Phenotypic and genotypic drug sensitivity profiles of Mycobacterium tuberculosis infection and associated factors in northeastern Ethiopia.

BACKGROUND: Tuberculosis is a devastating and a deadly disease despite the novel advances in its diagnostic tools and drug therapy. Drug resistant Mycobacterium contributes a great share to tuberculosis mortality. Status of drug resistance and patients' awareness toward the disease is unknown in northeastern Ethiopia. Thus, the aim of this study was to determine the phenotypic and genotypic drug sensitivity patterns and associated factors in Oromia Special Zone and Dessie Town, northeastern Ethiopia. METHODS: In a cross-sectional study, 384 smear positive tuberculosis cases were recruited and Löwenstein-Jensen culture was done. The performance of GenoTypic MTBDRplus assay using the conventional BACTEC MGIT 960 as a "gold standard" was determined. Drug resistant strains were identified using spoligotyping. Pearson Chi-square test was used to determine the association of drug sensitivity test and tuberculosis type, lineages, dominant strains and clustering of the isolates. RESULTS: The 384 smear positive Mycobacterium samples were cultured on LJ media of which 29.2% (112/384) as culture positive. A fair agreement was found between MTBDRplus assay and the conventional MGIT test in detecting the Mycobacterium tuberculosis with sensitivity, specificity, positive and negative predictive value of 94.2, 30.2, 68.4 and 76.5%, respectively. Among LJ culture positive samples 95 of them gave valid result for MTBDRplus assay and 16.8% (16/95) as drug resistant. Similarly, MGIT subculture was made for the 112 isolates and 69 of them gave positive result with 15.9% (11/69) as drug resistant. Cohen's kappa value showed almost a perfect agreement between the two testing methods in detecting rifampicin (sensitivity 100% and specificity 98.3%) and multi-drug resistance (sensitivity 83.3% and specificity 100%). Spoligotyping identified 76.5% (13/17) of the drug resistant isolates as Euro-American and family 33 as the predominant family. Significant association was observed between drug resistant isolates and the dominant strains (χ2: 34.861; p = 0.040) of the Mycobacterium. CONCLUSION: Higher magnitude of drug resistance was found in the study area. The GenoTypic MDRTBplus assay had an acceptable drug sensitivity testing performance.

Molecular epidemiology and drug sensitivity of Mycobacterium tuberculosis in homeless individuals in the Addis Ababa city, Ethiopia.

Although homeless segment of the society could be the hotspots for tuberculosis (TB) transmission, there is little data on TB in homeless individuals in Ethiopia. The objective of this study was to investigate the molecular epidemiology and drug sensitivity of Mycobacterium tuberculosis (M. tuberculosis) isolated from homeless individuals in Addis Ababa, Ethiopia. The study was conducted on 59 M. tuberculosis isolates, which were recovered by the clinical screening of 5600 homeless individuals and bacteriological examination of 641 individuals with symptoms of pulmonary tuberculosis (PTB). Region of difference-9 (RD9) based polymerase-chain reaction (PCR), Spoligotyping and 24-loci Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeat (MIRU-VNTR) typing were used for genotyping of the isolates. In addition, drug sensitivity test was performed on the isolates using BD Bactec Mycobacterial Growth Inhibition Tube (MGIT) 960. Fifty-eight of the 59 isolates were positive by spoligotyping and spoligotyping International type (SIT) 53, SIT 37, and SIT 149 were the dominant spoligotypes; each consisting of 19%, 15.5%, and10.3% of the isolates, respectively. The majority of the isolates (89.7%) were members of the Euro-American (EA) major lineage. MIRU-VNTR identified Ethiopia_3, Delhi/CAS, Ethiopia_2, TUR, X-type, Ethiopia_H37Rv-like strain, Haarlem and Latin-American Mediterranean (LAM) sub lineages. The proportion of clustering was 77.6% (45/58) in spoligotyping while it was 39.7% (23/58) in 24-loci MIRU-VNTR typing. Furthermore, the proportion of clustering was significantly lowered to 10.3% (6/58) when a combination of spoligotyping and 24-loci MIRU-VNTRplus was used. The recent transmission index (RTI) recorded by spoligotyping, 24-loci MIRU-VNTR typing, and a combination of the two genotyping methods were 58.6%, 27.6% and 5.2%, respectively. Young age and living in groups were significantly associated with strain clustering (P < 0.05). The drug sensitivity test (DST) result showed 8.9% (4/58) of the isolates were resistant to one or more first line ant-TB drugs; but multidrug resistant isolate was not detected. Clustering and RTI could suggest the transmission of TB in the homeless individuals, which could suggest a similar pattern of transmission between homeless individuals and the general population. Hence, the TB control program should consider homeless individuals during the implementation of TB control program.

High helminthic co-infection in tuberculosis patients with undernutritional status in northeastern Ethiopia.

BACKGROUND: Tuberculosis and parasitosis are the widely distributed diseases in Ethiopia with the leading cause of mortality and morbidity, respectively. There has been no information on the status of co-infections of tuberculosis and parasitosis in Oromia Zone of Amhara Region and South Wollo, Ethiopia. Hence, this study primarily focuses on determining the status of tuberculosis and parasitosis co-infections and associated factors. METHODS: The study was conducted in Oromia Special Zone of the Amhara Regional State and South Wollo Zone, northeastern Ethiopia from April 2015 to January 2017. Tuberculosis cases confirmed by health personnel at the health institutions were the source of the study sample. In a cross-sectional study 384 smear positive pulmonary and extra-pulmonary tuberculosis cases were recruited. Faecal specimens provided by the study participants were examined for parasitic co-infections using direct saline microscopic test, Kato-Katz and concentration techniques. Nutritional status was determined using body mass index and mid-upper arm circumferences. Data were analyzed using descriptive statistical methods and Pearson chi-square. RESULTS: Tuberculosis and parasitosis co-infection prevalence was 10.8%, and the proportion of intestinal helminths accounted for 9.7% while intestinal protozoa accounted for 1.9%. Cases with single parasitic infection was 89.3% among co-infected individuals. Co-infection of both disease was not significantly associated with gender and age (P > 0.05). The prevalence of undernutrition was 58.6% as determined using body mass index and 73.0% as determined using mid-upper arm circumference with no significant association with gender. Among all forms of tuberculosis cases (384) screened for the study, the bacterial positivity was relatively more common in males (55.5%) than females (44.5%). Tuberculosis lymphadenitis was found to be the most prevalent (85.9%) form of extra-pulmonary tuberculosis with cervical adenopathy (75.3%) being the commonly existing disease. CONCLUSIONS: The rate of helminthic co-infection is predominantly high than that of intestinal protozoa. Single parasitic co-infection was more common than double or multiple co-infections. Both body mass index and mid-upper arm circumference anthropometric parameters revealed greater risk of undernutrition in tuberculosis patients. Thus, screening and prompt treatment of parasites in tuberculosis patients and a support of nutritional supplementation for malnourished tuberculosis patients should be further studied which might enhance the disease treatment and minimize the risk of its complexity.

Assessment of the potential of competitor snails and African catfish (Clarias gariepinus) as biocontrol agents against snail hosts transmitting schistosomiasis.

The objective of this study was to assess the potential of the snails Physa acuta and Melanoides tuberculata and the African catfish Clarias gariepinus as biological control agents against the Schistosoma mansoni intermediate host Biomphalaria pfeifferi under laboratory conditions. Groups of five target and five competitor snails were raised together in experimental aquaria and same number in separate aquaria as controls. Shell size, number of eggs and mortality rate were recorded for twelve consecutive weeks. The stocking density for C. gariepinus was one fish per aquarium. Fish were provided with adequate or inadequate supplementary food and fifteen B. pfeifferi were added to each aquarium. The snails and their eggs were counted daily. Significant differences in shell growth and fecundity were noted between B. pfeifferi and M. tuberculata. Physa acuta was noted to be voracious in food consumption. Snail consumption was faster by fish provided with inadequate supplementary food. Based on the present findings, it is suggested that the two competitor snails and African catfish could be used as biological control agents against B. pfeifferi. Nevertheless, the susceptibility of the competitor snails to other trematodes in Ethiopia must first be ruled out before introducing these snails into new habitats. Follow-up field observation and rigorous laboratory studies remain areas for further research.

Prevalence of intestinal helminth infection among school children in Maksegnit and Enfranz Towns, northwestern Ethiopia, with emphasis on Schistosoma mansoni infection.

BACKGROUND: Schistosomiasis is endemic in Ethiopia and previously unknown transmission foci have been reported from time to time in different parts of the country. Further surveys are required in areas where endemicity of the disease is not known to cover them with control program if transmission is taking place. This study, therefore, aims to assess the magnitude of schistosomiasis mansoni and soil-transmitted helminthiasis in Maksegnit and Enfranz Towns, northwestern Ethiopia. METHODS: Cross-sectional parasitological and malacological surveys were conducted in three schools found in Maksegnit and Enfranz Towns. Stool specimens were collected from 550 randomly selected school children (age range 5 to 17 years) and processed for microscopic examination using Kato-Katz method (single smear per stool sample). Malacological survey was conducted in Gumara and Garno Rivers found in the study areas. Biomphalaria pfeifferi snails collected from the two rivers were individually exposed to artificial light in order to induce cercarial shedding. Laboratory-bred Swiss albino mice were exposed to the cercariae and definite identification of the schistosome species was made based on morphology. RESULTS: The overall prevalence of S. mansoni infection was found to be 49%; however, it varied by schools, with Selam having 60.7%, and Maksegnit Number 1 and 2 having 45.8 and 39.6%, respectively. The respective mean intensity of S. mansoni infection among school children in Selam, Maksegnit Number 1 and Maksegnit Number 2 Schools were 243, 194 and 183 eggs per gram of stool (epg). In all the study areas there was no difference in prevalence of S. mansoni infection in relation to age, however, the prevalence varied by sex, with males having highest prevalence (54.5% vs 44.1%) (p = 0.012). Adult S. mansoni worms were harvested from mice exposed to cercariae shed from B. pfeifferi on the 6(th) week post-exposure. The prevalence of Ascaris lumbricoides single infection was 16.5% while its co-infection with S. mansoni was 18.2%. CONCLUSION: Infections of young children, findings of schistosome infected snails, establishment of mice infection and harvesting adult worms from the lab-bred mice confirm that autochthonous transmission is taking place in the study areas. Hence, preventive chemotherapy with praziquantel should be put in place, complemented with other measures such as provision of sanitary facilities and health education, to control morbidity and transmission of schistosomiasis and soil-transmitted helminthiasis in the study areas.