When to Expand a Contact Investigation Jessica Quintero, BAAS October 20, 205 Comprehensive Care of Patients with Tuberculosis and Their Contacts October 9 22, 205 Wichita, KS EXCELLENCE EXPERTISE INNOVATION Jessica Quintero, BAAS has the following disclosures to make: No conflict of interests No relevant financial relationships with any commercial companies pertaining to this educational activity
WHEN TO EXPAND A CONTACT INVESTIGATION Jessica Quintero, BAAS Director of Education and Training Heartland National TB Center Why do we expand an investigation? Recent transmission is detected. Greater than expected rate of TB disease or TB infection among priority contacts. Evidence of secondary transmission TB disease among contacts not initially considered priority TB infection or TB disease in contacts younger than 5 years of age Change in contacts TST or IGRA status 2
Consider the Following Before Expanding a Contact Investigation Are program objectives being met for High/Medium contacts? Is the positivity rate 0% or twice the number expected in a SIMILAR population? National TB Program Objectives August 205 Objectives on Contact Investigations Contact Elicitation For TB patients with positive AFB sputum smear results, increase the proportion who have contacts elicited. Examination Treatment Initiation Treatment Completion For contacts to sputum AFB smear positive TB cases, increase the proportion who are examined for infection and disease. For contacts to sputum AFB smear positive TB cases diagnosed with latent TB infection, increase the proportion who start treatment. For contacts to sputum AFB smear positive TB cases who have started treatment for latent TB infection, increase the proportion who complete treatment. Targets 00% 93% 9% 8% National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention; Division of Tuberculosis Elimination http://www.cdc.gov/tb/programs/evaluation/indicators/default.htm 3
Calculating the Infection Rate The infection rate is defined as: The percentage of contacts with SIMILAR exposure who have a newly identified positive skin test (5mm or larger) OR IGRA. Here are the steps Determine the total number of contacts evaluated. Do not include previous positive TST or refusals Determine the infection rate. Divide the number of contacts with a new +TST documented (numerator) by total number of contacts evaluated (denominator) Multiply by 00 the resulting percentage is the infection rate. 4
Example 0 contacts were identified for a TB case contact had a previous + TST 6 were positive 3 were negative Of 9 tested 6 were + 0 ID 6 contacts +TST 9 contacts tested X 00 = 67% So, Now Lets Try Result 0mm 5mm 00mm 00mm Refused 20mm Contact Johnny Depp Arnold Schwarzenegger Harrison Ford Emma Watson Leonardo DiCaprio Tom Cruz Brad Pitt Result 00mm 00mm 00mm 8mm 00mm 4mm Contact Kate Winslet Tom Hanks Matt Damon Cameron Diaz Anne Hathaway Jessica Alba Jimmy Fallon Total Contacts id d Refused Total screened Total positive 4 2 4 5
Do the Math Total Contacts id d Refused Total screened Total positive 4 2 4 Of tested 4 were + 4 ID 3 ( PP& R) 4 contacts +TST contacts tested X 00 = 36% Case Study: Janet Jackson 27 year old female 2 roommates ( roommate has boyfriend that stays over & patient has boyfriend that stays over) Works full time at a local non profit organization Grad student at local university 6
Case Summary Household = 4 Classroom = 5 Work = 2 No previous positives, all screened 3 previous positives, 2 screened previous positive, refused, not read Total =3 Household 2 Classroom Work 2 Calculating Positivity Rate Household Classroom Work Total Contacts id d 4 Total Contacts id d 5 Total Contacts id d 2 0 3 Refused 0 Refused 0 Refused Total screened 4 Total screened 2 Total screened 9 Total positive 2 Total positive Total positive 2 4 2 9 0.5X00 0.08X00 0.X00 50% 8% % 7
Concentric Circle 50% % INDEX HIGH MEDIUM LOW 08% Should we expand this contact investigation? 8
Second Screening Evaluation Household Classroom Work Needs TST 2 Refused TST 0 Received TST 2 Positive 0 Needs TST Refused TST 0 Received TST 9 Positive Needs TST 8 Refused TST 0 Received TST 8 Positive 4 0 2 0.0X00 0% 9 0.X00 % 4 8 0.50X00 50% Concentric Circle 0% 50% INDEX HIGH MEDIUM LOW % 9
Should we expand this contact investigation? Lets follow up on this one. Household: Initial 2 of 4 = 50% Follow up 0 of 2 = 0% Classroom: Initial of 2 = 8% Follow up of 9 = % Work: Initial of 9 = % Follow up 4 of 8 = 50% Is there evidence of recent transmission? YES 0
Request to expand In school or worksite settings, requests are often made to expand an investigation based on fear and misunderstanding. People with little or no exposure may request testing. Those who wish to be tested should be referred to a testing center. The results of which should not be considered with the case findings. Reality Although a relatively brief exposure can lead to M. tuberculosis infection and disease, certain contacts are not infected even after long periods of intensive exposure. Available tests for M. tuberculosis infection lack sensitivity and specificity and do not differentiate between persons recently or remotely infected. Not all contacts with substantial exposure are identified during the contact investigation
REFERENCES Contact Investigation for Tuberculosis, self study Module, October 999 Guidelines for Investigation of Contacts of Person with Infectious tuberculosis, recommendations from the ntca and cdc, mmwr december 6, 2005/vol.54/no.rr 5 & Questions 2