Introduction

Tuberculosis (TB) is a leading cause of deaths in children globally.₁,₂,₃,₄ The HIV/AIDS pandemic has immensely affected the epidemiology of the disease given the high incidence among those affected by HIV/AIDS.₁,₂ Tuberculosis of the vertebral spine (Pott's disease) is the commonest presentation of tuberculosis of the bone.₃ It is a widely recognized pattern of presentation of the disease and is associated with spinal cord compression and axial deformity.₅ The prevalence of Pott's disease in Nigeria is unknown but it accounted for 6.7% of TB in children in one hospital-based report.₅ Survey of tuberculosis in 3 major hospitals in Calabar that treat the disease shows that Pott's disease accounted for about 30% of extra-pulmonary cases of tuberculosis.₆

Delayed treatment of TB spine could result in such avoidable poor outcome as longstanding disability from spastic paraplegia.₇,₈ This study is aimed at highlighting the clinical presentation of this curable condition, which is capable of causing significant morbidity and disability if the diagnosis or treatment is delayed.

Patients And Methods

Study design: Patients with TB of the vertebral spine were reviewed retrospectively over 12 years from January 1993 to December 2004 and the clinical features and radiological findings were described.

Setting: This study was carried out on hospital records of children admitted with TB spine to the University of Calabar Teaching Hospital, Calabar, southeastern Nigeria. The hospital is a referral center for the whole of Cross River State with a population of 2.8 million. It has bed capacity of 300, over 30% of which is occupied by children. The hospital runs a directly observed therapy short course (DOTS) unit, which is one of the networks of DOTS units supported by the National Tuberculosis and Leprosy Control Programme.

The predominant occupation of the inhabitants is subsistence farming and a smaller percentage are civil servants. There are very few industries in the area and the bulk of the population belongs to the low-income group.

Methods of data collection

Results

The total of 113 patients were admitted into the pediatric wards of the University of Calabar Teaching Hospital with tuberculosis during the period of this study. About thrice this number not requiring hospitalization were treated as outpatients in the DOTS units of the hospital. In the same city in 2004, 720 cases of tuberculosis were seen at the State Infectious Disease Hospital (IDH) of which fifty-two (7.2 %) were children aged less than 15 years. All cases of suspected TB of the vertebral spine were admitted for evaluation and anti-tuberculosis therapy at the intensive phase.

Sixteen (16) patients with confirmed Pott's disease met the inclusion criteria for this study and were enlisted. Thus, 14% of all hospitalized cases of tuberculosis during this period were due to Pott's disease. (Figure 1, 2 &3).

Figure 1

Figure 1: LATERAL VIEW OF COLLAPSED T9 – T11

Figure 2

Figure 2: AP VIEW OF SAME PATIENT

Figure 3

Figure 3: Gibbus at L3-L4 in a 12 year old boy

Table 1 shows that there was equal sex distribution and fifty-six percent (56%) of the patients were under five years of age at the time of presentation. The mean age of patients was 5.24 years and the age ranged from 1 to 12 years.

Figure 4

Table 1: Age, Sex and Site of affectation of children with Pott's disease in Calabar, Nigeria.

Symptoms and signs: Table 2 shows that the commonest symptom observed in this series was back swelling (94%) presented with gibbus deformity. (see table 3).

Figure 5

Table 2: Presenting symptoms in children with TB of vertebral spine bone in Calabar, Nigeria.

Figure 6

Table 3: Physical and basic laboratory findings of children with Pott's disease in Calabar, Nigeria.

Other clinical features were fever in 50% of them; inability to walk and pallor in 43.7%, cough and weight loss was recorded in 37% of the patients. The commonest neurological signs were hypertonia and hyperreflexia (31%), sustained ankle clonus (25%) and hypotonia (18%). Difficulty with breathing and pulmonary crepitations were found in 12.5% and 25% of the patients respectively. Significant lymphadenopathy was noted in 12% of patients. One patient presented with convulsion and neck stiffness.

Reontgenographs

Discussion

Pott's disease accounted for 14% of all hospitalized cases of tuberculosis seen in this hospital during this period. The prevalence is within the range of that reported from Singapore₁₀ where skeletal tuberculosis accounted for 10-20% of all extra-pulmonary cases. This was lower than the 30% reported by a collaborative review of extrapulmonary tuberculosis in three hospitals in Calabar.₆ Although, this is lower than the 6.7% reported from an hospital based study in Ibadan Nigeria,₅ the disease no doubt constitutes an important percentage of the burden of tuberculosis in this community. It has been suggested that the high contribution of Pott's disease to the extra pulmonary cases may be due to the ease of recognition of the associated vertebral collapse (gibbus) when it occurs.₆

In this study over half (56%) of the patients affected by Pott's disease were less than five years old (Table 1.). In the series reported by Campos et al,₁₁ 67% of the patients were less than 6 years old and two subjects were infants. The findings of these two studies are in keeping with what is already known that the burden of tuberculosis is high in children, particularly the under-fives.₃ For effective prevention of the disease in developing countries, efforts should be targeted at this age group. The younger patients have been shown to have better response to treatment as well as better prognosis than the older patients.₁₁,₁₂

This study showed equal males/females prevalence while other studies found either male or female preponderance of the disease.₁₂,₁₃,₁₄ However, it should be noted that the studies that showed female preponderance may be more representative since it covered a longer period (between 15 and 30 years) and with larger sample sizes.

Swelling of the back (gibbus) was the most common clinical feature in this study. In the study from Turkey₈ gibbus was the second commonest symptom after paralysis and Ikem et al₁₅in Ife found it as the fourth. The patients in this series reported late to hospital hence the high rate of spinal deformity on presentation. In other places where patients attend hospital early, back pain was the commonest presenting symptom.₇,₁₅Our patients may have sought help from non-formal providers like drug vendor or traditional herbalist before presenting to hospital. There is need to educate the populace on the early symptoms of Pott's disease like back pain, and need for patients with back pain to report promptly to hospital.

Fever was the second commonest clinical feature noted and was seen in 50% of patients in this study. Although fever is a non-specific feature in Pott's disease, its presence suggests that the tuberculosis was active at the time of presentation. Tuberculosis is known to cause low grade fever. Twenty-five (25%) of the patients had associated tuberculous pneumonia. Ikem et al₁₅ reported a slightly higher percentage of 26.5%. From these studies, it appears that about a quarter of patients with Pott's disease may have active pulmonary tuberculosis, some of which may have been disseminated tuberculosis.

Inability to walk (Pott's paralysis) which was the commonest symptom in the report from Turkey was the third commonest in this report.₈ In the same study, gibbus deformity, which was the commonest symptom in this study, was seen in only 46% of the patients.₈

There is need to educate the public on the importance of reporting all persistent back pain to health personnel for proper assessment. Health personnel especially at the primary and secondary levels of care should be taught to do thorough examine of the back of patients complaining of back pain in order to identify those with early deformities. Medical personnel and parents should not ignore the complaint of back pain in children (table 2). The DOTS programme of the National TB and Leprosy Control programme now provides anti-tuberculosis drugs free of charge, but this service should be made to reach many more rural communities. Implementation of effective health promotion strategies including immunization against childhood diseases (notably BCG and measles vaccines) could help reduce the incidence of disseminated TB (which sometimes includes Pott's disease and paralysis).

Acknowledgements

Correspondence to

Friday A. Odey Department of Paediatrics, P. M. B. 1278, Calabar. Telephone: +234-803-7135417(Mobile) E-mail: awhobe@yahoo.com