Stomoxys calcitrans, mechanical vector of virulent Besnoitia besnoiti from chronically infected cattle to susceptible rabbit

Cattle besnoitiosis caused by Besnoitia besnoiti (Eucoccidiorida: Sarcocystidae) is a re-emerging disease in Europe. Its mechanical transmission by biting flies has not been investigated since the 1960s. The aim of this study was to re-examine the ability of Stomoxys calcitrans (Diptera: Muscidae) to transmit virulent B. besnoiti bradyzoites from chronically infected cows to susceptible rabbits. Three batches of 300 stable flies were allowed to take an interrupted bloodmeal on chronically infected cows, followed by an immediate bloodmeal on three rabbits (Group B). A control group of rabbits and a group exposed to the bites of non-infected S. calcitrans were included in the study. Blood quantitative polymerase chain reaction (qPCR) analyses, and clinical, serological and haematological surveys were performed in the three groups over 152 days until the rabbits were killed. Quantitative PCR analyses and histological examinations were performed in 24 tissue samples per rabbit. Only one rabbit in Group B exhibited clinical signs of the acute phase of besnoitiosis (hyperthermia, weight loss, regenerative anaemia and transient positive qPCR in blood) and was seroconverted. Parasite DNA was detected in four tissue samples from this rabbit, but no cysts were observed on histological examination. These findings indicate that S. calcitrans may act as a mechanical vector of B. besnoiti more efficiently than was previously considered.

Surgeon's Definition of Complicated Appendicitis: A Prospective Video Survey Study

Aim

Definition of the type of appendicitis is based on examination of the peritoneum and appendix. Gomes et al. proposed a laparoscopic grading system of acute appendicitis (grades 1 and 2, noncomplicated appendicitis, grade 3-5 complicated appendicitis). The aim of this study was to evaluate the reproducibility of this score.

Patients and methods

All patients managed for acute appendicitis between January 2016 and June 2016 were included in this single-center prospective study. Laparoscopic appendectomy procedures were filmed by analogy to Sugerbaker's peritoneal carcinomatosis score (9 quadrants, all of the abdomen was filmed). The videos were then analyzed by seven staff surgeons blinded to each other and the operative report. The primary endpoint was to determine the concordance between staff surgeons for grading of appendicitis using the laparoscopic grading system of acute appendicitis described by Gomes et al.

Results

A total of 40 patients were included in this study. A concordance was observed between the seven staff surgeons in 85% of cases. For regional peritonitis, the mean ± (SD) number of quadrants in which the staff surgeons reported signs of peritonitis was 1.44 ± 0.63. For diffuse peritonitis, the mean (SD) number of quadrants in which the staff surgeons reported signs of peritonitis was 2.59 ± 0.51. On ROC curve analysis, two quadrants was the best cut-off between grade 4B (local peritonitis) and five (diffuse peritonitis) acute appendicitis (AUC = 0.92, Se = 100%, Sp = 92%, p = 0.005).

Conclusion

The classification used to determine the type of appendicitis is reproducible.

Clinical significance

To give a definition of complicated appendicitis.

How to cite this article

Mariage M, Sabbagh C, et al. Surgeon's Definition of Complicated Appendicitis: A Prospective Video Survey Study. Euroasian J Hepatogastroenterol 2019;9(1):1-4.

Multiple-resistance to ivermectin and benzimidazole of a Haemonchus contortus population in a sheep flock from mainland France, first report

Anthelmintic resistance was explored by fecal egg count reduction test in a sheep flock from the French Pyrenees at the request of the veterinary practitioner after a poor response to anthelmintics was noted. The FECRT confirmed the suspicion with a mean percentage of reduction in egg excretions of 45% (CI 95%: - 40 to 78.5) and 0% (CI95%: - 162 to 49) within the ivermectin and the benzimidazole groups respectively. Haemonchus contortus was shown to be the IVM and BZ resistant species after morphological and molecular characterizations whereas Teladorsagia circumcincta was probably resistant to BZ only. The H. contortus population was still susceptible to moxidectin, closantel and levamisole. As this sheep flock is a transhumant flock, the spread of this multiple-resistant Haemonchus contortus population to the other sheep flocks sharing the same pastures in Pyrenean Mountains is highly likely. From the knowledge of the authors, this is the first report of multi-resistance to ivermectin and benzimidazole of a Haemonchus contortus population in mainland France.

The Value of Abdominal Drainage After Laparoscopic Cholecystectomy for Mild or Moderate Acute Calculous Cholecystitis: A Post Hoc Analysis of a Randomized Clinical Trial

BACKGROUND

Although the preoperative management of mild and moderate (Grade I-II) acute calculous cholecystitis (ACC) has been standardized, there is no consensus on the value of abdominal drainage after early cholecystectomy.

METHODS

In a post hoc analysis of a randomized controlled trial (NCT01015417) focused on the value of postoperative antibiotic therapy in patients with ACC, we determined the value of abdominal drainage in patients having undergone laparoscopic cholecystectomy for Grades I-II ACC. All postoperative complications were analyzed after using a propensity score. A post hoc test was used to assess the statistical robustness of our results.

RESULTS

Of the 414 enrolled patients, 178 did not have abdominal drainage (forming the no-drainage group) and 236 had drainage (the drainage group). After matching on PS, the deep incisional site infection was 1.1 versus 0.8 %, p = 0.78. This result is similar for the superficial incisional site infections; the distant infections; the overall morbidity, and the readmission rate. Only the hospital length of stay was significantly longer in the drainage group (3.3 vs. 5.1 days, p = 0.003). Neither abdominal drainage nor the absence of postoperative antibiotic therapy was found to be a risk factor for deep incisional site infections.

CONCLUSIONS

The use of abdominal drainage depends on the surgeon's personal preferences but is often used in high-risk populations. However, abdominal drainage does not appear to be of any benefit (in terms of postoperative outcomes) and may even compromise recovery in patients having undergone early laparoscopic cholecystectomy for mild or moderate ACC.

Cavo-atrial bypass with a polytetrafluoroethylene graft for the treatment of a complete, traumatic transection of the suprahepatic inferior vena cava

In the event of injury to the vena cava, the surgeon's goal is to control the bleeding and then repair the vascular damage. Given the wide range of lesions observed, the repair step has not been standardized. There are a few case reports of simple venoplasty or cavocaval bypass with a polytetrafluoroethylene graft. The present report introduces another treatment option for total avulsion of the suprahepatic inferior vena cava when a lack of remnant venous tissue below the heart prevents direct repair: cavo-atrial bypass with a polytetrafluoroethylene graft.

Quantitative computed tomography to predict postoperative FEV1 after lung cancer surgery

BACKGROUND

Predicted postoperative FEV1 (ppoFEV1) must be estimated preoperatively prior to surgery for non-small cell lung cancer (NSCLC). We evaluated a lung volumetry approach based on chest computed tomography (CT).

METHODS

A prospective study was conducted over a period of one year in eligible lung cancer patients to evaluate the difference between ppoFEV1 and the 3-month postoperative FEV1 (poFEV1). Patients in whom CT was performed in another hospital and those with factors influencing poFEV1, such as atelectasis, pleural effusion, pneumothorax, or pneumonia, were excluded. A total of 23 patients were included and ppoFEV1 was calculated according to 4 usual Methods: Nakahara formula, Juhl and Frost formula, ventilation scintigraphy, perfusion scintigraphy, and a fifth method based on quantitative CT. Lung volume was calculated twice and separately by 2 radiologists. Tumor volume, and emphysema defined by a -950 HU limit were subtracted from the total lung volume in order to estimate ppoFEV1.

RESULTS

We compared 5 methods of ppoFEV1 estimation and calculated the mean volume difference between ppoFEV1 and poFEV1. A better correlation was observed for quantitative CT than for Nakahara formula, Juhl and Frost formula, perfusion scintigraphy and ventilation scintigraphy with respectively: R²=0.79 vs. 0.75, 0.75, 0.67 and 0.64 with a mean volume difference of 266±229 mL (P<0.01) vs. 320±262 mL (P<0.01), 332±251 mL (P<0.01), 304±295 mL (P<0.01) and 312±303 mL (P<0.01).

CONCLUSIONS

Quantitative CT appears to be a satisfactory method to evaluate ppoFEV1 evaluation method, and appears to be more reliable than other approaches. Estimation of ppoFEV1, as part of the preoperative assessment, does not involve additional morphologic examinations, particularly scintigraphy. This method may become the reference method for ppoFEV1 evaluation.

Pyopneumothorax and peritonitis due to perforated duodenal ulcer and associated pleuroperitoneal communication

Pleuroperitoneal communication is an anatomic entity that is typically asymptomatic but sometimes responsible for hydrothorax. This pleural manifestation can be explained by progressive transdiaphragmatic passage of intra-abdominal fluid because of abdominal hyperpressure. The object of this report is to present a hitherto unreported association of concomitant pleural effusion and acute infectious abdominal disease, due to perforated duodenal ulcer. This underscores that pleural effusion associated with acute abdominal pain may reveal the existence of a communication of this type, and requires surgical management.

Colectomy in patients with previous colectomy or occlusive vascular diseases: Pitfalls and precautions

Two principal branches from the aorta provide the colonic blood supply: the superior and inferior mesenteric arteries. There are numerous anatomical variations, which the surgeon must fully understand before embarking on any colonic surgery. A good knowledge of these variations is particularly important when the patient has already undergone colectomy or presents with occlusive vascular disease. The aim of this review is to summarize the standard anatomy and the main variations of the colonic blood supply as they apply to colorectal surgery in this setting.

Effectiveness of intraoperative cholangiography using indocyanine green (versus contrast fluid) for the correct assessment of extrahepatic bile ducts during day-case laparoscopic cholecystectomy

INTRODUCTION

During cholecystectomy, intraoperative cholangiography using contrast fluid (IOC-CF) is still the "gold standard" for biliary tract identification but has many associated pitfalls. A new IOC technique using indocyanine green (IOC-IG) appears to be promising. Here, we studied the effectiveness of IOC-IG (vs IOC-CF) during day-case laparoscopic cholecystectomy.

MATERIALS AND METHODS

Over a 6-month period, we included 23 patients (with no cirrhosis or risk factors for choledocholithiasis) scheduled for day-case laparoscopic cholecystectomy. The primary efficacy criterion was the "analyzability rate" (i.e., the ability to identify the cystic duct, the cystic duct-hepatic duct junction, and the common bile duct) for the IOC-CF and IOC-IG procedures after dissection. Indocyanine green was infused under general anesthesia. The same near-infrared laparoscopic imaging system was used for IOC-IG and conventional visual inspection. IOC-CF was always attempted after dissection. Each patient served as his/her own control. Cholecystectomies were video-recorded for subsequent off-line, blind analysis.

RESULTS

The analyzability rate was 74 % for IOC-IG after dissection, 70 % for IOC-CF (p = 0.03), 26 % for conventional visual inspection, and 48 % for IOC-IG before dissection. When each IOC modality (conventional visual inspection, IOC-IG before and after dissection) was considered as a diagnostic test, the accuracy for simultaneous identification of the three anatomic elements was respectively 48, 52, and 74 %. No adverse events occurred during the IOC-IG procedure.

CONCLUSION

IOC-IG was feasible and safe. Our results suggest that this technique is more effective than IOC-CF for biliary tract identification after dissection and may constitute a powerful diagnostic test for the detection of extrahepatic ducts.

No detection of Besnoitia besnoiti DNA in the semen of chronically infected bulls

Bovine besnoitiosis is a chronic and debilitating disease observed in many European countries that may cause important economic losses in cattle. The recent widespread of the parasite in Europe had led the European Food Safety Authority to declare bovine besnoitiosis as a re-emerging disease in Europe. Many aspects of the epidemiology of bovine besnoitiosis such as the main routes of transmission are still unclear and need to be further studied. Among the different hypotheses, a sexual transmission has not yet been investigated. Therefore, the aim of this study was to evaluate the presence of Besnoitia besnoiti DNA in the semen of naturally infected bulls by using a highly sensitive method (real-time qPCR). Both pre-sperm and sperm fractions of 40 bulls, including seronegative (n = 11), seropositive subclinically (n = 17), and seropositive clinically (n = 12) infected animals, were collected by electroejaculation and analyzed by real-time qPCR. No B. besnoiti DNA was detected in 27 pre-sperm and 28 sperm fractions of the 40 examined bulls, suggesting that the transmission of B. besnoiti infection by the semen of chronically infected bulls is very unlikely.

Two lessons from a 5-year follow-up study of laparoscopic sleeve gastrectomy: persistent, relevant weight loss and a short surgical learning curve

INTRODUCTION

Like Roux-en-Y gastric bypass, laparoscopic sleeve gastrectomy (LSG) has been validated as a bariatric surgery procedure in its own right. However, the few studies of the long-term outcomes of LSG have only featured small patient populations. The objective of the present study was to evaluate weight loss 5 years after LSG and assess the surgical learning curve for this procedure.

METHODS

We performed a retrospective, single-center study of a prospective database including all consecutive patients having undergone LSG at Amiens University Medical Center between November 2004 and July 2007. Data (weight, body mass index [BMI], percentage of excess weight loss [EWL], percentage of excess BMI loss, and percentage weight loss [PWL]) were collected during follow-up (particularly after 5 years).

RESULTS

The study population comprised 118 patients (100 females [85%]; mean ± SD age, 40 ± 11 years; mean preoperative weight, 131 ± 22 kg; mean preoperative BMI, 47.7 ± 7 kg/m(2)). LSG was performed after failure of gastric banding in 23 cases (19%) and after failure of an intragastric balloon in 1 (0.8%). In all, 95 patients (81%) were analyzed ≥60 months after the LSG (mean follow-up period, 71 ± 9 months). The PWL and EWL were 25 ± 14% and 46 ± 26%, respectively. Eleven patients had undergone a second bariatric operation within 5 years of the LSG. Concerning the 84 patients in whom only LSG was the only operation, the PWL and EWL were 23 ± 14% and 43 ± 25%, respectively. The EWL was >50% in 35 of these 84 patients (42%) and between 25 and 50% in 30 cases (36%). Optimal weight results were achieved after only 28 LSG had been performed, which testifies to a shorter learning curve than for most other bariatric surgery techniques.

CONCLUSION

Isolated LSG is a quickly mastered bariatric surgery technique with a short learning curve. It enables a mean PWL of >25% and an EWL of >50% in >40% of cases.

Are there any surgical and radiological correlations to the level of ligation of the inferior mesenteric artery after sigmoidectomy for cancer?

INTRODUCTION

The Société Française de Chirurgie Digestive and the American Society of Colon and Rectal Surgeons recommend a ligation at the origin of the primary feeding vessel for sigmoid cancer to ensure optimal lymphadenectomy. We evaluated the correlation between the level of ligation defined by the surgeon and the real level of ligation visualized on postoperative CT scan.

PATIENTS AND METHODS

From December 2004 to August 2010, in a series of 146 patients undergoing colectomy for sigmoid cancer, 51 (19 women) CT measurements (visualization of the left colonic artery (LCA), length of the arterial stump) were performed by a radiologist blinded to operative data.

RESULTS

This series comprised 63% of men with a mean age of 69 years. A correlation was demonstrated between the level of ligation assessed by the surgeon and the real level of ligation demonstrated on postoperative CT scan in 41% of cases. No risk factors for absence of correlation were identified (laparoscopy, gender, BMI, emergency, and ASA score). In the "no correlation" group, the site of ligation was overestimated in 70% of cases. No significant difference was observed between the "correlation" and "no correlation" groups for lymphadenectomy (21.6 and 18 lymph nodes, p=0.5593) or 5-year overall survival (71.4 and 93.1 months, p=0.57).

CONCLUSION

In conclusion, the surgical and radiological correlations are low as the intraoperative estimation of the level of IMA ligation was correlated with CT findings in less than 50% of cases. No risk factors for non-correlation were identified, and there was no impact on lymphadenectomy. Overestimation of the level of ligation was the most frequent situation but did not appear to have any impact on tumor staging or on patient management in this group of patients.

Giant squamous cell carcinoma as a complication of a chronic enterocutaneous fistula: complex parietal reconstruction

Treatment of an enterocutaneous fistula is complex and may require multidisciplinary management, especially when associated with a neoplastic process. Here, we describe the case of a 59-year-old patient with a squamous cell carcinoma that had invaded the abdominal wall through a chronic enterocutaneous fistula identified 30 years ago. We combined parietectomy with small intestine and colon resection and inguinal lymphadenectomy in order to obtain clear surgical margins. At the same time, plastic surgery involved the implementation of a large bioprosthesis and coverage with a vastus lateralis muscle free flap.

An inter-laboratory comparative study of serological tools employed in the diagnosis of Besnoitia besnoiti infection in bovines

Bovine besnoitiosis is considered an emerging chronic and debilitating disease in Europe. Many infections remain subclinical, and the only sign of disease is the presence of parasitic cysts in the sclera and conjunctiva. Serological tests are useful for detecting asymptomatic cattle/sub-clinical infections for control purposes, as there are no effective drugs or vaccines. For this purpose, diagnostic tools need to be further standardized. Thus, the aim of this study was to compare the serological tests available in Europe in a multi-centred study. A coded panel of 241 well-characterized sera from infected and non-infected bovines was provided by all participants (SALUVET-Madrid, FLI-Wusterhausen, ENV-Toulouse, IPB-Berne). The tests evaluated were as follows: an in-house ELISA, three commercial ELISAs (INGEZIM BES 12.BES.K1 INGENASA, PrioCHECK Besnoitia Ab V2.0, ID Screen Besnoitia indirect IDVET), two IFATs and seven Western blot tests (tachyzoite and bradyzoite extracts under reducing and non-reducing conditions). Two different definitions of a gold standard were used: (i) the result of the majority of tests ('Majority of tests') and (ii) the majority of test results plus pre-test information based on clinical signs ('Majority of tests plus pre-test info'). Relative to the gold standard 'Majority of tests', almost 100% sensitivity (Se) and specificity (Sp) were obtained with SALUVET-Madrid and FLI-Wusterhausen tachyzoite- and bradyzoite-based Western blot tests under non-reducing conditions. On the ELISAs, PrioCHECK Besnoitia Ab V2.0 showed 100% Se and 98.8% Sp, whereas ID Screen Besnoitia indirect IDVET showed 97.2% Se and 100% Sp. The in-house ELISA and INGEZIM BES 12.BES.K1 INGENASA showed 97.3% and 97.2% Se; and 94.6% and 93.0% Sp, respectively. IFAT FLI-Wusterhausen performed better than IFAT SALUVET-Madrid, with 100% Se and 95.4% Sp. Relative to the gold standard 'Majority of test plus pre-test info', Sp significantly decreased; this result was expected because of the existence of seronegative animals with clinical signs. All ELISAs performed very well and could be used in epidemiological studies; however, Western blot tests performed better and could be employed as a posteriori tests for control purposes in the case of uncertain results from valuable samples.

Immune response to Haemonchus contortus infection in susceptible (INRA 401) and resistant (Barbados Black Belly) breeds of lambs

The immune responses to Haemonchus contortus were compared in studies in resistant Barbados Black Belly (BBB) and susceptible INRA 401 (INRA) breeds of lambs. The cytokine patterns indicated a Th2-biased response in both breeds. A more persistent and elevated Th2 cytokine mRNA transcription and blood eosinophilia were noted in the BBB lambs. However, at days 4 and 30 post-infection, abomasal recruitment of eosinophils and mast cells were similar between the two breeds. Following primary infections, the BBB demonstrated a substantially lower faecal egg count compared to the INRA lambs. Furthermore, worm counts at 4 and 30 days post-infection, and adult female worm size and in utero egg counts 30 days after the first infection were significantly lower in the BBB than in the INRA breed. In the INRA breed, re-infection caused a significant reduction in most parasitological parameters compared with those observed after the primary infection. A similar response was not observed in the BBB sheep. In conclusion, while the major driving force in the response to H. contortus infection is a Th2-biased immunity in which the BBB showed its maximal performance during the primary infection, the INRA breed performed better after re-infection compared to its response to first exposure.

Comparison of infection rates of Oestrus ovis between sheep and goats kept in mixed flocks

Oestrosis is a nasal myiasis of sheep and goats caused by larvae of the fly Oestrus ovis and can lead to severe clinical signs, which together with the disturbance caused by the adult fly may result into serious economic losses. Infection rates and larval burdens are always higher in sheep than in goats after either natural or artificial infestation. The aim of this study was to compare the host preference of the adult fly O. ovis between sheep and goats in mixed flocks, where they are kept together under the same husbandry conditions and hence, are very similarly exposed to the fly preference. Blood sera samples were collected from a total of 397 sheep and 335 goats, from 43 mixed flocks located at different regions of Greece. Antibodies specific to O. ovis IgG were measured by ELISA. A flock was considered positive when at least one individual was positive, i.e. showed a seropositivity of >or=20% in relation to positive control sera. A total of 193 (48.6%) sheep and 58 (17.9%) goats were found to be seropositive against O. ovis. Thirty-eight (88.4%) out of 43 flocks had at least one seropositive animal. The mean seroconversion against O. ovis in animals from the different flocks was 38.6% and 13.6% for sheep and goats, respectively, whereas the variance of infection within each flock was 0-100%. The mean seropositivity between sheep that were found to be positive or negative was 60.6% and 5.4%, respectively, whereas the corresponding values between goats were 35.2% and 5.2%, respectively. No significant difference in the seroconversion values was noted between flocks from the different areas (P=0.817), whereas a very significant difference was observed between animal species (P=0.001). However, there was no significant difference when seroconversion comparisons were made within samples of the same animals species, sheep or goats from different flocks of all the regions included in the study (P=0.695). The results of this study clearly demonstrate that O. ovis has a widespread distribution in Greece, and the seroprevalence is significantly higher in sheep than goats (P=0.001).

Effects of four tanniferous plant extracts on thein vitroexsheathment of third-stage larvae of parasitic nematodes

The anthelmintic properties of tanniferous plants and of their secondary metabolites represent one possible alternative to chemotherapy that is currently being explored as a means of achieving sustainable control of gastrointestinal nematodes in ruminants. Previousin vivoandin vitroresults suggest that tanniferous plants can have direct anti-parasitic effect against different stages of nematodes. However, the mode of action of the bioactive plant compounds remains obscure. The objectives of the current study were (1) to examine the hypothesis that extracts of tanniferous plants might interfere with the exsheathment of third-stage infective larvae (L3); (2) to assess the role of tannins in the process by examining the consequence of adding an inhibitor of tannins (polyethylene glycol: PEG) to extracts. The effects of 4 tanniferous plant extracts on exsheathment have been examined on L3 ofHaemonchus contortusandTrichostrongylus colubriformis. Artificial exsheathment was inducedin vitroby adding hypochloride solution to larval suspension. The evolution of exsheathment with time was measured by repeated observations at 10-min interval for 60 min. The selected plants were: genista (Sarothamnus scoparius), heather (Erica erigena), pine tree (Pinus sylvestris), and chestnut tree (Castanea sativa), with tannin contents ranging from 1·5 to 24·7% of DM. Extracts of a non-tanniferous plant (rye grass, tannin content: 0·3% of DM) were included in the assay as negative controls. The extracts were tested at the concentration of 600 μg/ml and the effects were compared to the rate of exsheathment of control larvae in PBS. No statistical differences in the pattern of exsheathment was observed after addition of rye grass or genista extracts for both nematode species and with heather extracts forT. colubriformis. In contrast, pine tree extracts on larvae of both species and heather extracts withH. contortusinduced a significant delay in exsheathment. Last, contact with chest nut extracts led to a total inhibition of the process for both nematodes. These results suggest that extracts of tanniferous plants might affect a key process in the very early stages of larval invasion of the host. In most cases, the addition of PEG led to a total or partial restoration towards control values. This suggests that tannins are largely involved in the inhibitory process. However, other secondary metabolites may also interfere with the process that would help to explain some of the differences in response observed between the two nematode species.

Lack of effects of quebracho and sainfoin hay on incoming third-stage larvae of Haemonchus contortus in goats

The effects of tannins on adult populations of Haemonchus contortus, Trichostrongylus colubriformis and Teladorsagia circumcincta in goats are characterised mainly by a decrease in egg excretion without any significant changes in worm number. In contrast, the impact of tannins on T. colubriformis or T. circumcincta third-stage larvae (L3) is associated with a significant reduction in worm establishment. The objective of the present study was to examine the effects of quebracho extract tannins on H. contortus L3. The consequences of consumption of sainfoin hay were also examined. Twenty-one naïve kids were divided into three experimental groups. Group Q received quebracho extract and group S received sainfoin hay from days D3 to D5. Group C remained as an infected control group. All kids received 1500 L3 H. contortus on D0, D1 and D2. On D18, post-infection, the kids were slaughtered and the worm populations compared in the different groups. Compared to the control values, the worm counts decreased, respectively, by 33% and 38% in groups Q and S but the differences were not significant. No differences were found in pathophysiological measurements between the three groups. The results confirm differences in tannin effect according to nematode species but not parasitic stage.

Haemonchus contortus egg excretion and female length reduction in sheep previously infected with Oestrus ovis (Diptera: Oestridae) larvae

Mixed parasitic infection of animals is a common phenomenon in nature. The existence of one species often positively or negatively influences the survival of the other. Our experimental study was started with the objectives to demonstrate the interaction of Haemonchus contortus and Oestrus ovis in relation to cellular and humoral immune responses in sheep. Twenty-two sheep of Tarasconnais breed (France) were divided into four groups (O, OH, H and C) of five or six animals. Group O and OH received 5 weekly consecutive inoculations with O. ovis L1 larvae (total = 82 L1) in the first phase of the experiment between days 0 and 28. On the second phase, groups OH and H received 5000 L3 of H. contortus on day 48 while group C served as our control throughout the experimental period. Parasitological, haematological, serological and histopathological examinations were made according to standard procedures and all animals were slaughtered at day 95. There was no significant variation in the number and degree of development of O. ovis larvae between the two infected groups. Furthermore, in tissues examined in the upper respiratory tract (nasal septum, turbinate, ethmoide and sinus), group O and OH has responded similarly on the basis of cellular inflammatory responses (blood and tissue eosinophils, mast cells and globule leucocytes (GL)) and serum antibody responses against the nasal bots. This may indicate that the presence of H. contortus in the abomasa of group OH had no marked influence over the development of O. ovis larvae in the upper respiratory tract. On the other hand, we have observed a significantly lower H. contortus female worm length, fecal egg count (FEC) and in utero egg count in animals harbouring the nasal bot (OH) than in the mono-infected group (H). This was significantly associated with higher blood eosinophilia, higher packed cell volume (PCV) and increased number of tissue eosinophils and globule leucocytes. We conclude that, the establishment of O. ovis larvae in the upper respiratory tract has initiated higher inflammatory cellular activity in group OH there by influencing the development and fecundity of H. contortus in the abomasum.

Effects of the repeated distribution of sainfoin hay on the resistance and the resilience of goats naturally infected with gastrointestinal nematodes

Due to the high prevalence of anthelmintic resistance in goats, the need to explore novel approaches to control nematodes and to reduce the exclusive reliance on chemotherapy is strongly demanded in this host species. In sheep, several studies have shown that the consumption of tannin-rich legume forages was associated with positive effects on host resilience and resistance to parasite infection. In goats, studies on such interactions between tanniferous plants and nematode infections remain few. The objectives of the current study were to examine under natural conditions the effects of consumption of sainfoin hay by goats on the parasite populations and on host resilience. Eighteen adult cull goats naturally infected with Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis were used in the study. At the start of the assay, the goats were allocated into two groups, balanced according to weight and the levels of egg excretion. The two groups grazed separate pastures for 3 months with similar stocking rates. Goats from group S received each month indoors, for 7 days, sainfoin hay and control goats (group C) received hay of ryegrass. The diets in both groups were made isoenergetic and isoproteic and the refusals measured. Individual parasitological and pathophysiological measurements were performed fortnightly in order to compare host resistance and resilience. At the end of the study, five goats per group were necropsied. The distribution of sainfoin was associated with: (1) a higher consumption of hay; (2) significant, lower levels of nematode egg excretion which was associated with a decrease in worm fertility but no change in worm population; however, the number of intestinal worms was reduced by 50% in group S; (3) a better host resilience. In particular, after 2 months of grazing, two control goats died and half of the remaining animals needed to be treated whereas this was not the case in group S. These differences were related to significant changes in pepsinogen and phosphate values (PCV) but not in pepsinogen and phosphate concentrations. These results demonstrate that a repeated distribution of sainfoin hay to grazing goats might be beneficial in regard of pasture contamination and host resilience. They suggest that administration of sainfoin hay might represent a valuable alternative and adjunct to reduce nematode infections in dairy goat flock.

Examination of the migration of first instar larvæ of the parasite Œstrus ovis (Linne 1761) [Diptera: Œstridæ] in the upper respiratory tract of artificially infected lambs and daily measurements of the kinetics of blood eosinophilia and mucosal inflammatory response associated with repeated infection

Twelve lambs were divided into two groups: Group C control, non-infected, and Group O infected once a week for 5 weeks with OEstrus ovis L1 through the same nostril. The first objective of this experiment was to check whether larvae moving through a given nostril remain in the same side nasal cavity or might to spread in both nasal cavities. It has been observed that larvae invade and spread through the entire nasal cavities. The only possible passage way between both sides is via the choanae and velum palatinum. The second objective was to follow the kinetics of blood eosinophilia. A primary peak in eosinophil numbers was noted 4 days following infection, with a higher peak following the second infection. After that, no major changes were seen. Nevertheless, the numbers of eosinophils were always higher than in control animals until the end of the follow-up. The third objective of the study was an enumeration of reactive cells (mast cells, globule leucocytes, and eosinophils) in the mucosae of the upper and lower respiratory tract after necropsy of the animals of the two groups. As observed in previous experiments, there was a large accumulation of these cells in mucosae of the upper respiratory tract. It was also worth noting a significant accumulation of eosinophils in the tissues of the trachea, bronchae and lungs even though OE. ovis was not present there. This "distant" eosinophilic reaction may have important consequences on patho-physiology of other parasites living in these locations: eosinophils have the potential to kill them even though these cells are not activated by their specific antigens.

Concurrent parasitic infections of sheep: depression of Trichostrongylus colubriformis populations by a subsequent infection with Oestrus ovis

Concurrent infections of sheep with Oestrus ovis and trichostrongyles of the digestive tract are common in the field. Previous results have shown that a previous infection with O. ovis adversely affects worm populations of either Trichostrongylus colubriformis or Haemonchus contortus. However, no information was available to determine the influence of the succession of infections on the expression of interactions between these parasites located in remote anatomical sites. In order to investigate the role of these modulating factors, an experimental study was conducted on four groups of naïve sheep, examining the consequences of a delayed infection with O. ovis on a pre-existing population of T. colubriformis. group T was infected four times with 4000 T. colubriformis larvae on days 0, 14, 28 and 42 of experiment; group O received multiple infections with O. ovis first instar larvae on days 42, 49, 56, 70 and 77; sheep from group TO received both infections and animals from group C remained as uninfected controls. Faecal egg counts and eosinophilia were measured weekly throughout the study. At necropsy (day 91), the mucosal cellular responses in the nasal cavities (septum, turbinates, ethmoid and sinus) and in the digestive tract (stomach and small intestine) from all animals were analysed from histological sections. Infection of the digestive tract with nematodes did not modify the biology of Oestrus populations, as measured by the number and weight of larvae. In contrast, infections with O. ovis after T. colubriformis infection was related to significant reductions (P < 0.01) in nematode egg excretion and worm burdens. These changes were associated with significant modifications in populations of mast cells, globule leucocytes and eosinophils in the respiratory and digestive tracts. These results indicate that an antagonistic interaction exists between the populations of O. ovis in the nasal cavities and T. colubriformis in the small intestine but that the order of succession of infections with the two parasites is not a major modulating factor for expression of interactions. They also confirm that parasitic infection in one particular anatomical site induces "at distance" inflammatory reactions of the whole mucosal system.

Effects of condensed tannins on goats experimentally infected with Haemonchus contortus

Although the use of tanniferous plants or condensed tannins as an alternative to anthelmintics to control gastrointestinal nematodes has been largely documented in sheep, studies remain scarce in goats. The objective of this study was therefore to assess the possible impact of condensed tannins in goats infected with adult Haemonchus contortus. Two groups of cull goats were experimentally infected with 10.000 L3 of H. contortus. After 4 weeks, quebracho extracts, representing 5% of the diet DM, were administered for 8 days to one of the two groups. Goats of the second group remained as controls. One week after the end of quebracho administration, the goats were euthanised. Individual egg excretion and pathophysiological parameters were measured weekly during the study. At the end of the study, worm counts were assessed and histological samples from the abomasa were taken to count the numbers of mucosal mast cells, globule leukocytes and eosinophils. The administration of tannins was associated with a significant decrease in egg excretion, which persisted until the end of experiment. This reduction was not associated with any difference in worm number but with a significant decrease in female fecundity. No significant changes in the mucosal density of the three inflammatory cell types were detected between the two groups. These results indicate that the major consequence of tannin consumption in goats is a reduction in worm fecundity and egg output, which does not seem related to significant changes in the local mucosal response.

The relationship between nasal myiasis and the prevalence of enzootic nasal tumours and the effects of treatment of Oestrus ovis and milk production in dairy ewes of Roquefort cheese area

Infection by Oestrus ovis is common in Lacaune dairy ewes of Roquefort cheese area (Aveyron, France). It is believed by local breeders that there is a close relationship between nasal myiasis and the incidence of enzootic nasal tumour. In order to check these anecdotal reports, a serological survey was done on 658 breeding ewes before turn-out and 897 breeding and primiparous (hoggets) ewes at the end of the grazing season. By the time of sampling, it was clear whether the sheep were infected at the end of the winter or had been re-infected over summer. In April and September, 40.7 and 26.3%, respectively, were free of O. ovis infection, indicating that the autumn treatment was not completely effective and that O. ovis adult flies were circulating during the summer in many flocks. There were no differences in the incidence of adenocarcinoma between the groups indicating that there is no relationship between O. ovis infection and the presence of the cancer. Differences in milk production between the three groups were not statistically significant (Anova test P>0.05). In flocks where 1-5% of the ewes were infected or in non-infected flocks, ewes produced 3.6 and 8.56%, respectively, more milk than ewes from flocks where more than 5% of animals were infected. For primiparous ewes, the differences were of 8.5 and 12.24%.

Seroprevalence of Oestrus ovis infection in sheep in southwestern Germany

The aim of the survey was to determine the seroprevalence of Oestrus ovis infection in flocks in southwestern Germany. Serum samples collected from 1497 sheep (>6 months of age) of 110 flocks in 1997 and 1998 were examined for antibodies to crude somatic antigens of O. ovis second-stage larvae using an ELISA test. Data on the farm management were obtained by a questionnaire. Overall, 76% of the flocks had at least one seropositive animal, and the seroprevalence of anti-Oestrus antibodies was 50% in sheep. Flock size was the only risk factor significantly associated with the detection of antibodies. Larger flocks (>50 ewes) were more likely to be seropositive than smaller ones. These results show that Oestrus infections are widespread in sheep in southwestern Germany. Further investigations are required to estimate the economic importance of oestrosis and the efficiency of control measures.

Experimental concurrent infection of sheep with Oestrus ovis and Trichostrongylus colubriformis: negative interactions between parasite populations and related changes in the cellular responses of nasal and digestive mucosae

Concurrent infections of sheep with Oestrus ovis and trichostrongyles of the digestive tract are common in the field. In order to examine the possible occurrence of interactions between these two parasites and the consequences on parasite biology and the associated pathophysiological changes, an experimental study was conducted on four groups of naïve sheep. Group O was infected repeatedly with O. ovis larvae from D0 to D42 of experiment; group T received a single infection of Trichostrongylus colubriformis on D49; sheep from group OT received both infections, and animals from group C remained uninfected as controls. Parasitological and pathophysiological parameters were measured regularly. At necropsy (D94), the mucosal cellular responses in the nasal cavities and digestive tract from all animals were analysed from histological sections. Infection of the digestive tract with nematodes did not modify the biology of Oestrus populations. In contrast, the presence of O. ovis was related to significant reductions in nematode egg excretion, worm fecundity and worm burdens. These changes were associated with significant modifications in tissular populations of mast cells, globule leucocytes and eosinophils in the respiratory and digestive tracts. These results indicate that parasitic infection in one particular anatomical site induces "at distance" inflammatory reactions of the whole mucosal system. The relationships between the cellular response and the changes in worm biology are discussed.

Oestrus ovis (Diptera: Oestridae): sheep humoral immune response to purified excreted/secreted salivary gland 28 kDa antigen complex from second and third instar larvae

The potential of Oestrus ovis larvae excretory-secretory products (ESP), crude extract, salivary gland contents (SGc) and digestive tube contents (DTc) proteins from O. ovis larvae as antigens in serological assay were analyzed and compared. This study demonstrated that excretory-secretory proteins were produced mainly by digestive tube and salivary gland. The main antigenic component of ESP was a 28kDa protein complex (pc28) synthesized by the salivary gland ring. After purification, its diagnostic value was estimated by an ELISA using sheep sera sampled in summer (n=30) and winter (n=69) in order to investigate the relative importance of wintering hypobiotic first instar larvae on animal responsiveness. ELISA test based on pc28 antigen was compared to a reference ELISA test based on second instar larvae crude extract. After comparison it appeared that the pc28 test was much more specific (87%) and more sensitive (90%) in summer. Anti-pc28 antibody titers were significantly higher in summer than in winter demonstrating the impact of summer developing larvae on the humoral systemic immune response. This data was correlated to the maturation of larvae in summer as the number of larvae at necropsy was significantly higher in winter, when the larval population is only represented by first instar larvae, than in summer. No correlation was observed between the mean antibody titers and the number of larvae.

Oestrus ovis (Diptera: Oestridae): effects of larval excretory/secretory products on nitric oxide production by murine RAW 264.7 macrophages

Larvae of Oestrus ovis (Insecta: Diptera: Oestridae) are common parasites of nasal and sinus cavities of sheep and goats. Previous studies revealed that crude extracts of larvae modify NO synthesis by ovine monocyte derived macrophages. The aim of this study was to investigate the larval excretory/secretory products effects on nitric oxide production by murine tumour macrophages RAW 264.7. Stimulation of RAW macrophages by excretory/secretory products of the three instars larvae (25 microg/ml) significantly increased nitrite concentrations in culture supernatants compared to negative and positive Escherichia coli lipopolysaccharide control. This effect was time and dose dependent. Nitrite production in culture supernatants was due to induction of isoform NOS-2 because both NG monomethyl L-arginine (100 microM) and dexamethasone (20 microM) inhibited, by 60 and 50%, respectively, nitrite accumulation in culture supernatants. First steps of purification, by ion exchange chromatography, indicated that one protein of 29 kDa was able to induce NO synthesis by macrophages. Further studies are needed for a better characterization of these molecule and to investigate their immunogenicity for a vaccine approach.

Seasonal variation of Oestrus ovis-specific antibodies in sheep and goats mixed flocks in Greece

The aim of this survey was to investigate the year-round epidemiological patterns of Oestrus ovis ELISA sero-prevalence in sheep and goats kept together under the same husbandry system in an endemic area of Greece. Twenty-five adult female sheep and 25 adult female goats, coming from a large mixed flock, were randomly selected, eartaged and monthly blood sampled during 1 year period (November 1998-October 1999). Serological prevalence in sheep was 100% all around the year. Mean intensities of specific O. ovis antibodies follow a seasonal evolution with higher mean titers between March and July than in winter. In contrast, the serological prevalences in goats were low specially in winter months (from October to January). No significant difference were noticed in goats antibody levels during the year period. The possible reasons of this difference of O. ovis sero-prevalence between sheep and goats are discussed.

Prevalence and larval burden of oestrus ovis (Linné 1761) in sheep and goats in northern mediterranean region of France

A slaughterhouse survey to determine prevalence and larval burden of Oestrus ovis larvae in sheep and goats was performed monthly during one year in Pézenas, South of France, northern mediterranean region. A total of 1303 sheep and goat heads were selected at random. O. ovis larvae were found in 274 sheep out of 631 (43.4%), and the prevalence rate varied from 14.3% in February to 65% in October. The mean number of larvae in infected sheep heads was 10.86 with 9.24 L1, 0.91 L2 and 0.71 L3. One hundred and ninety-one goats out of 672 were infected (28.4%), and the prevalence rate varied from 6.25% in September to 47.1% in April. In infected goat heads, the mean parasitic burden was 5.35 with 4.04 L1, 0.73 L2 and 0.58 L3. These results confirm worldwide observations indicating that the prevalence and the parasitic burdens are less in goats than in sheep.

[Reactions of cells of nasal and sinusoidal mucosa of goats and sheep naturally infected by Oestrus ovis Linné 1758 (Diptera: Oestridae)]

OEstrosis is a very common myiasis of sheep and goats in mediterranean and tropical countries. Goats are suitable hosts for OEstrus ovis but the parasitic burden remain lower than in sheep. Cellular responses (mucous and serous mast cells, eosinophis and globules leucocytes) were measured in 30 infected and 30 non infected sheep and in 23 infected and 24 non infected goats. The presence of OEstrus ovis larvae led to an important inflammatory response in sheep and in goats as well. Furthermore, the intensity of the cellular response correlated with the larva burden, specially with globules leucocytes and eosinophils. Nevertheless, huge differences occurred between sheep and goats responses even in similar larval burden range. Infected sheep showed larger counts of mucous mast cells than goats, the differences were smaller in serous mast cells and eosinophils and no difference was detected in globules leucocytes (intraepithelial mast cells) counts between the two hosts species. These results were compared with those obtained in gastro-intestinal strongyles infections.

An improved method for the detection of heterozygosity of congenital virilizing adrenal hyperplasia

A modified short ACTH test for the detection of heterozygote carriers of 21-hydroxylase deficiency (21-OHD) was applied to twenty-one controls and fourteen parents of children with 21-OHD. The following modifications were introduced: (1) Endogenous ACTH was suppressed by dexamethasone administration prior to the test, (2) Plasma 17-hydroxyprogesterone (17-OHP), cortisol (F), progesterone (P), corticosterone (B) and delta 4- androstenedione (A) were measured, (3) Variables studied were the ratio of plasma increments (delta) between precursors and end products, (4) Data were analysed by a step-wise discriminant analysis. Significant alterations in the metabolic pathway of F, B and A were demonstrated. The discriminant analysis showed that the addition of B pathway data did not improve the discrimination potency of the test performed on F pathway data. The combination of variates which provided the best discrimination was the logarithmic sum of delta 170HP/delta F at 15 and 30 min. It led to a 94% correct classification for normals and carriers.