CDC Grand Rounds: discovering new diseases via enhanced partnership between public health and pathology experts

Abstract

Despite advances in public health, medicine, and technology, infectious diseases remain a major source of illness and death worldwide. In the United States alone, unexplained deaths resulting from infectious disease agents have an estimated annual incidence of 0.5 per 100,000 persons aged 1-49 years. Emerging and newly recognized infections, such as hantavirus pulmonary syndrome and West Nile encephalitis, often are associated with life-threatening illnesses and death. Other infectious diseases once thought to be on the decline, such as pertussis, again are becoming major public health threats. Animals increasingly are being recognized as potential vectors for infectious diseases affecting humans; approximately 75% of recently emerging human infectious diseases are of animal origin. Increasing global interconnectivity necessitates more rapid identification of infectious disease agents to prevent, treat, and control diseases.

FIGURE 1

Immunohistochemistry for detecting pathogens in tissue* * Red color indicates site of the pathogens: A) Hantavirus proteins can be seen in endothelial cells in the lung of a patient; B) Leptospira organisms are present in large blood vessels in the lung; C) West Nile virus antigens can be seen in neurons in a patient with encephalitis.

FIGURE 2

Unexplained deaths or critical Illnesses* — UNEX surveillance system, Minnesota, 1995–2005 Abbreviations: UNEX = Surveillance of Probable Infectious Etiology for Unexplained Death; GI = gastrointestinal. * In Minnesota, in addition to deaths, cases of unexplained critical illness also are included in the UNEX surveillance system. Cases in Minnesota include deaths or critical illnesses unexplained by routine testing that have premortem or postmortem findings suggestive of infectious etiology such as fever, leukocytosis, cerebrospinal fluid pleocytosis, or histopathologic evidence of an infection.