**4. Patch 3: Lima, Peru**

One of the coauthors of the present work (Olivia Horna), as a nurse responsible for coordi‐ nating the application of DOTS, realized that the TB Program was relaxing various aspects of the DOTS application, largely motivated by the economic conditions imposed in the area by the World Bank but also by recommendations from the Pan-American Health Organization itself: cessation of active case finding of coughers of 15 days or more on the grounds that the system was of low efficiency, and a switch to an ambulatory form of DOTS rather than in the patient's home, changes due to a shortage of funds to pay health technicians performing this function.

culin skin test (TST) administered. An induration greater than or equal to 10 mm was consid‐

Pulmonary Tuberculosis in Latin America: Patchwork Studies Reveal Inequalities in Its Control – The Cases of Chiapas

From these 104 workers, TST results were obtained for 73 (70.2%), of whom 56 (77%) were positive. We found that positivity was associated with the time they had worked on minibuses (more than two years, OR=11.04; 95% CI=3.17-38.43), and with working more than 60 hours per week (OR=9.8; 95% CI=2.85-33.72). This exposure gradient, a result of the working hours and time employed in the transport sector, stresses the importance of workers' job conditions. Furthermore, strict revision of clinical histories of active TB patients in the health centers associated to the health districts of these workers, showed that standardized incidence rates for transport sector workers were 2.7- 4.5 times higher than those in the total working-age male and global populations of the health micro-network studied. The associations between TB and being a transport worker, and between MDR-TB and being a transport worker are both strong (OR 3.06, 95%CI 2.2-4.2 and OR 3.14, 95%CI 1.1-9.1, respectively). These results indicate that the use of informal public transport is a risk factor for TB infection and an occupational risk in

1.1-1.9)

**Table 3.** Pulmonary Tuberculosis (PTB) and associated factors observed within studies performed by GRAAL members

TB, far from being under control, as was believed at the end of the decade of the 1990s, continues to cause many deaths, disability, and health expenditure; indeed, it has been recognized that the situation may be worsening due to an accumulation of structural condi‐

**5. The patchwork: What do these findings mean? Are they useful?**

TB associated with transport occupation (OR=3.06; CI 95%: 2.2-4.2) and with MDR-TB (OR= 3.14; CI 95%:

(Mexico), Chine (Ecuador) and Lima (Peru) http://dx.doi.org/10.5772/54950 451

Use of informal transport system: working away from home (OR= 6,99; CI 95%: 0.89-54.61; PPR = 6.06); commuting in minibuses (OR= 44.9; CI 95%: 1.06-23.09; PPR=4.09) and commuting more than one hour (OR=3.35; CI 95%: 1.12-10.1; PPR= 2.07)

High work-related exposure: more than two years in job (OR= 11.04; CI 95%: 3.17-38.43) and working more than 60 hours per week (OR= 9.8; CI 95%: 2.85-33.72).

countries with characteristics similar to those in Peru [20].

general population based on PHC micro-

Prevalence of PTB 12% among commuters in a suburban area of Lima

Prevalence of Mycobacterium

informal transport

in Peru

Tuberculosis infection through PPD test of 77% among minibus drivers in

CI: Confidence interval; OR: Odds Ratio; PPR: Positive Prevalence Ratio

Lima, Peru Incidence of PTB calculated within

net data

A summary of the main results obtained in Lima, is presented in table 3.

ered positive.

Given this situation combined with a feeling that the number of patients was rising at a higher rate than that calculated based on national rates, it was decided to perform a study to detect coughers of 15 days or more making use of the structure of the health system itself. The district of Ate-Vitarte was chosen to be targeted, since it consists mainly of lands occupied by migrants from the interior of the country, many forced off their lands due to violence between Peruvian armed forces and guerrilla movements from the interior, in particular Sendero Luminoso.

For this study, as in the cases of Chiapas, Mexico and of Chine, Ecuador, the health system approved and participated in order to guarantee anti-TB treatment and medical care for possible new cases identified by the study. Thus the same scheme was set up as employed previously in the outpatients department of Comitán hospital, whereby subjects recruited were people approaching the health system facilities in the area for medical care.

We interviewed 150 persons over 14 years of age who had productive chronic cough (fifteen days or more) seeking care in health services (primary care and hospitals). Of these, we obtained sputum samples from 142. The observed PTB prevalence rate was 12% [18], a figure very similar to that obtained in primary care centers in Chiapas (11%) [8]. None of the demographic or socioeconomic indicators analyzed were associated with PTB.

Of the variables studied, those found to be significantly associated with PTB, were: working away from home with respect those working at home (OR=6.99; 95% CI=0.89-54.61), persons commuting by minibuses compared with persons who used individual forms of transportation (OR=4.9; 95% CI=1.06-23.09), and commuting time one hour or more in a minibus (OR=3.35; 95% CI=1.12-10.1) [18].

Given the high prevalence of PTB in peripheral areas of Lima, as is the case of Ate-Vitarte District, and the results mentioned in the previous paragraph, we planned a study to determine whether the use of minibuses was associated with the spread of PTB. Commuting in these minibuses means that people travel in overcrowded situations with closed windows regardless of the weather, making trips of at least 30 minutes duration every day, in the company of TB patients going to a health center to receive DOTS treatment. Furthermore, if there is a strong association between using microbuses and the risk of infection, what would be expected among microbus drivers and fare-collectors that spend more than 8 hours per day in this environment?

Based on these precedents, we decided to carry out a study to assess infection by *Mycobacte‐ rium tuberculosis* and working conditions among workers of public transport [19]. In 2008 we performed a cross-sectional study with 104 workers from two public transport minibus companies of the Ate-Vitarte District. These minibus workers were interviewed and a tuber‐ culin skin test (TST) administered. An induration greater than or equal to 10 mm was consid‐ ered positive.

From these 104 workers, TST results were obtained for 73 (70.2%), of whom 56 (77%) were positive. We found that positivity was associated with the time they had worked on minibuses (more than two years, OR=11.04; 95% CI=3.17-38.43), and with working more than 60 hours per week (OR=9.8; 95% CI=2.85-33.72). This exposure gradient, a result of the working hours and time employed in the transport sector, stresses the importance of workers' job conditions.

Furthermore, strict revision of clinical histories of active TB patients in the health centers associated to the health districts of these workers, showed that standardized incidence rates for transport sector workers were 2.7- 4.5 times higher than those in the total working-age male and global populations of the health micro-network studied. The associations between TB and being a transport worker, and between MDR-TB and being a transport worker are both strong (OR 3.06, 95%CI 2.2-4.2 and OR 3.14, 95%CI 1.1-9.1, respectively). These results indicate that the use of informal public transport is a risk factor for TB infection and an occupational risk in countries with characteristics similar to those in Peru [20].


A summary of the main results obtained in Lima, is presented in table 3.

the DOTS application, largely motivated by the economic conditions imposed in the area by the World Bank but also by recommendations from the Pan-American Health Organization itself: cessation of active case finding of coughers of 15 days or more on the grounds that the system was of low efficiency, and a switch to an ambulatory form of DOTS rather than in the patient's home, changes due to a shortage of funds to pay health technicians performing this

Given this situation combined with a feeling that the number of patients was rising at a higher rate than that calculated based on national rates, it was decided to perform a study to detect coughers of 15 days or more making use of the structure of the health system itself. The district of Ate-Vitarte was chosen to be targeted, since it consists mainly of lands occupied by migrants from the interior of the country, many forced off their lands due to violence between Peruvian armed forces and guerrilla movements from the interior, in particular Sendero Luminoso.

For this study, as in the cases of Chiapas, Mexico and of Chine, Ecuador, the health system approved and participated in order to guarantee anti-TB treatment and medical care for possible new cases identified by the study. Thus the same scheme was set up as employed previously in the outpatients department of Comitán hospital, whereby subjects recruited

We interviewed 150 persons over 14 years of age who had productive chronic cough (fifteen days or more) seeking care in health services (primary care and hospitals). Of these, we obtained sputum samples from 142. The observed PTB prevalence rate was 12% [18], a figure very similar to that obtained in primary care centers in Chiapas (11%) [8]. None of the

Of the variables studied, those found to be significantly associated with PTB, were: working away from home with respect those working at home (OR=6.99; 95% CI=0.89-54.61), persons commuting by minibuses compared with persons who used individual forms of transportation (OR=4.9; 95% CI=1.06-23.09), and commuting time one hour or more in a minibus (OR=3.35;

Given the high prevalence of PTB in peripheral areas of Lima, as is the case of Ate-Vitarte District, and the results mentioned in the previous paragraph, we planned a study to determine whether the use of minibuses was associated with the spread of PTB. Commuting in these minibuses means that people travel in overcrowded situations with closed windows regardless of the weather, making trips of at least 30 minutes duration every day, in the company of TB patients going to a health center to receive DOTS treatment. Furthermore, if there is a strong association between using microbuses and the risk of infection, what would be expected among microbus drivers and fare-collectors that spend more than 8 hours per day in this

Based on these precedents, we decided to carry out a study to assess infection by *Mycobacte‐ rium tuberculosis* and working conditions among workers of public transport [19]. In 2008 we performed a cross-sectional study with 104 workers from two public transport minibus companies of the Ate-Vitarte District. These minibus workers were interviewed and a tuber‐

were people approaching the health system facilities in the area for medical care.

demographic or socioeconomic indicators analyzed were associated with PTB.

function.

450 Tuberculosis - Current Issues in Diagnosis and Management

95% CI=1.12-10.1) [18].

environment?

**Table 3.** Pulmonary Tuberculosis (PTB) and associated factors observed within studies performed by GRAAL members in Peru
