Minimum infective number

Strictly, disinfection means removing the risk of infection, but in the context of swimming pools the water cannot be sterile all the time. A few living, but normally harmless microorganisms will always be present, especially in open pools. Disinfection aims to keep their number to an acceptable minimum and to ensure that any harmful organisms entering the pool water are rapidly inactivated and eliminated so that the water will not transmit infection to the bathers. 

Many diseases, including anthrax, are most effectively treated before actual manifestation of the symptoms is observed. Presently a presumptive identification of Bacillus anthracis can be made in about 3 hours however, if a full laboratory response network (LRN) confirmation procedure is utilized, the theoretical time increases substantially to approximately 48 hours. During the recent anthrax cases 72 to 96 hours were common to complete the entire LRN protocol. In the meantime antibiotics were administered as a precaution based on the presumptive results to individuals thought to be exposed to B. anthracis spores or with anthrax symptoms. The mass administering of antibiotics from a cost standpoint, as well as from medical prudence to prevent the rise of antibiotic-resistant strains, is not the optimal answer to the anthrax infection problem. Therefore it is important that early tests be rapid and reliable with a minimum number of false positive and false negative results. 

The NME can now be administered to humans. The first step in clinical evaluation is one or more phase I studies designed to assess the drug s safety and pharmacokinetic profile. Phase I studies usually involve a small number of healthy volunteers who are closely monitored after receiving escalating doses of the drug candidate. Phase I studies of drugs for cancer or HIV infection must be carried out in patients, not in healthy subjects. Ordinarily, until more information is available, the minimum dose to induce side effects is stipulated as the upper dose limit for subsequent administration to human subjects. 

For statistical analysis, the greater the number of counts per culture the more accurate will be the statistics. The absolute minimum is triplicate values. Figure 2 shows the selective toxicity of EF13 for HIV-chronically infected cells over uninfected cells established using the Trypan blue exclusion test. 

A field clinical trial conducted in Isfahan, Iran, to determine the effectiveness of deet sticks against leishmaniasis in 430 students (50% male, 50% female) did not demonstrate any treatment effect." The intervention was reported to be effective for 18-20 hours, and its minimum effective concentration was 55-77 pg/cm. Deet placebo was randomized to 330 individuals and placebo stick was randomized to 100 controls, and the treatment allocation code of sticks was revealed only at the end of the study. The children were followed up for 10 months. The efficacy of these sticks was evaluated in terms of the reduction in infection by leishmaniasis using relative risk (RR). Confusingly, in the results section of the study the investigators reported a different number of treatments and controls out of 200 students who were protected using the placebo pen 2 students acquired leishmaniasis, and out of 230 students who were protected using the deet pen 8 students acquired leishmaniasis. Thus, the study cannot be accurately interpreted. 

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