Treatment optimization of patients with epithelial coccygeal passage complicated by an abscess

Background: Despite the wide variety of epithelial coccygeal passage treatment methods, the choice of the type of surgery is still an issue to be discussed. It is due to the heterogeneity of the clinical material, the variety of pathological processes and development of the pathology. In spite of the absence of serious complications in most cases, it causes a significant deterioration of life quality and reduction of work capacity in patients of the most active age group.Objective: Improvement of the treatment results of patients with epithelial coccygeal passage complicated by an abscess by means of vacuum therapy of a sutured postoperative wound (Russian Patent 2764499 date 07.04.2021).Material and methods: The study included 59 patients: 19 people in the main group, who underwent surgical treatment of the epithelial coccygeal passage complicated by an abscess, using vacuum therapy according to the proposed method. A retrospective analysis of the medical histories of patients who underwent surgical treatment of the epithelial coccygeal passage complicated by an abscess has been carried out by means of the traditional method of wound closure with drainage. These patients were included in the control group of 40 people.Results: In the control group purulent-inflammatory complications were recorded in 4 (10%) patients. Out of 19 people of the main group operated on according to the method proposed by us, purulent-septic complications were not recorded in any of the patients. Wound bandaging has been performed 71 times in 19 patients of the main group, and 454 times in 40 patients of the control group. For 19 patients of the main group the duration of the antibiotic therapy lasted 96 days, for 40 patients of the control group - 306 days. The average number of bed-days for patients of the control group was 10.63, in the main group - 7.56.Conclusion: The use of the proposed method of surgical treatment of epithelial coccygeal passage complicated by an abscess, by means of vacuum therapy at all stages of treatment, made it possible to improve treatment results in patients of the main group

Prevalence and risk factors for infection with Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in swine herds in Illinois (USA)

Infection of swine herds with Porcine Reproductive and Respiratory Syndrome virus (PRRSV) can cause significant economic losses. There have been few epidemiologic studies of PRRSV. Little is known about the risk factors for infection of swine herds with PRRSV. The objectives of this study were to use an existing (1992) serum bank of samples from Illinois (USA) swine herds to estimate the prevalence of PRRSV infection, and to identify risk factors for PRRSV infection and disease in Illinois swine farms. It was hypothesized that the risk of PRRSV infection and disease would increase with (1) increasing herd size, (2) total confinement housing, (3) a greater number of purchases of gilts and boars, (4) purchase of semen for artificial insemination, and (5) not isolating boars and gilts after purchase. In 1992, serum samples from sows on 176 swine farms were obtained from the Illinois state diagnostic laboratories as part of the state pseudorabies testing program. Thereafter these samples were kept frozen at -20 \,^\circC in a serum data bank. During 1997-98 these samples were thawed and tested for antibodies to the PRRS virus, using the USDA-approved IDEXX PRRS ELISA test. Telephone interviews on demographic, management, and housing characteristics had been obtained for 140 of these farms in 1992. Data relevant to testing of hypotheses about the risk of PRRSV infection included the following: (1) number of boars purchased in the last year, (2) number of gilts purchased in the last year, (3) average number of sows in the herd in the last year, and (4) type of housing (total confinement, partial confinement, outdoor lots, pasture). During 1997, 103 of these farms (74%) were re-contacted by telephone and an updated survey was conducted, specifically targeted towards obtaining information on PRRS and its risk factors. Of the 103 farms for which herd survey information was available for data analysis, 50 (49%) had been diagnosed with PRRSV infection between 1992 and 1997. In 37 (74%) of the herds diagnosed with PRRSV infection, there were clinical signs, mostly epidemic abortions (62%), pre-weaning mortality (36%) and respiratory signs in nursery (58%) and growing-finishing (52%) pigs. There were PRRSV serological test results on at least 20 sows for 54 of the surveyed herds. There was a mean of 34 serum samples tested per herd (median = 30; range: 20-76), with a mean seroprevalence of 28% (median = 10%), with 36 of the herds (67%) having at least one seropositive sow. Bivariate analysis of data from the herd surveys indicated that increased risk of PRRS diagnosis was associated with not isolating gilts after purchase (OR = 6.2; $\rm p < 0.001$), a higher number of sows (mean = 351 vs. 181 with no PRRS diagnosis; $\rm p < 0.001$), total confinement (OR = 3.0; $\rm p < 0.01$), purchasing semen for artificial insemination (OR = 2.5; p = 0.02), and more gilts purchased (mean = 40 vs. 17 with no PRRS diagnosis; p = 0.03). Similar results were obtained when the outcome analyzed was PRRS disease. Multiple logistic regression analysis indicated that an increased risk of PRRS diagnosis was associated with a higher number of sows (adjusted OR = 1.003; $\rm p < 0.01$), not isolating gilts after purchase (aOR = 3.3; p = 0.02), and purchase of semen for artificial insemination (aOR = 2.2; p = 0.04). Multiple linear regression analysis of risk factors for sow PRRSV seroprevalence in herds with survey results indicated only that the purchase of boars increased this risk $\rm (p < 0.01)$. Our conclusions are the following

Aujeszky's disease virus (ADV) in mammalian wildlife on swine farms in Illinois (USA): Potential for transmission to non-infected herds

After eradication of ADV from swine herds, non-porcine reservoirs can be potential sources for reintroduction of ADV. Vaccination of swine with modified live, gene-deleted vaccines, particularly intranasally (which promotes aerosol transmission), has the potential to immunize wildlife populations. Immunized wildlife can survive exposure to virulent wild-type ADV. Mammalian wildlife traveling between swine herds can also serve as vectors for between herd spread. The objective of this study was to determine the prevalence of infection of mammalian wildlife with wild-type and vaccine ADV on swine farms quarantined for ADV where vaccine was used, and to determine the potential for between herd spread of ADV by wildlife. Six swine farms in Illinois (USA) quarantined for infection with ADV were studied. All were in close proximity (maximum 30 km distance). Five farms studied in both 1996 and 1997 used modified live ADV vaccines with deletions for glycoprotein E (gE$^-$), one dose administered intranasally at 3-4 weeks of age, and the other intramuscularly at 9-10 weeks. The sixth farm, studied only in 1997, vaccinated pigs intramuscularly at 9 weeks of age with a gE$^-$gG$^-$ vaccine. Each farm was visited 6 times per year, between April and September. Overnight live trapping of wildlife (rodents and medium sized mammals) was conducted. Blood samples were obtained from all captured animals. Detection of anti-ADV antibodies was accomplished by using a serum neutralization (SN) test for sera from medium sized mammals and rats and a latex agglutination test (LAT) for sera from small rodents. All rodents were euthanized and their brains were harvested. Upon first capture, each medium sized mammal trapped was tattooed for identification and released. Upon recapture, if a medium sized mammal had been identified as seropositive for ADV on a previous trip, it was euthanized and its brain, trigeminal ganglia, and tonsils were removed. For all ADV seropositive animals, a polymerase chain reaction (PCR) for viral detection was performed on tissue samples (brains for rodents; brains, tonsils, and trigeminal ganglia for cats), using primers for glycoproteins C (gC) and E (gE). For each seropositive rodent, 4 matched (by trapping trip on the same farm) seronegative rodents were also tested using PCR. As another control, 6 rodents were selected from each of 2 trips on the only seronegative farm and tested using PCR. There were seropositive cats $(9/157 = 6\%)$ on 2 farms, house mice [Mus] $(10/3947 = 0.3\%)$ on 3 farms, and field mice [Peromyscus] $(1/100 = 1\%)$, rats $(1/207 = 0.5\%)$, and rabbits $(1/4 = 25\%)$ on 1 farm each; 5 of the 6 farms had seropositive wild mammals. There were no seropositive samples for raccoons $\rm (n = 98)$, opossums $\rm (n = 39)$, or skunks $\rm (n = 24)$. There were 3 seropositive cats that were recaptured and euthanized. Two were PCR$^+$ for gC and gE, indicating infection with wild-type ADV. One was PCR$^+$ only for gC, suggesting infection with gE$^-$ vaccine. Among the 64 individual cats, 8 (13%) were trapped on 2 farms, of which 2 were seropositive. The only seropositive rat was gC$^+$ and gE$^-$ by PCR, indicating infection with gE$^-$ ADV vaccine. Among the 11 seropositive mice, 9 (82%) were gC$^+$gE$^+$ (indicating infection with wild-type ADV) and 2 were gC$^+$gE$^-$ (indicating infection with gE$^-$ ADV vaccine). However, for the 40 matched seronegative mice on farms seropositive for wildlife, 38 (95%) were gC PCR$^+$, with 29 (73%) gE$^+$ (indicating wild-type ADV) and 8 (20%) gE$^-$ (indicating infection with gE$^-$ ADV vaccine). For the one farm that was entirely seronegative for wildlife, the 12 rodents tested were PCR$^-$. All PCR$^+$ results were confirmed by Southern blot. It was not possible to isolate ADV from any of the animals that were tested by PCR. Cats and rodents living on swine farms may be infected with ADV, either with wild-type or vaccine genotypes. Thus, these species may serve as a reservoir for possible reintroduction of ADV to swine. Seropositive cats can travel between farms, indicating that cats may serve as a vector for the transmission of ADV between swine farms. A comparison of LAT and PCR results for rodents indicates that the prevalence of ADV infection in rodents may be much higher than estimated by serological testing. ADV eradication programs must consider the role of rodents as a reservoir for reintroduction of ADV into swine herds, and cats as a possible vector for transmission of ADV between herds

Dioecy and the evolution of sex ratios in ants

Split sex ratios, when some colonies produce only male and others only female reproductives, is a common feature of social insects, especially ants. The most widely accepted explanation for split sex ratios was proposed by Boomsma and Grafen, and is driven by conflicts of interest among colonies that vary in relatedness. The predictions of the Boomsma–Grafen model have been confirmed in many cases, but contradicted in several others. We adapt a model for the evolution of dioecy in plants to make predictions about the evolution of split sex ratios in social insects. Reproductive specialization results from the instability of the evolutionarily stable strategy (ESS) sex ratio, and is independent of variation in relatedness. We test predictions of the model with data from a long-term study of harvester ants, and show that it correctly predicts the intermediate sex ratios we observe in our study species. The dioecy model provides a comprehensive framework for sex allocation that is based on the pay-offs to the colony via production of males and females, and is independent of the genetic variation among colonies. However, in populations where the conditions for the Boomsma–Grafen model hold, kin selection will still lead to an association between sex ratio and relatedness