Bacterial removal from inexpensive portable water treatment systems for travelers.

BACKGROUND: There are many personal portable water treatment systems for travelers on the market, including chemical agents, iodine resin purifiers and filters. However, information on the real efficacy of these systems in the field is often lacking. We have therefore estimated the capabilities of several inexpensive personal portable water treatment systems for travelers to remove bacteria in various situations of water quality, using stressed indigenous strains of bacteria. METHODS: Four chemical agents (Drinkwell chlorine, Hydroclonazone, Aquatabs, 2% iodine in ethanol), two iodine resin purifiers (the straw PentaPure Outdoor M1-E, the PentaPure Traveler purifying and filtration system) and four filters (the flexible bottle Pres2Pure, the hand-pump filters Mini Ceramic, First Need Deluxe and WalkAbout) were evaluated in triplicate using both turbid and clear water at 25 degrees C. Bacteria were counted by conventional culturing techniques, colorimetric and fluorescent assays of coliforms and Escherichia coli enzyme activities (Colilert)/Quantitray method), and viable but not culturable bacteria were assessed quantitatively by 5-cyano-2,3-dilotyl-tetrazolium staining. RESULTS: The best systems were the three hand-pump filters, Mini Ceramic, First Need Deluxe, and WalkAbout. All had a submicron filtration element that completely removed 3 log (99.9%) or more of viable bacteria, and no coliforms or E. coli were detected in the effluent. The PentaPure Traveler removed more than 99.3% of the viable bacteria. The only chemical agents that gave a bacterial inactivation of over 2 log in clear water were the Drinkwell chlorine, the Aquatabs, and the 2% iodine in ethanol. The three other devices, Hydroclonazone, Outdoor M1-E, and Pres2Pure, performed poorly, as coliforms and E. coli were detected in the treated water by the Colilert method. The chemical agents and the iodine resin straw performed poorly on raw river water; coliforms and E. coli were detected in the treated water. CONCLUSIONS: These data demonstrate the differences between the systems tested. The effectiveness of other devices on the market should also be tested, so as to help travelers and hikers select the most appropriate portable water treatment system.

A 3-week hepatitis B vaccination schedule provides rapid and persistent protective immunity: a multicenter, randomized trial comparing accelerated and classic vaccination schedules.

Hepatitis B (HB) vaccinations given once weekly for 3 weeks can provide early seroprotection. This study compared immune responses induced by the accelerated (A; days 0, 10, 21) and classic (C; days 0, 28, 56) HB vaccination schedules. Two hundred seventy healthy subjects (95 men, 175 women) with a mean age of 23.8 years received 3 doses of GenHevac B, a recombinant vaccine produced in mammalian cells. The subjects were randomly assigned to schedules A or C. A booster dose was given 1 year later. One month after the third dose, 70% (schedule A) and 92% (schedule C) of the subjects were seroprotected and 100% (A) and 99% (C) had developed anti-pre-S2 antibodies. Before booster injections, 93% (A) and 95% (C) of the subjects were seroprotected, and 1 month after the booster, almost all subjects were seroprotected. A 3-week HB vaccination schedule with GenHevac B can confer early protective immunity lasting up to 1 year.

[Rubella vaccine coverage and seroprotection in 11-year-old children in the Indre-et-Loire department]. / Couverture vaccinale et séroprotection vis-à-vis de la rubéole chez les enfants de 11 ans dans le département de l'Indre-et-Loire.

To determine the current rates of vaccination and seroprotection against rubella of French preadolescents, a survey was conducted among children in their first year of junior schools of the department of Indre-et-Loire (prefecture: Tours). The rate of vaccination against rubella during infancy or childhood was 58.8% for the girls and 9.4% for the boys, as compared with 99.5% for both sexes for the vaccination against diphteria, tetanus and poliomyelitis. An effective seroprotection against rubella was found more frequently in girls than in boys (90.4% vs 78%), and was also more frequent among vaccinated than non vaccinated preadolescents (98% vs 77%). From these data the authors recommend that a stronger policy of vaccination against rubella should be be adopted, ie. order to obtain the eradication of rubella in France.

[Health status of adolescents in the 7th grade at schools in Indre-et-Loire]. / L'état de santé des adolescents des classes de 5e d'Indre-et-Loire.

A survey of 1,316 pupils in the 7th grade in private or public schools in the department of Indre et Loire was conducted in order to establish the health status and needs of adolescents aged 12-15 years. Nutritional behavior, alcohol and tobacco consumption, obesity, hypertension, audio-visual disturbances, and dental status were the essential points of this survey. This study demonstrates the necessity of frequent and systematic health care supervision of adolescents, in an effort to detect and prevent or treat disturbances which may have long term adverse effects. The absence of such a structure in our medico-social armament is underlined along with the potential consequences that such a deficiency may have on the future adult generation.