Brigitte Bartholomot

An epidemiological and ecological study of human alveolar echinococcosis transmission in south Gansu, China.

Human alveolar echinococcosis (AE) is usually a rare, highly pathogenic zoonotic disease, transmitted across the northern hemisphere between fox and rodent hosts. In China the first cases were described in 1965; however very few epidemiological studies have been undertaken since. Following identification in 1991 of a serious focus of human AE in south Gansu province, detailed village-based community and ecological studies were carried out between 1994 and 1997. Hepatic ultrasound mass screening with serological testing (five tests) identified 84/2482 new AE cases (3%). An overall prevalence of 4.1% (135/3331) was recorded for the area when previous cases were also included. Based on a seropositive result only, without an ultrasound scan indication, no additional AE cases were identified. Of the evolutive AE cases, 96% were seropositive in at least one test, while up 15-20% of individuals who exhibited hepatic calcified lesions and 12-15% exhibiting hepatic nodular lesions were seropositive for specific Em2 or Em18 antibodies. Village (n=31) human AE prevalence rates varied from 0 to 15.8%. Questionnaire analysis indicated that total number of dogs owned over a period was a risk factor (P<0.006), but not a history of red fox hunting (P>0.6). Rodent ecology studies revealed an association between density indices of voles (Microtus limnophilus) and village AE prevalence rates, on the one hand, and village landscape characterised by a ratio of scrub/grassland to total area above 50% (P<0.005). Long-term transmission of Echinococcus multilocularis and risk of zoonotic infection of south Gansu farmers may be related ultimately to a process of deforestation driven by agriculture. This in turn probably results in creation of optimal peri-domestic habitats for rodents that serve as intermediate host species (such as M. limnophilus) and subsequent development of a peri-domestic cycle involving dogs.

A twenty-year history of alveolar echinococcosis: analysis of a series of 117 patients from eastern France.

Objectives Alveolar echinococcosis of the liver is a very rare and severe parasitic disease due to the growth of the larva of Echinococcus multilocularis. The aim of this paper was to describe a 20‐year study of the epidemiological, clinical and therapeutic aspects of alveolar echinococcosis in eastern France. Design One hundred and seventeen consecutive cases, diagnosed and followed in our liver unit, were studied from 1972 to 1993. Methods Data from 85 patients followed since 1983 (period B) were compared to data from a first series of 32 patients (period A) collected from 1972 to 1982; 1983 was chosen as the cut‐off year because of the numerous changes that occurred in the diagnosis, follow‐up and treatment of the disease at this time, in particular the introduction of parasitostatic benzimidazoles. Results The results of patient follow‐up were evaluated in December 1997. The cumulative prevalence was 2.5 per 100 000 persons in period A whereas it reached 6.6 per 100 000 in period B. The annual incidence in period B was 7.3 on average, compared with 2.7 in period A. Twenty‐nine per cent of patients from period B were asymptomatic at the time of diagnosis compared with 10% in period A. This change was correlated with less advanced liver lesions, and was related to the extensive use of abdominal ultrasound, and from 1987, serological screening. Curative resections were performed in 24% of the cases in period B versus only 3% in period A. From 1986, liver transplantations were performed in eight patients from period A and 13 patients from period B. In period B, palliative surgery was frequently replaced by radiological non‐operative procedures to treat abscesses and jaundice. From 1982, 73 patients received benzimidazoles for a period of time ranging from 4 to 138 months. Stabilization of the lesions was observed in two‐thirds of the patients. Episodes of jaundice or digestive haemorrhage due to portal hypertension were 31.5 and 11 times less frequent respectively in patients from period B compared with period A. Actuarial survival at 5 years improved from 67% in period A to 88% in period B in patients of similar age. Conclusions Radical changes in the diagnosis and the management of alveolar echinococcosis have occurred during the last decade. Together they have contributed to an improvement in the status of the patients affected by this very severe parasitic disease. Eur J Gastroenterol Hepatol 12:327‐336

Interactions between landscape changes and host communities can regulate Echinococcus multilocularis transmission

An area close to the Qinghai-Tibet plateau region and subject to intensive deforestation contains a large focus of human alveolar echinococcosis while sporadic human cases occur in the Doubs region of eastern France. The current review analyses and compares epidemiological and ecological results obtained in both regions. Analysis of rodent species assemblages within quantified rural landscapes in central China and eastern France shows a significant association between host species for the pathogenic helminth Echinococcus multilocularis, with prevalences of human alveolar echinococcosis and with land area under shrubland or grassland. This suggests that at the regional scale landscape can affect human disease distribution through interaction with small mammal communities and their population dynamics. Lidickers ROMPA hypothesis helps to explain this association and provides a novel explanation of how landscape changes may result in increased risk of a rodent-borne zoonotic disease.

Cystic echinococcosis in semi-nomadic pastoral communities in north-west China.

In order to determine the prevalence of human cystic echinococcosis (CE) in semi-nomadic traditional pastoralist groups in north-west China, 2 large community studies were undertaken in Altai and Tacheng Prefectures in 1990/91 and 1995/96, respectively. The Kekergash community (Altai) comprised mainly ethnic Kazakhs, whereas the Narenhebuke community (Tacheng) comprised mainly Mongolians. Populations were screened for CE by abdominal ultrasound scan (US) and serological tests. The total prevalence of confirmed human CE was higher in Narenhebuke (2.7%, 49/1844) than in Kekergash (0.9%, 17/1861; P < 0.01). Within each community there was no significant difference of CE prevalence between the Kazakh and Mongolian groups, although Han Chinese exhibited twice the rate of CE (4.9%) in Narenhebuke compared to the dominant Mongolian population. For each community, human CE prevalence increased with age and there was a greater risk associated with the practice of home slaughter of livestock. Dogs were screened for Echinococcus granulosus infection and re-infection levels using a highly specific coproantigen test. The proportion of dogs with positive coproantigen tests was significantly higher in Narenhebuke (36.0%, 50/139) compared to Kekergash (17.8%, 16/90). In Narenhebuke the re-infection levels of dogs, as determined by coproantigen positivity, were higher in the winter quarters (49.4%, 39/79) compared to the summer quarters (18.3%, 11/60; P < 0.01). Furthermore, coproantigen re-test positivity was 25% at 3 months and 29.2% at 7 months. Highest dog coproantigen positivity was obtained over the winter period.

Classification, follow-up and recurrence of hepatic cystic echinococcosis using ultrasound images

Ultrasound image and morphological structure of hepatic cystic echinococcosis (CE) were analysed in 277 human cases (385 hepatic hydatid cysts). These included 65 CE cases from community surveys carried out between 1995 and 2000 in 3 countries (China, Mongolia and Jordan) and 212 cases from a clinical hospital survey from Xinjiang, China. A new simplified WHO ultrasound classification for human CE was assessed, and considered useful. It is proposed that type, size and number in particular need to be included in the ultrasound classification of hepatic CE. For comparative purposes 6 categories of type were classified in the study as Type 0 to Type 5 (T0-T5): T0, univesicular without pathognomonic signs; T1, univesicular with pathognomonic signs; T2, cysts with sagging or floating laminated membrane; T3, cysts containing daughter cysts; T4, solid mass or mixed cysts; and T5, cysts with partial or full calcifications. This differs from the WHO classification wherein Type T3 cysts (daughter cysts present) are considered a pathological stage to occur in general prior to the sagging or floating membrane (T2) stage. Recurrent hydatid cysts in the liver were also studied based on morphological structures observed directly from surgical intervention. Case follow-up over 1-5 years since endocystectomy in the community surveys indicated 10% (2/10) recurrence of cysts in the residual surgical cavity. Recurrent CE included 2 (2/4) cases after percutaneous treatment.

Échinococcose alvéolaire en région parisienne

Une femme de 60 ans, résidant en banlieue parisienne depuis l’âge de 24 ans, dont les antécédents se limitaient à une appendicectomie en 1979, consultait son médecin généraliste début 1999 pour un bilan biologique systématique, comportant une mesure de la vitesse de sédimentation. Celle-ci revenait très accélérée à 65 — 115. La malade n’avait aucune plainte fonctionnelle particulière. L’examen physique relevait une volumineuse hépatomégalie, aux dépens des deux lobes du foie, de consistance ferme, non douloureuse. L’activité des aminotransférases, de la GGT et des phosphatases alcalines était normale. Une échographie abdominale permettait d’objectiver une volumineuse masse d’allure kystique de 16 cm de diamètre, développée au niveau du foie droit (figure 1), refoulant le foie gauche jusqu’au niveau de l’hypochondre gauche, refoulant également la rate et le rein gauche. Le hile apparaissait également refoulé. La branche portale gauche était bien visualisée, au contraire de la branche portale droite, qui ne pouvait pas être identifiée. On repérait également une dilatation des voies biliaires gauches, et une adénopathie hilaire de 3 cm de diamètre. Il n’y avait pas d’épanchement intra-péritonéal. La tomodensitométrie hépatique confirmait ces données. L’hypothèse d’une tumeur kystique (cystadéno-carcinome) ou d’une volumineuse métastase nécrosée était évoquée. Une ponction cytologique était effectuée au niveau de cette lésion associée à une biopsie hépatique au niveau du lobe gauche. L’examen du produit de ponction n’était pas contributif ne mettant en évidence que de nombreux polynucléaires avec présence de lymphocytes et de macrophages et relevait la présence de rares hépatocytes. La biopsie hépatique, au niveau du lobe gauche, montrait un parenchyme hépatique d’architecture normale, avec présence, au niveau d’un des espaces portes, d’un aspect de cholangite. Il existait une prolifération néoductulaire, associée à un infiltrat inflammatoire lympho-plasmocytaire et à des polynucléaires. Il était décidé de réaliser une coelioscopie à visée diagnostique pour biopsies. Cette exploration avait lieu début août 1999 et identifiait de nombreux nodules d’allure blanchâtre, très suspects de malignité. L’examen extemporané ne permettant pas de trancher et ne retrouvant aucun signe de malignité, une laparotomie était décidée. L’exploration confirmait la présence d’un très volumineux « kyste » sous-tension dans le lobe droit du foie et des adhérences inflammatoires inter-hépatodiaphragmatiques, qui étaient libérées sans difficulté. Le « kyste » était ponctionné, ramenant un liquide puriforme. Le contenu du kyste était aspiré après protection du champ opératoire par des champs imprégnés d’eau oxygénée : 1 300 mL de liquide puriforme étaient retirés. Une chirurgie large de la paroi du kyste était effectuée, sous forme d’une résection du dôme saillant au bistouri électrique. L’intérieur de la cavité apparaissait irrégulière. Une fistule biliaire était aveuglée par un point en X. Une cholangiographie à l’aide d’une sonde

Volume–cible anatomoclinique dans la radiothérapie préopératoire des cancers du rectum

Resume L’exerese totale du mesorectum permet d’augmenter nettement le taux de controle local des cancers rectaux, ce qui signifie que le mesorectum est l’espace anatomique principal au sein duquel les recidives locales vont se developper. Il devient donc l’element de base de la reflexion de l’oncologue radiotherapeute dans l’elaboration du volume–cible anatomoclinique dans le cadre d’une irradiation preoperatoire. Nous proposons de l’identifier sur les structures anatomiques d’une scanographie effectuee en position de traitement.