Vampires “consumption” Draining of blood making victim pale and
weak Masturbation
Leaving patient drained of energy Sin
Creativity Patients got burst of energy- made women
more beautiful and men more creative
Origin of Word - Tuberculosis – TB: Tubercle bacillus
Has often been referred to as ‘white plague’ and ‘consumption’
Eastern Mediterranean – 9250 to 8160 years ago TB lesions from a woman and infant buried
together PCR to examine bone samples
Mycobacterium tuberculosis Slow growing Acid fast bacillus Has waxy layer which prevents
drying
Less common causes: Mycobacterium bovis Mycobacterium africanum Mycobacterium canetti Mycobacterium microti
www.genomeindia.org/mycobacterium/
In healthy individuals or when only small amounts of bacteria are ingested, active macrophages will kill bacteria
The immune system will form a wall around the bacteria called a granuloma or tubercule, which can stay dormant for many years before reappearing (latent TB)
In some individuals a full blown infection will occur which often leads to death (miliary TB)
Taken from figure 19-1 in Salyers and Whitt, 2002
Miliary TB- TB infection in the lung that results in the bacteria getting into the pulmonary vein and going systemic
If untreated it is 100% fatal
In 25% of the cases, it will cross blood-brain barrier and cause tuberculous meningitis
M. tuberculosis is able to survive and grow within unactivated macrophages
Prevent fusion with lysosome (oxidative burst) due to waxy coated capsule
Inhibits IL-12 production which will prevent TH1 response
Important defenses: the T helper cells (CD4+) producing IFN-γ which
will stimulate macrophage activation the cytotoxic (CD8+) T cells killing infected
phagosomes that have been unable to destroy the bacteria
http://www.brown.edu/Courses/Bio_160/Projects1999/tb/tbbody.html
Respiratory droplets from coughing, sneezing, talking, or spitting
Aerosol droplets 0.5 to 5µm in diameter A single sneeze can release up to 40, 000
droplets
Infectious dose of tuberculosis is very low Inhalation of just a single bacterium can cause
a new infection. Dormant, which can later cause disease if
weakened Mechanism of transmission:
People who inject drugs using unsanitary needles Residents and employees of high-risk congregate settings Medically under-served and low-income populations Children exposed to adults in high-risk categories Patients immunocompromised (i.e. HIV/AIDS) Immunosuppressant drugs Health care workers serving high-risk patients
Transmission can only occur from people with active — not latent — TB
Factors influencing effective transmission: Number of infectious droplets expelled by a carrier The effectiveness of ventilation The duration of exposure The virulence of the M. tuberculosis strain
Chronic cough Blood in sputum Fever Night sweats Weight loss If it travels to other organs than the
lungs, then a wider range of symptoms may occur
1) Tuberculin Skin Test
2) Chest Radiograph
3) Bacteriological Smears & Cultures
4) Clinical Observations
Tuberculin injected intradermally Sensitivity of this extract that the
bacteria produces will appear as red circle
Those immunized or have previously had the infection will show the same result as those that now have the disease
Patient Status Positive Result
HIV + >5mm
Healthy individuals with exposure history or risk factors
>10mm
Healthy individuals with no exposure history
>15mm
The white arrows show bilateral pulmonary infiltrate, black arrows show caving formation
Sputum smear is tested for the presence of Acid-Fast-Bacilli Negative result will
rule out TB infection. Most definitive
diagnosis will come from culture of lung secretions Positive Acid-
Fast stain of TB
M. Tuberculosis culture
Clinical signs of active infection: Fatigue, fever, unexplained weight loss, night
sweats.
Symptoms of pulmonary TB include: Productive cough >3 weeks, coughing up
blood, and chest pain.
Extra-pulmonary TB will have a range of signs and symptoms depending on the site of primary infection.
Sanatoriums for both the rich and poor citizens
First sanatorium in Canada was at Muskoka lake in 1897 Patients received rest, fresh air, good nutrition
to support healing and isolation to prevent spread
Closed down mid 1900s after antibiotics were found to be better at treating patients
http://urbexbarrie.blogspot.com/2006/06/muskoka-regional-centre.html
First-line drugs taken for 6-8 months Isoniazid- inhibit mycolic acid synthesis Rifampin- inhibits bacterial RNA polymerase Ethambutol- inhibit mycolic acid synthesis Pyrazidamide- nicotinamide analog
Second-line drugs Streptomycin, capreomycin, clofazamine,
amikacin, ethionamide, ofloxacin, ribabutin, kanamycin, fluoroquinolones
Taken from http://www3.niaid.nih.gov/topics/tuberculosis/Understanding/WhatIsTB/ScientificIllustrations/firstLineIllustration.htm
Directly Observed Treatment (DOT) Used to deal with the high number of
noncompliant patients who do not take the drugs every day for the full length of time
Important since not taking the drugs as prescribed is a main cause of drug resistance
Proof of its effectiveness: 1986- prior to DOT 26% of patients acquired drug
resistance After 1990- thanks to DOT, drug resistance is 7%
MDR-TB -> multi-drug resistant (1980s)-resistance to 2 of the first line drugs (often
isoniazid and rifampicin) XDR-TB -> extremely drug resistant
-first reported outbreak was in 2006
-resistance to 2 of the first line drugs, atleast 1 quinolone and atleast 1 of the second line anti-TB injection drugs
-can take 6-16 weeks to diagnose CDR-TB -> completely drug resistant
-resistance to all known drugs
Screening Programs Testing those in high risk groups
Vaccine: BCG (Bacillus Calmette-Guerin)
Developed in the 1920’s Live, attenuated M. Bovis strains Only lasts ~15 years Given to children to prevent TB meningitis or
miliary TB Effectiveness ranging from 0%-80% Use was previously widespread in Canada
www.phac-aspc.gc.ca/tbpc-latb/fa-fi/bcg-eng.php
Who qualifies for a BCG vaccine?
Children of families with a strong history of TB Groups of people that display an uncommonly
high rate of infection. Health care workers who are working with the
bacteria or patients Newborn infants whose mother has infectious TB
at the time of delivery Individuals travelling to TB-laden areas for an
extended period of time (i.e. six months or more).
http://www.lung.ca/tb/tbtoday/prevention/bcg.html
Variable efficiency. Reasons may include: Interference with non-tuberculous mycobacteria Genetic variation in BCG strains Genetic variation in the population
Severe local inflammation and scarring occurring in patients
Tuberculin skin test must be performed first and if positive then they can’t vaccinate
Immunocompromised individuals often will get a miliary TB infection
Annually, 8 million people become ill with tuberculosis 2 million people will die from the disease,
worldwide
Growing problem In 2004: 14.6 million people active TB disease 9 million new cases
In Canada, still an endemic Northwest Territories
Country # (per 100, 000)
Africa 356
North & South America 41
Switzerland (2005) 1262
London 40
Portugal 31.3
China 113
Brazil 64
United States 4.9
↑ HIV infections
Neglect of TB control programs
Drug-resistant strains
↑ migration, international travel, and tourism
↑ incidence of AIDS
Co-infection with HIV Smoking (>20
cigarettes/day) ↑ risk by 2x-4x
Diabetes mellitus
Hodgkin lymphoma, End-stage renal
disease Chronic lung disease Malnutrition Alcoholism
QUESTIONS?