Survey of the Incidence of TB Infection among Patients attending TBL of Gombe State Specialist Hospital, Gombe State Nigeria

This study was conducted on the incidence of tuberculosis among patients attending Tuberculosis Laborarory (TBL) of Gombe State Specialist Hospital Gombe. Three hundred (300) samples from 100 patients were collected in three phases as initial spot, morning and final spot, and were analysed for the presence of the tubercle bacilli. Of the 100 patients scrutinised, 55 were males and the remaining 45 were females. Out of the 55 males, 17(30.1%) were found to be positive for TB and the remaining 38(69.9%) were negative. For the females however, 8 (17.8%) were positive for TB while the remaining 37(82.2%) were negative. Of the 300 samples, 28(82.4) were found to be positive for TB in both spots (initial and final) while 16(94%) were found positive for morning spot. In all, males were having the higher incidence than their female’s counterparts (Stybio, 1986) because of the higher expossure and lesser hygienic condition than their female counterparts.


INTRODUCTION
Tuberculosis commonly referred to as TB is an infectious, chronic, common and in many cases lethal and contagious disease affecting the lungs (pulmonary) and other parts of the body (extra pulmonary TB).It is caused by various strains of Mycobacteria, usually Mycobacterium tuberculosis.It remains one of the most important causes of mortality and morbidity in the world (Corbett et al., 2003).It can cause serious respiratory problems which can be life threatening with certain symptoms such as fever, shortness of breath, cough, weight loss, night sweat and loss of appetite (Mims et al., 2000).
A person can have active or inactive (latent) TB infection, those with active TB can pass it to any one they come in close contact with, through cough, sneezes and spits, And can infect an average of 10-15 people every year (WHO, 2005).

Sample collection:
The samples collected were the sputa of the patients.Three different samples were collected from each and every patient i.e. spot, early morning and spot.The method used was Ziehl-Neelsen technique.And it was carried out based on NTSOPM (NATIONAL TB STANDARD OPERATING PROCEDURES MANUAL).The reason for this technique is that, most mycobacteria grow at a relatively slow rate; therefore the acid-fast smear plays an important role in the early diagnosis and treatment of mycobacterial infections.Acid-fast bacilli are difficult to stain because of the lipid content of the cell wall.Heating during staining dissolves the lipid sufficiently to allow penetration of the primary stain.The cell wall retains the primary stain even after exposure to the decolourizing agent, the acid alcohol.The resistance to decolorization by acid alcohol is required for an organism to be termed acid-fast.Counter-stain was then employed to highlight the stain organism.The specimens were arranged and a glass slide labelled with a diamond marker was allocated to each sample.
Using applicator stick a portion of the specimen was transferred to the centre of the slide and a thin smear on the slide was made with concentric circular movements to make the smear to the recommended size (1-2cm).The slides were then placed on a flat surface with the smear facing upward.They were then allowed to air dry for about one hour.After thorough drying, smears were fixed by passing 3 times through a blue flame, ensuring that smears were facing upward Fixed slides to be stained were arranged on a staining rack, and ensured that they were not touching each other.The slides were flooded with carbol fuchsin solution, heated and allowed to stain for 5 minutes.
They were then washed off with running tap water to remove excess carbol fuchsin (until no more colour runs off) and drained off excess rinsing water.
The slides were flooded again with acid alcohol for 3 minutes to decolorize until the red colour disappeared, they were then washed with running tap water and drained off the excess rinsing water.The slides were finally counterstained with Methylene blue for one minute, rinsed again with tap water and drained.The slides were finally counterstained with Methylene blue for one minute, rinsed again with tap water and drained.Microscope was switched on , and a dry smear was placed on the stage of the microscope, then viewed using x10 objective at low power to identify fields to be examined.
A drop of an immersion oil was placed on the smear and switched to (x100),and the smear examined for the presence of acid-fast bacilli.

NUMBER OF AFB FOUND RECORDS REPORT
No AFB in at least 100 fields 0 Negative

DISCUSSION
25 patients indicated positive reaction for TB based on the procedures employed and this makes the (25%) of the total samples collected .This is simalar to the work of (CDC,2005) who worked on the prevalence of TB infection resource poor counties.In table 2, the study showed that females were less infected with TB infection because only 8 were foud to be positive and this makes the 17% out of the 45 samples collected.The number of males tested positive for TB infection were 17 and this makes of the 30.17% of the total samples collected .Table 4 shows the incidence of TB in relation to age groups.This research indicated that TB infection is high among people between the age of 20-40 with the higher percentage in males found positive within this range, and this corressponds with the work of Stybio (1986) and Harris (1990) who reported that the epidemics of HIV has altered the patients of TB disesae in many coutries, particularly in Africa where the prevalence of TB is high and up to the population between 20 and 40 years of age have been infected with the disesae.

CONCLUSION
The result of this investigation show high incidence of tuberculosis infection among males because of their higher exposure and lesser hygienic condition than their female counterparts.This research also indicated that TB infection is high among people within the age of 20-40 with higher percentage of both males and females that were found positive within this range.However, children were less infected and this may be due to the advent of immunization against TB , BCG vaccine that is given to children at their infancy while older people were not opportuned to have the immunization during their childhood.

RECOMMENDATION
We wish to acknowledge the effort of TB Laboratory of the Gombe state specialist hospital who gave us the samples and the necessary materials needed for the research to be effectively conducted.

Table ( 3
) shows the Incidence of TB infection among male patients.Table (4) shows the incidence of TB among male and female in relation to age groups.