Monthly Archives: September 2010

Subjects and Methods

WITS. The present analysis was conducted using retrospective data obtained from mother‐infant pairs enrolled in the WITS cohort during 1989–2004. WITS is a prospective observational, multicenter study that was established in 1989. The study population is recruited from 6 sites in the United States and Puerto Rico (Boston and Worcester, Massachusetts; Brooklyn and Manhattan, New […]

Hematologic Values in HIV‐Uninfected Children

There has been a dramatic decrease in perinatal HIV infection in the United States and other resource‐rich countries since 1994, when Pediatric AIDS Clinical Trials Group protocol 076 showed that administration of zidovudine to the HIV‐infected woman during pregnancy and labor and to her newborn reduced the risk of mother‐to‐child HIV transmission by nearly 70%. […]

Residual insecticide quantification. Part 5

The current study also observed that Olyset generally retained more insecticide when it was dried in direct sunlight or hanging under the shade compared to other nets. The high insecticide retention by OlysetR netting recorded in this study and its unavailability on the surface to cause corresponding mosquito mortality suggests that this requirement is still […]

Residual insecticide quantification. Part 4

When the bioefficacy was also measured, using the standard WHO cone bioassay method, mortalities of An. gambiae also varied with the number of washes, net brand and washing method. When the residual insecticide contents were compared using statistical procedures, it was also found that, the four drying regimens and the three washing procedures were significantly […]

Residual insecticide quantification. Part 3

The mean knockdown and mortalities of mosquitoes exposed on nets after repeated washing using two local methods: hand rubbing and beating on rocks are presented in. In general, it was observed that nets washed by machine recorded higher knockdown after one hour post exposure and 24-hour mortality respectively compared to nets washed by the other […]

Residual insecticide quantification. Part 2

The four drying regimens were also statistically compared on individual net brand. For PermaNetR and TNT, overall there were no significant differences observed between the four drying regimens on these nets (p = 0.7944 and 0.4703) respectively). For BASF nets that were dried hanging under the shade performed better compared to nets dried using other […]

Residual insecticide quantification

After bioassay the second piece cut from each net were individually labelled with the name of treatment group and number of washes and stored in the dark for subsequent residual insecticide quantification by high performance liquid chromatography (HPLC). For ease of identification the nets were marked with indelible ink using permanent markers before washing was […]

Washing by beating on rocks

In this experiment, 5 grams of OMO detergent was thoroughly mixed with 2 litres of rain waster. Each net was individually immersed in soap solution in a 10-litre water bowl. Nets were then removed from the water bowl then beaten against a concrete slab several times for a total of 10 minutes. Between these beatings, […]

Nets used in the study

Washing of nets by hand The nets were hand washed and dried outdoor at KEMRI Centre for Global health research in Kisian village, western Kenya. Four field assistants from the local community were hired to do the washing. Hand washing was done by immersing the netting in a measured volume of water using a measured […]

Long-lasting insecticide-treated nets (LLINs)

Long-lasting insecticide-treated nets (LLINs) are currently preferred to conventionally insecticide-treated nets (ITNs) for use in malaria control programmes. Although LLINs offer an alternative solution to regular net re-treatment, their actual wash durability under field conditions is not known. For example the frequency of washing, the washing methods, and drying regimens that are used in the […]