Texas has confirmed cases of swine flu. The original two confirmed cases of swine flu have recovered. Additionally, cases of novel swine flu have been identified in California, Kansas and in Mexico. The characterization of the virus in Mexico shows it is the same as the swine flu virus in the Texas cases. CDC epidemiologists have been deployed to Texas, Mexico, and California. Suspected cases are being investigated in other states.
Clinicians throughout Texas should enhance surveillance of patients who present with illness consistent with influenza disease and no alternate explanation for the illness. This is especially important since fewer cases of influenza are presenting at this time.
Unless there is evidence to the contrary, swine influenza should be highly suspected in persons with influenza-like illness.
Laboratory Testing Protocol for Persons with Influenza-Like Illness or Acute Respiratory Illness:
1. Perform influenza testing on all patients with influenza-like illness (ILI: fever >100° F and cough and/or sore throat)
2. Perform influenza testing on all patients with acute respiratory illness (ARI: recent onset of at least two of the following: rhinorrhea or nasal congestion, sore throat, cough (with or without fever or chills) and
- a history of recent travel to Mexico (within 7 days) or
- contact with a person who has been diagnosed with Influenza A.
Perform rapid flu testing, if available, for immediate decisions regarding communicability. However, rapid flu testing is not sufficiently sensitive to rule out influenza. Regardless of results of rapid flu testing, collect and submit specimen (see acceptable specimens below) for viral culture.
Submit all specimens to the Department of State Health Services or the appropriate public health department laboratory even if viral culture specimens are routinely submitted to another laboratory. Collection and submission instructions are below.
Specimen Collection Guidelines for Influenza Specimens
Acceptable specimens for influenza testing include a nasopharyngeal or throat swab, nasal wash, or nasal aspirates. Preferred specimen is a combination throat/nasal pharyngeal swab or oral pharyngeal swab or nasal wash. Other routine respiratory specimens, such as a bronchial wash, or sputum will be acceptable.
Samples should be collected within the first 4 days of illness. Swabs used for specimen collection should have a Dacron tip and an aluminum or plastic shaft. Swabs with calcium alginate or cotton tips and wooden shafts are not recommended, as these have substances that can interfere with PCR procedure. Specimens should be put into an approved biohazard bag and placed at 4°C immediately after collection.
Influenza Types Detected
|RT-PCR||A and B||Nasopharyngeal swab, throat swab, nasal wash, bronchial wash, nasal aspirate, sputum||Cold on Ice Packs –or- Frozen on Dry Ice.
Submit same day as collection
Transport cold on ice packs or freeze at – 70° C and ship on dry ice. Although specimens are acceptable for culture within 4 days of collection, due to the current situation, please submit specimens the same day as collected.
When influenza A is detected in your clinic by rapid testing methods, please send an aliquot (1-2 ml) of the original suspension (not exposed to test kit reagents) in viral transport media or equal; or if an additional original specimen swab in viral transport media is available, that is preferable.