The data shows that lymph node TB is the dominant type of extrapulmonary tuberculosis in Damascus city. Several studies in different countries have shown that the dominant type of extrapulmonary tuberculosis differs with different geographical locations. For example, lymph node TB was the most common type in the Netherlands (39%), the United States (40%), and the United Kingdom (37%)3-4-5, while pleural tuberculosis was the most common in Poland (36%) and Romania (58%).6 There could be a possible reason for the difference in the most common sites of EPTB between Syria and other countries, which is that the BCG vaccine that is used in Syria, provides immunity to various types of TB, and thus may cause the absence or decrease in the appearance of certain types of TB, while in countries where this vaccine is not given, the rates of emergence of the types that the BCG vaccine decreases may be higher .7-8
The highest infection rate among the patients in the sample was in the age range 25-34 years (22.43%), this age range was also the most age range associated with extrapulmonary TB in a similar Indian study.9 Although extrapulmonary tuberculosis primarily affects adults, 19.51% of cases occurred in children under the age of 15 years, and this may be because of the lack of vaccination due to the war in Syria and due to displacement cases, which amounted to 20.97%.
The majority of patients infected with extrapulmonary TB were females (65.85%), this was also the case in an Iranian study, which indicates that there’s a relation between the female gender and extrapulmonary TB.10
As mentioned previously, the percentage of patients infected with extrapulmonary tuberculosis was higher in the city of Damascus compared to its countryside, at a rate of 78.68%, This may have been contributed by the far distance between the city center where most of the hospitals and TB centers are located and the countryside, and thus decreasing the number of patients coming from the countryside, and the movement of most of the rural population to the city, especially during the war years.
In cases that were associated with chronic diseases, the study showed that Hypertension was the most common accompanying disease with a rate of 23.41%, as well as in a Taiwanese and an Indian study. 11-12 In studying the relationship between hypertension and extrapulmonary TB there was a statistical significance for not having Hypertension. In studying the relationship between diabetes mellitus and extrapulmonary TB there was a statistical significance for not having diabetes mellitus, this was also the case in a Brazilian and Taiwanese study. 13-14 In studying the relationship between COPD and extrapulmonary TB there was a statistical significance for not having COPD. In studying the relationship between kidney disease and extrapulmonary TB there was a statistical significance for not having kidney disease. In studying the relationship between Covid-19 and extrapulmonary TB there was a statistical significance for not having Covid-19. As for the relationship between AIDS and extrapulmonary tuberculosis, the National Center for Tuberculosis Control in Damascus stopped conducting all HIV-related tests in 2011 to this day due to the war’s circumstances.
On the other hand, extrapulmonary tuberculosis (EPTB) was not associated with Pulmonary TB risk factors, as in studying the relation between having them and extrapulmonary TB, there was a statistical significance for not having them. Although smoking is considered common in Syria, only 73 cases were recorded of smoking between active and passive smoking. Perhaps this is due to the small sample size, or the absence of an actual connection between smoking as a risk factor and between the infection with extrapulmonary tuberculosis which was the case in a Taiwanese study.15
The most common presentation in lymph nodes TB was site swelling near the infected nodes (90.19%), while in a study conducted in India, the most common presentation was painless single node enlargement with fever. The most common symptom of pleural tuberculosis was dry nonproductive cough (80.76 %), followed by pleural pain (73.07%). These results are similar to what was mentioned in a Turkish study by Cohen and Richard about the most common symptoms of pleural tuberculosis. 16 The results of Pott's disease "spinal tuberculosis" were similar to those of an Indian study, where the most common symptoms were spinal pain and back pain. 17 In urogenital tuberculosis, the results were similar to those in an Indian study. 18 In Peritoneal tuberculosis, the most common symptom was ascites 28/28 (100%), followed by fever, abdominal pain, and vomiting, 23/28 (82.14%) for each. In meningeal tuberculosis, the most common symptoms were fever, headache, stiff neck, and confusion. These results are similar to a study conducted in Turkey. 19 Tuberculosis of the skin and soft tissues had various symptoms such as hard, painless ulcers 4/5 (80%), fever 3/5 (60%), and painful erythematous area 1/5 (20%). In Skeletal tuberculosis, limitation of joint movement was the most common presentation with a percentage of 7/7 (100%), similar to a study conducted in northern Iran. 10 In gastrointestinal tuberculosis, the common symptoms were abdominal pain 4/5 (80%), weight loss 3/5 (60%), and nausea and vomiting 2/5 (40%). Abdominal pain was also the most common (74%) in a study conducted in the United Kingdom, while nausea and vomiting accounted for (31%) of the symptoms and were the second most common symptom. 20 In Pericardial tuberculosis, the most common symptoms were fever and dyspnea (100%), followed by coughing and chest pain (66%). In Ocular tuberculosis, eye redness and gradual vision loss were the most common (100%). As for ear tuberculosis, we had one patient who suffered from gonorrhea and progressive hearing loss. Regarding breast tuberculosis, there was one affected woman who had a painful lump in the right breast.
In the cases of recurrence, the rate of recurrence in Pott's disease was the highest (18.18%) compared to the rates of recurrences in other extrapulmonary TB types.
According to the records of the National Center for Tuberculosis Control in Damascus over 18 years (2003-2020), it was found that the rate of extrapulmonary tuberculosis was almost stable between 2003 and 2010, but in 2011 and 2015 there was a significant increase in the infection rates before they returned to their usual rates between the years 2016 and 2020, this increase may be strongly attributed to the war that took place in Syria, where not all children were able to obtain the national vaccination program, which led to an increase in the incidence of many diseases, including tuberculosis, in addition to the re-emergence of other diseases such as polio for example.