphasis Type="Italic">Babesia bovis</Emphasis> in commercial dairy farms of Puerto Rico

A cross-sectional study was conducted to determine individual cow seroprevalence of Babesia bovis in adult lactating dairy cattle of Puerto Rico (PR), to assess the associations of farm management factors on herd seroprevalence, and to document the species of ticks infesting cattle within these farms. Antibody activity against B. bovis was determined using an indirect fluorescent antibody test (IFAT). Serum samples were obtained from 2,414 adult lactating dairy cattle from 76 randomly selected commercial dairy farms. Herd seroprevalence ranged from 0 to 51% with an overall individual cow seroprevalence for B. bovis of 26%. Ticks were collected from animals on 7 (9%) of the 76 participating commercial dairy farms. All collected ticks (n = 87) were Rhipicephalus (Boophilus) microplus. Factors associated with high herd seropositivity were dairy farms with calf but not heifer raising facilities (OR = 16, 95% CI = 3.0-86), having more than 4 neighbors with cattle (OR = 17, 95% CI = 1.6-178), same producer owning more than one farm (OR = 7.2, 95% CI = 1.6-32), and use of government services to apply amitraz on cattle (OR = 5.5, 95% CI = 1.5-20).     

Molecular Typing of Mycobacterium bovis Isolates in Argentina: First Description of a Person‐to‐Person Transmission Case

Bovine tuberculosis is caused by Mycobacterium bovis, a mycobacterium highly similar to M. tuberculosis that belongs to the M. tuberculosis complex. The main host of M. bovis is cattle but it also affects many other mammalians including humans. Tuberculosis in humans caused by either M. bovis or M. tuberculosis is clinically hard to distinguish. During 2004–2005, samples from 448 patients with diagnosis of TB were collected from different regions of Argentina. The PRA technique identified 400 isolates with representative patterns of mycobacterium. The predominant ones were the M. tuberculosis complex, the M. avium–M. intracellulare complex and M. gordonae. Samples with M. tuberculosis complex PRA restriction profiles were analyzed with a multiplex PCR to differentiate between M. tuberculosis and M. bovis. Multiplex PCR identified nine M. bovis. The results allowed the possibility to establish that 2% of pulmonary tuberculosis was due to M. bovis. Isolates of M. bovis from humans were examined using spoligotyping. These isolates presented five different spoligotypes. The main spoligotype was also the most frequently one found in cattle. The remaining human spoligotypes (grouped in clusters) are occasionally found in cattle. Variable number tandem repeat (VNTR) analysis identified five different patterns. By combining the results of spoligotyping and VNTR analysis, we were able to differentiate seven M. bovis isolates. The remaining two M. bovis samples showed the same spoligotype and VNTR profile and belonged to household contacts. An MDR‐M. bovis was isolated from the samples of these household contacts. The identification of two epidemiologically linked cases of human M. bovis infection suggests person‐to‐person transmission of an MDR‐M. bovis.