Showing papers by "Sally Blower published in 1999"

Global elimination of trachoma: how frequently should we administer mass chemotherapy?

Abstract: The World Health Organization has recommended repeat mass drug administration as part of their global initiative to eliminate blinding trachoma by the year 2020. The efficacy of repeat treatment will be tested empirically, but the results will not be available for many years, and recommendations for the necessary frequency of treatment are needed immediately. We have developed a mathematical model that uses available epidemiological data from a variety of countries. We recommend, based on our analysis, that in areas where trachoma is moderately prevalent ( 50% in children), it should be treated biannually.

Antibiotic resistance--to treat...

Abstract: To the editor—An earlier article emphasized the need to carefully reconsider the use of antibiotics in medicine and to complete the body of scientific evidence before any specific prescribing or control policy is effected. In orthopedic surgery, the use of antibiotics is common in joint replacement with biomaterials. The biofilm mode of growth protects infectious microorganisms on implants against the host immune system and antibiotics. Therefore, infected orthopedic implants must be removed from the patient and the infection cured before a new implant can be placed. To prevent implant-related infections, about 90% of the orthopedic surgeons in the US use prophylactic antibiotic-releasing bone cements, even though it is known that these cements only release up to 10% of the antibiotic incorporated and little is known about the antibiotic concentration around an actual orthopedic implant in the body. Most surgeons are aware of the lack of scientific evidence regarding the efficacy of antibiotics in these applications but nonetheless use antibiotic-loaded bone cements “to be on the safe side.” Recently, a 67-year-old patient of the University Hospital Groningen complained of pain associated with a hip prosthesis that was cemented in his right hip 4 years earlier. His left hip was revised 5 years ago with gentamicin-impregnated cement and was without symptoms. X-rays showed loosening of the right hip prosthesis and, consequently, the hip was revised. As the removed hip was covered with a slimy layer positive for Gram staining, 60 gentamicinloaded cement beads were left in the patient, as is usual in these cases, to cure the infection. After 2 weeks, the gentamicinloaded cement beads were removed aseptically, and a gentamicin-resistant staphylococcal strain was isolated from them. This observation evokes the question “Did we help this patient or did we stimulate the development of an antibioticresistant strain in his body?” Without overinterpreting this single case, the adhesion and growth of a staphylococcal strain on gentamicin-loaded bone cement beads in a patient is worrisome. Given the growing doubts about the efficacy of prophylactic use of antibiotic-releasing cements for the fixation of implants, the conclusion seems to be justified that the current generation of antibiotic-releasing bone cements contribute to the development of antibiotic resistance, as their release rates are insufficient.