A quantitative and qualitative evaluation was conducted to assess the performance of the tuberculosis surveillance system using the Centers for Disease Control and Prevention’s (CDC) updated guidelines for Evaluating Public Health Surveillance Systems [6].

The study was carried out in 28 tuberculosis sentinel sites for the whole population in their assigned catchment areas in Sana’a City during October 1 to December 31, 2018.

All participants have interviewed based on their involvement with key aspects of tuberculosis surveillance activities: seven managers and one data entry personnel at a central level and one tuberculosis coordinator and one lab supervisor at the governorate level, and at the peripheral level, 10 tuberculosis coordinators from the district level and 11 medical officers and 24 lab technicians from the health facilities.

The National Tuberculosis Control Program (NTCP) documents (strategic plan, guidelines, annual reports, and databases) were reviewed to describe the system. In-depth interviews were used with participants based on their involvement with key aspects of tuberculosis surveillance activities. Verbal consent was obtained from all respondents who participated in the study. Semistructured questionnaires were used to collect information related to surveillance system attributes including flexibility, stability, simplicity, and acceptability at the four levels. The usefulness level was assessed using questions with (yes 1 or no 0) answers, while the other surveillance attributes were assessed using a three-point Likert scale (3 agree, 2 neutral, 1 disagree).

Specific indicators were used to assess each performance attributes.

The score percent was calculated by the following:

The overall score percent was calculated by the following:

The score percent of each attribute was interpreted as the following: greater than 80% was ranked as good, between 60% to 80% was ranked as average, and lesser than 60% was ranked as poor [7,8]. Data quality was assessed by reviewing documents such as quarter report, while the sensitivity and positive predictive value (PPV) were calculated using the following equation:

Sensitivity = (true positive A / true positive A + false negative C) (3)

Predictive value = (true positive A / true positive A + false negative B) (4)

The date was analyzed using Excel 2013 (Microsoft Corporation) and Epi Info version 7.2 (CDC) to calculate frequency and percentage.

A total of 54 participants were involved, 57% (n=31) were males and 43% (n=23) females. Almost half of the participants 50% (n=27) were lab technicians.

Although the tuberculosis surveillance system had strength points that included the presence of an infrastructure system, qualified human resources, availability of antituberculosis drugs, and the presence of the coordination for tuberculosis activities at all levels, it had many weak points such as depending on external donors and a bureaucrat structure (a large number of hard copies) that lead to delay in its implemented activities in addition to a lack the motivation of human resources, lack of refreshment training for medical officers, poor coordination with other health sectors (private), and high turnover among medical officers at a peripheral level due to political crises and security situations.

Evaluation of any surveillance system is the cornerstone for its improvement and ensuring proper morbidity and mortality indicators. It is important to identify the weaknesses and strengths of the system and provide decision makers with evidence-based data to decide on its continuity.

Our study findings showed that the tuberculosis surveillance system was useful. It helps in monitoring trends of tuberculosis and estimates the need for antituberculosis drugs and laboratory reagents at all levels. These findings are similar to other studies in Afghanistan, Yemen, and Pakistan [7,8,12].

The flexibility of the tuberculosis surveillance system was ranked as average. It has been integrated with HIV and AIDS. The NTCP has a counseling clinic where each tuberculosis case was referred to undergo voluntary counseling and testing. Our findings are consistent with the results found in previous evaluations carried out in Pakistan and Zimbabwe [12,13].

Regarding the stability of the tuberculosis surveillance system, it was poor because of its total dependency on the donors in addition to the government’s support for first-line antitubercuolosis drugs and the salary of the staff being completely suspended since 2014, as consequences of political and security crises. In addition, prolonged procedures to release funds from the Global Fund to implement tuberculosis control activities may lead to abandoning the activity implementation. Although, this finding is similar to what has been reported in Yemen and Zimbabwe [8,13]. Other studies showed stable tuberculosis surveillance systems [7,14].

The simplicity of the system was poorly rated for several reasons including data collection being time-consuming, the staff not receiving adequate training on tuberculosis surveillance, training courses not performed frequently, and report forms not easy to fill. Similar findings have been reported in Afghanistan and Zimbabwe [7,13]. However, this finding is not consistent with the findings in previous studies in Yemen, Pakistan, and South Africa [8,12,14].

This evaluation shows that the acceptability was average, as the focal points are willing to participate in the dengue surveillance system; however, they were poorly satisfied. This finding agrees with the findings of others in Afghanistan and Yemen [7,8] but disagrees with other studies in Harare City [15].

The data quality of the tuberculosis system was average. These findings were consistent with findings of other studies conducted in Harare City [15] but inconsistent with another study in the Republic of South Africa [14,16].

The sensitivity and the PPV of the system were good and average, respectively. These results are aline with a previous study in Afghanistan and Eden District [7,14]. However, they disagree with a study in Pakistan [12].

This evaluation was carried out in Sana’a City and targeted only the health facilities providing tuberculosis services (purposive sample) due to time and funds constraints.

The tuberculosis surveillance system was found useful. Flexibility, PVP, and data quality were average. Stability, acceptability, and simplicity were poor. The sensitivity was good.

The main weaknesses in the tuberculosis surveillance system included a lack of governmental finances, a paper-based system, and a lack of regular staff training. Developing an electronic system, securing governmental financial support, and training the staff on tuberculosis surveillance are strongly recommended to improve the system performance.