To date there is no evidence that chemoprophylaxis is useful in this population. So I recommend observation.

I will observe

To my mind, chemo-prophylaxis would eventually increase the magnitude of the drug resistance. I would really recommend early detection and treatment.

Treatment should always be individualized for each case

Between the variables to considering: Infectious degree of the case source, Intensity of exposure to MDR tuberculosis, Probability of which the contact progresses to TB's disease, including factors as:  Immunosuppression (HIV, steroids), Age (less than 5 years, oldness), and Diabetes, Renal Insufficiency and other medical certain conditions.

I would recommend observation.

The WHO recommends that particularly all persons with special risk factors for acquiring TB who are close contacts of a person with TB disease (irrespective of whether it is drug-sensitive or drug resistant) should first be screened for TB before a decision is made regarding whether to treat or place on chemo-prophylaxis. These risk groups include children especially

yes

I don't think chemioprophylaxis could be useful in this case; I agree with Lawal: screening is the best option

in my opinion, contact subject under observation first.

Give a chemioprophylaxis without any clinical indication could in contrast increase the drug resistance probability.

In case of latent tuberculosis infection, there are only small numbers of Mycobacteria in the body, therefore I don`t expect emerging of new resistance. If you have the chance of giving a sensitive drug it could work. Anyway there is no evidence for this procedure.

1.Some close contacts of  a confirmed MDR TB case may incubating subclinical diseases or

2. there might be  possibility that previously treated MDRTB case may be possible source of infection in the family in which a new MDRTB case (Primary drug resistance case)

3. We can't asure drug compliance in a healthy contact taking chemoprophylaxis.

4. However it may be beneficial for certain risk group like children, immunocompromised. 

Dear Aref Shabana

There is some controversy regarding treatment of these cases (for example in treatment of children who have ongoing exposure)

1. transmission of MDR-TB to HCW, children and immunocompromised persons is well documented

2. There are limited data regarding usefulness of IGRAs for investigating contacts of

MDR-TB cases

3. To accurate TST interpretation consider risk assesment in any px

4. Rule out TB disease

5. Consider treatment of LTBI with drug-resistant TB or MDR-TB, given

the high morbidity and mortality

6. Perior to start Px in these cases, assess risk benefit ratio for use of second line agents (Safty and efficacy)

6. Contacts to a MDR TB patient should be continually reassessed, due to the potential for a prolonged period of infectiousness (for a minimum of 2 years following exposure)

The best is to do prophylactic treatment, don't wait when MDR TB will develop, and after treat 24 month!!!

Which factors should be evaluated to inform the decision whether to provide preventive therapy to MDR TB contacts considered to have LTBI?

When evaluating an MDR TB contact and deciding between the two options (to provide preventive therapy and/or careful clinical observation and information), an overall individual risk assessment should be conducted, taking into consideration the following: the MDR TB contact’s risk for progression to TB disease; the drug

susceptibility pattern of the source case of infection; and the contact’s risk for adverse drug events if initiating preventive therapy.

The systematic review showed that it is not possible with the available evidence to support or reject preventive therapy. Only a limited amount of evidence supports the effectiveness of preventive therapy. More research and particularly clinical trials are warranted before any recommendations in favour of (or against) preventive therapy

can be made. An intervention with second-line preventive therapy for MDR TB contacts in two outbreaks in Chuuk, Federated States of Micronesia, showed the benefit of preventive therapy in MDR TB contacts (provisional unpublished data). The associated studies are awaiting publication, but the outbreaks have been previously described in short reports 

Referenced

1. Two simultaneous outbreaks of multidrug-resistant tuberculosis--Federated States of Micronesia, 2007-2009. MMWR Morb Mortal Wkly Rep. 2009 Mar 20;58(10):253-6.

2. Bamrah S, Brostrom R, Setik L, Fred D, Kawamura M, Mase R. Abstracts of the 41th World Conference on Lung Health of the International Union Against Tuberculosis and Lung Disease (IUATLD). Berlin, Germany, 11-15 November, 2010. Int J Tuberc Lung Dis. 2010 Nov;14(11 Suppl 2):S11-387.

3. Brostrom R, Fred D, Heetderks A, Desai M, Song R, Haddad M, et al. Islands of hope: building local capacity to manage an outbreak of multidrug-resistant tuberculosis in the Pacific. Am J Public Health. 2011 Jan;101(1):14-8.

4. Fred D, Desai M, Song R, Bamrah S, Pavlin BI, Heetderks A, et al. Multi-drug resistant tuberculosis in Chuuk State Federated States of Micronesia, 2008-2009. Pac Health Dialog. 2010 Apr;16(1):123-7.

first thing is confirmation of MDR through molecular diagnostic as it gives the result immediately and once its been confirmed than go for medication and should not be delayed.

A difficult question and one that requires better diagnostic tests for both latent MDR infection, active MDR disease as well as preventative treatment.

A multi-site RCT using a fluoroquinolone as chemo-prophylaxis for high risk MDR-TB contacts is in the pipeline.

In the meantime one needs to take a considered individual approach to

1. Exclude active MDR-TB using all available and appropriate tests to obtain a laboratory confirmed diagnosis (DNA or culture or histology) or clinical opinion in the absence of hard data.

2. Asses risk benefit ratio for individual patient using factors such as exposure risk of individual and infectivity of source case. Co-morbidities and risk of progression to active disease.

3. Availability and cost of preventative treatment.

4. Patient factors such as likelihood of completing prophylactic therapy, patient preferences, ability to follow up patient, age and functional status etc.

a great question and one that will not have a clear answer for a while

I think !

There might be risks in non adherence for healthy subjects in taking chemoprophylaxis and might lead to complications. But the best course would be to adress the healthy subjects as you would MDR-TB patients and do proper adherence counseling. 

In reality, there is not enough evidence to recommend preventive therapy for household contacts of MDR TB patients. (http://www.ecdc.europa.eu/en/publications/Publications/201203-Guidance-MDR-TB-contacts.pdf)

But, there is some experience reporting effectivity of preventive therapy in children. (http://pediatrics.aappublications.org/content/109/5/765.short).