[Assessment of mother-to-child HBV transmission at the prenatal consultation in Vientiane, Laos]. / Évaluation du risque de transmission materno-fœtale du virus de l'hépatite B en consultation prénatale à Vientiane, Laos.

Chronic infection with hepatitis B virus (HBV) remains highly endemic in Laos, mainly related to mother to child transmission. Despite the introduction of the vaccination against HBV in the Expanded Programme on Immunization in 2001 and the administration of a vaccine birth dose as part of a 3-dose schedule since 2004, infant immunization coverage remains inadequate because most mothers are not aware of the risks. A survey was conducted in early 2013 in Vientiane capital among women who undergo serologic screening for hepatitis B at the prenatal consultation, to assess their knowledge and risk factors of HBV infection. It included the administration of a standardized questionnaire divided into four parts (socio-demographic data, knowledge about hepatitis B, risk factors and immunization status) and a screening test for the HBV surface antigen (HBsAg). A total of 200 pregnant women were recruited consecutively in Mahosot hospital. They were aged 14-39 years (mean 27 ± 4.76 years), civil servants (37%) or housewives (33.5%) with a secondary or higher education level (80%). Most were multiparous (68.5%) and attended antenatal care in the third trimester of pregnancy (61%). Sixteen (8%) tested HBsAg positive. The HBsAg seroprevalence was higher in the 26-30 years age group, among women above the primary school education level and women practicing the profession of shopkeeper or civil servant, but these differences were not significant. Hepatitis B was known by a small majority (53%) but 26% could name the routes of transmission, 28% considered it as a serious illness and 24.5% were aware of the HBV vaccine. No risk factor for blood or sexual exposure to HBVinfection was significantly linked to the HBsAg carriage. In this sample of pregnant women mostly urban, educated and multiparous with access to a central hospital, the high rate of HBV infection and the low level of knowledge about the risk of mother-to-child HBV transmission reveals a major gap in information and advice that should be provided during prenatal visits. A large scale program of health education focused on the prevention of vertical transmission of HBV should be implemented, parallel to the extension of HBV vaccine coverage including a birth dose for the Lao children.

Bleach treatment of sputum samples aids pulmonary tuberculosis screening among HIV-infected patients in Laos.

BACKGROUND: Laos has a high prevalence of tuberculosis (TB) and a slowly increasing prevalence of human immunodeficiency virus/acquired immunedeficiency syndrome (HIV/AIDS). Sputum smear microscopy is the only method currently available for routine screening of pulmonary TB, although it only detects one in three cases among persons living with HIV (PLWH). Bleach treatment of sputum samples (bleach method) has been shown to significantly improve the sensitivity of the test; however, its effectiveness in PLWH remains to be determined in Laos. OBJECTIVES: To determine the performance of the bleach method as a diagnostic tool for pulmonary TB in PLWH and to assess its cost-effectiveness in Laos. RESULTS: Of 174 sputum samples collected from 92 patients, 29 were culture-positive for Mycobacterium tuberculosis in 17 patients. The sensitivity of the direct method and the bleach method was respectively 59% and 93%, and specificity was 100% for both methods. The incremental cost-effectiveness ratio for screening an additional case was US$17.40. CONCLUSION: The bleach method is simple, cheap, easy to perform and cost-effective in PLWH. Its implementation in laboratories involved in routine screening of pulmonary TB among PLWH would allow practitioners to start the treatment of this life-threatening co-infection earlier.

[Viral hepatitis of enteric origin]. / Les hépatites virales d'origine entérique.

Hepatitis viruses of oral-fecal origin are responsible for a high morbidity and mortality throughout the world, even if they never result in chronic hepatitis. Two viruses, the virus of hepatitis A (VHA) and of hepatitis E (VHE) are at present the cause of severe viral hepatitis of enteric origin. Water is the principle vector in the spread of these viruses. However, the epidemiological aspects vary according to the pathogenic agent. VHA is excreted in a highly concentrated form in the feces for a relatively short period of time. Since it resists in an exterior environment, the virus remains infectious for a long time. VHE is excreted for a short period of time and in low concentrations. The viral particles are fragile in vitro and their variability in the environment is little known. The possible reservoir role of certain animals has been envisaged. Epidemics arise especially in countries suffering from poor hygiene and massive water pollution. Hepatitis A should no longer be considered a benign disease of childhood. The progress made in hygiene and economic development in industrialized countries have made contacts with this virus scarce, rendering the populations more receptive to it and epidemics more widespread. When the sickness occurs later in life, infection is more often symptomatic and can be serious, resulting sometimes long-term indisposition. Hepatitis E has a vast distribution throughout the world and manifests itself either in epidemic or endemic-sporadic form in many poor countries. In developed countries, it comes about mostly as a result of imported pathology, even if there exists a "substratum" of infection in these areas. The main clinical aspects, such as we were able to study them in 39 cases of military men from Tchad, Guyana and Somalia, are comparable to those of hepatitis A. The reasons for the particular gravity of symptoms in pregnant women are unknown. These affections have no specific treatment. In the field of prevention, vaccination is at present the best means for hepatitis A prophylaxis. Until a vaccine against hepatitis E is found, prevention depends on hygiene, sanitation measures et distribution of drinking water.