Molecular biological approaches to the study of vectors in relation to malaria control.

To a large extent, control of malaria vectors relies on the elimination of breeding sites and the application of chemical agents. There are increasing problems associated with the use of synthetic insecticides for vector control, including the evolution of resistance, the high cost of developing and registering new insecticides and an awareness of pollution from insecticide residues. These factors have stimulated interest in the application of molecular biology to the study of mosquito vectors of malaria; focussing primarily on two aspects. First, the improvement of existing control measures through the development of simplified DNA probe systems suitable for identification of vectors of malaria. The development of synthetic, non-radioactive DNA probes suitable for the identification of species in the Anopheles gambiae complex is described with the aim of defining a simplified methodology which is suitable for entomologist in the field. The second aspect to be considered is the development of completely novel strategies through the genetic manipulation of insect vectors of malaria in order to alter their ability to transmit the disease. The major requirements for producing transgenic mosquitoes are outlined together with the progress which has been made to date and discussed in relation to the prospects which this type of approach has for the future control of malaria.

Molecular biological approaches to the study of vectors in relation to malaria control

To a large extent, control of malaria vectors relies on the elimination of breeding sites and the application of chemical agents. There are increasing problems associated with the use of synthetic insecticides for vector control, including the evolution of resistance, the high cost of developing and registering new insecticides and an awareness of pollution from insecticide residues. These factors have stimulated interest in the application of molecular biology to the study of mosquito vectors of malaria; focussing primarily on two aspects. First, the improvement of existing control measures through the development of simplified DNA probe systems suitable for identification of vectors of malaria. The development of synthetic, non-radioactive DNA probes suitable for identification of species in the Anopheles gambiae complex is described with the aim of defining a simplified methodology wich is suitable for entomologist in the field. The second aspect to be considered is the development of completely novel strategies through the development of completely novel strategies through the genetic manipulation of insect vectors of malaria in order to alter their ability to transmit the disease. The major requirements for producing transgenic mosquitoes are outlined together with the progress wich has been made to date and discussed in relation to the prospects which this type of approach has for the future control of malaria

Cystic fibrosis screening by dried blood spot trypsin assay: results in 75,000 newborn infants.

Seventy-five thousand 5-day-old babies were screened for cystic fibrosis by blood spot immunoreactive trypsin (IRT) assay as part of a statewide screening program. IRT was elevated in 433 babies; retesting revealed persistent elevation in 38. Sweat testing confirmed cystic fibrosis in 35 babies and was normal in two babies, whose IRT remained elevated at the time of the test. Sweat testing was refused by one mother. Of the 35 babies with cystic fibrosis, 13 had meconium ileus or an already diagnosed affected sibling, but the diagnosis was unsuspected in 22, although all but four had some symptoms suggestive of cystic fibrosis. Stool trypsin activity at the time of the diagnostic screen was normal in nine and reduced in seven of the babies with cystic fibrosis. One baby did not have elevated IRT, and the cystic fibrosis was missed by the screening test. In a retrospective study of blood spot samples from 36 newborn infants, who were later diagnosed as having cystic fibrosis, all had IRT levels greater than in matched controls. Our study confirms that elevated IRT is characteristic of newborn babies with cystic fibrosis, and shows that this test is very specific and sensitive when used as a newborn screening test.