Naegleria fowleri is a protozoan found naturally in hot springs and warm surface waters. It can cause usually lethal primary amoebic meningoencephalitis. The goal of this study was to determine the occurrence of N. fowleri in drinking water supply wells in Arizona. Nested polymerase chain reaction was used to detect trophozoites and cysts, but not to assess viability. A total of 185 samples were collected from 113 wells before disinfection. The presence of N. fowleri deoxyribonucleic acid was confirmed in 10.6% of wells. No correlations were found between the presence of N. fowleri and heterotrophic bacteria, coliforms, Escherichia coli, temperature, specific conductance, or turbidity. N. fowleri was detected in 10.0% of initial and 17.2% of purged well samples, suggesting that N. fowleri may be present in the aquifer or detach from the well casing or pump column during pumping.

Naegleria fowleri is a water-based protozoan found naturally in soil and warm waters. The deaths of two children due to N. fowleri in the Phoenix, Arizona, metropolitan area occurred in 2002, and the drinking water obtained from groundwater was found to be the source of the exposure. A survey was conducted of municipal drinking water wells in central and southern Arizona. N. fowleri was identified in 11 of 143 wells tested. The calculated Ct (chlorine concentration × time) for N. fowleri cysts by free chlorine was 31 for a 99% reduction at room temperature, pH 7.5 and trophozoites 6. Chlorination can be used to control N. fowleri transmission via drinking water with appropriate guidance related to proper dosages and contact times.

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The intracellular fate of ³H-labeled exogenous herpes simplex virus type 2 DNA following the exposure of recipient cells to selected DNA facilitators and the ultrastructural changes which ensued in transfected cultures were examined. In most cases, electron microscopic radioautography demonstrated that exogenous DNA reached the nucleus within 1 h postinoculation. At later time periods, enlargement of nuclei and margination of chromatin were noted. Cells treated with polyornithine differed significantly from those treated with other facilitators in that large cytoplasmic accumulations of labeled material associated with electron-dense, membrane-bound bodies persisted after 1 h postinoculation. In contrast, labeled DNA released by intact virions was detected in the nucleus as early as 20 min postinfection (p.i.), and progeny virus was evident by 8 h p.i. These results suggest that the efficiency of each facilitator is related to the rapidity with which exogenous DNA penetrates the recipient cell, traverses the cytoplasm, and the amount of DNA which is finally associated with the nuclear compartment.