Drug-sensitivity and passive immunity mathematical epidemiological model for tuberculosis

Regardless of many decades of research, the widespread availability of a vaccine and more recently highly visible WHO efforts to promote a unified global control strategy, Tuberculosis remains a leading cause of infectious mortality. In this paper, a Mathematical Model for Tuberculosis Epidemic with Passive Immunity and Drug-Sensitivity is presented. We carried out analytical studies of the model where the population comprises of eight compartments: passively immune infants, susceptible, latently infected with DS-TB. The Disease Free Equilibrium (DFE) and the Endemic Equilibrium (EE) points were established. The next generation matrix method was used to obtain the reproduction number for drug sensitive (𝑅𝑜𝑠) Tuberculosis. We obtained the disease-free equilibrium for drug sensitive TB which is locally asymptotically stable when 𝑅𝑜𝑠 < 1 indicating that tuberculosis eradication is possible within the population. We also obtained the global stability of the disease-free equilibrium and results showed that the disease-free equilibrium point is globally asymptotically stable when 𝑅𝑜𝑠 ≤ 1 which indicates that tuberculosis naturally dies out.

Milk From Women Diagnosed With COVID-19 Does Not Contain SARS-CoV-2 RNA but Has Persistent Levels of SARS-CoV-2-Specific IgA Antibodies

BackgroundLimited data are available regarding the balance of risks and benefits from human milk and/or breastfeeding during and following maternal infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).ObjectiveTo investigate whether SARS-CoV-2 can be detected in milk and on the breast after maternal coronavirus disease 2019 (COVID-19) diagnosis; and characterize concentrations of milk immunoglobulin (Ig) A specific to the SARS-CoV-2 spike glycoprotein receptor binding domain (RBD) during the 2 months after onset of symptoms or positive diagnostic test.MethodsUsing a longitudinal study design, we collected milk and breast skin swabs one to seven times from 64 lactating women with COVID-19 over a 2-month period, beginning as early as the week of diagnosis. Milk and breast swabs were analyzed for SARS-CoV-2 RNA, and milk was tested for anti-RBD IgA.ResultsSARS-CoV-2 was not detected in any milk sample or on 71% of breast swabs. Twenty-seven out of 29 (93%) breast swabs collected after breast washing tested negative for SARS-CoV-2. Detection of SARS-CoV-2 on the breast was associated with maternal coughing and other household COVID-19. Most (75%; 95% CI, 70-79%; n=316) milk samples contained anti-RBD IgA, and concentrations increased (P=.02) during the first two weeks following onset of COVID-19 symptoms or positive test. Milk-borne anti-RBD IgA persisted for at least two months in 77% of women.ConclusionMilk produced by women with COVID-19 does not contain SARS-CoV-2 and is likely a lasting source of passive immunity via anti-RBD IgA. These results support recommendations encouraging lactating women to continue breastfeeding during and after COVID-19 illness.

Status of Trace Minerals And Colostral Immunoglobulin’s In Periparturient Goats And Its Significance On Morbidity And Mortality of Goat Kids In Semi-Arid Zone of Northern Plains of India

The present study was designed to evaluate the variations of trace minerals status in blood at different stages of periparturient periods and colostrum and milk, colostrum immunoglobulin’s and morbidity and mortality were also evaluated in various recognized breeds of goats maintained at organized farms of CIRG in comparison to the non-descript goats maintained at farmers field flock. The results reveal that blood, colostrum and milk levels of zinc (Zn), copper (Cu), iron (Fe) manganese (Mn) and cobalt (Co) were found to be significantly lower at different stages of periparturient period in the Non-descript breed of goats of maintained at farmers field flock. The colostrum immunoglobulin’s (IgG, IgM and IgA) were also found to be lowest in the non-descript breed of goats than recognized breeds of goats. The morbidity and mortality were found to be highest in goat kids born of non-descript breed of goats during pre weaning period in comparison to the recognized breeds. It can be concluded that the lower level of trace minerals during periparturient period in non-descript goats of farmers field flocks might results in lower level of colostral immunoglobulin’s hence poor transfer of passive immunity in goat kids. Therefore, high morbidity and mortality of goat kids during pre weaning period than recognized breed of goats of the organized farms.

Maternal Supply of Ruminally-Protected Lysine and Methionine During Close-Up Period Enhances Immunity and Growth Rate of Neonatal Calves

The objective of this study was to evaluate the effect of supplying ruminally-protected lysine (RPL), methionine (RPM), or the two in combination (RPML) to transition dairy cows on the immunity and performance of their offspring. Eighty heifer calves (n = 20 calves per group) were assigned to four treatments based on their dam diet; basal diet (CON), a basal diet with lysine [RPL, 0.33% of dry matter (DM)], a basal diet with methionine (RPM, 0.16% DM), or with the combination (RPML). Calves were fed colostrum from their dams within 2 h of birth. Calves were then fed milk only (d 2–22), a combination of milk and milk replacer (d 23–25), and milk replacer (d 25–60). Starter feed was fed to the calves twice daily after liquid feeding. Calves blood samples were collected after calving on 0, 12, 24, and 48 h and 5 and 7 d after birth. Data were analyzed by SAS software v9.4. Providing ruminally-protected amino acids (RPAA) to transition cows improved colostrum quality compared to the CON (Brix; P &lt; 0.01). Serum total protein concentrations were higher in calves from supplemented cows than in calves from unsupplemented cows (P &lt; 0.01). Calves born to dams in the RPM, RPL, and RPML groups had higher plasma immunoglobulin G (IgG) concentrations 0, 12, 24, and 48 h and 7 d after birth than those born to dams in the CON group (P &lt; 0.05). The percentage of calves with adequate passive immunity transfer was increased with RPM and RPL or the two in combination (P &lt; 0.01). However, there was no difference in the percentage of calves with adequate passive immunity transfer between the RPM and RPL groups (P = 0.21). Calves from cows that receive supplemental RPAA have a greater average daily gain (ADG) than those born to cows in the CON group (P &lt; 0.01). These results indicate that maternal supplementation with RPM or RPL or the two in combination during the periparturient period could be an alternative strategy to improve the performance of calves, especially in accelerated growth programs in calves.

Risk factors related to the appearance of umbilical disorders in dairy calves

ABSTRACT The objective of this study was to determine the types of calve housing used in dairy farms, the prevalence of umbilical disorders and related risk factors. The 16 farms studied were visited to characterize the types of installation and possible risk factors, as well as information obtained from a questionnaire applied to the farmers. 806 Holstein calves were physically examined, in addition to collecting blood samples for the evaluation of Failures in Passive Immunity Transfer (FPIT), in animals that manifested inflammatory omphalopathies, and were also submitted to ultrasound examination. The prevalence of omphalopathies was assessed by Fisher's test, and multivariate logistic regression to assess risk factors. Eight types of installation were found: tropical house, suspended cage, collective stall, collective picket, Argentinean type, single-story cage, individual stall, and collective picket with chain. Omphalopathies accounted for 6.45% of the calves. Small size farms (up to 99 lactation cows) had high risk for umbilical disorders, ground floor collective calves, without side protection, with sand floor, in closed sheds and without heatstroke were considered risk factors for omphalopathies. Adequate colostrum and umbilical antisepsis are not associated with disease, its appearance being related to the housing conditions of the animals.

Nutritional and Functional Properties of Colostrum in Puppies and Kittens

The present review aims toward a better understanding of the nutrition of newborn puppies and kittens. The post-natal period is very sensitive in dogs and cats, as in other animal species. During the first two weeks of life, puppies and kittens are at high risk of dehydration, hypothermia, and hypoglycemia, as well as infectious diseases as they start to acquire the physiological functions of the adult. Neonatal hepatic glycogen storage is low, and newborns depend on colostrum intake to survive. Colostrum provides immunoglobulins and other important substances such as lipids and carbohydrates. Immunoglobulins are central to the immunological link that occurs when the mother transfers passive immunity. The mechanism of transfer varies among mammalian species, but in this review, we focused our attention on dogs and cats. Furthermore, there are components of colostrum which, although their presence is not absolutely necessary, play an important role in nutrition. These components have received considerable interest because of their presumed safety and potential nutritional and therapeutic effects both in humans and animals; however, unfortunately, there are few recent studies in companion animals. Here, we have gathered the published articles that describe studies involving different species of animals, emphasizing companion animals. In particular, the purpose of this narrative of the nutritional and functional proprieties of queens’ and bitches’ colostrum.

Current Diagnostic Methods for Assessing Transfer of Passive Immunity in Calves and Possible Improvements: A Literature Review

Several direct or indirect methods can be used to assess immunoglobulin G (IgG) concentrations in calves, which evaluates the transfer of passive immunity (TPI). Radial immunodiffusion (RID) is the gold standard method to measure serum IgG in bovines. Previous studies have shown that colostrum provides several molecules in addition to immunoglobulins, which play an important role in the passive immunity of the calf. However, no studies have yet determined the level of interference of these components in the immunity, health and survival of calves. In this sense, the objective of this study is to review the methods of evaluation available for the laboratory and field diagnosis of TPI in calves and discuss the main aspects of each technique. Several methods available for TPI evaluation in calves may provide insights into the various components of colostrum involved in passive immunity.

67 Association of Morbidity and Failure of Transfer of Passive Immunity in Beef-dairy Crossbred Calves

The objective of this prospective cohort study was to describe the prevalence of failure of transfer of passive immunity (FTPI) in beef-dairy crossbred calves, and its association with morbidity up to 30 d of life. A total of 393 one d old calves were enrolled upon arrival at a calf facility in Central Valley, California, from Jan-Mar 2021. Farm of origin, breed, sex, and weight were recorded at the day of arrival. Blood was collected at 24 ± 1 h post-arrival to evaluate total serum protein (TSP) and % Brix reading. Calves were classified as having FTPI if TSP &lt; 5.2 g/dL, and brix &lt; 8.2%. Farm personnel performed daily health evaluations and recorded diseases. Descriptive statistics, logistic regression, and survival analysis were conducted using SAS. Calves’ breeds were Angus × Holstein (AN × HO, 58%), Charolais × Jersey (CH × JE, 37%), and Angus × Jersey (AN × JE, 5%). Prevalence of FTPI was 36% (TSP) and 34% (brix). TSP and %Brix readings had a strong correlation (r = 0,99, P &lt; 0.0001). Overall morbidity was 78% (70% had only diarrhea, 7% only respiratory disease and 23% both). The odds of disease up to 30 d was not associated with sex (female vs. male, OR = 0.77, 95% CI = 0.36–1.62), or breed (AN × HO vs. CH × JE, OR = 1.35, CI = 0.63–2.91; AN × JE not included in this analysis). FTPI was associated with greater odds of disease (OR = 2.91, CI = 1.19–7.09, P = 0.01). There was a tendency for association between FTPI and the hazard of disease up to 30 d (HR = 1.43, CI = 0.96–2.10, P = 0.07). Therefore, FTPI may predispose beef-dairy crossbred calves to diarrhea and respiratory disease up to 30 d of life.

PSIX-14 Active and passive immunity in calves vaccinated with a subunit targeted vaccine against BVDV

Bovine viral diarrhea virus (BVDV) infects ruminants, with a worldwide distribution, the virus causes a broad spectrum of clinical diseases and economic losses. Vaccination against BVDV is an important component of prevention and control programs. Currently, only modified live vaccines (MLV) and inactivated vaccines are used. Both have historical disadvantages; MLV in terms of safety and inactivated vaccines in terms of immunogenicity. We have previously reported the development and efficacy trials of the first targeted subunit vaccine against BVDV. The core of the vaccine is a fusion of the BVDV structural protein, E2, to a single-chain antibody, APCH, together termed, APCH-E2. The APCH antibody targets the E2 antigen to the MHC-II present on antigen-presenting cells. The goal of this work was to evaluate passive immunity through colostrum and active immunity of calves immunized with the novel vaccine. 24 A. angus heifers were divided into two groups, 12 immunized with the vaccine and 12 received placebo, in the last trimester of gestation. Serum samples from calves were taken at day 30 of age and analyzed by competitive ELISA. In the vaccinated group, 92% of the d30 old calves maintained medium (25%) or high (67%) antibody levels against BVDV, while 50% of the animals in the control group presented low antibody level (Pearson’s chi-squared p:0,07) (Table 1). At 5 months of age, calves of both groups were immunized with the targeted vaccine. Thirty days later, 96% of the calves had medium or high antibody levels against BVDV, which was independent of their respective heifer vaccine status. These results confirm the new targeted subunit vaccine against BVDV is safe and efficacious to be used in pregnant cattle and can passively immunize newborn calves. They also show that these maternal antibodies do not interfere with the active immunization of calves.