Background Information of TB
in New Orleans
Louisiana especially the New Orleans area has TB rates that are higher than the
national average. The most striking feature of the tuberculosis epidemiology
in Louisiana is the vast disparity in the incidence of TB in gender and specific
ethnic groups. Males, older age groups, African Americans and minorities are
the most affected. Although cluster cases have been reported in some parishes
of Louisiana, high rates in Orleans parish have been seen due the concentration
of population with high-risk factors such as homelessness, incarceration, HIV
infection, alcoholism and illicit substance abuse. These cases are seen more
in the indigenous population, foreign-born persons representing only a small
fraction of tuberculosis cases in Louisiana.
TB Treatment and Control
If diagnosed early and appropriately treated, not only is TB curable, but
also, new cases can be prevented. The first priority, therefore, is
to identify infectious and active cases so that they can be treated
and cured. Treatment must be supervised to ensure that the patients
take correct medications for the right length of time. This strategy
is called DOT (Direct Observed therapy) and such a program improves
patient compliance and adherence to treatment. DOT however, requires
the use of outreach field workers and a comprehensive follow-up mechanism.
TB control measures also include identifying medical risk factors in
persons who may develop active disease and monitoring persons in high-prevalence
community venues such as homeless shelters, substance abuse clinics
and correctional facilities. These persons are then screened for TB
by skin tests and candidates identified for chemoprophylaxis. This
approach is critical because those who are infected but who yet have
no active disease form a human reservoir of infection. The likelihood
of their developing active disease is greatest in the first two years
after infection with a lifetime risk of 10 %. In HIV infected patients
this risk increases to 10 % per year. Preventive treatment or chemoprophylaxis
and patient adherence to treatment programs can significantly reduce
this risk. Further, spread of the disease can also be reduced by engineering
and environmental public health measures. Continuous public awareness
and education plays a major role in this regard.
Atypical TB
The Wetmore Foundation and LSUHSC Clinics are seeing more and more of the
patients with Atypical TB. During the last year, these clinics had
about 320 visits by patients with this problem. At any one time, these
clinics are following the treatment of about 15 patients with atypical
TB.
Atypical Mycobacteria also called Mycobacterium other than M. tuberculosis
(MOTT) or Non Tuberculosis Mycobacteria (NTM) are generally free-living
organisms that are ubiquitous in the environment. They have been recovered
from surface water, tap water, soil, domestic and wild animals, milk, and
food products. As modern microbiological methods were developed, the importance
of NTM in human disease became increasingly evident. In broad terms, NTM
cause four distinct clinical syndromes:
• Progressive pulmonary disease with or without apparent underlying lung
disease, caused primarily by M. avium complex (MAC) and M. Kansasii and affecting
all population groups.
• Superficial lymphadenitis, especially cervical lymphadenitis, in children
caused by MAC, M. scrofulaceum.
• Disseminated disease in severely immunocompromised patients.
• Skin and soft tissue infection usually as a consequence of direct inoculation.
FREQUENCY OF INFECTION — The frequency of disease due to the different
species of NTM is unknown. A nationwide survey of 32,000 mycobacterial isolates
(not patients) reported to the Centers for Disease Control and Prevention
(CDC) in 1979 to 1980 revealed that approximately one-third were NTM .The
most commonly recognized species were MAC (61 percent), M. fortuitum complex
(19 percent), and M. kansasii (10 percent). Most of the reported isolates
were from respiratory specimens. A second study, covering the period 1981
to 1983, revealed a similar distribution and estimated the prevalence rate
to be 1.8 cases of NTM disease per 100,000 population within the United
States. By the early 1990s laboratories in the United States informally
reported that approximately two-thirds of recovered mycobacterial species
were NTM and only one-third were M. tuberculosis. Some of this increase
relates to the high incidence of disseminated MAC disease in patients with
AIDS; however, there may also have been an increase in other patient populations
as well. Disseminated NTM disease occurred in 5.5 percent of AIDS cases
reported to the CDC from 1981 to 1987, 96% of which were due to MAC.
MYCOBACTERIUM AVIUM COMPLEX (MAC) — MAC are ubiquitous, free-living
organisms readily recovered from natural reservoirs including soil and water,
domestic and wild animals, and foodstuffs. However, mycobacteria can become
aerosolized from aqueous sources, and the more easily aerosolized strains
are often phenotypically the same as those that cause pulmonary infections.
Isolates similar or identical to clinical isolates have also been recovered
from both naturally occurring surface water and piped hot water systems.
LUNG INFECTION — Since MAC is not a reportable disease, precise prevalence
and incidence data are not available. Although rigorous data are lacking,
there is widespread impression that the frequency of MAC lung disease may
be increasing. It would be helpful to have a registry of these patients
to find out the incidence in the New Orleans area. Three clinical syndromes
of Non-HIV MAC lung disease are recognized in the Wetmore –LSUHSC
clinics:
• Major risk factors for MAC lung disease (cavitary lung disease) have
included the presence of underlying lung disease, age, alcoholism, and male sex.
Thus, the "typical" patient with upper lobe cavitary MAC lung disease
was a middle-aged or older male smoker with chronic obstructive pulmonary disease
(COPD) and alcohol abuse. Some patients had healed TB, pneumoconiosis, bronchiectasis,
and/or malignancy.
• The second clinical syndrome consists of patients with no underlying
lung disease or immunosuppression, who present with mid-lung field nodular bronchiectasis.
In one report of 21 such patients, most were nonsmoking women over age 50. The
typical presenting symptoms were persistent cough and purulent sputum, usually
without fever or weight loss; the mean duration of cough was 25 weeks before
the diagnosis was made. This clinical syndrome, seen in Caucasian women is called
Lady Windermere’s Syndrome.
• The third form of MAC lung disease consists of adolescents or adults
with cystic fibrosis.
.
MYCOBACTERIUM KANSASII — Because large-scale testing of skin test
reactivity to M. kansasii antigens has not been performed, the geography
of M. kansasii is less well known than that of MAC. Based upon reports of
clinical disease, the organism seems to predominate along the southeastern
and southern parts of USA. The CDC surveys noted previously found that M.
kansasii was the third most common respiratory NTM isolate in state laboratories
in the United States. M. kansasii causes pulmonary disease resembling tuberculosis.
Affected patients tend to be in their fifth decade or older, with an approximate
3:1 male predominance. Certain occupational groups are at increased risk,
including miners, welders, sandblasters, and painters.
Problems Associated With Management
of Patients With Atypical TB
There are four potential
problems associated with the management and follow-up
of these patients.
- The clinical nature of the disease process
is chronic, indolent and causes severe morbidity.
- The duration of therapy is extended.
- The State System does not provide funds for
the treatment of these patients.
- The treatment entails a regular long-term medical
follow-up in view of its chronic nature, incidence
of side effects and compliance issues.
Need
It is because of these confounding
issues that we need to design and implement a comprehensive
cost
effective clinical and public health management
strategy based on the available resources to identify
patients and ensure efficient service to the indigent
population who are suffering from this disease.
Specifics of Current Welcrest Program
Based
on the discussion above and enclosed data, a problem-focused
plan for the future is presented
below. The goal of this three-year program is two
pronged ( Part A & B):
Above programs to be revived post-Katrina July 2007
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