Although these problems do not have much significance in the Environmental Pathway to Malaria Suppression described in my previous blog, they are two major problems for folks following the WHO Chemical Dependency Pathway. They are:
1. The Immunity Trap. If the high-maintenance costs of continuing on the Chemical Pathway - that is the annual costs of drugs and biocides (which run currently about half a billion US Dollars for the US PMI) are ever interrupted because of financial, political or technical problems, the previously protected people will have lost their immunity and will experience deadly malaria attacks. It has happened at least twice in Sudan.
2. The Resistance Treadmill. Once biocides and drugs are applied massively by programs such as the US PMI, resistance of the mosquitoes to the biocides and of the parasites to drugs becomes a major source of technical and financial problems. This is what sank the WHO GMEP in 1969. Both Pakistan and Sudan had gone through 8 major classes of insecticides before their spray programs collapsed.
Conversely, if the Environmental Pathway is followed, these problems are reduced or eliminated, since permanent measures are used instead of the ephemeral drugs, biocides and nets. Thus a failure of the program does not result in resurgence of transmission, because once a swamp is filled and turned into a cornfield, it doesn't have to be filled again. Ask the Italians who now have one of the most productive agricultural areas in what used to be the pestilential Pontine Marshes.
So why are RBM, WHO and the USPMI staying on the Chemical Pathway?
Bill, quite puzzled