Southeast Asia accounted for 34% of new TB cases in 2005

 

Fact sheet N°104
Revised March 2007

Tuberculosis

Infection and transmission

Tuberculosis (TB) is a contagious disease. Like the common cold, it spreads through the air. Only people who are sick with TB in their lungs are infectious. When infectious people cough, sneeze, talk or spit, they propel TB germs, known as bacilli, into the air. A person needs only to inhale a small number of these to be infected.

Left untreated, each person with active TB disease will infect on average between 10 and 15 people every year. But people infected with TB bacilli will not necessarily become sick with the disease. The immune system "walls off" the TB bacilli which, protected by a thick waxy coat, can lie dormant for years. When someone's immune system is weakened, the chances of becoming sick are greater.

• Someone in the world is newly infected with TB bacilli every second.
• Overall, one-third of the world's population is currently infected with the TB bacillus.
• 5-10% of people who are infected with TB bacilli (but who are not infected with HIV) become sick or infectious at some time during their life. People with HIV and TB infection are much more likely to develop TB.

Global and regional incidence

The World Health Organization (WHO) estimates that the largest number of new TB cases in 2005 occurred in the South-East Asia Region, which accounted for 34% of incident cases globally. However, the estimated incidence rate in sub-Saharan Africa is nearly twice that of the South-East Asia Region, at nearly 350 cases per 100 000 population.

It is estimated that 1.6 million deaths resulted from TB in 2005. Both the highest number of deaths and the highest mortality per capita are in the Africa Region. The TB epidemic in Africa grew rapidly during the 1990s, but this growth has been slowing each year, and incidence rates now appear to have stabilized or begun to fall.

In 2005, estimated per capita TB incidence was stable or falling in all six WHO regions. However, the slow decline in incidence rates per capita is offset by population growth. Consequently, the number of new cases arising each year is still increasing globally and in the WHO regions of Africa, the Eastern Mediterranean and South-East Asia.

 

HIV and TB

HIV and TB form a lethal combination, each speeding the other's progress. HIV weakens the immune system. Someone who is HIV-positive and infected with TB bacilli is many times more likely to become sick with TB than someone infected with TB bacilli who is HIV-negative. TB is a leading cause of death among people who are HIV-positive. In Africa, HIV is the single most important factor contributing to the increase in incidence of TB since 1990.

WHO and its international partners have formed the TB/HIV Working Group, which develops global policy on the control of HIV-related TB and advises on how those fighting against TB and HIV can work together to tackle this lethal combination. The interim policy on collaborative TB/HIV activities describes steps to create mechanisms of collaboration between TB and HIV/AIDS programmes, to reduce the burden of TB among people and reducing the burden of HIV among TB patients.

Drug-resistant TB

Until 50 years ago, there were no medicines to cure TB. Now, strains that are resistant to a single drug have been documented in every country surveyed; what is more, strains of TB resistant to all major anti-TB drugs have emerged. Drug-resistant TB is caused by inconsistent or partial treatment, when patients do not take all their medicines regularly for the required period because they start to feel better, because doctors and health workers prescribe the wrong treatment regimens, or because the drug supply is unreliable. A particularly dangerous form of drug-resistant TB is multidrug-resistant TB (MDR-TB), which is defined as the disease caused by TB bacilli resistant to at least isoniazid and rifampicin, the two most powerful anti-TB drugs. Rates of MDR-TB are high in some countries, especially in the former Soviet Union, and threaten TB control efforts.

While drug-resistant TB is generally treatable, it requires extensive chemotherapy (up to two years of treatment) with second-line anti-TB drugs which are more costly than first-line drugs, and which produce adverse drug reactions that are more severe, though manageable. Quality-assured second-line anti-TB drugs are available at reduced prices for projects approved by the Green Light Committee.

The emergence of extensively drug-resistant (XDR) TB, particularly in settings where many TB patients are also infected with HIV, poses a serious threat to TB control, and confirms the urgent need to strengthen basic TB control and to apply the new WHO guidelines for the programmatic management of drug-resistant TB.

The Stop TB Strategy, the Global Plan to Stop TB, 2006–2015 and targets for TB control

In 2006, WHO launched the new Stop TB Strategy. The core of this strategy is DOTS, the TB control approach launched by WHO in 1995. Since its launch, more than 22 million patients have been treated under DOTS-based services. The new six-point strategy builds on this success, while recognizing the key challenges of TB/HIV and MDR-TB. It also responds to access, equity and quality constraints, and adopts evidence-based innovations in engaging with private health-care providers, empowering affected people and communities and helping to strengthen health systems and promote research.

The six components of the Stop TB Strategy are:

• Pursuing high-quality DOTS expansion and enhancement. Making high-quality services widely available and accessible to all those who need them, including the poorest and most vulnerable, requires DOTS expansion to even the remotest areas. In 2004, 183 countries (including all 22 of the high-burden countries which account for 80% of the world's TB cases) were implementing DOTS in at least part of the country.
• Addressing TB/HIV, MDR-TB and other challenges. Addressing TB/HIV, MDR-TB and other challenges requires much greater action and input than DOTS implementation and is essential to achieving the targets set for 2015, including the United Nations Millennium Development Goal relating to TB (Goal 6; Target 8).
• Contributing to health system strengthening. National TB control programmes must contribute to overall strategies to advance financing, planning, management, information and supply systems and innovative service delivery scale-up.
• Engaging all care providers. TB patients seek care from a wide array of public, private, corporate and voluntary health-care providers. To be able to reach all patients and ensure that they receive high-quality care, all types of health-care providers are to be engaged.
• Empowering people with TB, and communities. Community TB care projects have shown how people and communities can undertake some essential TB control tasks. These networks can mobilize civil societies and also ensure political support and long-term sustainability for TB control programmes.
• Enabling and promoting research. While current tools can control TB, improved practices and elimination will depend on new diagnostics, drugs and vaccines.

The strategy is to be implemented over the next 10 years as described in The Global Plan to Stop TB, 2006–2015. The Global Plan is a comprehensive assessment of the action and resources needed to implement the Stop TB Strategy and to achieve the following targets:

• Millennium Development Goal (MDG) 6, Target 8: Halt and begin to reverse the incidence of TB by 2015
• Targets linked to the MDGs and endorsed by the Stop TB Partnership:
  • by 2005: detect at least 70% of new sputum smear-positive TB cases and cure at least 85% of these cases
  • by 2015: reduce TB prevalence and death rates by 50% relative to 1990
  • by 2050: eliminate TB as a public health problem (1 case per million population)

Progress towards targets

In 2005, an estimated 60% of new smear-positive cases were treated under DOTS – just short of the 70% target.

Treatment success in the 2004 DOTS cohort of 2.1 million patients was 84% on average, close to the 85% target. However, cure rates in the African and European regions were only 74%.

The 2007 WHO report Global TB Control concluded that both the 2005 targets were met by the Western Pacific Region, and by 26 individual countries (including 3 of the 22 high-burden countries: China, the Philippines and Viet Nam.

The global TB incidence rate had probably peaked in 2005, and if the Stop TB Strategy is implemented as set out in the Global Plan, the resulting improvements in TB control should halve prevalence and death rates in all regions except Africa and Eastern Europe by 2015.

WHO

Tuberculosis in the 21st century: an emerging pandemic?

 

ABSTRACT

Since the mid-1980ies the world has witnessed a dramatic increase in tuberculosis. Our knowledge of

tuberculosis epidemiology was established during the previous epidemic that, at least in Europe, took two

hundred years from rise to fall. It is difficult to understand the new epidemic if we assume that the genetics

of the host-parasite relationship is unchanged from the previous epidemic.

The paper discusses how both host and parasite genetics may have changed. Molecular epidemiology

done in Archangel, Russia, where most of the classical reasons for increase in tuberculosis were absent, in-

dicated that strains of Mycobacterium tuberculosis with changed biological properties could be responsible.

Strains belonging to the so-called Beijing family were strongly associated with primary drug resistance and

caused clusters ten times as big as “traditional” strains.

The paper describes how the research consortium takes these observations further to explore the impor-

tance of “new” strains of tubercle bacilli in the on-going pandemic. What are the changes in biological

properties and what genetic changes do they reflect? The previous epidemic may have changed the genetic

susceptibility of the human host by selection, but what has constituted a selective pressure for the bacillary

population? The two most dramatic changes in the environment of M. tuberculosis are mass introduction of

chemotherapy and BCG vaccination. We explore further the nature of drug resistance in these strains and

the possibility that BCG may fail to protect against bacilli of the new pandemic.

Lastly the paper points at some action that can be taken instantly and that may have a major impact on

transmission, even before the questions mentioned above are answered. The clue here is to shorten the time

of transmission by a rapid test to secure early diagnosis and treatment. What is needed, however, is not a

diagnostic test for tuberculosis, but a simple screening test with high sensitivity that could tell us whom

among the numerous people who have a chronic cough and systemic symptoms who are the true “tubercu-

losis suspects” eligible for rapid examination of sputum by smear microscopy.

link

Economic Benefit of Tuberculosis Control

A Policy Research Working Paper,

Number: 4295

Code: WPS4295

Author: Ramanan Laxminarayan, Eili Klein, Christopher Dye, Katherine Floyd, Sarah Darley, Olusoji Adeyi,

Abstract:

Tuberculosis is the most important infectious cause of adult deaths after HIV/AIDS in low- and middle-income

countries. This paper evaluates the economic benefits of extending the World Health Organization’s DOTS

Strategy (a multi-component approach that includes directly observed treatment, short course chemotherapy

and several other components) as proposed in the Global Plan to Stop TB, 2006-2015. The authors use

a model-based approach that combines epidemiological projections of averted mortality and economic

benefits measured using value of statistical life for the Sub-Saharan Africa region and the 22 high-burden,

tuberculosis-endemic countries in the world. The analysis finds that the economic benefits between

2006 and 2015 of sustaining DOTS at current levels relative to having no DOTS coverage are significantly

greater than the costs in the 22 high-burden, tuberculosis-endemic countries and the Africa region.

The marginal benefits of implementing the Global Plan to Stop TB relative to a no-DOTS scenario exceed the

marginal costs by a factor of 15 in the 22 high-burden endemic countries, a factor of 9 (95% CI, 8-9) in the

Africa region, and a factor of 9 (95% CI, 9-10) in the nine high-burden African countries. Uncertainty analysis

shows that benefit-cost ratios of the Global Plan strategy relative to sustained DOTS were unambiguously greater

than one in all nine high-burden countries in Africa and in Afghanistan, Pakistan, and Russia. Although

HIV curtails the effect of the tuberculosis programs by lowering the life expectancy of those receiving treatment,

the benefits of the Global Plan are greatest in African countries with high levels of HIV.

Link

WHO REPORT 2007 GLOBAL TUBERCULOSIS CONTROL - VIETNAM

 

Viet Nam has exceeded WHO targets for 9 consecutive years, and yet the overall case notification rate has remained stable. The success of

the programme in treating patientsand cutting transmission is threatened bythe spread of HIV infection,insufficient access to high-quality

TB care for poor and vulnerable populations, poor TB management practices in the growing private sector, and funding gaps for first-line

drugs and for the management of MDR-TB. Some combination of these factors is responsible for the apparent increase in incidence among

young adults, especially men. The 2006–2010 strategic plan addresses these risks, but will require urgent action to move forward without

loss of momentum.

http://www.who.int/globalatlas/predefinedReports/TB/PDF_Files/vnm.pdf

HIV/AIDS and Tuberculosis in Hochiminh City Vietnam

 

 

In Ho Chi Minh City, Vietnam, reporting rates for tu-

berculosis (TB) are rising in an emerging HIV epidemic. To

describe the HIV epidemic among TB patients and quan-

tify its impact on rates of reported TB, we performed a re-

peated cross-sectional survey from 1997 through 2002 in

a randomly selected sample of inner city TB patients. We

assessed effect by adjusting TB case reporting rates by the

fraction of TB cases attributable to HIV infection. HIV preva-

lence in TB patients rose exponentially from 1.5% to 9.0%

during the study period. Young (<35 years), single, male pa-

tients were mostly affected; injection drug use was a potent

risk factor. After correction for HIV infection, the trend in TB

reporting rates changed from a 1.9% increase to a 0.4% de-

crease per year. An emerging HIV epidemic, concentrated

in young, male, injection drug users, is responsible for in-

creased TB reporting rates in urban Vietnam.

 

 

http://www.cdc.gov/eid/content/13/10/pdfs/1463.pdf

Health Communication and Tuberculosis control in Vietnam and Perus

 

This is an 37-slide presentation at Johns Hopkins Bloomberg School of Public Health Center for Communication Programs.

The speaker is:

Youssef Tawfik

Associate Director,  Health Sciences

 

Time of presentation:

February 2005

Main content: TB Burden in Vietnam, TB control in Vietnam, Health system, TB communication

http://www.stoptb.org/wg/advocacy_communication/assets/documents/8%20Vietnam%20&%20Peru%20case%20studies-03-29.pdf

Tuberculosis in Viet Nam ranks 13th in 2007

Vietnamese News Agency (VNA)

January 17, 2008 Thursday

Viet Nam has, over the past 9 years, constantly obtained the World
 Health Organisation (WHO) targets of detecting 70 percent of tuberculosis
 cases and curing 85 percent of the patients.

The statistics were released at a conference in Ha Noi on January 17 to
review a national project on TB prevention and control and the Global
 Fund for TB Prevention. The event was hosted by the National
 Anti-Tuberculosis Programme and the Ministry of Public Health.

However, participants at the conference were told that TB infection
 rate remains high in Viet Nam , with that among young people at the age of
 15-24 being on the rise.

Viet Nam now ranks 13 th among the 22 countries with the highest number
 of TB patients in the world.

According to WHO, in 2007, the newly-contracted case rate per 100,000
people was 175 in Viet Nam , with the mortality rate per 100,000 people
being 23.

The national anti-TB programme up to 2011 aims to lower the death,
infection and spread rates in the community, while increasing the
opportunities to access health care services for poor and ethnic
minority people.

Under the programme, a strategy will be mapped out to increase
co-ordination between the public and private health care sectors in the
fight against TB in urban areas in 12 provinces and cities.

According to Dr. Dinh Ngoc Si, head of the anti TB project's steering
board and Director of the National Hospital of Tuberculosis and
Respiratory Diseases, the State will spend 70 billon VND, or 10 percent
increase, on anti-TB programme in 2008.

The programme will continue to receive financial and technical
 assistances from governmental and non-governmental organisations as well as
 financial resources from the Dutch government and the Global Fund for anti-TB/HIV
prevention programme.

235 out of every 100,000 Vietnamese were infected with TB in 2007

VIETNAM NEWS BRIEFS, January 18, 2008 Vietnam authorities have reported an additional 95,000 TB patients a year, and ranks 13th among 22 countries with the largest number of tuberculosis patients since 2000, said Dinh Ngoc Si, director of the National Hospital of TB and Lung Diseases. Si said up to 235 out of every 100,000 people were infected with TB last year. New TB cases accounted for 175 in every 100,000 and the death rate was 23 for every 100,000 people Multi drug-resistant TB cases increased from 2.3% in 1996-1997 period to 2.7% in 2005-2006 period, which is a difficulty for the country in the fight against TB as one person with Multi drug-resistant TB can transmit the disease to 10-15 other people. Si emphasized that TB rates were still high among the young, particularly males aged between 15 and 24 years old.

He also noted that multi-drug-resistant TB treatments, HIV/AIDS combined TB treatments and problems of treatment among minorities remained the greatest obstacles for Vietnam's TB prevention. However, despite difficulties, the National Program on TB Prevention had helped over 90% of TB patients recover from the disease in 2007. Over the past 9 years, the country has constantly obtained the World Health Organization (WHO) targets of diagnosing 70% of tuberculosis cases and curing 85% of the patients. Separately, vice head of the National Program on TB Prevention Bui Duc Duong said, the program will start carrying out a project provide treatment for multi drug-resistant TB carriers in Ho Chi Minh City from the second quarter of this year. The Global Fund will grant $6 million for the project to offer free medicines for the patients and build treatment centers. Copyright 2008 Vietnam News Briefs