Lawrence Yamuah
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The organizations/institutes from the scholar's latest article
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Research Interests
Lawrence Yamuah has a total of 107 co-authors. Here are the top co-authors by number of shared publications:
- Abraham Aseffa
Armauer Hansen Research Institute, Addis Ababa, Ethiopia
14 shared publications - Liya Wassie
Armauer Hansen Research Institute, Addis Ababa, Ethiopia
6 shared publications - Markos Abebe
Armauer Hansen Research Institute (AHRI), Addis Ababa, Ethiopia
6 shared publications Berhanu Seyoum
3 shared publicationsDaniel Asrat
3 shared publications- Elena Hailu
Armauer Hansen Research Institute, Addis Ababa, Ethiopia
3 shared publications
Latest Publications
- Open Access
- 3 March 2015
- Published by Springer Nature in BMC Infectious Diseases
- Vol. 15 (1) , 1-10
Investigation of the high rates of extrapulmonary tuberculosis in Ethiopia reveals no single driving factor and minimal evidence for zoonotic transmission of Mycobacterium bovis infection
Ethiopia, a high tuberculosis (TB) burden country, reports one of the highest incidence rates of extra-pulmonary TB dominated by cervical lymphadenitis (TBLN). Infection with Mycobacterium bovis has previously been excluded as the main reason for the high rate of extrapulmonary TB in Ethiopia. Here we examined demographic and clinical characteristics of 953 pulmonary (PTB) and 1198 TBLN patients visiting 11 health facilities in distinct geographic areas of Ethiopia. Clinical characteristics were also correlated with genotypes of the causative agent, Mycobacterium tuberculosis. No major patient or bacterial strain factor could be identified as being responsible for the high rate of TBLN, and there was no association with HIV infection. However, analysis of the demographic data of involved patients showed that having regular and direct contact with live animals was more associated with TBLN than with PTB, although no M. bovis was isolated from patients with TBLN. Among PTB patients, those infected with Lineage 4 reported “contact with other TB patient” more often than patients infected with Lineage 3 did (OR = 1.6, CI 95% 1.0-2.7; p = 0.064). High fever, in contrast to low and moderate fever, was significantly associated with Lineage 4 (OR = 2.3; p = 0.024). On the other hand, TBLN cases infected with Lineage 4 tended to get milder symptoms overall for the constitutional symptoms than those infected with Lineage 3. The study suggests a complex role for multiple interacting factors in the epidemiology of extrapulmonary TB in Ethiopia, including factors that can only be derived from population-based studies, which may prove to be significant for TB control in Ethiopia.
- 3 March 2015
- Published by Springer Nature in BMC Infectious Diseases
- Vol. 15 (1) , 1-10
Open AccessInvestigation of the high rates of extrapulmonary tuberculosis in Ethiopia reveals no single driving factor and minimal evidence for zoonotic transmission of Mycobacterium bovis infection
Ethiopia, a high tuberculosis (TB) burden country, reports one of the highest incidence rates of extra-pulmonary TB dominated by cervical lymphadenitis (TBLN). Infection with Mycobacterium bovis has previously been excluded as the main reason for the high rate of extrapulmonary TB in Ethiopia. Here we examined demographic and clinical characteristics of 953 pulmonary (PTB) and 1198 TBLN patients visiting 11 health facilities in distinct geographic areas of Ethiopia. Clinical characteristics were also correlated with genotypes of the causative agent, Mycobacterium tuberculosis. No major patient or bacterial strain factor could be identified as being responsible for the high rate of TBLN, and there was no association with HIV infection. However, analysis of the demographic data of involved patients showed that having regular and direct contact with live animals was more associated with TBLN than with PTB, although no M. bovis was isolated from patients with TBLN. Among PTB patients, those infected with Lineage 4 reported “contact with other TB patient” more often than patients infected with Lineage 3 did (OR = 1.6, CI 95% 1.0-2.7; p = 0.064). High fever, in contrast to low and moderate fever, was significantly associated with Lineage 4 (OR = 2.3; p = 0.024). On the other hand, TBLN cases infected with Lineage 4 tended to get milder symptoms overall for the constitutional symptoms than those infected with Lineage 3. The study suggests a complex role for multiple interacting factors in the epidemiology of extrapulmonary TB in Ethiopia, including factors that can only be derived from population-based studies, which may prove to be significant for TB control in Ethiopia.
- Open Access
- 10 August 2014
- Published by Springer Nature in BMC Research Notes
- Vol. 7 (1) , 1-8
A 24-well plate assay for simultaneous testing of first and second line drugs against Mycobacterium tuberculosis in a high endemic setting
Early detection of drug resistance is one of the priorities of tuberculosis (TB) control programs as drug resistance is increasing. New molecular assays are only accessible for a minority of the second line drugs and their availability in high endemic settings is also hampered by high cost and logistic challenges. Therefore, we evaluated a previously developed method for drug susceptibility testing (DST) including both first- and second line anti-TB drugs for use in high endemic areas. Baseline mycobacterial isolates from 78 consecutive pulmonary TB patients from Addis Ababa, Ethiopia who were culture positive for Mycobacterium tuberculosis at the end of a two-month directly observed treatment short course (DOTS) were included. The isolates were simultaneously tested for isoniazid, rifampicin, ethambutol, streptomycin, amikacin, kanamycin, capreomycin, ofloxacin, moxifloxacin, ethionamide and para-aminosalicylic acid susceptibility using the indirect proportion method adopted for 24-well agar plates containing Middlebrook 7H10 medium. Applying the 24-well plate assay, 43 (55.1%) isolates were resistant to one or more of the first line drugs tested (isoniazid, rifampicin and ethambutol). MDR-TB was identified in 20.5% of this selected group and there was a perfect correlation for rifampicin resistance with the results from the genotype MTBDRplus assay. All isolates were susceptible to aminoglycosides and fluoroquinolones in agreement with the genotype MTBDRsl assay. The only tested second line drug associated to resistance was ethionamide (14.1% resistant). The method was reproducible with stable results for internal controls (one multi-drug resistant (MDR) and one pan-susceptible strain (H37Rv) and DST results could be reported at two weeks. The 24-well plate method for simultaneous DST for first- and second line drugs was found to be reproducible and correlated well to molecular drug susceptibility tests. It is likely to be useful in high-endemic areas for surveillance as well as for the detection of second line drug resistance in targeted groups such as in those who fail empirical MDR treatment.
- 10 August 2014
- Published by Springer Nature in BMC Research Notes
- Vol. 7 (1) , 1-8
Open AccessA 24-well plate assay for simultaneous testing of first and second line drugs against Mycobacterium tuberculosis in a high endemic setting
Early detection of drug resistance is one of the priorities of tuberculosis (TB) control programs as drug resistance is increasing. New molecular assays are only accessible for a minority of the second line drugs and their availability in high endemic settings is also hampered by high cost and logistic challenges. Therefore, we evaluated a previously developed method for drug susceptibility testing (DST) including both first- and second line anti-TB drugs for use in high endemic areas. Baseline mycobacterial isolates from 78 consecutive pulmonary TB patients from Addis Ababa, Ethiopia who were culture positive for Mycobacterium tuberculosis at the end of a two-month directly observed treatment short course (DOTS) were included. The isolates were simultaneously tested for isoniazid, rifampicin, ethambutol, streptomycin, amikacin, kanamycin, capreomycin, ofloxacin, moxifloxacin, ethionamide and para-aminosalicylic acid susceptibility using the indirect proportion method adopted for 24-well agar plates containing Middlebrook 7H10 medium. Applying the 24-well plate assay, 43 (55.1%) isolates were resistant to one or more of the first line drugs tested (isoniazid, rifampicin and ethambutol). MDR-TB was identified in 20.5% of this selected group and there was a perfect correlation for rifampicin resistance with the results from the genotype MTBDRplus assay. All isolates were susceptible to aminoglycosides and fluoroquinolones in agreement with the genotype MTBDRsl assay. The only tested second line drug associated to resistance was ethionamide (14.1% resistant). The method was reproducible with stable results for internal controls (one multi-drug resistant (MDR) and one pan-susceptible strain (H37Rv) and DST results could be reported at two weeks. The 24-well plate method for simultaneous DST for first- and second line drugs was found to be reproducible and correlated well to molecular drug susceptibility tests. It is likely to be useful in high-endemic areas for surveillance as well as for the detection of second line drug resistance in targeted groups such as in those who fail empirical MDR treatment.
- 1 January 2014
- p. 1-6
Human immunodeficiency virus infection among new smear positive pulmonary tuberculosis patients in Addis Ababa, Ethiopia.
It has been few years since the launching of provider-initiated HIV counselling and testing (PICT) for all tuberculosis (TB) suspected patients and patients presenting with signs and symptoms of TB. However, little is known about the prevalence of HIV in new smear positive confirmed TB cases in Addis Ababa. To determine the proportion of HIV among newly diagnosed smear positive TB cases, who were screened between February 2007 and July 2010 in Addis Ababa. A total of 418 pulmonary TB patients and 188 HIV positive non-TB cases were recruited from different health centres in Addis Ababa. All TB patients were tested for HIV. Of the total 418 new smear positive TB patients tested for HIV, 97 (23.2%) were HIV positive. The occurrence of HIV among TB patients was significantly higher in females, 50/182 (27.7%) compared to males, 47/236 (19.7%) (P < 0.05). The mean CD4 lymphocyte count among HIV positive active TB cases was significantly lower (P < 0.05) (210 +/- 23.9 cells/microL) compared to the counts among non-TB HIV positive cases (407.01 +/- 31.3 cells/microL). The proportion of HIV was significantly higher in the age group 31-40 (46.3%) and > 41 (42.2%) year (p < 0.001) compared to younger, 18-20 (3.75%) and 21-30 (17.8%) years of age groups. The occurrence of HIV in smear positive TB cases is high, with a higher proportion seen among females compared to males.
- 1 January 2014
- p. 1-6
Human immunodeficiency virus infection among new smear positive pulmonary tuberculosis patients in Addis Ababa, Ethiopia.
It has been few years since the launching of provider-initiated HIV counselling and testing (PICT) for all tuberculosis (TB) suspected patients and patients presenting with signs and symptoms of TB. However, little is known about the prevalence of HIV in new smear positive confirmed TB cases in Addis Ababa. To determine the proportion of HIV among newly diagnosed smear positive TB cases, who were screened between February 2007 and July 2010 in Addis Ababa. A total of 418 pulmonary TB patients and 188 HIV positive non-TB cases were recruited from different health centres in Addis Ababa. All TB patients were tested for HIV. Of the total 418 new smear positive TB patients tested for HIV, 97 (23.2%) were HIV positive. The occurrence of HIV among TB patients was significantly higher in females, 50/182 (27.7%) compared to males, 47/236 (19.7%) (P < 0.05). The mean CD4 lymphocyte count among HIV positive active TB cases was significantly lower (P < 0.05) (210 +/- 23.9 cells/microL) compared to the counts among non-TB HIV positive cases (407.01 +/- 31.3 cells/microL). The proportion of HIV was significantly higher in the age group 31-40 (46.3%) and > 41 (42.2%) year (p < 0.001) compared to younger, 18-20 (3.75%) and 21-30 (17.8%) years of age groups. The occurrence of HIV in smear positive TB cases is high, with a higher proportion seen among females compared to males.
- 1 January 2014
- p. 7-14
Characterization of the etiological agents of tuberculous lymphadenitis in Dera Woreda, North Showa, Ethiopia.
Tuberculous lymphadenitis (TBLN) is a common form of extra pulmonary tuberculosis where lymph nodes particularly from cervical, axillary and inguinal sites are mostly involved, however, its diagnosis poses a major challenge in resource limited settings. To identify the etiological species of Mycobacteria responsible for TBLN in Derra area, a rural district in Ethiopia, where the status of TBLN is unknown. A total of 153 patients who were clinically suspected for TBLN, between the periods of August 2004 and February 2005 were included in the study. Fine needle aspirates (FNA) were collected and processed from 145 participants and further analyzed using Ziehl Neelsen staining, culture, cytology and polymerase chain reaction (PCR) using sets of primers, targeting the IS6110 insertion sequence and the pncA gene allelic variation at position 169. Out of the 145 FNA samples, 66 (45.5%) demonstrated growth on Lowenstein-Jensen (LJ) medium and 115 (79.3%) cases were confirmed as TBLN by a combination of results from acid fast bacilli (AFB) smear examination, culture, cytology and PCR. From the 145 clinically suspected TBLN cases, 108 (75%) were identified by PCR at complex level of which 107/108 (99.1%) were positive for M. tuberculosis and 1/108 (0.9%) was positive for M. bovis using pncA primers. The study indicates that M. tuberculosis is the major cause of tuberculous lymphadenitis in Dera area.
- 1 January 2014
- p. 7-14
Characterization of the etiological agents of tuberculous lymphadenitis in Dera Woreda, North Showa, Ethiopia.
Tuberculous lymphadenitis (TBLN) is a common form of extra pulmonary tuberculosis where lymph nodes particularly from cervical, axillary and inguinal sites are mostly involved, however, its diagnosis poses a major challenge in resource limited settings. To identify the etiological species of Mycobacteria responsible for TBLN in Derra area, a rural district in Ethiopia, where the status of TBLN is unknown. A total of 153 patients who were clinically suspected for TBLN, between the periods of August 2004 and February 2005 were included in the study. Fine needle aspirates (FNA) were collected and processed from 145 participants and further analyzed using Ziehl Neelsen staining, culture, cytology and polymerase chain reaction (PCR) using sets of primers, targeting the IS6110 insertion sequence and the pncA gene allelic variation at position 169. Out of the 145 FNA samples, 66 (45.5%) demonstrated growth on Lowenstein-Jensen (LJ) medium and 115 (79.3%) cases were confirmed as TBLN by a combination of results from acid fast bacilli (AFB) smear examination, culture, cytology and PCR. From the 145 clinically suspected TBLN cases, 108 (75%) were identified by PCR at complex level of which 107/108 (99.1%) were positive for M. tuberculosis and 1/108 (0.9%) was positive for M. bovis using pncA primers. The study indicates that M. tuberculosis is the major cause of tuberculous lymphadenitis in Dera area.
- 1 January 2014
- p. 31-5
Tuberculosis among Addis Ababa city bus drivers and cash collectors.
The risk of transmission of tuberculosis is high in crowded conditions. Addis Ababa has a relatively high burden of tuberculosis and its city buses are often filled with commuters. Tuberculosis is a potential occupational hazard for city bus drivers and cash collectors. The objective of this study was to estimate the proportion of tuberculosis among city bus drivers and cash collectors. We estimated the proportion of tuberculosis of all forms among city bus drivers and cash collectors of the Addis Ababa City Bus Organization, from January 2003 to December 2004. Study participants were screened with clinical, bacteriological and chest X-ray examination from January 2003 to December 2004. Sixteen cases of tuberculosis were identified among 903 study participants (466 city bus drivers and 437 cash collectors) examined, of whom 12 were already on anti-TB treatment and 4 were diagnosed during the study. The proportion of all forms of tuberculosis, smear-positive pulmonary tuberculosis and extra-pulmonary tuberculosis was 16/903 (1772/100,000), 4/903 (443/100,000) and 3/903(332/100,000), respectively. The proportion of all forms of tuberculosis among the study population was higher than the notification case rates for Addis Ababa reported in 2003, which indicates the need for a routine screening of city bus drivers and cash collectors. Measures such as opening windows and reducing crowding in buses are recommended as a means of reducing the risk of exposure to bus drivers and cash collectors.
- 1 January 2014
- p. 31-5
Tuberculosis among Addis Ababa city bus drivers and cash collectors.
The risk of transmission of tuberculosis is high in crowded conditions. Addis Ababa has a relatively high burden of tuberculosis and its city buses are often filled with commuters. Tuberculosis is a potential occupational hazard for city bus drivers and cash collectors. The objective of this study was to estimate the proportion of tuberculosis among city bus drivers and cash collectors. We estimated the proportion of tuberculosis of all forms among city bus drivers and cash collectors of the Addis Ababa City Bus Organization, from January 2003 to December 2004. Study participants were screened with clinical, bacteriological and chest X-ray examination from January 2003 to December 2004. Sixteen cases of tuberculosis were identified among 903 study participants (466 city bus drivers and 437 cash collectors) examined, of whom 12 were already on anti-TB treatment and 4 were diagnosed during the study. The proportion of all forms of tuberculosis, smear-positive pulmonary tuberculosis and extra-pulmonary tuberculosis was 16/903 (1772/100,000), 4/903 (443/100,000) and 3/903(332/100,000), respectively. The proportion of all forms of tuberculosis among the study population was higher than the notification case rates for Addis Ababa reported in 2003, which indicates the need for a routine screening of city bus drivers and cash collectors. Measures such as opening windows and reducing crowding in buses are recommended as a means of reducing the risk of exposure to bus drivers and cash collectors.
- 1 January 2014
- p. 37-41
Recent trends of cutaneous leishmaniasis in Alert Hospital, Addis Ababa.
Cutaneous leishmaniasis is endemic to many parts of the world and has re-emerged in a number of endemic countries in recent years. Environmental changes, immune status of the host and treatment failure are the three most important risk factors associated with the re-emerging and spread of Leishmaniasis. Cutaneous leishmaniasis (CL) ranges from localized, self-healing type to the disfiguring mucocutaneous and diffuse cutaneous type. To access the trend of CL patient flow in ALERT Hospital, Addis Ababa, Ethiopia. Patients' clinical and laboratory records were collected retrospectively for 1651 leishmaniasis suspected individuals from ALERT Hospital, from January 1, 2007 to December 30, 2010. From the suspected individuals, 234 cases were positive for Leishmania species with Giemsa stain and/or histopathology and confirmed for CL, of whom 30 (12.8%) were diagnosed in 2007, 29 (12.4%) in 2008, 75 (32.1%) in 2009, and 100 (42.7%) were in 2010. The overall proportion of cases with leishmaniasis among the suspected cases was 234/1651 (14.2%). The distribution of CL reports was higher for patients coming from Addis Ababa surrounding areas and Oromia region, 96/234 (41.03%) and 71/234 (30.34%), respectively. In general, the trend of leishmaniasis in and around Addis Ababa seems to be increasing, which calls for further detailed epidemiological studies, including vector and reservoir host studies, to help in the prevention and control of the disease.
- 1 January 2014
- p. 37-41
Recent trends of cutaneous leishmaniasis in Alert Hospital, Addis Ababa.
Cutaneous leishmaniasis is endemic to many parts of the world and has re-emerged in a number of endemic countries in recent years. Environmental changes, immune status of the host and treatment failure are the three most important risk factors associated with the re-emerging and spread of Leishmaniasis. Cutaneous leishmaniasis (CL) ranges from localized, self-healing type to the disfiguring mucocutaneous and diffuse cutaneous type. To access the trend of CL patient flow in ALERT Hospital, Addis Ababa, Ethiopia. Patients' clinical and laboratory records were collected retrospectively for 1651 leishmaniasis suspected individuals from ALERT Hospital, from January 1, 2007 to December 30, 2010. From the suspected individuals, 234 cases were positive for Leishmania species with Giemsa stain and/or histopathology and confirmed for CL, of whom 30 (12.8%) were diagnosed in 2007, 29 (12.4%) in 2008, 75 (32.1%) in 2009, and 100 (42.7%) were in 2010. The overall proportion of cases with leishmaniasis among the suspected cases was 234/1651 (14.2%). The distribution of CL reports was higher for patients coming from Addis Ababa surrounding areas and Oromia region, 96/234 (41.03%) and 71/234 (30.34%), respectively. In general, the trend of leishmaniasis in and around Addis Ababa seems to be increasing, which calls for further detailed epidemiological studies, including vector and reservoir host studies, to help in the prevention and control of the disease.
- 1 January 2014
- p. 43-8
Chronic meningitis in immunocompromised adult Ethiopians visiting Tikur Anbessa Teaching Hospital and Ye'huleshet Clinic from 2003-2004.
Chronic meningitis is inflammation of the meninges where signs and symptoms develop and last for at least four weeks without alleviation. Little is known about the current etiology and incidence of the disease in adults living in developing countries. The objective of this study was to elucidate the most common etiologies of chronic meningitis in adult Ethiopian patients and give an aid in the empiric therapy. A total of 53 adult patients (median age 32 years) having chronic meningitis and who were admitted at Tikur Anbessa Teaching Hospital and Ye'huleshet Clinic, Addis Ababa, Ethiopia were recruited between 2003 and 2004. Of the 53 patients, bacteriological, molecular and immunological investigations were done for 52 of the study participants to detect Cryptococcus neoformans, Mycobacterium tuberculosis, Toxoplasma gondii, Brucella and Neisseria meningitides infections. Forty eight of the participants were HIV positive and 15% (8/52) of the CSF were positive with Cryptococcal latex antigen detection test; in addition, M. tuberculosis DNA was detected using PCR from CSF ofpatients infew of the patients. Multiple infections were observed in studyparticipants with < 0.1 to 1 CD4 to CD8 ratio. Chronic meningitis mostly occurred in HIV infected patients, where most of the infections were attributed to Cryptococcus neoformans whereas M. tuberculosis appeared secondary.
- 1 January 2014
- p. 43-8
Chronic meningitis in immunocompromised adult Ethiopians visiting Tikur Anbessa Teaching Hospital and Ye'huleshet Clinic from 2003-2004.
Chronic meningitis is inflammation of the meninges where signs and symptoms develop and last for at least four weeks without alleviation. Little is known about the current etiology and incidence of the disease in adults living in developing countries. The objective of this study was to elucidate the most common etiologies of chronic meningitis in adult Ethiopian patients and give an aid in the empiric therapy. A total of 53 adult patients (median age 32 years) having chronic meningitis and who were admitted at Tikur Anbessa Teaching Hospital and Ye'huleshet Clinic, Addis Ababa, Ethiopia were recruited between 2003 and 2004. Of the 53 patients, bacteriological, molecular and immunological investigations were done for 52 of the study participants to detect Cryptococcus neoformans, Mycobacterium tuberculosis, Toxoplasma gondii, Brucella and Neisseria meningitides infections. Forty eight of the participants were HIV positive and 15% (8/52) of the CSF were positive with Cryptococcal latex antigen detection test; in addition, M. tuberculosis DNA was detected using PCR from CSF ofpatients infew of the patients. Multiple infections were observed in studyparticipants with < 0.1 to 1 CD4 to CD8 ratio. Chronic meningitis mostly occurred in HIV infected patients, where most of the infections were attributed to Cryptococcus neoformans whereas M. tuberculosis appeared secondary.
- 1 January 2014
- p. 49-52
A pilot study on detection and genotyping of humanpapilloma virus isolated from clinically diagnosed Ethiopian women having cervical intraepithelial neoplasia.
Human Papilloma virus associated cervical cancers are more prevalent in developing countries compared to developed countries. Cervical cancer is reported as the most frequent malignancy among women visiting hospitals in Ethiopia. This study is a pilot study designed to examine the prevalence and genotypes of HPV in twenty Ethiopian women, clinically diagnosed to have cervical neoplasia, while visiting gynecology unit of a tertiary level referral hospital in Addis Ababa. The objective of this study was to detect the presence of HPV L1 gene and respective genotypes among women clinically diagnosed with different grades of cervical neoplasia. A total of 20 fresh biopsy samples were collected from clinically diagnosed cases, DNA extracted and further amplified using PCR for HPV L1 and beta globin genes. The PCR amplicons were denatured and allowed for hybridization onto a nitrocellulose strip containing the type-specific probes for 27 HPV genotypes representing both high and low risk groups as well as beta globin genes. Socio-demographic characteristics and clinical findings of the participants were recorded on structured questionnaires. Amplification of HPV L1 gene by PCR detected 17 cases out of 20. Based on reverse line blot hybridization assay, the most frequent genotype identified was HPV16 (13/20). Mixed infection of HPV 16 with HPV 33, HPV 35, HPV 45 and HPV 58 was detected from other four study participants. Human papilloma virus type 16 was the most prevalent genotype identified from the subjects screened. Further investigation with statistically sound sample size would help to clearly visualize the existing trend in Ethiopia regarding factors for high risk HPV positivity and multiple gravidity, young age at first coitus and cervical neoplasia.
- 1 January 2014
- p. 49-52
A pilot study on detection and genotyping of humanpapilloma virus isolated from clinically diagnosed Ethiopian women having cervical intraepithelial neoplasia.
Human Papilloma virus associated cervical cancers are more prevalent in developing countries compared to developed countries. Cervical cancer is reported as the most frequent malignancy among women visiting hospitals in Ethiopia. This study is a pilot study designed to examine the prevalence and genotypes of HPV in twenty Ethiopian women, clinically diagnosed to have cervical neoplasia, while visiting gynecology unit of a tertiary level referral hospital in Addis Ababa. The objective of this study was to detect the presence of HPV L1 gene and respective genotypes among women clinically diagnosed with different grades of cervical neoplasia. A total of 20 fresh biopsy samples were collected from clinically diagnosed cases, DNA extracted and further amplified using PCR for HPV L1 and beta globin genes. The PCR amplicons were denatured and allowed for hybridization onto a nitrocellulose strip containing the type-specific probes for 27 HPV genotypes representing both high and low risk groups as well as beta globin genes. Socio-demographic characteristics and clinical findings of the participants were recorded on structured questionnaires. Amplification of HPV L1 gene by PCR detected 17 cases out of 20. Based on reverse line blot hybridization assay, the most frequent genotype identified was HPV16 (13/20). Mixed infection of HPV 16 with HPV 33, HPV 35, HPV 45 and HPV 58 was detected from other four study participants. Human papilloma virus type 16 was the most prevalent genotype identified from the subjects screened. Further investigation with statistically sound sample size would help to clearly visualize the existing trend in Ethiopia regarding factors for high risk HPV positivity and multiple gravidity, young age at first coitus and cervical neoplasia.
- 1 March 2012
- Published by Lepra in Leprosy Review
- Vol. 83 (1) , 40-51
The pattern of bacterial isolates and drug sensitivities of infected ulcers in patients with leprosy in ALERT, Kuyera and Gambo Hospitals, Ethiopia
Introduction: Leprosy remains a public health problem, mainly in Africa, Asia and Latin America. Leprosy has many complications that include leprosy reactions, development of plantar and hand ulcerations, lagophthalomus and corneal anesthesia. Objectives: In Ethiopia there is scarce information on the pattern of bacterial isolates and drug sensitivities of infected ulcers in patients with leprosy. This study was undertaken to identify the bacteriology of infected ulcers and to determine their antimicrobial susceptibility pattern. Study design: A descriptive cross-sectional study was conducted in 245 informed and consented leprosy patients with infected ulcers visiting ALERT, Kuyera and Gambo hospitals during the period August 2006 to May 2007. Material and methods: Wound aspirate specimens were collected from ulcers of each patient aseptically and inoculated into standard bacteriological media. Antimicrobial susceptibility testing was performed for all isolates according to the criteria of the National Committee for Clinical Laboratory Standards (NCCLS) by disk diffusion method. Results: Of the 245 patients investigated, 64.1% were males and 35.9% females(P < 0.05). The average age of the patients was 50 years (age range 13 to 92 years). According to Ridley-Jopling classifications, patients presented with TT (3.7%), BT, (31.4%), BL (44.5%) and LL (15.9%) types of leprosy. Plantar and hand ulcers were observed in 92.2% and 7.8% of patients, respectively. According the patients, the commonest cause of their ulcers was ‘spontaneous’ (56.7%). There were 44% Grampositive and 56% Gram negative bacteria (P > 0.05). Proteus spp. accounted for 29.5% of the total isolates followed by Staphylococcus spp. (28.8%), β-hemolytic streptococci (15.1%) and different types of Gram-negative bacteria (26.2%). Multiple organisms (two or three) were isolated from 19.6% patients. Of the 212 wound samples cultured anaerobically, 5.2% were positive for anaerobic culture. In this study both Gram-positive and Gram negative bacteria showed decreased sensitivity to most antimicrobial agents tested. Conclusion: Proteus spp. was the most common isolate from infected ulcers. Ciprofloxacin, norfloxacin and gentamicin were the most effective drugs against the tested bacteria mainly for Gram-negative bacteria. This refers to the in vitro-sensitivity during the study period. The results of this study may help inform clinicians about the selection of an antibiotic in situations where use of an antibiotic may be indicated.
- 1 March 2012
- Published by Lepra in Leprosy Review
- Vol. 83 (1) , 40-51
The pattern of bacterial isolates and drug sensitivities of infected ulcers in patients with leprosy in ALERT, Kuyera and Gambo Hospitals, Ethiopia
Introduction: Leprosy remains a public health problem, mainly in Africa, Asia and Latin America. Leprosy has many complications that include leprosy reactions, development of plantar and hand ulcerations, lagophthalomus and corneal anesthesia. Objectives: In Ethiopia there is scarce information on the pattern of bacterial isolates and drug sensitivities of infected ulcers in patients with leprosy. This study was undertaken to identify the bacteriology of infected ulcers and to determine their antimicrobial susceptibility pattern. Study design: A descriptive cross-sectional study was conducted in 245 informed and consented leprosy patients with infected ulcers visiting ALERT, Kuyera and Gambo hospitals during the period August 2006 to May 2007. Material and methods: Wound aspirate specimens were collected from ulcers of each patient aseptically and inoculated into standard bacteriological media. Antimicrobial susceptibility testing was performed for all isolates according to the criteria of the National Committee for Clinical Laboratory Standards (NCCLS) by disk diffusion method. Results: Of the 245 patients investigated, 64.1% were males and 35.9% females(P < 0.05). The average age of the patients was 50 years (age range 13 to 92 years). According to Ridley-Jopling classifications, patients presented with TT (3.7%), BT, (31.4%), BL (44.5%) and LL (15.9%) types of leprosy. Plantar and hand ulcers were observed in 92.2% and 7.8% of patients, respectively. According the patients, the commonest cause of their ulcers was ‘spontaneous’ (56.7%). There were 44% Grampositive and 56% Gram negative bacteria (P > 0.05). Proteus spp. accounted for 29.5% of the total isolates followed by Staphylococcus spp. (28.8%), β-hemolytic streptococci (15.1%) and different types of Gram-negative bacteria (26.2%). Multiple organisms (two or three) were isolated from 19.6% patients. Of the 212 wound samples cultured anaerobically, 5.2% were positive for anaerobic culture. In this study both Gram-positive and Gram negative bacteria showed decreased sensitivity to most antimicrobial agents tested. Conclusion: Proteus spp. was the most common isolate from infected ulcers. Ciprofloxacin, norfloxacin and gentamicin were the most effective drugs against the tested bacteria mainly for Gram-negative bacteria. This refers to the in vitro-sensitivity during the study period. The results of this study may help inform clinicians about the selection of an antibiotic in situations where use of an antibiotic may be indicated.
- 1 April 2011
- Vol. 49 (2) , 125-30
Throat carriage rate and antimicrobial susceptibility pattern of group A Streptococci (GAS) in healthy Ethiopian school children.
Group A Streptococci (GAS) or Streptococcus pyogenes are the most frequent cause of pharyngitis and skin infection in children and lead to post infection complications including acute rheumatic fever and glomerulonephritis. Pharyngeal carriage rates of GAS among healthy school children vary with geographical location and seasons. There is not much information on the screening of children for carriage of GAS in Ethiopia. The study aimed at assessing the carriage rate of Group A Streptococci and antimicrobial susceptibility of the isolates in healthy Ethiopian school children. A total of 937 children residing in Addis Ababa (n=491), Gondar (n=265) and Dire-Dawa (n=181) were investigated during a period between November 2004 and January 2005. Throat specimens were collected and cultured using standard procedure. Beta haemolytic streptococci were serogrouped by agglutination tests using specific antisera. Antimicrobial susceptibility testing of the isolates was performed by diffusion method. The median and the mean ages of the study participants were 11 (range 6-14) years. Girls constituted 52% (486/937) of the study participants. A total of 167 (17.8%) beta haemolytic streptococci were recovered from 937 children investigated GAS accounted for 91/167 (54.5%) of beta hemolytic streptococcal isolates. The carrier rate for GAS was 9.7% (91/937) of the screened children followed by group G with 3.2% (30/937) and group C streptococci with 2.2% (21/937). All GAS isolates were sensitive to oxacillin, penicillin, erythromycin, clindamycin and trimethoprim-sulphamethoxazole. Lower frequency of resistance was observed against tetracycline and vanocmycin. The present study revealed that GAS was the most predominant beta-haemolytic streptococcus among healthy Ethiopian school children. Our results showed that pharyngeal carriage of GAS in school children should not be underestimated. Therefore it is recommended to conduct regular screening and GAS surveillance in schools, and maintain rational use of antibiotics to minimize GAS resistance.
- 1 April 2011
- Vol. 49 (2) , 125-30
Throat carriage rate and antimicrobial susceptibility pattern of group A Streptococci (GAS) in healthy Ethiopian school children.
Group A Streptococci (GAS) or Streptococcus pyogenes are the most frequent cause of pharyngitis and skin infection in children and lead to post infection complications including acute rheumatic fever and glomerulonephritis. Pharyngeal carriage rates of GAS among healthy school children vary with geographical location and seasons. There is not much information on the screening of children for carriage of GAS in Ethiopia. The study aimed at assessing the carriage rate of Group A Streptococci and antimicrobial susceptibility of the isolates in healthy Ethiopian school children. A total of 937 children residing in Addis Ababa (n=491), Gondar (n=265) and Dire-Dawa (n=181) were investigated during a period between November 2004 and January 2005. Throat specimens were collected and cultured using standard procedure. Beta haemolytic streptococci were serogrouped by agglutination tests using specific antisera. Antimicrobial susceptibility testing of the isolates was performed by diffusion method. The median and the mean ages of the study participants were 11 (range 6-14) years. Girls constituted 52% (486/937) of the study participants. A total of 167 (17.8%) beta haemolytic streptococci were recovered from 937 children investigated GAS accounted for 91/167 (54.5%) of beta hemolytic streptococcal isolates. The carrier rate for GAS was 9.7% (91/937) of the screened children followed by group G with 3.2% (30/937) and group C streptococci with 2.2% (21/937). All GAS isolates were sensitive to oxacillin, penicillin, erythromycin, clindamycin and trimethoprim-sulphamethoxazole. Lower frequency of resistance was observed against tetracycline and vanocmycin. The present study revealed that GAS was the most predominant beta-haemolytic streptococcus among healthy Ethiopian school children. Our results showed that pharyngeal carriage of GAS in school children should not be underestimated. Therefore it is recommended to conduct regular screening and GAS surveillance in schools, and maintain rational use of antibiotics to minimize GAS resistance.