Snapshots for January 2004

Field: Medicine (Health Sciences)

Discontinuation of Cefixime (Suprax) Tablets In July, 2002, Wyeth Pharmaceuticals announced the discontinuation of production of cefixime tablets (Morbid Mortal Weekly Revs, 2002; 51: 1052 ), in light of expiration of their patent in November, 2002. So far, no other manufacturer has announced an interest in producing the drug. Cefixime, which could be given in a single dose for the treatment of uncomplicated gonorrhea, is the only oral antimicrobial recommended by the CDC to which the organism has not developed significant resistance. Fluoroquinolones, which can also be given in a single oral dose, should not be given for infections contracted in Asia, the Pacific Islands, or California, because of high rates of resistance. An intramuscular injection of ceftriaxone (125 mg) should be used for infections acquired in those areas. 1 Encephalitis in the United States Investigators from the CDC analyzed data from the National Hospital Discharge Survey for the period 1988–1997 to determine the healthcare burden of encephalitis (Khetsuriani et al). There was an average of about 19,000 hospitalizations and 1400 deaths per year. Among hospitalized patients, no etiologic agent was recorded in almost 60% of cases. In cases with an etiologic diagnosis, 38% were viral and 34% were other infectious. The two most common agents were Herpes simplex and toxoplasma, each accounting for about 11% of encephalitis-related hospitalizations. HIV infection was listed among the discharge diagnoses in 15.6% of patients. The rates of encephalitis-related hospitalization were highest for the very young (<1-year-old) and the old (>65 years). The annual cost of hospitalization for encephalitis was estimated to be $ 650 million. The authors did not attempt to quantify the long-term costs or effects of encephalitis. Other studies have shown a similarly high rate of encephalitis of unknown etiology, including prospective studies with extensive testing. Presumably, a more current analysis would show an important contribution of the newly endemic West Nile Virus. 2 Erythrocytes: Another Reservoir for HIV HIV infects many cells and organs in the body, besides the well-known CD4 lymphatic cell. These reservoirs include brain, bowel, lung, heart, and kidney, as well as macrophages, dendritic cells in the central nervous system, and B cells and lymphoid follicular dendritic cells. Integrated into the cellular chromosomes, virus can persist in these sites indefinitely. A recent study (Hess, et al) shows that, among patients with chronic HIV infection, erythrocytes can serve as a reservoir for HIV even after plasma levels of the virus have been rendered undetectable by antiretroviral treatment. In the case of erythrocytes, the virus appears to be bound to the cell membrane by immune complexes from which it can readily be released. Cell-bound (rather than integrated) virus has been found on the surface of other cells, notably, lymphoid follicular dendritic cells, CD8 cells, platelets and neutrophils. Virus bound to cells by immune complexes seems to be more stable than cell-free virus and such cell-bound virus could be important in transmission in genital, among other, fluids. 3 The Ideal Mosquito Larvicide Several newspapers, including Reuters Health, carried a story about what appears to be an ideal means of mosquito control. The essential ingredient is a hormone called trypsin modulating oostatic factor (TMOF). This hormone is produced in the ovaries of mosquitoes. Injected into or fed to the insects, it turns off the ability of the digestive tract to absorb a blood meal. The effect on mosquito larvae is to starve them to death. A biochemist at the University of Florida, named Dov Borovsky, has isolated the gene for the hormone and spliced it into yeast cells, which readily produce large amounts of the substance. Mosquitoes apparently are fond of eating the yeast granules. Preliminary studies show that sprinkling of the granules into the usual habitats of mosquitoes sharply reduces mosquito populations. The hormone is thought to affect no other species and to be environmentally safe.