Biological Evidence 2018, Vol.8, No.1, 1-5
2
et al., 2016; Etim and Briyai, 2017; 2018), and it has been on the increasing trend (Sharma et al., 2011; Range et al.,
2012).
Several methods have been adopted for the diagnosis of tuberculosis. Sputum smear-microscopy is one of the
widely used approaches especially in developing countries (Cattamanchi et al., 2010; Desikan, 2013; Rye, 2015).
This typically involves smearing sputum on a slide, stained appropriately and viewed under high power
microscopy to detect the causative acid-fast bacillus
M, tuberculosis
(Chew et al., 2011). Fluorescence microscopy,
Nucleic acid amplification tests are other methods of tuberculosis diagnosis (Desikan, 2013). Gene xpert machine
have also been adopted for rapid diagnosis of tuberculosis in many hospitals worldwide. Possible infection of
laboratory technicians in poorly equipped laboratory is a major problem associated with smear microscopy
method of tuberculosis diagnosis (Nyirenda et al., 1998; Chew et al., 2011). Joshi et al. (2006) reported a higher
incidence of tuberculosis disease risk among laboratory technicians compared to the general public. Several
methods are used for sterilization during diagnosis of
Mycobacterium tuberculosis
.
During diagnosis of tuberculosis, chemicals are used in many middle- and high-income countries to enhance the
diagnostic sensitivity (Cattamanchi et al., 2010). Sodium hypochlorite popularly called bleach is ideal processing
chemical agent widely used in many low-income nations (Cattamanchi et al., 2010; Chew et al., 2011). It’s used as
disinfectant. Best et al. (1990), Cattamanchi et al. (2010) reported that bleach may be useful in infection control in
laboratories lacking biosafety facilities. Authors have reported that it could be used for the diagnosis of
Mycobacterium tuberculosis
(Bonnet et al., 2008;
Ongkhammy
et al., 2009; Cattamanchi et al., 2010; Chew et al.,
2011). Bonnet et al. (2008), Cattamanchi et al. (2010), Van Deun et al. (2000) reported that it could improve
microscopy field clarity through digestion of mucus and debris, and concentrating bacilli through centrifugation or
sedimentation during diagnostic sensitivity of sputum. This study aimed at assessing the effect of bleach on the
diagnosis of
Mycobacterium tuberculosis
.
1 Materials and Methods
1.1 Study area
This study was carried out in Central Hospital Benin City, Edo State. Edo state lies between longitude 06
o
04
’
E and
06
o
43
’
E and latitude 05
o
44
’
N and 07
o
34
’
N with a land mass of 17, 450 sq.km located. Edo state is one of the Niger
Delta state with a population of over 3.1 million. The study area has personnel’s in civil services probably due to
the presence of higher institutions and other government agencies. Farming is a major occupation of indigenes of
the area. Petty trading is also a source of livelihood to several families in the area.
1.2 Participants and selection criteria
Participants were drawn from Direct Observation Therapy (DOT) centre in Central Hospital Benin City. Informed
consent(s) of the participant(s) from the DOT clinics of the hospital were obtained. The age of the participants
was > 15 years. The inclusion criteria include individuals that have coughed for more than two weeks, weight loss,
night sweat, swelling at the neck, hand or armpit and fever. While individuals with diabetes and known cases of
cardiovascular diseases were excluded.
1.3 Sample collection
Sixty sputum (60) samples were collected from DOT centre between March and July, 2014. Triplicate sputum
samples were collected over two consecutive days for the new case patients, while for the follow up cases,
patients submitted two sputum samples. The initial sputum sample was collected in the laboratory at first visit to
the clinic while the second sputum samples were in the morning before mouth cleaning at the participant’s home,
and the last samples were collected at the laboratory. The participants were educated on the method to produce
quality sputum and method of collection especially at the second sputum collection that was done at home.
Samples were collected in in well-ventilated area.
1.4 Sample preparation and analysis
The smear method previously described by Chew et al. (2011) was employed in this study. Approximately 40 µl
of the sputa were used to make smears for unprocessed or bleached samples and was applied over a single area of
