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Hantavirus Disease -- Southwestern United States, 1993

Since May 1993, the state health departments in Arizona, Colorado, New Mexico, and Utah; the Indian Health Service; and CDC, with the assistance of the Navajo Nation Division of Health, have been investigating an outbreak of acute respiratory illness related to a newly recognized hantavirus (1-5). This report updates the investigation and presents information on a recent case of hantavirus-associated respiratory disease in a resident of Nevada.

Through July 27, laboratory evidence of acute hantavirus infection * has been confirmed in 18 persons in the four-corners area who were ill during 1993: 12 persons in New Mexico, four in Arizona, and two in Colorado. The median age of the 18 case- patients was 31 years (range: 13-64 years). Of these persons, 14 (78%) have died. The most recent onset of illness among the patients with confirmed cases was July 3 (Figure 1). Illnesses in an additional 28 persons in the four states are under investigation; 10 (36%) of these persons have died.

On July 10, CDC was contacted about a case of acute respiratory illness in a 24-year-old resident of central Nevada whose reported onset of illness was July 7. The case-patient had bilateral interstitial infiltrates and severe hypoxemia; she recovered fully. She had not traveled outside central Nevada during the 3-month period before illness onset. A serum specimen obtained July 10 demonstrated hantavirus-specific immunoglobulin M enzyme-linked immunosorbent assay antibodies. CDC and the Division of Health, Nevada State Department of Human Resources, are continuing the investigation of this case.

Through July 27, specimens from 55 persons with unexplained acute respiratory distress syndrome submitted by health authorities in 24 states outside the four-corners area and in the District of Columbia have been tested for evidence of hantavirus infection at CDC. In addition to the Nevada resident, specimens from a previously reported 58-year-old eastern Texas resident and a previously reported resident of another state who traveled to the four-corners area in 1992 have been positive (4,5).

Reported by: C Ward, DO, TB Callister, MD, H Hayes, Nye Regional Medical Center, Tonopah; LM Oksenholt, DO, Reno; D Nelson, AF DiSalvo, MD, State Health Laboratory, D Kwalick, MD, State Health Officer, Div of Health, Nevada State Dept of Human Resources. MJ Burkhardt, MPH, N Kalishman, MD, M Gallaher, MD, R Voorhees, MD, M Samuel, DrPH, M Tanuz, G Simpson, MD, L Hughes, PhD, E Umland, MD, G Oty, MS, L Nims, MS, CM Sewell, DrPH, State Epidemiologist, New Mexico Dept of Health. K Komatsu, MPH, C Kioski, MPH, K Fleming, MA, J Doll, PhD, C Levy, MS, TM Fink, P Murphy, B England, MD, M Smolinski, MD, B Erickson, PhD, W Slanta, L Sands, DO, Acting State Epidemiologist, Arizona Dept of Health Svcs. P Shillam, MSPH, RE Hoffman, MD, State Epidemiologist, Colorado Dept of Health. S Lanser, MPH, CR Nichols, MPA, State Epidemiologist, Utah Dept of Health. L Hubbard-Pourier, MPH, Div of Health, Navajo Nation, Window Rock, Arizona. J Cheek, MD, A Craig, MD, R Haskins, MPH, B Muneta, MD, B Tempest, MD, M Carroll, MD, LA Shands, MPH, JP Sarisky, MPH, RE Turner, P Bohan, MS, Indian Health Svc. Div of Field Epidemiology, Epidemiology Program Office; Div of Bacterial and Mycotic Diseases, Div of Vector-Borne Infectious Diseases, Scientific Resources Program, and Div of Viral and Rickettsial Diseases, National Center for Infectious Diseases, CDC.

Editorial Note

Editorial Note: Newly diagnosed cases of respiratory illness with evidence of acute hantavirus infection continue to be detected in the four-corners area. However, the detection of persons with evidence of acute hantavirus infection associated with respiratory illness in Texas and Nevada indicates that the potential for infection is not confined to the four-corners region of the Southwest. The continued occurrence of cases in the Southwest demonstrates the importance of adherence to recommended measures to minimize risk for exposure to rodents or their excreta (6). Examination of rodents trapped in the four-corners area indicates that Peromyscus maniculatus (deer mouse) continues to be the species most commonly trapped and most likely to show evidence of hantavirus infection.


  1. CDC. Outbreak of acute illness -- southwestern United States, 1993. MMWR 1993;42:421-4.

  2. CDC. Update: outbreak of hantavirus infection -- southwestern United States, 1993. MMWR 1993;42:441-3.

  3. CDC. Update: outbreak of hantavirus infection -- southwestern United States, 1993. MMWR 1993;42:477-9.

  4. CDC. Update: outbreak of hantavirus infection -- southwestern United States, 1993. MMWR 1993;42:495-6.

  5. CDC. Update: outbreak of hantavirus infection -- southwestern United States, 1993. MMWR 1993;42:517-9.

  6. CDC. Hantavirus infection -- southwestern United States: interim recommendations for risk reduction. MMWR 1993;42(no. RR-12) (in press).

    • Any of the following tests positive: IgM antibodies to hantavirus antigens; fourfold or greater increase in antibody titers to hantavirus antigens in paired serum specimens; a positive immunohistochemical stain for hantavirus antigen in tissues; or positive polymerase chain reaction from tissue specimens.

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