Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

Peer reviewe

Development of an Effective Whole-Spore Vaccine To Protect against Microsporidial Gill Disease in Rainbow Trout (Oncorhynchus mykiss) by Using a Low-Virulence Strain of Loma salmonae▿

In determining the effective vaccine spore dose of a low-virulence strain of Loma salmonae to limit microsporidial gill disease in trout, we found that fish receiving 103 to 105 killed spores had the best protection against experimental infection, with 85% fewer xenomas in their gills than in the controls. Intraperitoneal delivery of the vaccine was effective, and the addition of adjuvant did not improve vaccine performance against this disease-causing microsporidian

Clinical and Vaccine Immunology 14 12 1652 1654 AMER SOC MICROBIOLOGY WASHINGTON; 1752 N ST NW, WASHINGTON, DC 20036-2904 USA

In determining the effective vaccine spore dose of a low-virulence strain of Loma salmonae to limit micro-sporidial gill disease in trout, we found that fish receiving 10(3) to 10(5) killed spores had the best protection against experimental infection, with 85% fewer xenomas in their gills than in the controls. Intraperitoneal delivery of the vaccine was effective, and the addition of adjuvant did not improve vaccine performance against this disease-causing microsporidian.CR: CARRINGTON AC, 2006, VET IMMUNOL IMMUNOP, V112, P87, DOI 10.1016/j.vetimm.2006.03.015 KEELING PJ, 2002, ANNU REV MICROBIOL, V56, P93, DOI 10.1146/annurev.micro.56.012302.160854 KENT ML, 1998, J AQUAT ANIM HEALTH, V10, P211 KENT ML, 2005, FOLIA PARASIT, V52, P1 LEIRO J, 1996, VET IMMUNOL IMMUNOP, V55, P235 RAMSAY JM, 2001, J FISH DIS, V24, P453 RODRIGUEZTOVAR LE, 2006, FISH SHELLFISH IMMUN, V21, P170, DOI 10.1016/j.fsi.2005.11.009 RODRIGUEZTOVAR LE, 2006, VET IMMUNOL IMMUNOP, V114, P72, DOI 10.1016/j.vetimm.2006.07.006 SANCHEZ JG, 2001, J FISH BIOL, V59, P427 SANCHEZ JG, 2001, J FISH BIOL, V59, P442 SANCHEZ JG, 2001, J FISH DIS, V24, P33 SOBOTTKA I, 2001, PARASITOL RES, V87, P1 SOMMERSET I, 2005, EXPERT REV VACCINES, V4, P89, DOI 10.1586/14760584.4.1.89 SPEAR DJ, 1998, J COMP PATHOL, V119, P459 SPEARE DJ, 1999, J COMP PATHOL, V121, P241 SPEARE DJ, 1999, J FISH DIS, V22, P27

Multiple courses of antenatal corticosteroids for preterm birth (MACS): a randomised controlled trial

BACKGROUND: One course of antenatal corticosteroids reduces the risk of respiratory distress syndrome and neonatal death. Weekly doses given to women who remain undelivered after a single course may have benefits (less respiratory morbidity) or cause harm (reduced growth in utero). We aimed to find out whether multiple courses of antenatal corticosteroids would reduce neonatal morbidity and mortality without adversely affecting fetal growth. METHODS: 1858 women at 25-32 weeks' gestation who remained undelivered 14-21 days after an initial course of antenatal corticosteroids and continued to be at high risk of preterm birth were randomly assigned to multiple courses of antenatal corticosteroids (n=937) or placebo (n=921), every 14 days until week 33 or delivery, whichever came first. The primary outcome was a composite of perinatal or neonatal mortality, severe respiratory distress syndrome, intraventricular haemorrhage (grade III or IV), periventricular leucomalacia, bronchopulmonary dysplasia, or necrotising enterocolitis. Analysis was by intention to treat. All patients and caregivers were unaware of the treatment given. This trial is registered as number ISRCTN2654148. FINDINGS: Infants exposed to multiple courses of antenatal corticosteroids had similar morbidity and mortality to those exposed to placebo (150 [12.9%] vs 143 [12.5%]). Those receiving multiple doses of corticosteroids also weighed less at birth than those exposed to placebo (2216 g vs 2330 g, p=0.0026), were shorter (44.5 cm vs 45.4 cm, p<0.001), and had a smaller head circumference (31.1 cm vs 31.7 cm, p<0.001). INTERPRETATION: Multiple courses of antenatal corticosteroids, every 14 days, do not improve preterm-birth outcomes, and are associated with a decreased weight, length, and head circumference at birth. Therefore, this treatment schedule is not recommended. FUNDING: Canadian Institutes of Health Research

Maternal side-effects after multiple courses of antenatal corticosteroids (MACS): the three-month follow-up of women in the randomized controlled trial of MACS for preterm birth study

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Effect of antenatal corticosteroids on fetal growth and gestational age at birth

OBJECTIVE: To estimate the effect of multiple courses of antenatal corticosteroids on neonatal size, controlling for gestational age at birth and other confounders, and to determine whether there was a dose-response relationship between number of courses of antenatal corticosteroids and neonatal size. METHODS: This is a secondary analysis of the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study, a double-blind randomized controlled trial of single compared with multiple courses of antenatal corticosteroids in women at risk for preterm birth and in which fetuses administered multiple courses of antenatal corticosteroids weighed less, were shorter, and had smaller head circumferences at birth. All women (n=1,858) and children (n=2,304) enrolled in the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study were included in the current analysis. Multiple linear regression analyses were undertaken. RESULTS: Compared with placebo, neonates in the antenatal corticosteroids group were born earlier (estimated difference and confidence interval [CI]: -0.428 weeks, CI -0.10264 to -0.75336; P=.01). Controlling for gestational age at birth and confounding factors, multiple courses of antenatal corticosteroids were associated with a decrease in birth weight (-33.50 g, CI -66.27120 to -0.72880; P=.045), length (-0.339 cm, CI -0.6212 to -0.05676]; P=.019), and head circumference (-0.296 cm, -0.45672 to -0.13528; P<.001). For each additional course of antenatal corticosteroids, there was a trend toward an incremental decrease in birth weight, length, and head circumference. CONCLUSION: Fetuses exposed to multiple courses of antenatal corticosteroids were smaller at birth. The reduction in size was partially attributed to being born at an earlier gestational age but also was attributed to decreased fetal growth. Finally, a dose-response relationship exists between the number of corticosteroid courses and a decrease in fetal growth. The long-term effect of these findings is unknown. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00187382. LEVEL OF EVIDENCE: II