STD (Sexually Transmitted Diseases) Reports
January 2007

Monthly STD Report − January 2007
St. Charles County Department of Community Health and the Environment
Kristy Baumgart, MPH

For the month of January, St. Charles County had 38 laboratory confirmed STD cases (as of 2/26/07), which is much lower than both 2006 (n =62) 2005 January totals (n = 75). A Using the 2005 census information as the total population (n= 329,940) of St. Charles County, the incidence rate for STDs during January 2007 is 11.5 cases/100,000 people. For comparison, the incidence rate for 2006 was 18.8 cases/100,000 and for 2005 were 22.7 cases per 100,000. Because 06 and 07 population estimates have not been released, the actual rates may be slightly slower. The County has a rough approximate growth rate of 10,000/ year. The graph below shows the number of diagnoses for each STD during the month of January in 2004, 2005, 2006, and 2007.

STD Counts for the Month of January
St. Charles County Department of Community Health and the Environment, 2004-2007

This graph clearly shows that the number of STD cases in this past January were much lower than previous years. The result is surprising; given the rapid population growth of this county and that the higher numbers in January past indicate a correlation with college students returning for spring semester. Preliminary reports for February indicate that numbers are more typical for winter in this County and outside factors may be affecting when patients are being tested/screened for STDs.

The chart below compares monthly STD case totals from 2004-2007. January 2007 was unusually low for St. Charles County. This graph is intended to show the seasonality of STDs in St. Charles County. A better way to show this data would be to plot the STD rates; however, the most current population information we have is from 2005, and would not show the increase in population from year to year. This population growth would likely cause the rates to appear lower for 2006 and 2007.



The following chart shows the January 2007 rate of STD cases per zip code per 100,000 people, using the 2000 population estimates for each zip code. The rates most likely are inflated due to the current 2007 population estimate for each each zip code. For instance, the 63341 zip code has the highest rate (31.7 per 100,000 people); however, this zip code has experienced rapid growth since the 2000 census.

Zip Code	Number of STD Cases	Population	Rate/100,000
63301	10	46059	21.7
63303	2	41575	4.8
63304	2	38586	5.2
63341	1	3154	31.7
63366	8	57519	13.9
63367	2	8350	23.9
63376	3	68970	4.3
63385	3	13931	21.5
unknown	7	unknown	unknown

The chart below is intended to see if the month of diagnosis has a relationship with the zip code of residence. Because St. Charles County has a significant college-aged population within a particular zip code, the relationship may prove helpful as the year progresses.





As noted by the chart below, females clearly outnumber the number of males with lab-confirmed STDs. This gross difference may be due to the fact that females tend to seek treatment and/or get tested for STDs more frequently than males. Tailoring prevention messages to males may be an important tool for future educational programs.



The highest numbers of STD cases have occurred within the young adult population. Steps to improve STD interventions and/or education may need to be addressed. The month of January was very similar to previous years, where the large majority of cases occurred within the 15-24 year olds.