Emerging disease syndromic surveillance for Hurricane Katrina evacuees seeking shelter in Houston's Astrodome and Reliant Park Complex.

Transmission of infectious diseases became an immediate public health concern when approximately 27,000 New Orleans-area residents evacuated to Houston's Astrodome and Reliant Park Complex following Hurricane Katrina. This article presents a surveillance system that was rapidly developed and implemented for daily tracking of various symptoms in the evacuee population in the Astrodome "megashelter." This system successfully confirmed an outbreak of acute gastroenteritis and became a critical tool in monitoring the course of this outbreak.

Widespread outbreak of norovirus gastroenteritis among evacuees of Hurricane Katrina residing in a large "megashelter" in Houston, Texas: lessons learned for prevention.

BACKGROUND: After Hurricane Katrina, an estimated 200,000 persons were evacuated to the Houston metropolitan area, >27,000 of whom were housed in 1 large "megashelter," the Reliant Park Complex. We investigated an outbreak of gastroenteritis reported among the evacuees who resided in the Reliant Park Complex to assess the spread of the infectious agent, norovirus, and to implement and evaluate the effectiveness of interventions used for control. METHODS: Public health authorities conducted surveillance of gastroenteritis among evacuees treated at the Reliant Park Medical Clinic during 2-12 September 2005. Basic demographic and clinical data were recorded. Specimens of stool and vomitus were collected and tested for bacteria, parasites, and viruses. Shelter census data were used to estimate the daily incidence of disease. RESULTS: During a period of 11 days, >1000 patients were treated at the clinic for gastroenteritis, which accounted for 17% of all clinic visits. Norovirus was the sole enteric pathogen identified, but multiple different strains were involved. Among the evacuees residing in the Reliant Park Complex, the incidence of gastroenteritis was estimated to be 4.6 visits per 1000 persons per day, and among the evacuees who resided there for 9 days, 1 (4%) of 24 persons would have been ill. Intensive public health measures were promptly instituted but did not definitively slow the progression of the outbreak of norovirus gastroenteritis. CONCLUSIONS: Our investigation underscores the difficulties in managing such outbreaks in crowded settings and the need for rapid, sensitive laboratory assays to detect norovirus. Additional research is needed to establish more effective measures to control and prevent this highly contagious gastrointestinal illness.

Hepatitis B outbreak associated with a home health care agency serving multiple assisted living facilities in Texas, 2008-2010.

We investigated a multifacility outbreak of acute hepatitis B virus infection involving 21 residents across 10 assisted living facilities in Texas during the period January 2008 through July 2010. Epidemiologic and laboratory data suggested that these infections belonged to a single outbreak. The only common exposure was receipt of assisted monitoring of blood glucose from the same home health care agency. Improved infection control oversight and training of assisted living facility and home health care agency personnel providing assisted monitoring of blood glucose is needed.

Identification of dengue fever cases in Houston, Texas, with evidence of autochthonous transmission between 2003 and 2005.

Houston, Texas, maintains an environment conducive to dengue virus (DENV) emergence; however, surveillance is passive and diagnostic testing is not readily available. To determine if DENV is present in the area, we tested 3768 clinical specimens (2138 cerebrospinal fluid [CSF] and 1630 serum) collected from patients with suspected mosquito-borne viral disease between 2003 and 2005. We identified 47 immunoglobulin M (IgM)-positive dengue cases, including two cases that were positive for viral RNA in serum for dengue serotype 2. The majority of cases did not report any history of travel outside the Houston area prior to symptom onset. The epidemic curve suggests an outbreak occurred in 2003 with continued low-level transmission in 2004 and 2005. Chart abstractions were completed for 42 of the 47 cases; 57% were diagnosed with meningitis and/or encephalitis, and 43% met the case definition for dengue fever. Two of the 47 cases were fatal, including one with illness compatible with dengue shock syndrome. Our results support local transmission of DENV during the study period. These findings heighten the need for dengue surveillance in the southern United States.