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  • Airborne Infection Control [AIC]

    Content

    Mycobacterium tuberculosis is transmitted in airborne particles called droplet nuclei that are expelled when a person with pulmonary TB coughs, sneezes, shouts, or sings. People nearby may breathe in these bacteria and become infected. 

    Airborne infection control is essential to prevent the spread of TB within a health facility and other settings.

     

    Hierarchy of Controls to Reduce Risk of Transmission of TB (see the Figure)

    Figure: Hierarchy of controls to reduce risk of transmission of TB

     

    Environmental factors that influence transmission of M. tuberculosis are elaborated in the table below.

    Table: Environmental factors that influence the transmission of M. tuberculosis; Source: Tuberculosis Infection Control
    Factor Description
    Concentration of infectious bacilli The more bacilli in the air, the more probable that M. tuberculosis will be transmitted
    Space Exposure in small, enclosed spaces
    Ventilation Inadequate local or general ventilation that results in insufficient dilution or removal of infectious droplet nuclei
    Air circulation Recirculation of air containing infectious droplet nuclei
    Specimen handling Improper specimen handling procedures that generate infectious droplet nuclei
    Air pressure Positive air pressure in an infectious patient's room that causes M. tuberculosis organisms to flow to other areas

     

     

     

     

     

    Resources

    1. Guidelines on Airborne Infection Control in Healthcare and Other Settings.
    2. Tuberculosis Infection Control.

     

     

    Question

    Answer 1

    Answer 2

    Answer 3

    All

    Correct answer

    Correct explanation

    Page id

    Part of Pre-test

    Part of Post-test

    The hierarchy of controls to reduce the risk of transmission of TB includes which of the following?

    Environmental controls

    Administrative controls

    Personal protective equipment

    All of the above

    4

    The hierarchy of controls to reduce the risk of transmission of TB includes administrative controls, environmental controls and the use of personal protective equipment.

  • Prevention of TB in facilities caring for HIV-infected persons

    Content

    With a high burden of TB patients in close proximity to large numbers of vulnerable patients frequently visiting the ART centre, there is an increased risk of TB transmission. Factors like overcrowding, inadequate natural ventilation and re-circulating air-conditioners add to this risk.

    ART centres are required to initiate the following measures aimed at reducing the exposure of HIV-infected patients to M. tuberculosis:

    1. Infection control activities

    • All the team members of ART centre shall be trained in universal workplace precautions, waste segregation and disposal and Airborne Infection Control (AIC) practices, with special reference to tuberculosis.
    • Conduct TB risk assessment in collaboration with National TB Elimination Programme (NTEP) and National AIDS Control Organisation (NACO).
    • Develop a written TB infection control plan by the Hospital infection control committee and ART nodal officer. This may be incorporated into the facility infection control plan.
    • Hospital infection control committee and ART nodal officer should be assigned the responsibility for TB infection control at ART centres.
    • Display proper IEC material on cough and hand hygiene practices in the hospital, hospital waiting area, ART centre, and particularly the waiting area of the ART centre. Notice to be put up that patients with cough shall be seen on a priority.
    • Make surgical masks, tissues, and appropriate no-touch disposal receptacles available.

     

    2. ART centres with specific location and design

    • ART centres should be located at a distance from chest clinics, Direct Microscopy Centres (DMCs), or DOT Centres, with no shared waiting areas.
    • There should be a well-ventilated waiting & seating area. Open outdoor roofed additional waiting areas are encouraged.
    • There should be a separate, well-ventilated waiting area for respiratory symptomatic wherever possible (particularly in busier ART centres).
    • Adhere to ventilation standards for airborne infection control (>15 air exchanges per hour [ACH] throughout). Where natural ventilation is of concern, augmenting ventilation through the well-planned use of exhaust fans may be considered. Installation should be properly designed and maintained, and electrical power must be consistently available.
    • Any cooling/ heating systems should be implemented in a way that adheres to ventilation standards (>15 ACH). Use of re-circulating (split) air conditioners should be avoided.

     

    3. Screening of clients for respiratory symptoms

    • Care coordinators or nurses should screen all clients arriving at the ART centre as early as possible for respiratory symptoms. Patients with respiratory symptoms should be educated on cough hygiene, kept in a separate, well-ventilated waiting area if possible, and fast-tracked through their visit.
    • Educate people with respiratory symptoms on cough hygiene.
    • Educate Healthcare Workers (HCWs), patients, family members, and visitors on the importance of cough etiquette to help prevent the transmission of airborne infections (both TB and respiratory viruses). Instruct patients about covering their mouth and nose with a tissue when coughing and dispose of used tissue in waste containers.
    • Provide a disposable surgical mask to coughing patients.

     

    4. Fast-tracking of known pulmonary TB patients and persons with respiratory symptoms

    • Fast-tracking of patients with respiratory symptoms is critical in reducing the time the patient is in the facility to reduce possible contamination of air and spread of disease.
    • Care coordinator or nurse of the ART centre shall facilitate the fast-tracking of patients with respiratory symptoms. These patients will be helped by the nurse to get them counselled by the counsellors, examined by the doctors and provided with the drugs quickly, without making them wait in the regular queue.
    • Presumptive TB shall be referred to the DMC/ DOTS centre for their sputum smear examination as a part of Intensified Case Finding (ICF). This will facilitate early recognition and identification of possible pulmonary TB patients.
    • A signboard display of the fast-tracking policy within the ART centre should be visible to avoid confusion among waiting patients.

     

    References

     

    Assessment

    Question Answer 1 Answer 2 Answer 3 Answer 4 Correct Answer Explanation Page ID

    Part of Pre-test

     

    Part of Post-test

     
    Which of the following is true? The ART centre should be ideally located adjacent to the NTEP clinic. Patients attending ART clinic should be served on a ‘first come, first serve’ basis irrespective of symptoms. PLHIV are equally at risk of catching TB and dying from it, compared to the general population. ART centres are high transmission settings for TB. 4

    1- ART centres should be located at a distance from chest clinics, Direct Microscopy Centres, or DOT Centres, with no shared waiting areas.

    2- Patients who are symptomatic of TB should be fast-tracked.

    3 – PLHIV are at higher risk of getting TB infection and dying from it, compared to the general population.

    		 3262 Yes Yes

  • Co-trimoxazole prophylactic therapy in HIV-infected TB cases

    Content

    The objective of Co-trimoxazole Preventive Therapy (CPT) is to reduce morbidity and mortality among People Living with HIV (PLHIV) from opportunistic infections.

    CPT is effective in preventing a range of bacterial fungal and protozoal opportunistic infections in PLHIV including Pneumocystis Pneumonia (PCP) caused by the fungus Pneumocystis jirovecii, toxoplasmosis, bacterial pneumonias, nocardiasis and isosporiasis. Hence, CPT is a standard component of HIV care.

    Co-trimoxazole is a combination of two drugs – Sulfamethoxazole (SMX) and Trimethoprim (TMP). A single-strength tablet contains 400 mg SMX and 80 mg TMP

    There are two types of CPT prophylaxis:

    1. Primary prophylaxis - Aims to avoid the first occurrence of infection

    2. Secondary prophylaxis - Aims to avoid the recurrence of infection after successful treatment 

    Table 1: CPT for Adults and Adolescents living with HIV

    Prophylaxis

    Recommendations

    Commencing primary CPT

    Initiated in PLHIV with:

    •      CD4 count < 350/mm3 OR
    • PLHIV with Pulmonary TB or Extra-Pulmonary TB 

    Commencing secondary CPT

    For all patients who have completed successful treatment for Pneumocystis pneumonia (PCP)

    Timing the initiation of Co- trimoxazole in relation to initiating ART
    •     Start CPT first
    •      Start Antiretroviral Therapy (ART) after starting CPT or as soon as CPT is tolerated, and the patient has completed the “preparedness phase “of counselling

    Dosage of Co-trimoxazole in adults and adolescents

    One double-strength tablet (or two single-strength) tablets once daily – total daily dose of 960 mg (800 mg Sulfamethoxazole (SMX) + 160 mg Trimethoprim (TMP))

    Co-trimoxazole for pregnant and breastfeeding women
    •      Women who fulfil the criteria for CPT should continue it throughout pregnancy
    •      If a woman requires CPT during pregnancy, it should be started regardless of the stage of pregnancy
    •      Breastfeeding women should continue CPT where indicated

    Patients allergic to sulpha- based medications
    •     Use dapsone 100 mg per day
    •      Co-trimoxazole desensitisation may be attempted but not in patients with a previous severe reaction to co-trimoxazole or other sulpha- containing drugs

    Monitoring

    No specific laboratory monitoring is required in patients receiving co-cotrimoxazole the a 

    Discontinuation of CPT (primary or secondary)

    When CD4 count > 350/mm3 on two different occasions 6 months apart with an ascending trend and devoid of any WHO clinical stage 3 and 4 conditions

    Table 2: CPT in Infants/children exposed to/living with HIV

    Group

    When to start Co-trimoxazole?

    When to discontinue CPT prophylaxis?

    Notes

    All HIV- exposed infants/ children

    From 6 weeks of age (or at first encounter with health services)

    HIV infection has been reliably excluded by a negative antibody test at 18 months, regardless of ARV initiation. 

    In infants confirmed to be HIV infected, CPT should be continued till 5 years of age

    All HIV- infected infants and children up to 5 years 

    Irrespective of WHO stage or CD4 counts or CD4%

    At 5 years of age, when clinical or immunological indicators confirm restoration of the immune system for more than 6 months i.e. in a child > 5 years of age with a WHO T- stage 1 or 2 and CD4 count of > 350 cell/mm3 on two occasions not less than 3 months apart

    Children with history of severe adverse reactions (grade 4 reaction) to co-trimoxazole or other sulpha drugs as well as children with glucose-6-phosphate dehydrogenase deficiency (G6PD) should not be initiated on CPT. The alternative drug, in this case, is Dapsone 2 mg/kg once daily (not to exceed 100 mg/day) orally.

    All HIV-infected
    children > 5 years of age

    WHO Stage 3 and 4 irrespective of CD4
    OR
    CD4 < 350 cells/mm3 irrespective of WHO staging

    When clinical or immunological indicators confirm restoration of the immune system for more than 6 months i.e. in a child > 5 years of age with a WHO T- stage 1 or 2 and CD4 count of > 350 cell/mm3 on two occasions not less than 3 months apart

    As secondary prophylaxis

    After completion of treatment for PCP

    < 5 years old: Do not stop
    > 5 years old: may consider stopping as per the adult guidelines

     

    Table 3: Weight bands and dosage of CPT in children

    Weight (kg)

    Approx. Age

    Cotrimoxazole once a day

    Syrup 5ml (40 TMP/200 SMX)

    Child Tablet (20 TMP, 100 SMX)

    Single strength adult (80 TMP/ 400 SMX)

    Double strength adult tablet (160 TMP/800 SMX)

    <5

    6 weeks – 2 months

    2.5 ml

    1 tablet

    -

    -

    5-10

    2-12 months

    5 ml

    2 tablets

    ½ tablet

    -

    10-15

    1-2 years

    7.5 ml

    3 tablets

    ½ tablet

    -

    15-22

    2-5 years

    10 ml

    4 tablets

    1 tablet

    ½ tablet

    >22

    >5 years

    15 ml

    -

    1 ½ tablet

    ½ to 1 tablet depending on weight

    Dispensation of CPT: The Medical Officer at the ART Centre assesses the patient and prescribes CPT. The tablets are dispensed by the pharmacist at the ART centre.

     

    References

     

    Assessment

    Question

    Answer 1

    Answer 2

    Answer 3

    Answer 4

    Correct answer

    Explanation

    Page ID

    Part of pre-test

    Part of post-test

    Which of the following statements is true?

    A PLHIV diagnosed with PTB or EPTB should be given CPT.

    A CLHIV diagnosed with PTB or EPTB should be given CTP.

    An infant diagnosed with TB and is born to a mother with HIV should be given CPT.

    All the above

     4

    All the statements are true.

    Yes

    Yes

  • Isoniazid Preventive Therapy [IPT] in People Living with HIV [PLHIV]

    Content

    Isoniazid Preventive Therapy (IPT) administration in People Living with HIV (PLHIV) prevents the incidence and relapse of TB and is a key public health intervention for TB prevention in PLHIV. Concomitant administration of Anti-retroviral Therapy (ART) and IPT, restores TB-specific immunity and prolongs the beneficial effect of IPT.

    Combined use of IPT with ART is recommended for all Children Living with HIV (CLHIV)/ PLHIV regardless of:

    • Degree of immunosuppression

    • Previous treatment for TB  

    • Pregnancy

    ART should not be delayed while starting or completing a course of IPT. If there is any doubt about the TB status of a patient, IPT should be delayed.

    PLHIV/ CLHIV are offered IPT by the treat-only policy, i.e., tests for TB infections, like Tuberculin Skin Test (TST) or Interferon Gamma Release Assay (IGRA) are not warranted. However, active TB disease must be ruled out before starting IPT.

     

    Ruling Out Active TB

    • In adults and adolescents living with HIV: Screen for active TB with a clinical algorithm, for the four symptoms (current cough, night sweats, fever, weight loss). (4S symptom negative, i.e., 4S -ve) identifies PLHIV with a very low probability of having TB disease and who can be reliably initiated on IPT. 

    • In CLHIV (more than 12 months of age): Screen for current cough, fever, poor weight gain and history of contact with a TB case. When negative (4S -ve), they are unlikely to have active TB. A chest X-ray may be useful.

    • Infants aged <12 months living with HIV who are in contact with a person with TB should undergo clinical evaluation. Those who are unlikely to have active TB should receive TB Preventive Treatment (TPT).

     

    Contraindications to IPT

     

    • Signs and symptoms of peripheral neuropathy such as persistent tingling, numbness and burning sensation in the limbs
    • Regular and heavy alcohol consumption
    • Active hepatitis
    • Concurrent use of other hepatotoxic medications
    • Contact with a Multidrug-resistant TB (MDR-TB) case
    • PLHIV who have completed DR-TB treatment

     

    IPT Work-up: The patient should be examined for signs of liver disease (jaundice, tenderness in the right upper quadrant of the abdomen) and neuropathy. Wherever available, routine Liver Function Tests (LFTs)/ Alanine Aminotransferase (ALT) should be performed, but a lack of LFTs/ALT results should not delay the initiation of IPT in asymptomatic patients. 

    Dosage in Adults and Adolescents: Isoniazid 300 mg + Pyridoxine 50 mg (Vitamin B6) per day x 6 months

    Table 1: Paediatric Dosages

    Weight Range (Kg)

    Number of 100 mg tablets of INH to be administered per dose (Total Dose 10 mg/kg/day)

    Dose (mg)

    <5

    1⁄2 tablet

    50

    5.1–9.9

    1 tablet

    100

    10–13.9

    11⁄2 tablets

    150

    14–19.9

    2 tablets

    200

    20–24.9

    21⁄2 tablets

    250

    >25

    3 tablets or one adult tablet

    300

    Non-availability of pyridoxine should not be a reason to withhold TPT. Alternatively, the multivitamin/ B-complex formulations with the requisite prophylactic dose of pyridoxine may be given.

     

    IPT Initiation and Follow-up

    •      All 4S -ve patients should be assessed by the Senior Medical Officer (SMO)/ MO to determine eligibility for IPT. IPT should be considered for both on-ART and pre-ART patients and initiated if not contraindicated. IPT drugs must be provided monthly (30 days) to all eligible patients.
    •      In case a patient becomes 4S +ve during the IPT course, he/she should be investigated for TB and if found positive, IPT should be stopped, and appropriate anti-TB treatment should be initiated.

     

    References

     

    Assessment 

    Question

    Answer 1

    Answer 2

    Answer 3

    Answer 4

    Correct answer

    Explanation

    Page ID

    Part of pre-test

    Part of post-test

    Which of the following statements is false?

    IPT should be for all infants living with HIV with a history of contact with a PTB case, after ruling out active TB

    IPT can be given to a pregnant woman with HIV

    If there is any doubt of active TB disease, IPT should be withheld

    IGRA  should be done before administering IPT to a PLHIV

    4

    Tests for TB infection are not indicated in PLHIV. They are offered TPT after ruling out active TB disease by the “Treat only” policy.

    3260

    Yes

    Yes