Risk of pocket hematoma in patients on chronic anticoagulation with warfarin undergoing electrophysiological device implantation: a comparison of different peri-operative management strategies.

OBJECTIVE: Periprocedural management of warfarin remains challenging in patients requiring electrophysiological device surgery. For patients at high risk of thromboembolic events, guidelines recommend bridging therapy with heparin; however, this strategy is associated with a high risk of pocket hematoma. This paper systematically reviews studies appraising the risk of pocket hematoma with different perioperative anticoagulation strategies. METHODS: All relevant studies identified in MEDLINE/PubMed, The Cochrane Collaboration CENTRAL, clinicaltrials.org and in bibliographies of key articles. Estimates were combined using a fixed effects model. Heterogeneity was assessed by p values of χ2 statistics and I2. Publication bias was assessed by visual examination of funnel plots and by Egger test. Fifteen studies enrolling 5911 patients met all inclusion criteria and were included in this review. RESULTS: Heparin bridging compared with no heparin was associated with increased risk of pocket hematoma (OR = 4.47, 95% CI 3.21-6.23, p < 0.00001), and prolonged hospital stay (9.13 ± 1.9 days vs. 5.11 ± 1 .39 days, p < 0.00001). Warfarin continuation was not associated with increased pocket hematoma compared to warfarin discontinuation (p = 0.38), but was associated with reduced risk of pocket hematoma compared with heparin bridging (OR = 0.37, 95% CI 0.2-0.69, p = 0.002). Thromboembolic complications were reduced with heparin bridging vs. no heparin (0.50% vs.1.07%, p = 0.02), and no significant differences were reported between heparin bridging vs. warfarin continuation (p = 0.83). CONCLUSIONS: Heparin bridging is associated with a higher risk of pocket hematoma and a prolonged hospital stay. Perioperative continuation of warfarin reduces the occurrence of pocket hematoma compared with heparin bridging without any significant differences in thromboembolic complications.

[ Bancroftian lymphatic filariasis: toward its elimination from the Pacific?]. / Filariose lymphatique de Bancroft: vers l'elimination dans le Pacifique?

The region of the Pacific is historically affected by lymphatic filariasis (LF). Following the World Health Assembly resolution in 1997, the Global Program to Eliminate Lymphatic Filariasis (GPELF) was launched. In the Pacific, the World Health Organization (WHO) has implemented from 1999, the Pacific Program to Eliminate Lymphatic Filariasis (PacELF) bringing together the 22 countries and territories, in a common effort to eliminate the disease. The strategy is based on Mass Drug Administration (MDA); in annual single dose during 5 years of a Diethycarbamazine/Albendazole association distributed to all the population at risk. Among the 22 countries and territories of the Pacific, 16 are endemic and 6 are non endemic. The classification is based according to the filarian antigen prevalence upper or lower than 1%. MDA are decided when the rate of the filarian antigen prevalence is > 1%. The objective of PacELF is to reduce this rate down to < 1%, threshold under which the transmission is supposed to be stopped. From 1999 to 2007, 14 of the 16 endemic countries organized MDA. Eleven of them completed the cycle of 5 treatments and even beyond. But, these MDA reached only 19% of the at risk population, because of logistic difficulties in Papua New Guinea, the most populated country in the Pacific. The investigations carried out in sentinel sites showed a public health impact, by the fall of the number of microfilaria carriers, often down to a rate < 1%. However the rate of circulating antigen prevalence remains often above the required threshold of 1%. Prevalence surveys carried out in 2007, in different endemic countries, revealed the necessity to intensify efforts and to refine strategy for elimination of FL from the Pacific. A lot of progress were obtained, but few problems were identified. Reflexions are imperative and in progress about: the MDA coverage rates while at the same time a certain lassitude appears in the populations and among health staff, the methods to evaluate the effectiveness of MDA, the reliability of the diagnostic tools to decide of the stop of MDA and to certify the absence of the transmission, the relevance of univocal biological criteria for the whole Pacific area, the need for an active surveillance during several years after stopping MDA, particularly in the countries affected by the very efficient vector Aedes polynesiensis. Seven years after its launching, despite undeniable success, the PacELF program did not achieve its very ambitious goal of stopping the transmission. Three years before its term, strong efforts have to be done and additional strategies be implemented. However; it is reasonable to expect the prolongation of the program in order to achieve the final objective. Beyond, in some countries, it will be still necessary to ensure a sustained global drug pressure and an active surveillance to prevent the re-emergence of the disease.

Lot quality assurance sampling for screening communities hyperendemic for Schistosoma mansoni.

Lot quality assurance sampling (LQAS) was evaluated for rapid low cost identification of communities where Schistosoma mansoni infection was hyperendemic in southern Madagascar. In the study area, S. mansoni infection shows very focused and heterogeneous distribution requiring multifariousness of local surveys. One sampling plan was tested in the field with schoolchildren and several others were simulated in the laboratory. Randomization and stool specimen collection were performed by voluntary teachers under direct supervision of the study staff and no significant problem occurred. As expected from Receiver Operating Characteristic (ROC) curves, all sampling plans allowed correct identification of hyperendemic communities and of most of the hypoendemic ones. Frequent misclassifications occurred for communities with intermediate prevalence and the cheapest plans had very low specificity. The study confirmed that LQAS would be a valuable tool for large scale screening in a country with scarce financial and staff resources. Involving teachers, appeared to be quite feasible and should not lower the reliability of surveys. We recommend that the national schistosomiasis control programme systematically uses LQAS for identification of communities, provided that sample sizes are adapted to the specific epidemiological patterns of S. mansoni infection in the main regions.

[Non-tubercular bacterial meningitis in children in Antananarivo, Madagascar]. / Les méningites bactériennes non tuberculeuses de l'enfant à Antananarivo, Madagascar.

OBJECTIVE: To determine the bacterial causal agents of meningitis and their pattern of resistance, in children more than one month to 14 years of age. METHODS: A 2 years, prospective study (June 1998 to June 2000) on bacterial meningitis in children was carried out in the main hospitals in Antananarivo. The enrollment criteria upon admission were fever with symptoms of meningitis and/or convulsions and/or coma. A lumbar puncture was systematically performed in each child. The aspect of the cerebrospinal fluid was described, the level of protein and glucose estimated, soluble antigens measured. Following the examination of a Gram straining, an aliquot of the fluid was cultured on specific medium. Antimicrobial sensitivity testing of isolated pathogens was performed. RESULTS: Bacterial meningitis was confirmed in 119 children: 95 (80%) and 111 (93%) were less than 12 and 24 months of age, respectively. The sex distribution was 1:1. Three predominant microorganisms were identified: Streptococcus pneumoniae (45%), Haemophilus influenzae b (43%) and Neisseria meningitidis (10%) of which ten of 12 cases were belonging to serogroup B. The other microorganisms isolated were E. coli (2%). S. pneumoniae were found to be sensitive to penicillin G and H. influenzae were found to be sensitive to the third generation cephalosporins. Seven percent of the S. pneumoniae strains were mildly resistant (R + I) to chloramphenicol and between 29 and 50% to aminoglucosides. A moderate resistance against gentamicin and amoxicillin was found in 22-29% of the H. influenzae strains. The mortality rate was high (31%) and among the surviving children 30% presented with neurosensitive disorders. CONCLUSION: According to these data we may recommend the inclusion of vaccination against H. influenzae in the children immunization program in Madagascar. The early diagnosis and treatment with appropriate antibiotics, such as third generation of cephalosporins, are other critical measures to be taken in order to reduce the risk of developing severe complications associated to bacterial meningitis.

[Seroprevalence of viral hepatitis B in the city of Mahajanga, Madagascar in 1999]. / Séroprévalence de l'hépatite virale B dans la ville de Mahajanga à Madagascar en 1999.

A seroepidemiological study was carried out to assess the prevalence of hepatitis B virus (HBV) in the city of Mahajanga, Madagascar in July 1999. A total of 654 serum samples were collected from randomly selected subjects over the age of 2 years. The ELISA technique was used to detect serum markers of HBV infection. Prevalence rates were 14.2 p. 100 for HBs, 1.4 p. 100 for HBe antigens, and 49.5 p. 100 for HBV infection as defined by the presence of at least one serum markers. HBs antigens were detected in 20.8 p. 100 of children between the ages of 2 and 4 years and 15.3 p. 100 of women of childbearing age. In the latter age group, 5.6 p. 100 demonstrated HBe antigens, which are considered as a replication marker. The findings of this study are in agreement with those of a previous study in Madagascar and indicate that an expanded program of immunization against hepatitis B virus is warranted.

[Acquired antibiotic resistance in Madagascar: first evaluation]. / Résistances acquises aux antibiotiques à Madagascar: première évaluation.

The purpose of this study was to evaluate the incidence of acquired resistance to antibiotics in Madagascar. Testing was carried out on total of 1267 strains of medically significant bacteria isolated from specimens sent to the Pasteur Institute of Madagascar in Antananarivo between October 1997 and October 1998. Antibiograms were performed using the diffusion technique on gel media with antibiotic disks. Results were read according to the criteria of the Antibiogram Committee of the French Society of Microbiology. Preliminary findings documented a high incidence of resistance to widely available, low-price antibiotics including penicillin G and tetracycline for which 84 p. 100 and 65 p. 100 of Staphylococcus aureus respectively demonstrated resistance; tetracyclin to which 80 p. 100 of streptococcus were resistant; and ampicillin, cotrimoxazole, and phenicoles to which 60 p. 100, 60 p. 100 and 28 p. 100 of Escherichia coli respectively and 77 p. 100, 83 p. 100, and 71 p. 100 of Shigella sp. respectively were resistant. Second-line antibiotics including penicillin M, macrolides, nalidixic acid, and nitrofuranes were still relatively active, thus providing an effective alternative. Newly developed antibiotics such as fluoroquinolones and third-generation cephalosporines were highly effective but a few resistant strains were observed. Although not representative of Madagascar as a whole, the findings of this preliminary study indicate that acquired resistance must be taken into account in designing simplified decision charts for front-line laboratories, that appropriate information must be made available to health care workers, and that further testing is needed to monitor the evolution of antibiotic resistance.

[First cases of cholera observed in children at the Befelatanana General Hospital--Antananarivo University Hospital Center (Madagascar)]. / Premiers cas de choléra observés chez l'enfant à l'Hôpital général de Befelatanana--Centre Hospitalier Universitaire d'Antananarivo (Madagascar).

Ravages caused by cholera among children are well known. The disease invaded Madagascar in 1999 May. This retrospective study reported the first childhood cholera cases. The survey was carried out at the Befelatanana Hospital during the period of cholera outbreak from April 23th to July 31st. The purpose of the study was to specify clinical, epidemiological and bacteriological characteristics of the disease. 5 out of 178 suspected cholera cases were less than 15 years old. 2 young girls out these 5 children, inhabitants of Antananarivo-City were hospitalized for acute diarrhoea with serious dehydratation. Their disease was confirmed by bacteriology. Vibrio cholera O1 strain, serovar Ogawa was identified. Epidemiological investigation allowed to identify the contamination modal in the file no 1. The authors conclude that cholera is an important problem of public health in developing country like Madagascar. Disease control needs environmental sanitation and good individual hygiene practices.

[Cancer in Madagascar. Experience of the Institut Pasteur de Madagascar from September 1992 to June 1996]. / Le cancer à Madagascar. Expérience de l'Institut Pasteur de Madagascar de début septembre 1992 à fin juin 1996.

The Unit of the anatomo-pathology in the "Institut Pasteur de Madagascar" (IPM) examined in the period from September 1992 to June 1996 tissue specimens from 10,275 patients. Tumorous pathology presented 40% of the tissues and half of which were of malign etiology. 64% of the cancer diagnosed were in females. Cervical cancer was most frequently observed (17%), followed by breast cancer (16%). Cancer in the gastro-intestinal tract (15%) was most often located in the colon without sex difference. Stomach cancer occurring predominantly in males presented 25% of the total cases of cancer in the gastro-intestinal tract. Cancer of liver is rarely diagnosed despite the high prevalence of infection with hepatitis B virus. Skin cancer constituted 9% of the malign diagnosis and was mainly found in males. Children under 15 years old presented 7.4% of the total cases of malignancy with the haematopoietic tissues (30%) and the eyes (17%) as the most frequent topic locations. Due to a very low seroprevalence of the HIV in Madagascar, malign tumours associated to AIDS were only seen in a few rare cases. The review of cancer cases in the IPM may not be representative for the cancer epidemiology of Madagascar because of a general very low level of health care coverage, especially in the rural areas. Furthermore, a major part of the specimens originates from easily accessible organsystems, whereas other organs seem less investigated due to lack of appropriate available technique. Therefore, it is not feasible for the moment to establish a cancer register in Madagascar, although the Unit of Pathology in the IPM can offer a valid cancer diagnostical service.

La peste : maladie réémergente à Madagascar

La peste est aujourd'hui considérée par l'OMS comme une maladie résurgente dans le monde. A Madagascar, on assiste à sa recrudescence : 150 à 250 cas par an sont notifiés confirmés ou probables. La peste sévit surtout sur les Hauts-Plateaux où 32 Services de Santé de District sont concernés. Parmi eux, le district d'Antananarivo-ville où 23 cas contrôlés ont été recensés en 1996. Sur les côtes, la maladie a réapparu en 1991, dans la ville portuaire de Mahajanga après 63 années de silence apparent; entre 1991 et 1997, 3 épidémies sont survenues : 180 cas ont été confirmés ou probables de peste. A Antananarivo, la surveillance de la population murine a montré une circulation intense du bacille pesteux. Fait préoccupant, les puces vectrices, Xenopsylla cheopis, récoltées des rats capturés ont montré une résistance aux principales familles d'insecticides dont les pyréthrinoïdes. Cette situation alarmante exige un système d'alerte et de riposte. La mise à disposition d'un test de diagnostic simple, très rapide et sûr aux services sanitaires périphériques devrait améliorer les mesures de riposte devant un cas confirmé de peste

Hepatitis B virus infection in general population in Madagascar: evidence for different epidemiological patterns in urban and in rural areas.

To describe the features of hepatitis B virus (HBV) infection in Madagascar, a randomized sero-epidemiological survey was undertaken in the general population > or = 1 year old of two provinces which represents 45% of the total population. In the 921 sera tested, the prevalence of HBV markers was 20.5% for HBsAg, 38.2% for anti-HBc and 6.9% for HBeAg. HBsAg and anti-HBc prevalence rates were significantly higher in males. A large difference in HBsAg prevalence was observed between urban (5.3%) and rural areas (26.0%). The same contrast in prevalence was noticed for the other HBV markers. In rural areas, HBV infection was more frequently acquired early in infancy, which suggests predominantly perinatal or postnatal transmission. The presence of HBV markers was not significantly associated with a history of blood transfusion, surgery or parenteral injection. High infectivity carriers represented 5.3% and the overall frequency of chronic carriers was 10.4%. These results place Madagascar among areas of high endemicity.

[Street-vendor foods: quality of ice creams, sherbets and sorbets sold in the urban agglomeration of Antananarivo]. / Aliments de rue: qualité des glaces, crèmes glacées et sorbets commercialisés dans l'agglomération urbaine d'Antananarivo.

A survey of selling conditions and bacteriological examinations of ice-cream was carried-out in Antananarivo from June 1996 to May 1997. The way of investigation by vendors and of bacteriological examinations were widely described. Sellers had classic features of a street-vended food vendor: uneducated, no having professional training and mishandling foodstuffs. 202 samples of ice-cream were collected. The contamination prevalence rate was of 95% +/- 3.7%. Salmonella typhimurium was isolated from one sample. Immediate and rigourous measures ought to be put into effect by authorities to right this alarming situation.

[Control of hepatitis B in French Polynesia with a program of systematic vaccination of newborns with the Genhevac B vaccine]. / Lutte contre l'hépatite B en Polynésie française par un programme de vaccination systématique des nouveau-nés avec le vaccin Genhevac B.

In 1988, a 5-year vaccination program against hepatitis B was launched for all newborns in a pilot area, the Austral archipelago in French Polynesia. Genhevac B, a recombinant vaccine produced from mammalian cells was administered. Three different immunization schedules were used, none of them including additional specific immunoglobulin: i) four doses, one at each months (M) 0, 1, 2, and 12; ii) three doses one at each MO, M1 and M6; and iii) three doses one at each MO, M1 and M12. Each year during the 5 year period a serological survey was conducted. Of the 837 children who received at least one vaccine dose, 5 were HBsAg carriers. Seroprotection rates for anti-HBs and anti-PreS2 antibodies were 88% after one dose and 97% after two doses. After the third dose, seroprotection rates and geometric mean titers of anti-HBs antibodies were 95% and 217 mIU/ml for schedule (i) (three dose only); 92% and 389 mIU/ml for schedule (ii) and 93% and 344 mIU/ml for schedule (iii) respectively. After four doses (schedule i) the values were 100% and 1228 mIU/ml. Of the 18 newborns whose mothers were positive for both HBsAg and HBeAg, one was a HBsAg carrier. The estimated protective rate for prevention of perinatal transmission was 94%. This study suggests that in field conditions, systematic vaccination of newborns without using specific immunoglobulins can confer early protection. The schedule recommended for use in French Polynesia was three doses, at MO, M1 and M6-12 (between 6 and 12 months) with an additional booster dose at age 6 years, the last year of nursery school. Since April 1992, all children born in French Polynesia have been vaccinated according to this schedule. A catch-up program has been implemented for children aged 4 to 10 years old using a similar immunization schedule.

Alpha-thalassaemia and globin gene rearrangements in French Polynesia.

The prevalence of alpha-thalassaemia and various globin gene rearrangements was determined in 1992 individuals living on 11 islands in French Polynesia. The gene frequencies for alpha(+)-thalassaemia (almost exclusively the -alpha 3.7III deletion form) range from 5.3% to 19.2%. Haematological indices on 177 heterozygotes and 27 homozygotes for the -alpha 3.7III variant showed considerable overlap with indices of normal individuals; although there was a broad correlation of average indices with alpha-globin genotype, individual values were a poor indication of genotype. A non-deletion form of alpha(+)-thalassaemia (alpha alpha Th), triplicated alpha genes (alpha alpha alpha) and single zeta gene (-zeta) chromosomes were present at low frequencies (< 1%), whereas triplicated gamma gene (gamma gamma gamma) and triplicated zeta (zeta zeta zeta) arrangements were more common (1.1-16.3%). alpha 0-thalassaemia, probably introduced from Southeast Asia in the early part of this century, was observed in a number of individuals of Chinese and Chinese/Polynesian ancestry. Because of the high frequency of alpha(+)-Thalassaemia on some islands, it therefore seems likely that haemoglobin H disease (resulting from the interaction between alpha 0 and alpha(+)-thalassaemia) must occur in parts of French Polynesia.

Grating-assisted phase-matched second-harmonic generation from a polymer waveguide.

Diffraction gratings can be used to achieve phase matching between the fundamental modes of a slab or confined waveguide. Compared with the usual techniques such as quasi-, Cerenkov, and intermodal phase matching, the matching method used here involves spatial harmonics of the guided electromagnetic field that are generated by the corrugated grating. This grating acts simultaneously as a linear waveguide coupler at both the pump and harmonic frequencies. Using the third spatial harmonic, we report what we believe to be the first observation of grating-assisted phase-matched second-harmonic generation between counterpropagating TM(0) modes of an organic waveguide.

Grating-enhanced second-harmonic generation in polymer waveguides: role of losses.

A numerical study of second-harmonic (SH) generation in a corrugated polymer waveguide is performed with a rigorous electromagnetic theory. Comparison with experiment reveals the role of losses inside the waveguide-small losses do not significantly affect the nonresonant response and reduce the resonant enhancement of SH generation. High losses can lead to the opposite effect-instead of enhancement, dips in the SH efficiency are observed in the vicinity of guided-wave excitation. The peculiarities of the angular dependencies of SH generation are explained from the phenomenological point of view, and the role of phase matching is discussed.