Consideration of ethics in primaquine therapy against malaria transmission.

Millions of people receive primaquine against sexual plasmodia responsible for malaria transmission. These gametocytes cause no symptoms and do not threaten the host, but they infect mosquitoes and threaten the community. Primaquine causes hemolysis in the small minority of patients with glucose-6-phosphate dehydrogenase deficiency (G6PDd). Clinical studies in the 1950s demonstrated gametocytocidal primaquine to be safe without G6PDd screening. However, the evaluated G6PDd variant, African A-, represents mild sensitivity to primaquine. The view of primaquine as a safe gametocytocide thus rests largely upon observations from a G6PDd variant that is unlikely to challenge safety. The early clinical work does not seem to afford an adequate assessment of safety in G6PDd patients. Potential risk of harm without clinical benefit to the patient raises ethical questions that should be examined.

Vaginal myeloperoxidase and flora in the pig-tailed macaque.

Myeloperoxidase (MPO) is an enzyme in neutrophils and monocytes which reacts with H2O2 and chloride to kill microbes after phagocytosis. Instillation of MPO into the vagina may augment vaginal defenses against sexually transmitted diseases, since the normal vaginal flora is characterized by the presence of H2O2-producing lactobacilli. We assessed the menstrual cycle stage, vaginal flora, pH, macroscopic appearance, and endogenous MPO in the adult female pig-tailed macaque (Macaca nemestrina) at baseline (n = 26; 60 observations) and at 0, 4, and 24 hours in untreated animals (n = 6) or in animals treated with intravaginal MPO gel at time 0 (n = 5). Baseline MPO levels were highly variable, and there was no detectable effect of cycle stage. In untreated animals, there was no significant effect of vaginal swab collection on vaginal flora or MPO levels. MPO treatment did not reduce vaginal H2O2-producing organisms, and vaginal MPO levels tended to increase at 4 hours in treated animals. Vaginal/cervical colposcopic changes were not detected in either group.

Urinary leukocyte esterase screening for asymptomatic sexually transmitted disease in adolescent males.

The objective of this study was to evaluate the effectiveness of urinary leukocyte esterase on random urine specimens as a screening test for chlamydial and gonococcal urethral infections in asymptomatic males. Random urine specimens were obtained on 106 consecutive asymptomatic adolescent males during intake physical examination at a residential vocational training program. Results of urinary leukocyte esterase were compared to those of urethral cultures for Chlamydia trachomatis and Neisseria gonorrhoeae. Five subjects had positive chlamydia cultures, three subjects had positive gonococcal cultures, and one patient had positive cultures for both organisms. Sixteen subjects had leukocyte esterase tests reported as "trace" or greater. When compare to positive culture results for either Chlamydia or gonorrhea, urinary leukocyte esterase activity had a sensitivity of 78%, specificity of 91%, and positive predictive value of 44%. A random urine specimen for urinary leukocyte esterase activity is a cost-effective screening method for chlamydial and gonococcal urethral infections in asymptomatic adolescent males.