TB or not TB? - DPChallenge Forums

02/01/2007 02:19:36 AM · #1

EDIT ON THURSDAY: POSITIVE RESULT

So I had a Tuberculosis skin test (aka a PPD test) on Tuesday for the second time since August. My dentist whom I'm interning with said I should get retested because last time it measured 9mm, which is borderline for active TB. However, my doctor said that since I was healthy it was considered a "negative" reaction.

BUT, after reading information about tuberculosis, it said that anyone over 5mm is considered active if they are immune-compromised or had contact with someone with active TB (I went to Mexico last summer), anyone with a reaction of 10mm is active who is considered at moderate risk level, and a reaction of 15mm is active in a low risk person.
...I don't think my doctor took into consideration that my dad had immunity problems, or that I was in very close contact (clubs) with people in Mexico.

I don't have any symptoms of TB, so I don't think I'm "active", but I think it's possible that I could have "latent TB" which means I carry the bacteria for TB, but won't get sick unless my immune system goes way down. I am worried about this though because if I'm contagious, everyone I've had contact with will have to be tested, and I teach classes to children! Very concerning.

So, I have some questions:
1) Could this all just be an allergic reaction to the injection?
2) Is having latent TB the same as being a carrier? meaning, can I spread it to others w/out being sick myself?
3) If I have latent TB, should I go on the antibiotics even though there's only a 10% chance of me actually getting full-blown tuberculosis? Keep in mind that I work in a medical field and you have to take the antibiotics for 9 months to a year.
4) If I have the same test result as I had in August and my doctor says it's negative, should I insist on a blood test like my 'employer' suggested?
5) Should I go to another doctor after for a second opinion?

Here is a picture 22 hours after the injection. I know that the measurement doesn't count until 48-72 hours after the shot, but I just want to keep track. I will keep uploading new pics as I take them.
The red lines represent the width of the hard inner circle (the one that is measured) and the blue lines indicate the non-measured circle (not important)

Here it is after 52 hours

Message edited by author 2007-02-02 00:26:17.

02/01/2007 02:24:18 AM · #2

C'mon people, you can't catch TB over the internet! It's a bacteria, not a virus ;p

DjFenzl

02/01/2007 02:33:55 AM · #3

Originally posted by Blue Moon:

C'mon people, you can't catch TB over the internet! It's a bacteria, not a virus ;p

It's been 5 minutes since you posted and it's the middle of the night for most DPCers ;)

I don't know much about TB other than if you have it I believe your doctor has to report it somewhere or some such thing. IF your doctor says you don't have it I'd trust him/her - it's not the kind of thing they take lightly.

It's kind of funny that you are recording your "progress" because I do the same thing with injuries and the likes. My family thinks I'm a weirdo (well... they're probably right but that's for a different post) because any time I have surgery or some one has a big bruise or whatever I always have to take pictures of it.

Try not to get too worked up about it though. You either have it or you don't and you won't really know for close to 3 days. Getting freaked out about the possibilities isn't going to help you or anyone else.

It'll be ok :)

Message edited by author 2007-02-01 02:34:16.

Canon EF 24-105mm f/4.0L IS

02/01/2007 02:45:07 AM · #4

One thing we're taught in class is to not put all of your trust into any one doctor. They're people too and make mistakes. However, if I have 2 doctors telling me the same thing, I will have a lot less doubt in my mind. I'm not really getting worked up, I'm just kinda curious...it's kind of a good thing to be curious about :P

Thanks for your response, you insomniac, you.

DrAchoo

Panasonic Lumix DMC-LX5

02/01/2007 02:45:15 AM · #5

I've been under the impression that in a normal immune competent person the cutoff was 10-15mm of induration. You are under on either count. My own TB tests are often 8mm (although the last one was smaller for some reason) and I attribute it to having worked in a mission hospital in Africa for a month. The TB contact issue is whether you have had close contact with a known TB case, not that you were in Mexico and may have come in contact with someone with TB.

If you do not have symptoms then I would say you do not need to be treated nor do you pose a risk to anybody else. The next step in diagnosing active TB is, I believe, a chest xray, or a sputum sample, not a blood test. I'm not sure which blood test your 'employer' is recommending.

This isn't completely out of my realm of expertise, but I would take it all with a small grain of salt. I may be wrong on some of the above. If you work in a medical field and have at least a little knowledge of the "jargon" you can google "emedicine and tuberculosis" and they generally have pretty good summaries.

Nikon AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II

02/01/2007 02:51:34 AM · #6

Originally posted by DrAchoo:

I think he means to test to see if I carry the bacteria. As for exposure, I worked in a city dental clinic (among people who did have TB) for a few months, but that was after the initial test. The only reason I mention mexico is the fact that I have no idea how else I could heve been exposed to it. You did answer a couple of my questions though, so thank you.
.
edit:can't spell

Message edited by author 2007-02-01 02:57:23.

dacrazyrn

Nikon D300

02/01/2007 03:15:19 AM · #7

It is a 48 hour test, right? It will get smaller. The thing you worry about is the INDURATION. Like a knotty feeling underneath the skin. That is what the size they are talking about.
check here and read this
//www.webmd.com/hw/lab_tests/hw203560.asp
Didn't catch the questionable false positive...and this is the second. Stressing about it won't change it. Stop measuring. Wait until they recheck it and see what they say. Positives end up with Xrays, etc. and then followup and maybe meds.
I work in an ED. The hospital has put off TB testing yearly (been doing it yearly since for the 10 years in nursing), without reason. Only new hires. Our ED gets ALOT of illegal (mexican) immigrants, too.
It is not HARD to pass on TB, but it isn't real easy either, you usually get it from someone within a 3 feet of you, because of sneezing/coughing, it gets in the air and then drops, you breath it into your lungs. The 3 feet is one of the standard precautions we use. Even though there are studies of 6 feet would be better.

Message edited by author 2007-02-01 03:35:04.

Tamron SP AF 28-75mm f/2.8 XR Di for Canon

02/01/2007 09:33:43 PM · #8

Yeah, so I went in today and it was Positive. The induration (bump) was 12mm and I have to go back in tomorrow for a chest xray to see if it's active or not. ugh, I have to take antibiotics for 9 months :(
Anybody here been treated for TB?

Oh well, if I end up being out of school at least I can perfect my photography skils :D

I'll post pics as soon as I find some good lighting and my batteries are charged...

Message edited by author 2007-02-01 21:35:07.

strangeghost

Canon EOS-7D

02/01/2007 09:40:01 PM · #9

My mother has been TB positive for over 50 years (she's 74 now). She was probably exposed during her training as a nurse. She's never developed the disease, and most likely never will, but always had to go through a hoop-jumping scenario any time a job opportunity required a TB test.

BeeCee

Nikon D40

Nikon AF-S DX Zoom-Nikkor 18-55mm f/3.5-5.6 ED

02/01/2007 10:04:47 PM · #10

My mom also had a positive test (actually looked pretty much like the photo) when we were all tested about 45 years ago. She knew who had exposed her to TB, but she never developed it. (She died in Sept at 87)

I've only known 1 person who was treated for TB, and it seemed no biggy. They found a wee spot, he took medication for a few months, and was fine. I guess the important part is to faithfully follow the course of treatment.

Message edited by author 2007-02-01 22:05:18.

asimchoudhri

Canon EOS-5D Mark III

Canon EF 17-40mm f/4.0L USM

02/01/2007 10:05:28 PM · #11

Unless you are immunocompromised, 9mm is normal. Period.

>15mm is abnormal in general population
>10mm is considered abnormal if you have diabetes, renal failure, or have history of exposure (presumed for health care workers)
>5mm is considered abnormal if you are immunocompromised (HIV with low CD4 count, chemotherapy, chronic steroid use...)

If you exceed the threshold, you may have infection with the tuberculosis bacteria, and a chest x-ray will be performed. The chest x-ray may show signs of active infection, or scarring from previous infection. For most people, the chest x-ray will be negative, which either signifies a false-positive with the skin test or a "latent" infection. We see dozens of chest x-rays each week on individuals with a positive PPD, and the incidence of positive findings in 2007 in the United States is exceedingly low, even in high risk populations (prisoners, chemotherapy, tnf-alpha inhibitors).

One common misconception is regarding "vaccination" with BCG (given in some countries). People used to think that if you had BCG vaccination that you will likely have a positive PPD and thus need a chest xray. It is now felt that if the BCG vaccine was more than 5 years prior (which is the case for most adults), the PPD should be interpreted with the above guidelines.

In the off-chance that you are recommended to take isoniazid (INH) therapy to treat a latent infection, make sure you take a multivitamin or vitamin B6 supplement. PM/email me if you have further questions.

asimchoudhri

Canon EOS-5D Mark III

Canon EF 17-40mm f/4.0L USM

02/01/2007 10:11:19 PM · #12

Originally posted by BeeCee:

[...] I guess the important part is to faithfully follow the course of treatment.

This is an understatement! In many places, the Department of Health has a policy of DOT (directly observed therapy) for cases of active tuberculosis (note this is for active, not latent infections). This means that every day they watch you take your medicine, either at the Department of Health or at your house. If you are found to not comply, they have the authority to have you arrested as a public health menace. I have actually taken care of patients who were imprisoned for not taking their medicine. It sounds harsh, but this person also infected several others, including a child. For this reason, patients on DOT are not supposed to be in the same household as a child or immunocompromised individual.

Tuberculosis is exceedingly rare in the United States, Canada, and Western Europe. These vigilant efforts are one reason why.

asimchoudhri

Canon EOS-5D Mark III

Canon EF 17-40mm f/4.0L USM

02/01/2007 10:18:41 PM · #13

Originally posted by Blue Moon:

[...] I have to go back in tomorrow for a chest xray [...]

I'll post pics as soon as I find some good lighting and my batteries are charged...

If you want to use the image of your chest x-ray for any project (collage, abstract stuff, whatever) you can ask for a cd-rom with the original DICOM data before you go home (HIPAA says you have the right to a copy). you can then use open-source software to export the DICOM data as .jpg or .tiff files, which can be merged in photoshop with other images. You can create cool effects this way...

And, if you have a copy you will always have it in case you need a comparison at some point in the future.

Nikon AF Nikkor 50mm f/1.8D

02/01/2007 10:21:17 PM · #14

Originally posted by asimchoudhri:

Yes, 9mm was my result in August, but today it was 12mm which my doctor attributed to me interning at a city dental clinic for a few months, thus giving me "more" exposure. The reason why they are going to put me on antibiotics is because I work in a health field (dental assisting) and teach children. I'm not sure if I ever had the vaccine, but if I did it was when I was a baby, so the results (as you said) are still valid.

I didn't know anything about the DOT policy, so I'm not sure if they do it in California (though it wouldn't suprise me). I realize that TB is very rare in the US (something like 50 cases a year) which is why it suprised me so much.

Thanks for the tip about the vitamins! I was going to ask my doctor about that tomorrow.

jpeters

Nikon D200

02/01/2007 10:26:04 PM · #15

Originally posted by strangeghost:

Did she have a BGC vaccination? I don't know if it has even been around for 50 years, but the BGC vaccination is used in other countries to prevent TB, however it can also cause PPD tests to show up as falsely positive. I believe that's why they don't use it in the US.

On a side note, every time I have had a PPD test, the spot disappeared completely in just an hour or two.

edit: I guess I should have read further before I posted... asimchoudhri already mentioned BGC...

Message edited by author 2007-02-01 22:31:44.

PhantomEWO

Canon EOS-5D Mark II

Canon EF 70-200mm f/2.8L IS USM

02/01/2007 11:22:20 PM · #16

It used to be if marginal you can expect a year of INH therapy. Not sure if that is still the case. After returning from Korea after living there for a year, back in the 80's, I had a marginal skin test. The USAF immediately put me on INH for a year. I was told that any further tests would now always be positive. All x-rays and other tests were negative but that didn't matter to them. I guess it was just a precaution.

karmat

Apple iPhone 7

Canon EF 70-200mm f/4.0L USM

02/01/2007 11:51:04 PM · #17

I had a friend whose father had TB (active, not latent). He lived to be close to 90.

02/02/2007 12:24:23 AM · #18

Eh, screw bad lighting! Here y'all go...a picture of the reaction.

as you can see the outer red circle has all but disappeared and only the induration bump remains.

Message edited by author 2007-02-02 00:25:41.

02/02/2007 12:28:03 AM · #19

Originally posted by karmat:

I had a friend whose father had TB (active, not latent). He lived to be close to 90.

0.0 wow, he must have either been treated or have been a miracle man! 90, Awesome.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

02/02/2007 01:45:04 AM · #20

Originally posted by Blue Moon:

I realize that TB is very rare in the US (something like 50 cases a year) which is why it suprised me so much.

Not even close -- from the US Centers for Disease Control (CDC):

Number of new tuberculosis cases: 14,874 (2003) (last year with full statistics).

The number has been gradually increasing, at least in California. Additionally, the rise in resistant TB (not treatable with the most common antibiotics) is more rapid.

Isoniazid (INH) and rifampin are the drugs of first choice, but can be harmful to the liver. If you've ever had any kind of hepatitis, you should consider the risk/benefit ratio of prophylactic treatment very carefully.

You cannot give TB to someone else unless you have active disease; latent disease should not make you a public health threat.

Note that while the lungs are the pathway to and most common site of infection, TB can actually infect almost any organ, including the bones.
=========================
Pathophysiology article on TB at emedicine.com.

From the first few paragraphs ...

Background: Tuberculosis (TB) is the number one infectious disease killer worldwide. The World Health Organization estimates that 2 billion people have latent TB, while another 3 million people worldwide die each year due to TB.

In the United States, the isoniazid (INH) resistance rate was 7.8% in 2005, with the individual state rates varying from 0-14.9%. The overall rate of multidrug resistant TB (MDR-TB; with resistance to at least isoniazid and rifampin) was 1.2%, with the individual state rates varying from 0-3.7%. Worldwide, the number of new MDR-TB cases in 2005 was estimated at 460,000.

Pathophysiology: Humans are the only known reservoir for Mycobacterium tuberculosis. TB is transmitted by airborne droplet nuclei, which may contain fewer than 10 bacilli. Exposure to TB occurs by sharing common airspace with a patient who is infectious. When inhaled, droplet nuclei are deposited within the terminal airspaces of the lung. Upon encountering the bacilli, macrophages ingest and transport the bacteria to regional lymph nodes.

The bacilli have 4 potential fates: (1) they may be killed by the immune system, (2) they may multiply and cause primary TB, (3) they may become dormant and remain asymptomatic, or (4) they may proliferate after a latency period (reactivation disease). Reactivation disease may occur following either (2) or (3) above.

Frequency:

In the US: Beginning in 1985, a resurgence of TB was noted. The increase was primarily observed in ethnic minorities and especially in persons infected with HIV. TB control programs were revamped and strengthened across the United States. After peaking at 25,287 cases in 1993, the number of reported cases began to fall again. In 2005, 14,903 cases of TB were reported to the US Centers for Disease Control and Prevention (CDC). This corresponds to a rate of 4.8 cases per 100,000 population. In 2005, 7,656 cases (54.3% of all cases in the United States) were reported among foreign-born persons. More than half (56%) of cases involving foreign-born individuals in 2005 were reported in persons from Mexico (25%), the Philippines (11%), Vietnam (8%), India (7%), and China (5%). Foreign-born persons account for a steadily increasing proportion of all reported TB cases. An estimated 10-15 million people in the United States have latent infection.
Internationally: An estimated 20-33% of the world's population is infected with M tuberculosis. Countries with the highest prevalence include Russia, India, Bangladesh, Pakistan, Indonesia, Philippines, Vietnam, Korea, China, Tibet, Hong Kong, Egypt, most sub-Saharan African countries, Brazil, Mexico, Bolivia, Peru, Colombia, Dominican Republic, Ecuador, Puerto Rico, El Salvador, Nicaragua, Haiti, Honduras, and areas undergoing civil war (eg, Balkan countries). Countries in Eastern Europe have an intermediate prevalence. Costa Rica, western and northern Europe, the United States, Canada, Israel, and most countries in the Caribbean have the lowest prevalence.

02/02/2007 02:10:37 AM · #21

Wow, GeneralE! You sure know how to relay your info! I still find it strange that I have at least latent TB because I've never lived outside of the Bay Area. However, there are obviously a lot of (mostly) mexican immigrants here and I suppose I could have been coughed or sneezed on at a time in my life. I also went to mexico when I was 2, 10, and 18.

However, I was also thinking of the time I went to a concert where it was just a giant mass of hundereds of hot, sweating, spitting, screaming teenagers in a mosh pit. It was really gross, me and my friend actually sweat thru our jeans...and I'm pretty sure it wasn't all of our sweat X'P

Another question I thought of was that my college instructor said that kids have to get the TB vaccine before going into kindergarden. If I did get ithe shot, how could I have aquired the bacteria? Does that mean I was exposed to the drug resistant TB? I know I'm thinking way to much into this, but it's pretty interesting.

As for the lymph nodes, I always seem to have enlarged neck lyph nodes/tonsils with frequent acute tonsil infections.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

02/02/2007 02:24:26 AM · #22

I've administered an average of about 5 PPD tests per week for about the last 20 years ...

AFAIK, the BCG vaccine is not used in the USA, and it is not one of the required immunizations for kids here.

Exposure is most common when there are a lot of people in a confined space for a period of time: jails, barracks, planes, and buses are examples of "higher-risk" locations.

From the California Department of Education (emphasis added):

All children under eighteen years of age entering a California public or private elementary or secondary school for the first time, or transferring between schools, must present a written immunization record, including at least the month and year of receipt of each dose of required vaccines (or an exemption to the immunization requirements). Otherwise, the child will not be allowed to attend school. To meet California's school entry requirements, children entering kindergarten will need a total of five DTP (diptheria, tetanus, and pertussis) immunizations; four polio immunizations; two MMR (measles, mumps, rubella) immunizations; three hepatitis B immunizations; and one varicella (chicken pox) immunization. Students entering seventh grade must show proof of three hepatitis B shots and a second measles (or MMR) shot. Students can be admitted if they have had at least the first in the three-shot hepatitis B series on condition that the remaining shots are completed when due.

02/02/2007 02:30:52 AM · #23

Originally posted by GeneralE:

I've administered an average of about 5 PPD tests per week for about the last 20 years ...

Wow, what are you a Doctor, medical assistant, nurse? How often on average would you say that the skin tests come back positive?

I THOUGHT that that vaccine wasn't given in the U.S.
...ooooh, I'll get to teach my teacher something, how fun :')

Message edited by author 2007-02-02 02:32:24.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

02/02/2007 02:49:58 AM · #24

I'm a Physician Assistant -- essentially the same 2-year program through which you'd become a Nurse Practitioner, if you were already an RN. We do the intake exams and most of the direct medical care and referrals, consulting with the supervising physician as needed.

I work in an outpatient drug-treatment program, so we have a fair number of PPD-positive clients (maybe 10-20%), though most of them were exposed (and often treated) before they came to our program. I'd estimate we only have a very few (1-5) new "converters" (who were previously negative and are now positive) each year.

Clients who are PPD-positive are asked annually about suggestive symptoms, and have to get a chest xray every two years. New clients who are PPD-negative get another test, unless we can document a negative test given within the previous two months. Staff are tested yearly.

Oops -- gotta go now -- I have to be at work in six hours ... : (

Message edited by author 2007-02-02 02:51:18.