The three types of plague are the result of the route of infection: bubonic plague, septicemic plague, and pneumonic plague. Bubonic plague is mainly spread by infected fleas from small animals. It may also result from exposure to the body fluids from a dead plague-infected animal.
In October 2016, an outbreak of cholera began in war-ravaged Yemen. WHO called it "the worst cholera outbreak in the world". Although much is known about the mechanisms behind the spread of cholera, this has not led to a full understanding of what makes cholera outbreaks happen in some places and not others.
By a case definition we mean the standard criteria for categorizing an individual as a case. Establishing a case definition (the criteria that need to be met in order to be considered "a case") can be tricky, particularly in the initial phases of the investigation.
Learn what an outbreak is as compared to an epidemic or pandemic, plus get information on how outbreaks are prevented, investigated, and controlled. Learn what an outbreak is as compared to an epidemic or pandemic, plus get information on how outbreaks are prevented, investigated, and controlled.
Developing Hypotheses. After interviewing affected individuals, gathering data to characterize the outbreak by time, place, and person, and consulting with other health officials, a disease detective will have more focused hypotheses about the source of the disease, its mode of transmission, and the exposures which cause the disease.
Step 5: Find cases systematically and record information. As noted earlier, many outbreaks are brought to the attention of health authorities by concerned healthcare providers or citizens. However, the cases that prompt the concern are often only a small and unrepresentative fraction of the total number of cases.
Between late May to mid-June, 19 locally-acquired P. vivax malaria cases were identified in one village of the Aswan Governorate in Egypt. CDC continues to recommend that travelers to the Aswan Governorate in Egypt use mosquito avoidance measures to prevent malaria.
It is an axiom of field epidemiology that if you cannot generate good hypotheses (for example, by talking to some case-patients or local staff and examining the descriptive epidemiology and outliers), then proceeding to analytic epidemiology, such as a case-control study, is likely to be a waste of time.
Thousands of years ago, variola virus (smallpox virus) emerged and began causing illness and deaths in human populations, with smallpox outbreaks occurring from time to time. Thanks to the success of vaccination, the last natural outbreak of smallpox in the United States occurred in 1949.
Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection (LTBI) and TB disease.
Step 2: Verify the Diagnosis & Presence of an Outbreak We noted that an outbreak is an increase in the frequency of a disease above what is expected in a given population. However, an apparent outbreak can result from either incorrect diagnoses, multiple diseases with similar symptoms, or even changes in record keeping or surveillance practices.