1999-2000 Texas Influenza Surveillance Activity
Surveillance
*includes reports of culture positive specimens from sources other than Texas Department of State Health Services Viral Laboratory/DSHS surveillance
Influenza Active Surveillance sites
IDEAS in cooperation with the Texas Department of State Health Services' Medical Virology Branch, and the Baylor College of Medicine actively monitors influenza activity around the state at the indicated labeled County sites. Dates of initial viral strain isolation and total number of cases will be provided in the below table.
Active Surveillance Site Isolates
Sites: 1=Bell, 2=Bexar, 3=Cameron, 4=Dallas, 5= El Paso, 6= Galveston, 7=Harris, 8=Lubbock, 9=Nueces, 10=Potter, 11= Smith, 12=Tarrant, 13=Travis, 14=Wichita
Influenza Isolated |
Site 1 10/14 |
Site 2 11/03 |
Site 3 |
Site 4 11/05 |
Site 5 11/23 |
Site 6 |
Site 7 10/18 |
Site 8 12/16 |
Site 9 12/14 |
Site 10 11/03 |
Site 11 1/20 |
Site 12 1/03 |
Site 13 10/25 |
Site 14 1/10 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A/not subtyped | 222 | 42 | 218 | |||||||||||
| A (H1N1) | 1 | |||||||||||||
| A (H3N2) | 1 | 13 | 31 | 6 | 5 | 6 | 14 | 1 | 2 | >202 | 6 | |||
| B |
| Week Ending | 10/ 9 |
10/ 16 |
10/ 23 |
10/ 30 |
11/ 6 |
11/ 13 |
11/ 20 |
11/ 27 |
12/ 04 |
12/ 11 |
12/ 18 |
12/ 25 |
1/ 1 |
1/ 8 |
1/ 15* |
1/ 22* |
1/ 29* |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Total # Specimens Submitted | 5 | 6 | 8 | 12 | 21 | 21 | 22 | 76 | 80 | 80 | 137 | 113 | 142 | 190 | 164 | 138 | 58 |
| Total Influenza Positive | 0 | 1 | 3 | 1 | 7 | 5 | 8 | 11 | 16 | 36 | 49 | 53 | 66 | 97 | 68 | 48 | 15 |
Influenza activity is defined as influenza-like illness and/or culture-confirmed influenza. Many sources of information are used to determine level of influenza activity. These include but are not limited to DSHS and other laboratories, regional and local health department surveillance, research facilities, the CDC Sentinel Physician Surveillance Network, and reports from private physicians. Isolate totals are derived are from specimens submitted to the DSHS laboratory.
*Reporting is incomplete for these weeks so numbers may change as more reports are received.
Influenza activity is being reported and confirmed earlier this year compared to previous years. There are several explanations to account for this. The most likely reason is that this reflects a heightened awareness and increase surveillance for influenza activity. It is unlikely this activity is related to previously reported outbreaks in Alaska and other areas of the United States.
Weekly summary for the week ending January 29, 2000
The Texas Department of State Health Services (DSHS) is reporting flu activity to for the week ending 1/29/2000 as regional. This is the first week of regional flu activity after 6 consecutive weeks of widespread flu. The actual number of confirmed cases of influenza reported to DSHS declined again during the week. Preliminary indications for the week ending 2/5/2000 is that this decline is likely to continue. Total number of specimens to several labs including the DSHS lab has decreased dramatically.
All culture confirmed influenza remains influenza A. Cultured specimens continue to be almost entirely influenza A (H3N2) Sydney-like strain. This is the third year that this strain of flu has dominated the influenza season and the second year that the flu vaccine has protected against this strain. Specimens from Texas and other areas of the United States continue to confirm a good match between the vaccine and the circulating strain of the flu.
For the week ending 1/29/00 flu activity was reported in Travis, Bexar, Bell, Dallas, McLennan, Harris, Brazoria, Collin, and Hidalgo, counties. Anecdotal reports of flu activity from telephone calls to the DSHS have declined substantially.
Influenza activity is defined as influenza-like illness and/or culture-confirmed influenza. Many sources of information are used to determine level of influenza activity. These include but are not limited to DSHS and other laboratories, regional and local health department surveillance, research facilities, the CDC Sentinel Physician Surveillance Network, and reports from private physicians.
***Levels of Influenza Activity
No Activity: No cases of either influenza like illness(ILI)***** or culture confirmed influenza detected
Sporadic Activity: Sporadically occurring cases of either ILI or culture-confirmed influenza with no outbreaks detected.
Regional Activity: Outbreaks of either ILI or culture-confirmed influenza in counties having a combined population of <50% of the population of Texas.
Widespread Activity: Outbreaks of ILI or culture-confirmed influenza in counties with a combined population of >50% of the states' population.