Cost-effectiveness assessment of three components of the bovine tuberculosis surveillance system by intradermal tuberculin testing in French cattle farms by a scenario tree approach.

In most officially bovine tuberculosis (bTB)-free countries, bTB has not been fully eradicated. Costly and time-consuming surveillance and control measures are therefore still in place to control this infection. An officially bTB-free status, both at the national and at the herd level, influences whether and when animals can be sold. Thus, this infection is still an economic issue, justifying measures towards its eradication. An evaluation of the cost-effectiveness of such measures would be highly useful, especially to optimise the costs of control measures and their adaptation to a local epidemiological context. We evaluated the cost-effectiveness of three mandatory surveillance protocols currently used in France by herd type (type of production, size, and turnover of the herd) under French field conditions. The first protocol ("strict") implies the direct slaughter and post-mortem analyses of any intradermal cervical tuberculin test (ICT) reactor, and negative results to a second intradermal cervical comparative tuberculin test (ICCT) to regain bTB-free status of the herd. In the second protocol ("compliant quick-path") bTB-free status can be regain if post-mortem analyses of reactors to the first ICT are negative. In the third protocol ("compliant slow-path"), ICCT-reactive animals are tested using the interferon gamma assay; the results of this test influence the path of further investigation. We built scenario trees for each of these protocols at the animal level. They allowed us to estimate herd sensitivity and the total cost of each protocol by herd type. The protocols could be ordered by decreasing herd sensitivity and cost, regardless of the herd type, as follows: strict protocol, compliant quick-path protocol, and compliant slow-path protocol. We calculated a cost-effectiveness index to evaluate the cost-effectiveness of each protocol. The strict protocol was never the most cost-effective, regardless of herd type, due to higher costs relative to the other protocols, despite better herd sensitivity. We found the compliant quick-path to be the most cost-effective protocol for big beef, big dairy, and mixed herds. The compliant slow-path was the most cost-effective for small-scale beef and dairy herds. All differences were significant. This comparison of the cost-effectiveness of the protocols by herd type could help authorities to choose the most suitable protocol in the investigation of suspected cases, depending on the herd type, but could be improved by accounting for important sociological data, such as the acceptability of the protocols.

[Determinants of group B streptococcus maternal colonization and factors related to its vertical perinatal transmission: case-control study]. / Déterminants de la colonisation maternelle à streptocoque B et facteurs associés à sa transmission verticale périnatale: étude cas-témoins.

OBJECTIVES: To investigate the determinants of Group B streptococcus (GBS) maternal colonization, as well as factors associated with its vertical transmission. PATIENTS AND METHODS: Case-control study on all singletons pregnancies delivered beyond at least 24 weeks of amenorrhoea in Southern Reunion maternities for which GBS screening was known. Multiple logistic regression analysis using 2004-2007 dataset of South Reunion birth registers. RESULTS: Out of 17,430 women delivered between 1st January 2004 and 31st December 2007, 2911 (16.7%) carried GBS. In a model adjusted on antenatal care, risk groups for GBS carriage were the women indigenous from another island of the Indian Ocean than Reunion (OR: 1.29, CI95%: 1.05-1.57) and obese women (body mass index ≥ 30, OR: 1.19, CI95%: 1.03-1.18). Protective factors included birthplace in mainland France (OR: 0.82, CI95%: 0.69-0.97) and underweight (OR: 0.81; CI95%: 0.69-0. 95). In a model controlling for a composite obstetrical variable delineating the protective roles of C-section and antibioprophylaxis as well as the putative role of meconium-stained fluids (thin, thick or fetid), all previously found in our setting, three key factors were independently associated with GBS vertical mother-to-child transmission: obesity (OR: 1.48, CI95%: 1.05-2.09), fetal tachycardia (OR: 4.92, CI95%: 2.79-8.68) and late preterm birth (35 to 36 wks, OR: 2.14, CI95%: 1.32-3.45). CONCLUSION: These findings strengthen the putative roles of corpulence and ethnicity in GBS acquisition previously found in the United States, while confirming an authentic role of obesity in its vertical transmission, independently of other classical cofactors lighted by our study.

[Chikungunya infection in pregnancy: Evidence for intrauterine infection in pregnant women and vertical transmission in the parturient. Survey of the Reunion Island outbreak]. / Infection à Chikungunya chez la femme enceinte et risque de transmission materno-foetale.

PURPOSE: Since February 2005, an outbreak of Chikungunya virus (CHIKV) infections occurred in Reunion Island. It is transmitted by the Aedes albopictus mosquito. Neonatal cases observations suggest possible fetal transmission during pregnancy. MATERIAL [corrected] AND METHODS. Observations made in 160 pregnant mothers infected by CHIKV between June 1, 2005 and February 28, 2006, in the south of Reunion island were recorded. RESULTS: Three of nine miscarriages before 22 weeks of gestation could be attributed to the virus. 3,829 births took place during this time. Among the 151 infected women, 118 were viremia negative at delivery, and none of the newborns showed any damage. Among the 33 with positive viremia at delivery, 16 newborns (48.5%) presented neonatal Chikungunya. DISCUSSION: Though fetal contamination risks appear to be rare before 22 weeks of gestation, they are potentially dangerous. After 22 weeks gestation, newborns infection occurs if the mother is viremia positive at delivery. Transplacental transmission is suspected, but the pathogenic mechanism remains unknown.