Contact Tracing

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Tsang, Kenneth, W., et al., “A Cluster of cases of severe acute respiratory syndrome in Hong Kong,” THE NEW ENGLAND JOURNAL OF MEDICINE, Vol. 348, Iss. 20, May 2003, pg 1977,

Quarantine, Contact Tracing, SARS


Hughes, Christine, M. et al., “Vaccinia Virus Infections in Martial Arts Gym, Maryland, USA, 2008,Emerg Infect Dis. 2011 Apr.

  1. “To our knowledge, this is the first reported cluster of community acquired VACV in which an obvious source-person was not identified. This cluster highlights the need to reinforce transmission precautions to recent vaccinees and indicates that physicians should include VACV infections on the differential of vesiculopustular rash lesions and take appropriate infection control precautions, even in the absence of a known exposure to smallpox vaccine.” p. 4
  2. “Vaccinia virus (VACV) is the virus used in the live vaccine against smallpox. Smallpox was declared eradicated by the World Health Organization in 1980, and routine childhood smallpox vaccination ceased after 1972 in the United States. Since 2002, smallpox vaccinations have again been administered to some military personnel and health care workers, and they continue to be recommended for laboratory workers who work with nonattenuated orthopoxviruses. VACV infections are transmissible and can cause severe complications in those with weakened immune systems.” p. 1
  3. “The patient was asked whether he recently received smallpox vaccination or had history suggestive of exposure to orthopoxviruses such as monkeypox virus (i.e., contact with animals, recent international travel). He reported having neither…” p. 2
  4. “The patient reported belonging to a martial arts gym; he reported having several military personnel as recent sparring partners before the onset of his illness. He also reported that a recent sparring partner had exhibited a rash around the same time. This person, a 28-year-old man (case-patient 2), was contacted and described having a 4-day rash on his right forearm in mid to late June with no systemic symptoms.” p.3
  5. “In the absence of an explanation for these 2 VACV (ACAM2000) infections, Maryland public health officials launched an investigation at the gym to identify additional cases and pinpoint the source of infection. Approximately 400 surveys were distributed to gym members through email and by hand at the gym. Members were asked whether they had any recent skin lesions similar to those shown in an attached photo. They were asked whether they had recently received a smallpox vaccination or had contact with someone recently vaccinated. Ninety-five gym members responded to the survey.” p. 3
  6. “The source of virus introduction into the martial arts gym remains unknown. No further infections have been identified among gym members or health care workers exposed to case-patients.” p. 4
  7. “This cluster of community-acquired VACV infection was possibly the result of sequential person-to-person spread of virus through direct physical contact, although transmission through fomites cannot be ruled out. The ultimate source-person responsible for introducing the virus into the gym was not identified, but given the limited time that ACAM2000 had been available to providers in the region (late February 2008), the most likely source was a recent vaccinee. … Unrecognized transmission of VACV among gym members may have been ongoing over several months.” p. 4
  8. “Multiple cases of VACV infection caused by secondary transmission have been noted recently (8–13). Materials such as towels and bedding used by the vaccinee should be treated as potential fomites and should not be shared with others.” p. 4

Vaccination, Smallpox, Contact Tracing, Public Health


Swaan, Corien, M. et al,Timeliness of contact tracing among flight passengers for influenza A/H1N1 2009“, BMC Infectious Diseases, December 28, 2011.

  1. ”During the initial containment phase of influenza A/H1N1 2009, close contacts of cases were traced to provide antiviral prophylaxis within 48 h after exposure and to alert them on signs of disease for early diagnosis and treatment.”
  2. ”Passengers seated on the same row, two rows in front or behind a patient infectious for influenza, during a flight of ≥ 4 h were considered close contacts.”
  3. ”This study evaluates the timeliness of flight-contact tracing (CT) as performed following national and international CT requests addressed to the Center of Infectious Disease Control (CIb/RIVM), and implemented by the Municipal Health Services of Schiphol Airport.”
  4. ”In a retrospective study, dates of flight arrival, onset of illness, laboratory diagnosis, CT request and identification of contacts details through passenger lists, following CT requests to the RIVM for flights landed at Schiphol Airport were collected and analyzed.”
  5. ”24 requests for CT were identified. Three of these were declined as over 4 days had elapsed since flight arrival. In 17 out of 21 requests, contact details were obtained within 7 days after arrival (81%). The average delay between arrival and CI was 3,9 days (range 2–7), mainly
    caused by delay in diagnosis of the index patient after arrival (2,6 days). In four flights (19%), contacts were not identified or only after >7 days.”
  6. ”CI involving Dutch airlines was faster than non-Dutch airlines (P < 0,05). Passenger locator cards did not improve timeliness of CI. In only three flights contact details were identified within 2 days after arrival.”
  7. ”CT for influenza A/H1N1 2009 among flight passengers was not successful for timely provision of prophylaxis. CT had little additional value for alerting passengers for disease symptoms, as this information already was provided during and after the flight.”
  8. ”Public health authorities should take into account patient delays in seeking medical advise and laboratory confirmation in relation to maximum time to provide postexposure prophylaxis when deciding to install contact tracing measures. International standardization of CT guidelines is recommended.”

Contact Tracing, Flu, Public Health, Netherlands