Seroconversion rates following 2 doses of measles- mumps- rubella vaccination given at the ages 12 and 18 months: data for possible additional dose at older age.

BACKGROUND: Despite high rate of vaccination coverage with 2-doses of measles containing vaccine among Iranian children, outbreaks of measles occurred among different age groups and fully vaccinated subjects. Although the main reason for these outbreaks is unknown, however, vaccine failure was supposed to be an important cause. This study was designed to determine the seroconversion rates to measles- mumps- rubella (MMR) vaccine currently in use among Iranian children. METHODS: This prospective study was conducted among healthy children older than 12 months who were candidates of scheduled MMR vaccination. Blood samples were obtained from each mother- infant pair just before vaccination, and from infants 4-6 weeks after MMR1 and MMR2 immunization. Collected sera were tested for specific lgG antibodies against MMR agents using ELISA method. The proportion of seroprotected subjects among mother- infant pairs before vaccination as well as the prevalence rates of seroconversion after MMR1 and MMR2 vaccination were calculated. Collected data were analyzed using descriptive statistical methods. RESULTS: During 22-months study period, 92 mother- infant pairs were participated. Seroimmunity rates against MMR viruses were 85.8%, 84.7% and 86.9% for mothers, and 3.2%, 2.1% and 1.0% for children, respectively. After MMR1 vaccination from 52 seronegative children, 80.7%, 78.8% and 75% were seroconverted. These rates increased to 94.8%, 89.7% and 94.8% after the MMR2 vaccination. Also, the specific immunity was enhanced among seropositive children. CONCLUSION: Majority of the mothers and few infants were immune to MMR viruses prior to MMR1 vaccination. Immune responses detected after MMR1 injection, and overall seroconversion rates achieved after 2-doses of MMR vaccination were less than expected and inadequate to preserve long-term protection against MMR agents.

Measles and rubella serosusceptibity among population vaccinated with different schedules: the potential impact on measles-rubella elimination in Iran.

BACKGROUND: Iranian children were vaccinated with the scheduled two doses of monovalent measles vaccine (mMV) from 1984. In December 2003, a nationwide campaign of measles-rubella (MR) immunization was established to vaccinate 5-25 year- old individuals. In 2004, the mMV was replaced with measles- mumps- rubella (MMR) vaccine. Despite the high vaccination coverage, the outbreaks of measles still occur in the country. In this Study, the MR immunity status of various age groups, vaccinated with different schedules was investigated, and the immunologic response of seronegative subjects to revaccination was examined. METHODS: This cross-sectional study was conducted among 7-33-year-old healthy individuals with a documented history of measles vaccination from November 2017 to June 2018. The subjects were categorized as follows: group A, including 20-33 year-old individuals; vaccinated with 1-2 doses of mMV at ages 9 and 15 months, and revaccinated with MR, group B, including 15-19-year-old individuals, vaccinated with two doses of mMV at 9 and 15 months of age, and received additional dose of MMR upon school entrance, group C, including 11-14 year-old individuals, vaccinated with two-doses of MMR at the ages of 15 months and 6 years, and group D, including 7-10 year-old individuals vaccinated with two-doses of MMR vaccine at the ages 12 and 18 months, respectively. Levels of antimeasles- antirubella IgG antibodies in the collected sera were measured. Also antimeasles- antirubella IgM and IgG of seronegative individuals were reexamined at 4-6 weeks after MMR revaccination. The collected data were analyzed using descriptive statistical methods. RESULTS: A total of 635 individuals were investigated in this study. Group A, 98; group B, 295; group C, 139; and group D, 103 persons. Overall, 12.3 and 18.4% of the population were seronegative for measles and rubella antibodies. This rate varied greatly between the 4 groups: group A, 0/0-2%; group B,15.2-25.0%; group C,11.5-17.2%; and groupD,14.6-18.4%. After revaccination, 92 and 94.9% of seronegative individuals showed IgG response to measles and rubella vaccines, respectively. CONCLUSION: Despite the high coverage rate of M-R containing vaccines, a significant number of vaccinated subjects were seronegative for measles and rubella, possibly because of secondary vaccine failure; this may negatively affect measles-rubella elimination targets in the country. If these findings are confirmed in similar future studies, a more robust regional/national supplementary immunization activity will be considered.

Economic evaluation of sexed semen use in Iranian dairy farms according to field data.

In this study, at first, the reproductive consequences of sexed semen use were quantified and then the cost-benefit of sexed semen use on Iranian commercial dairy farms was evaluated. Retrospective data collected during 2006 to 2013 from four large dairy farms in the Isfahan province of Iran were used for this study. These data included of 13,003 heifers records, from which 11.2% used sexed semen from 33 different bulls. All data were analysed using a multivariable logistical regression model, GENMOD procedure from SAS software. The analyses included economic values (EVs) when sexed semen was used in 1, 2 and 3 consecutive services compared with conventional semen use for all insemination. Results showed that rates of female born from sexed semen (86.3%) were 1.8 times higher than those from conventional semen (48.5%). Conception rates were 43.8% for sexed and 59.2% for conventional semen (p < 0.0001). Abortion (4.4% vs. 5.4%) and stillbirth (8.4% vs. 7.2%) rates were not significantly different between sexed and conventional semen (p = 0.09). Dystocia rates were 15.5% for sexed and 19.6% for conventional semen (p = 0.002). Sexed semen use showed negative EVs through all investigated scenarios. The EVs from the implementation of 1, 2 and 3 sexed semen breedings were estimated to be $-6.69, $-14.01 and $-19.08, respectively. Total insemination cost and increased cost of age at first calving were the most important components associated with negative EV for sexed semen. Sensitivity analysis showed that proportion of conception rates of sexed semen to conventional semen and female calf value were the most important biological and economic factors influencing on the EV of sexed semen, respectively. Breakeven would be obtained with 77.4%-79.3% conception rates or female calf value of $719.5-$754.7 through investigated breeding scenarios when all other factors remained the same.

Effects of Dietary Fiber Level and Forage Particle Size on Growth, Nutrient Digestion, Ruminal Fermentation, and Behavior of Weaned Holstein Calves under Heat Stress.

This experiment was designed to investigate the effects of feeding diets with different fiber content and forage particle size on the performance, health, nutrient digestion, rumen fermentation, and behavioral and sorting activity of Holstein dairy calves kept under elevated environmental temperature. Sixty weaned Holstein female calves (age = 96.7 ± 7.62 days old; body weight = 82.4 ± 10.4 kg) were randomly assigned to one of 4 treatments arranged in a 2-by-2 factorial design in a 70-day experiment. Dietary forage content (moderate, 22.5%; or high, 40.0% on DM basis) and alfalfa hay particle size (short, 4.39 mm; or long, 7.22 mm as geometric mean) were the experimental factors, resulting in the following combinations: (1) high-fiber (HF) diets with forage-to-concentrate ratio of 40:60 and long particle-sized alfalfa hay (LPS; HF-LPS); (2) HF diets with short particle-sized alfalfa hay (SPS; HF-SPS); (3) moderate-fiber (MF) diets with forage-to-concentrate ratio of 22.5:77.5 with LPS (MF-LPS); and (4) MF diets with SPS (MF-SPS). The temperature-humidity index averaged 73.0 ± 1.86, indicating that weaned calves experienced a moderate extent of heat stress. Fiber level and AH particle size interacted and affected dry matter intake, with the greatest intake (4.83 kg/d) observed in MF-SPS-fed calves. Final body weight was greater in calves receiving MF vs. HF diets (164 vs. 152 kg; p < 0.01). Respiration rate decreased when SPS vs. LPS AH was included in HF but not MF diet. Lower rectal temperature was recorded in calves fed MF vs. HF diet. Digestibility of dry matter and crude protein was greater in calves fed MF than HF diets, resulting in lower ruminal pH (6.12 vs. 6.30; p = 0.03). Fiber digestibility was greater in calves fed SPS compared with those fed LPS alfalfa hay. Feeding HF compared with MF diet increased acetate but lowered propionate molar proportions. The inclusion of SPS vs. LPS alfalfa hay decreased lying time in HF diet (920 vs. 861 min; p < 0.01). Calves fed MF vs. HF diets spent less time eating but more time lying, which is likely indicative of better animal comfort. Dietary fiber level and forage particle size interacted and affected sorting against 19 mm particles, the extent of which was greater in HF-SPS diet. Overall, dietary fiber level had a stronger effect than forage particle size on the performance of weaned calves exposed to a moderate degree of heat stress as feeding MF vs. HF diet resulted in greater feed intake, final body weight, structural growth measures, nutrient digestion, as well as longer lying behavior. The inclusion of SPS alfalfa hay in MF diets increased feed consumption.

Assessing the consequences and economic impact of retained placenta in Holstein dairy cattle.

Retained placenta (RP) is as an important reproductive disorder which adversely affects the economic performance of dairy cows. Understanding the consequences and economic losses associated with RP can persuade dairy farmers to consider it more effectively in their management decisions. Hence, the aims of this research were to assess the effect of RP on production and reproduction attributes as well as economic losses in Iranian Holstein cows. The data was collected from nine Holstein dairy herds in Isfahan province of Iran. The final dataset comprised of 139,508 records of 58,086 cows which calved between March 2011 and December 2018. A linear mixed model was developed to evaluate the effect of RP on individual performance of primiparous and multiparous cows. The economic losses associated with the RP were finally estimated. The average incidence of RP per cow over a year was 12.3% (ranged between 9.0 and 15.4%). Each incidence of RP significantly reduced milk, fat and protein yields in primiparous and multiparous cows (P < 0.05). The adverse effect of RP on the milk production was much higher in the cows at the early phase of lactation (i.e. 100-d lactation group) than the cows in mid or late lactation. The estimated production losses (±standard deviation) due to the RP event were 282.1 ± 43.0 and 295.7 ± 40.8 kg per cow for a 305-d lactation period in primiparous and multiparous cows, respectively. However, the fertility performance was less affected by the RP in primiparous compared to multiparous cows. The average of days open increased by 8.3 ± 5.3 and 19.8 ± 7.1 d in primiparous and multiparous cows, respectively. The financial losses associated with RP were on average US$ 350.4 and US$ 481.2 per incidence in primiparous and multiparous cows, respectively, ranged from US$ 311.9 to 456.2 depending on the parity number (primi- or multiparous) and herd management. The highest financial losses due to RP were associated with reduction in milk production (38.5% of total loss) and low fertility (28.5% of total loss) had the highest contribution in in primiparous and multiparous cows, respectively. The results of our research highlight the economic importance of improved calving management to reduce RP occurrence in dairy cows.

Farm and cow factors and their interactions on the incidence of retained placenta in holstein dairy cows.

Risk factors for retained placenta (RP), as a common and economically important disorder, have been widely investigated. However, comprehensive studies are rare. Therefore, this study sought to identify herd-cow factors and their interactions on the risk of RP in Iranian dairy herds. The data were collected from nine Holstein dairy herds in Isfahan province, Iran. The final dataset included 154,048 records for 59,610 cows which calved between March 2011 and December 2018. A logistic regression model was used to separately analyze the risk factors and their interactions for RP in primiparous and multiparous cows. The average rate of RP was 12.3% (9.0-15.4%) at the herd level. The highest rate of RP was recorded in spring compared with other seasons. Regardless of calving season, occurrence of dystocia, stillbirth and twinning increased the odds ratio (OR) of RP. In primiparous cows, occurrence of dystocia and stillbirth increased OR of RP 4.30 and 3.33 times, respectively. In multiparous cows, dystocia, twinning and stillbirth increased OR of RP 4.36, 3.94 and 1.29 times, respectively. Cows with an age at first calving of >28 months had the highest rate of RP compared with other cows. Multiparous and primiparous cows with a short (less than 271 d) and long (more than 281 d) pregnancy, respectively, had the highest risk of RP compared to cows in other groups. Furthermore, multiparous cows with an extended dry period length (more than 75 d) and produced milk yield more than 13,000 kg/lactation were at higher risk of RP with an average of 13.5%. With an interaction analysis, although the potential effect of each factors depends on the effect of other factors, but in general dystocia, stillbirth, an extended age at first calving (>28 months), and calving during the spring increased risk of RP for both groups. In conclusion, identification of risk factors for RP with an interaction analysis can help farm managers to employ the best strategies to reduce the occurrence of this reproductive disorder.

Pertussis resurgence in a highly vaccinated population, Mazandaran, North of Iran 2008-2011: an epidemiological analysis.

OBJECTIVE: To describe the epidemiological characteristics of pertussis cases reported to Mazandaran Center for Diseases Control and Prevention (P-CDC) during the years 2008-2011 in Mazandaran, North of Iran. METHODS: The patients included were those who fulfilled the WHO definition for pertussis or those clinically diagnosed by physicians. The demographic features of cases, their vaccination status, the incidence rate per 100,000 population, the relative proportion of cases for each age group, and their relation to vaccination status of the patients were all determined. RESULTS: During the study period, a total of 518 cases of pertussis were reported; of which 43 were confirmed. The highest incidence rate and the largest proportion were 135.5 cases/100,000 and 37.7 %, respectively, observed in infants <12 mo of age. Almost 35.7 % of the cases were under vaccinated, however 54.4 % of them were fully vaccinated. CONCLUSIONS: Pertussis infection has re-emerged in Mazandaran. It has caused a significant health problem in the susceptible young infants, and also among completely vaccinated children. Implementing strategies to protect these vulnerable infants and studies to evaluate the immunogenicity and efficacy of pertussis vaccine in Iran is recommended. It was difficult to confirm pertussis in the majority of cases, therefore, providing and improving laboratory diagnostic methods seems to be an urgent requirement.

Intraarticular Administration of Tranexamic Acid Following Total Knee Arthroplasty: A Case-control Study.

BACKGROUND: Tranexamic acid (TXA) has received extensive attention in management of blood loss in orthopedic surgeries. However, the ideal method of TXA administration is still controversial. This study aims to determine whether intraarticular injection of TXA reduces blood loss after total knee arthroplasty (TKA). METHODS: Through a retrospective case-control study consecutive TKA patients receiving intraarticular TXA (Case group) were compared with similar patients undergoing TKA using traditional blood management strategy (Control group). Hemoglobin levels (Hb) before and after the surgery, need for transfusion, and reoperation due to massive blood loss were compared between the two groups. RESULTS: Fifty TXA patients were compared with 50 patients of the control group. There was no significant difference between the two groups in terms of age, gender, and preoperative Hb. Postoperative blood loss and transfusion rate were significantly reducedin TXA patients compared to the control group (P<0.05). CONCLUSIONS: Our study revealed that intraarticular administration of TXA reduces postoperative blood loss as well as need for blood transfusion in patients undergoing TKA.