الفهرس 
List of tablesOnly 14 pages are availabe for public view
 |  | from | 203 |  |  |
| | | from | 203 | | |
Abstract
The diseases produced by species of the genus Mycobacterium are important causes of morbidity and mortality in the world, particularly in third world countries; they have increased due to HIV infections ( Sadeghian et al., 2005).
Tuberculosis (TB) remains one of the leading infectious diseases causing significant morbidity and mortality worldwide. Although, pulmonary TB is the most common presentation and is the main transmissible form of the disease, extrapulmonary TB also significantly contributes to the burden of disease and can cause severe complications and disabilities (Singh and Jain,2015).
Also nontuberculous mycobacteria (NTM) has been identified in human pulmonary and extrapulmonary diseases and are of great concern for clinicians and microbiologists because of their increasing global incidence (Umrao et al., 2016).
For the previous reasons our study was done. It was conducted from September 2016 to January 2018 at Sohag University. The study included patients in different departments at Sohag University Hospital and patients in another hospitals & private clinics at Sohag Governorate who suspected by clinician to have (EPTB).
One hundred (100) clinical specimens collected during the study period were screened for mycobacterial infection from this 100 patients, 66 patients had extrapulmonary mycobacterial infection.
The age of patient with mycobacterial infection was ranging between 8 years and 80 years with Mean ± S.D (45.8 ± 17.33) and the highest incidence of mycobacterial infection occur in age group (41-50 years old) in percent 22.7% followed by 21.2% in age group (31-40 years old), 15.2 % in age group (51-60 years old), 13.6% in age group(61-70 years old), 10.6% in age group (71-80 years old), 7.6% in age group (21-30 years old), 6.06% in age group (11-20 years old) then 3.04% in age group (0-10 years old). The Mycobacterial infections were more among males (69.7%) than females (30.3%).
The most prevalent risk factor associated with mycobacterial infection in our study was drinking un boiled/ unpasteurized Milk and its derivative products (83.3%), followed by Smoking (45.5%), hypertension (30.3%), diabetes (15.2%), hepatitis (12.1%), renal impairment (7.6%) and anemia (4.5%).
In our study patients with mycobacterial infection may be presented by more than one symptom at the same time. In patient with mycobacterial infection in urinary system the most common symptom was frequency and dysuria (each represented 85.2%) followed by loin pain (represented 44.4%), nocturnal enuresis(represented 18.5% ), hematuria & recurrent renal stones (each represented 11.1%) then perineal pain (represented 7.4%) while patient with the infection in the abdomen the most common symptoms was chronic diarrhea (represented 80%) followed by chronic abdominal pain (represented 60%) then abdominal distention due to ascites (represented 12%) and patient with mycobacterial infection in other extrapulmonary organs (rather than urinary system and abdomen) the most common symptoms was Pleural symptoms in form of dyspnea and cough (represented 36%), followed by laryngeal symptoms in form of hoarseness of voice, lymphatic system symptoms in form of enlarged cervical lymph node, breast symptoms in form of breast abscess, pain and discharge ( each represented 14%) then skin symptoms in forms of Ulceration & nodules in the skin, skin sinus and cold abscess in the chest (each represented 7%).
During the present study the total number of collected extrapulmonary samples was 100. They were mostly urine samples (represented 45%) followed by stool samples (represented 35%) then other extrapulmonary samples rather than urine and stool (represented 20%).
The largest percent of positive samples for mycobacterial infection were other extrapulmonary samples (represented 85% of collected other extrapulmonary samples distributed as pleural fluid (5), ascetic fluid (3), cervical lymph node biopsy(2), and pus from breast abscess(2), biopsy from skin nodule& ulceration (1), swab from skin sinus (1), biopsy from laryngeal mass (1), biopsy from vocal cord lesion (1) & Pus from chest abscess(1) ) followed by stool samples (represented 62.9% of collected stool samples) then urine samples (represented 60 % of collected urine samples).
In our study the overall positivity for mycobacterial infection in all extrapulmonary samples was 66/100(66%). Out Of 66 isolates, 53 (80.3%) were characterized as MTBC and 13 (19.7%) as NTM.
In our study MTBC strains of EPTB were mostly isolated from urine samples( 24 isolates, representing 45% of total number of EPTB isolates), followed by stool samples ( 15 isolates, representing 28% ) then other extrapulmonary samples (14 isolates, representing 26.4%, 5 strains from pleural fluid, 3 strains from ascitic fluid, 2 strains from cervical lymph nodes biopsies, one strain from each Biobsy from skin nodule &ulceration, biopsy from laryngeal mass, biopsy from vocal cord lesion & Pus from chest abscess). However, NTM strains in our study were mostly isolated from stool samples ( 7 isolates, representing 53.8% of total number of NTM isolates), followed by urine samples (representing 23%), Pus from breast abscess (representing 15%), then Swab from skin sinus (representing 7.6%).
We tried in our study to evaluate the use of ZN stain in detection of mycobacteria in extrapulmonary samples, by comparing its results with the gold standard L.J Culture media. ZN stain method revealed Sensitivity of 71.21%, Specificity 100%, Positive predictive value 100%, Negative predicative value 64.15%, Accuracy 81%.
In our study total number of positive culture for MTBC from total extrapulmonary samples were 53. The incidence of EPTB samples had positive film with positive culture were 37/53 (representing 69.8% of total MTBC strains) while incidence of negative film with positive culture in EPTB samples were16/53 (representing 30.2% of total MTBC strains). So samples with negative film & positive culture were mainly MTBC 16/19 (representing 84.2%).
In our study the largest percent of negative film with positive culture was present in stool samples (8/22, represented 36.4% of total positive stool samples for mycobacteria), followed by urine samples (8/27, represented 29.6% of total positive urine samples for mycobacteria), then other exrapulmonary samples (3/17, represented 17.6%, plural fluid (2) and cervical lymph node biopsy (1)).
During our study we tried to identify MTBC strains from 66 culture positive mycobacteria which isolated from extrapulmonary samples by using biochemical tests as a conventional method for identification and compare them with the gold standard PCR , the biochemical tests showed Sensitivity 100%, specificity 76,9%, positive predictive value 94.6%, negative predicative value 100%, accuracy 95.5%.
Also we tried in our study to use immunochromatographic test as a non conventional method for identification of MTBC and compare its results with both biochemical tests & PCR. immunochromatographic test revealed good reliable results with using PCR as a gold standard test) , with Sensitivity100%, specificity 100%, positive predictive value 100%, negative predicative value 100%, accuracy 100%.
Antibiotic susceptibility pattern of isolated MTBC strains showed the highest sensitivity rates were to both Ethambutol and Kanamycin ( each represented 98.1%), Capreomycin( 96.2%), Streptomycin(94.3%), Amikacin ( 92.5%) then Rifampicin (90.6%). Meanwhile, the highest resistance rates were to Isoniazid(13.2%) , Ofloxacin(11.3%), Rifampicin(9.4%), Amikacin(7.5%).
in our study the incidence of MDR was 9.4% of total MTBC isolated strains while incidence of XDR: represented 1.9% of total MTBC isolated strains.
In conclusion, extrapulmonary mycobacterial infection rate in Sohag governorate was high and rapid speciation that distinguishes MTBC from NTM is an important prerequisite for the proper management of patients with mycobacterial infections.
Our result suggests that due attention and emphasis should be given on diagnosis of EPTB and antibiotic susceptibility pattern should be done for each of isolated MTBC strains to optimize efficient anti-TB treatment and to avoid development of MDR- TB which ultimately leads to extensively drug resistant-tuberculosis (XDR-TB).
Recommendation
1- The culture is the gold standard in diagnosis of mycobacterial infection and the use of liquid media alongside the solid media, increase the chance for isolation of mycobacteria from extrapulmonary samples.
2-The differentiation of NTM from MTBC is important because positive microscopy cannot differentiate M. tuberculosis complex from NTM infection, causing diagnostic and clinical dilemmas. Management of patients with MTBC and NTM is entirely different; therefore prompt isolation, detection, and differentiation of mycobacteria are necessary for suitable management.
3-Conventional biochemical tests used to identify different mycobacterial species are complex and time consuming and according to our results we recommend the use of ICT(immunochromatography) test on direct culture positive mycobacterial specimens, it does not require any special equipment, The low cost, simplicity, rapidity, high sensitivity and high specificity for the MPT 64 antigen detection make the ICT as a useful diagnostic tool for diffentiation between MTBC and NTM and can help in appropriate management of tuberculosis and may be introduced as a required standard into routine laboratory diagnostics in tertiary care centers in developing counties.
4- Non-specific clinical presentation of EPTB, make the clinician must to have high rate of suspicion of EPTB in different cases.
5- An early and rapid TB diagnoses as well as distinction between the different MTBC members are essential to determine the EPTB etiology and to optimize efficient anti-TB treatment since Mycobacterium bovis and Mycobacterium bovis BCG are intrinsically resistant to pyrazinamide (PZA), an important first-line anti-TB drug. Also the natural modes of infection and surveillance measures for EPTB differ between complex members.
6- Zoonotic potential exposures (ZE) by occupation and consumption of raw milk and derivative products that place individuals in direct and indirect contact with animals and their excretions/secretions increase the risk for zoonotic TB in Sohag, especially among those with EPTB. Therefore, measures such as efficient control of bovine TB, distribution of pasteurized milk and its derivative products, and the diagnosis and monitoring of zoonotic TB in humans are essential steps, and further studies are necessary.
7- Further study in the future to know The prevalence of Mycobacterium bovis and other mycobacterial species in livestock specimens and milk and correlation of these strains with the affected persons to know the source of infection.
8-The problem of MDR in extra pulmonary tuberculosis (EPTB) cannot be overlooked and we recommend the use of culture along with proportion method of antibiotic susceptibility test for the diagnosis of drug resistance in extra pulmonary tuberculosis.
9- Trial to introduce Xpert MTB/RIF technique in Sohag Governorate as it is a recent molecular test for rapid detection of TB and MDR-TB.
10- Searching for latent tubercular infection (LTBI) cases before they turned to an active TB and treat them.
11- More detailed study is necessary in the future using more advanced phenotypic and genotypic methods to have better picture about EPTB in Sohag Governorate, traces the sources of the infection and detection of the resistance pattern in the detected cases.