Infectious disease outbreaks reporting

The value of spotting the unusual has been demonstrated by a number of infectious disease outbreaks in the United States. A classic example is the initial reports of the human immunodeficiency virus epidemic. Alert clinicians in California and New York City noted clusters of rare illnesses, Kaposi s sarcoma and Pneumocystis carinii pneumonia, among homosexual male clients in their practices (CDC, 1981a, 1981b). In May 1993, a New Mexico medical examiner reported two deaths from acute respiratory failure 5 days apart (CDC, 1993). 

On the contrary, there are numerous reports of outbreaks of faecal-oral waterborne infectious diseases following heavy rain episodes. 

There are some descriptions of water-borne outbreaks, or even small epidemics of acute gastroenteritis (diarrhoea), cholera and hepatitis E associated with catastrophic floods that occurred in developing countries, such as Sudan [34, 35], Nicaragua [36], Mozambique [37] and West Bengal [37]. On the contrary, no changes in the base-line outbreak incidence have been reported in developed countries after major floods [37, 38]. When infrastructures and water management are adequate, outbreaks of faecal-oral water-borne infectious diseases do not follow flood events, even in the case where water flooding has compromised the security of water facilities [37]. 

Case Example An outbreak of an infectious disease leads public health officials to believe that a bioterror attack has occurred. To avoid panic in the public, however, they have made no public announcement of their suspicions. They have requested, however, that nurses be on the alert for new cases of the infectious disease and to report it to them immediately, along with certain information about the patient. A nurse asks her supervisor if she can legally make such reports. 

Reporting suspected outbreaks and cases of notifiable illness to local health authorities is vital to allow measures to be taken to investigate threats of enteric infection arising from increasingly global and industrialized food supplies. The reporting of specific infectious diseases to the appropriate public health authorities is the cornerstone of public health surveillance, outbreak detection, and prevention and control efforts. 

Cholera (vibrio cholera) is a bacterial disease that is contracted by ingestion of contaminated water or food. However, it does not spread easily from person to person. Cholera occurs natnrally in many nnderdeveloped conntries and has cansed widespread outbreaks in Sonth America, with over 250,000 cases reported jnst in Peru. It can be spread throngh ingestion of food or water contaminated with feces or vomitus of patients, by dirty water, hands contaminated with feces, or flies. Cholera is an acute infectious disease, represented by a sndden onset of symptoms. Victims may experience nansea, vomiting, profnse watery diarrhea with rice water appearance, and the rapid loss of body flnids, toxemia, and freqnent collapse. Not everyone exposed will show symptoms. In some cases, there may be as many as 400 people without symptoms for every patient showing symptoms. Where cases go untreated, the death rate can be as high as 50%. With treatment, the death rate drops to below 1%. 

Infectious patients present a difficult challenge when trying to protect health care workers. These patients must be isolated from the health care workers as well as from the other patients in the hospital. Special isolation rooms are used for this purpose. These rooms are generally used for isolation of infectious tuberculosis (TB) patients, but could be used for patients with other airborne-transmitted diseases. In the United States, there were 22 812 new cases of tuberculosis in 1993, equal to 8.7 per 100 000 population. This represents a 2.8% increase since 1985, following a 6-7% annual decline from 1981-1984.Several studies have documented higher than expected tuberculin skin test (TST) conversion rates in hospital personnel.The National Institute for Occupational Safety and Health " reports that multiple-drug-resistant (MDR) strains of TB have been reported in 40 states and have caused outbreaks in at least 21 hospitals, with 18-35% of exposed workers having documented TST conversions. 

Hepatomegaly, jaundice, and altered liver function tests have been reported in accidental poisonings with DME An outbreak of toxic liver disease was associated with DME exposure at a fabric coating factory. Thirty-six of 58 workers had elevations of either aspartate aminotransferase or alanine aminotransferase. Serological tests excluded known infectious causes of hepatitis in all but two cases. After modification of work practices and removal of the most severely affected from exposure, improvement in liver enzyme abnormalities and symptoms occurred in most patients. Medical surveillance of the working population for 14 months revealed no further cases of toxic liver... 

The first scientific report of an orally transmitted outbreak of Chagas disease in Brazil was made in 1968 (Nery-Guimaraes et ah, 1968). This occurred in the district of Teutonia, municipality of Estrela (Rio Grande do Sul state) in the year 1965, between March 13 and March 22. Seventeen people from an Agricultural School (workers, students, and lecturers that usually had meals there) fell sick. The initial unconfirmed diagnosis was typhoid fever. Other possible diagnoses like infectious hepatitis, toxoplasmosis, infectious mononucleosis, and food poisoning were also discarded. Then, some of the infected people presented with clinical symptoms of acute myocarditis, and, based on clinical observations,... 

The occurrence of laboratory-acquired infections in research workers is not the only problem in biosafety. The other major concern is the potential for release of infectious agents that may cause secondary infections in nonlaboratory workers and other contacts. Fortunately, the potential for such serious outbreaks of laboratory-acquired disease seems to be small. Data derived from studies at the U.S. Department of Agriculture National Animal Disease Center showed that, during the years from 1960 to 1975, no instances of secondary infection in other laboratory workers or in nonlaboratory contacts occurred as the result of the laboratory-acquired infections of 18 research workers who used animal pathogens that were also infective for humans (448). However, the potential for outbreaks of laboratory-associated disease does exist as there are reports in the literature of instances of secondary transmission of laboratory-acquired Marburg disease (283), Q fever (38), and smallpox (105,518). Fortunately, the low level of occurrence of such incidents suggests that... 

---