CDC officials recommend that by age 2, children should have received a series of 14 or 15 doses of vaccines for diphtheria, tetanus, pertussis, polio, measles, mumps and other diseases. The worry is that many children will miss these vaccinations or receive the same vaccine twice because there is no comprehensive national tracking system or all-encompassing legislation that requires immunization registration. An underimmunized population is at the greatest risk for epidemics. Add the increased mobility of families and the ever-changing face of health insurance coverage, and the situation becomes even more dangerous. Some health departments are taking a cue from geographic information systems and using one of epidemiology's oldest and handiest tools.
History shows that the mapping of disease data has proved effective when other methods failed.
In 1854, Dr. John Snow plotted the location of deaths from cholera in a London neighborhood. Snow's map showed that the highest concentration of deaths occurred near the Broad Street water pump. The water pump handle was removed, and the epidemic ended. Arizona officials recently began incorporating a GIS mapping feature into their immunization tracking system. STC created GIS middleware called QuickMap that retrieves patient data from Arizona's central immunization registry, which is stored in an Oracle7 database on a Sun Microsystems Inc. server in Phoenix, Tatham said.