CDC finds racial differences in pandemic flu hospitalizations

Feb 25, 2010 (CIDRAP News) – Racial minority groups have been more heavily impacted by pandemic H1N1 flu hospitalizations, with severe illness during the fall wave hitting American Indian and Alaska Native populations especially hard, the US Centers for Disease Control and Prevention (CDC) said yesterday in an update.

During both pandemic waves, minority groups have consistently shown higher rates of serious pandemic flu illness and hospitalizations, with rates double those of whites, the CDC said. However, during the spring wave, blacks had the highest hospitalization rate.

The CDC is able to gather information on ethnicity and illness patterns through its Emerging Infections Program, which conducts weekly surveillance for lab-confirmed flu illnesses in 60 counties that cover 13 metropolitan areas in 10 states. In addition, the CDC collected racial data as part of its Behavioral Risk Factor Surveillance System (BRFSS) from Sep 1 through Dec 31, a period that coincided with much of the fall pandemic flu wave.

The CDC's report on the pandemic flu burden in minority groups seems to mirror what some states have reported. For example, in January Massachusetts officials said they would target $1 million of its federal funding toward vaccination efforts aimed at minority groups after they found that pandemic flu was taking a heavier toll on black, Hispanic, and Asian groups.

California, Illinois, and Wisconsin are also among the states reporting that hospitalizations and deaths from flu have been higher in minority groups than in whites.

During the first flu wave, the most heavily affected minority group were blacks, followed by Hispanics, Asian/Pacific Islanders, and native populations. However in the second wave, native populations had the highest hospitalization rates, followed closely by Hispanic and black groups.

The spike in illnesses in native populations during the second wave was also borne out in the CDC's BRFSS data: The number of self-reported flu-like illnesses in that group was double that of all other groups.

Using BRFSS data, the CDC explored how likely all racial groups were to seek medical care for flu-like illness during the second pandemic wave. About 43% of respondents said they sought healthcare for their flu symptoms, and the rates were similar for all groups—even native populations.

The CDC said in its report that the reasons for the racial disparities in flu hospitalizations are not yet known. It added that the pandemic so far has consisted mainly of focal, urban disease outbreaks, and that socioeconomic factors such as access to medical care and the presence of underlying health conditions may play a role.

See also:

Feb 24 CDC information on pandemic H1N1 impact by race and ethnicity

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