the interaction between tb and hiv

Anna Grinsted

Overview of TB and HIV Evidence of interaction

Epidemiological, clinical and cellular levels Implications Conclusions

Mycobacterium tuberculosis 2 billion people - roughly one-third

of the world population - are infected Primary infection most commonly

respiratory Typical presentation = Productive

cough, weight loss, fever, night sweats, fatigue, loss of appetite.

Transmitted by respiratory droplets Infectious dose = 1-10 bacilli Destructive effects entirely due to

hypersensitivity reaction of host

• Over 40 million people are infected worldwide

• 3 million deaths/yr

• HIV-1 (and HIV-2)

• enveloped RNA Retrovirus

• Transmission: sexual, blood-borne, perinatal.

Worldwide TB Incidence (2009)

25% of deaths of people living with HIV are

attributed to TB

In Africa:50% of those with HIV

develop TB,80% with TB are HIV positive

Co-infection increases morbidity and mortality

Lifetime TB risk in immunocompetent persons is 5-10%, but in HIV +ve individuals, the annual TB risk is 5-15%

HIV is the most powerful known risk factor for reactivation of Latent to active TB

Reduced generation time

IL-1beta IL-6 IL-8 GMCSF...enhances viral replication

synergistic reduction in macrophage viability

Macrophage

DOTS = Directly Observed Therapy, Short course

HAART

3 I’s strategy— Intensified case finding, Infection control, Isoniazid antibiotic prophylaxis

All people living with HIV should be evaluated forTB at the time of initial HIV diagnosis and during follow-up.

HIV testing should be considered in new cases of TB.

Co-ordination of services Multidisciplinary approach

Research How to combine services Diagnostic tests for TB in the immunocomprimised How to combine treatment Prophylaxis

High index of suspicion Difficult diagnosis in immunocompromised

Infection Control Don’t wait for a positive culture to isolate!

Drug Resistance DR-TB, MDR-TB, XDR-TB

See TB ---- think HIVSee HIV --- think TB!

• TB and HIV interact on many levels and act in synergy, resulting in increased morbidity and mortality• There are considerations for both the individual and for public health•There are implications for clinical practice and research• A co-ordinated approach is required

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online http://www.who.int/tb/challenges/hiv/en/ Pictures available from:

medicineworld.org, kashmirnewz.com, http://www.labgrab.com/users/labgrab/blog/you-can-see-lot-just-looking-yogi-berra_id=884, http://gamapserver.who.int/mapLibrary/Files/Maps/HIVPrevalenceGlobal2006.png, http://gamapserver.who.int/mapLibrary/Files/Maps/TBincidence_2009.png