Nega Berhe | Addis Ababa University (original) (raw)
Papers by Nega Berhe
Inflammatory Bowel Diseases, 2004
Interferon (IFN)- gamma plays an important role during immune responses against leishmaniasis. Pr... more Interferon (IFN)- gamma plays an important role during immune responses against leishmaniasis. Production of IFN-gamma is regulated by interleukin (IL)-12, IL-18, and IL-15. Interferon-gamma-inducible protein (IP)-10 and monokine induced by IFN-gamma (Mig) are CXC chemokines, the production of which, at least in part, is IFN-gamma dependent. A follow-up study of individuals infected with Leishmania donovani was undertaken in an area of Ethiopia endemic for visceral leishmaniasis (VL). Plasma levels of IFN-gamma, IL-12p40, IL-18, IL-15, IP-10, and Mig were markedly elevated in symptomatic VL patients (n = 70) compared with individuals with asymptomatic Leishmania infections (n = 39), malaria patients (n = 13), and healthy controls from the endemic area (n = 12). A significant decrease of IFN-gamma and all mediators was observed after treatment of VL patients (n = 33). These data show that increased plasma levels of IFN-gamma, as well as the mediators involved in the production and the activity of this cytokine, are characteristic of active VL in humans, and may play an important immunopathogenic role. The data also suggest that in patients with VL, the production of type 1 cytokines is not depressed, but there appears to be an unresponsiveness to the stimuli of type 1 cytokines. The underlying causes of immunologic unresponsiveness remain a subject of further investigation.
Ethiopian medical journal
As part of an epidemiological investigation of visceral leishmaniasis, entomological surveys were... more As part of an epidemiological investigation of visceral leishmaniasis, entomological surveys were conducted in Ziway-Langano, Dimtu-Bilate and Wadjifo-Mirab Abaya areas located in the middle course of the Ethiopian Rift Valley between November 1994 and June 1996. A total of 4518 sand flies (Diptera: Psychodidae) were collected from the study areas using CDC light traps and oiled plastic sheets which were identified to nine species of Phlebotomus and 14 species of Sergentomyia. Most of the Phlebotomus species were from Ziway-Langano area and they included P. martini and P. orientalis, which are the principal vectors of visceral leishmaniasis in Ethiopia. Among 339 females of nine Phlebotomus species dissected, natural infections with flagellates were detected in 11 specimens (two P. duboscqi and nine P. rodhami) from Ziway-Langano area, but were different from mammalian Leishmania species by their position in the insect gut, morphology and behaviour in cultures. However, the reasons ...
Interferon (IFN)- plays an important role during immune responses against leishmaniasis. Producti... more Interferon (IFN)- plays an important role during immune responses against leishmaniasis. Production of IFN- is regulated by interleukin (IL)-12, IL-18, and IL-15. Interferon-�inducible protein (IP)-10 and monokine induced by IFN- (Mig) are CXC chemokines, the production of which, at least in part, is IFN- dependent. A follow-up study of individuals infected with Leishmania donovani was undertaken in an area of
Ethiopian journal of health sciences, 2014
Schistosomiasis is one of the chronic and neglected tropical diseases affecting rural communities... more Schistosomiasis is one of the chronic and neglected tropical diseases affecting rural communities. Heavy infections contribute to anemia and can retard children's growth, physical activity and cognitive function. This study was conducted in order to determine the prevalence, intensity and variation of Schistosoma mansoni infection among human subjects in geographically apart localities. The prevalence and intensity of Schistosoma mansoni infection was assessed in three geographically apart endemic areas of Ethiopia from May to August 2010 through cross-sectional approach. A total of 1073 individuals (528 males and 545 females) were found eligible for the study. Their age ranged from 5-60 years with mean age of 11 years in Wondo Genet, 22 years in Kemissie and 24 years in Sille-Elgo. Small plastic sheets were distributed to the study participants and sizable stool specimens were collected and examined using Kato-Katz method (41.7mg template). The prevalence of Schistosoma mansoni...
Ethiopian medical journal, 2011
The search for a correlation between chemokine levels in plasma or serum and protection from HIV ... more The search for a correlation between chemokine levels in plasma or serum and protection from HIV infection or progression to AIDS has been attempted by a number of workers. Chemokines are also suggested to play a role in immunity to Leishmania and Leishmania co-infection with HIV. To assess plasma level of alpha chemokine (CXCL12, formerly known as SDF-1alpha) and beta chemokines (CCL3, CCL4 and CCL5, formerly known as MIP-1alpha, MIP-1beta and RANTES, respectively) in HIV Visceral Leishmaniasis (VL) and HIV/VL coinfection. Frozen serum samples from a cross sectional study were used. The samples (n = 80) were comprised of healthy controls (n = 20), HIV patients (n = 20); Visceral Leishmaniasis (VL) patients (n = 22), and HIV/VL coinfected patients (n = 18). Chemokine levels of MIP-1alpha, MIP-1beta, RANTES, and SDF-1alpha of the serum samples were determined using ELISA. MIP-1alpha and MIP-1beta expression were significantly elevated in Leishmania infected (p < 0.001) and in HIV/...
The American journal of tropical medicine and hygiene, 2007
To elucidate determinants of morbidity in schistosomiasis mansoni, a community-based study was un... more To elucidate determinants of morbidity in schistosomiasis mansoni, a community-based study was undertaken involving 2,451 subjects (mean age, 18.8 +/- 15.3 [SD] years) from four endemic sites in Ethiopia. Overall prevalence of infection was 65.9%, reported blood in stools was 35.8%, and schistosomal periportal thickening/fibrosis (PPT/F) was 4.6%. Similarly, 43.2% were positive for at least one marker of hepatitis B virus (HBV), 5.3% were HBsAg positive, and 1.3% were anti-hepatitis C virus (HCV) positive. Prevalence of PPT/F increased significantly with increasing community prevalence and intensity of S. mansoni infection. In a multiple logistic regression analysis, intensity of egg excretion, markers of HBV infection, age, and male sex were significantly associated with PPT/F, whereas co-infection with other intestinal helminths was associated with lower odds for PPT/F. HCV was not associated with S. mansoni infection or with schistosomal PPT/F. In conclusion, integrated helminth ...
The American journal of tropical medicine and hygiene, 2008
To study outcome determinants of schistosomal periportal thickening/fibrosis (PPT/F), 199 subject... more To study outcome determinants of schistosomal periportal thickening/fibrosis (PPT/F), 199 subjects (mean age = 24.0 years, range = 7-68 years), 109 with mild (image pattern C) PPT/F, 69 with moderate (image pattern D) PPT/F, and 21 with severe (image patterns E and F) PPT/F were treated with praziquantel and evaluated every six months for a mean duration of 26 months. Subjects excreting Schistosoma mansoni eggs during any of the six-month evaluations were offered repeat treatment. Thirty-five had some improvement, and 69 had total resolution of PPT/F, of which 63.8% resolved within one year. Compared with subjects with moderate lesions, a significantly higher proportion of subjects with mild lesions had resolution/improvement of PPT/F (40.6% versus 69.7%, P < 0.001). Subjects with severe PPT/F showed no improvement. Resolution of PPT/F was significantly more frequent at a younger age, among seronegative for hepatitis B virus and among those with a lower frequency of post-treatmen...
Ethiopian medical journal, 2002
In June 1996, a study on the economic impacts of onchocercal skin disease was initiated in southw... more In June 1996, a study on the economic impacts of onchocercal skin disease was initiated in southwestern Ethiopia. We made parasitological and clinicoepidemiological investigations among 1619 workers of a coffee plantation firm in Teppi, south-western Ethiopia. Sixty percent of the workers were included in the study. The prevalence of onchocercal skin disease (OSD) was 85.3%. Severe OSD (SOSD) was found in 17.3% of the study subjects. This was 1/5 of all OSD cases. The overall nodule carrier rate was 44.2%, which differed significantly by age classes from a rate of 12.3% to 73.0%. This rate varied by sex, 51.7% in males and 22.6% in females. Microfilarial carrier rate (MFCR) was 77.6%. This rate did not vary neither with severity of disease nor with presence or absence of pruritus or onchodermatitis. Mean microfilarial count was determined to be 38.1 per mg of skin snip or 44.4 per mg of infected skin snips. The geometric mean of microfilarial load per infected skin was 23.8. The com...
Parasitology International, 1998
Parasites & Vectors, 2010
Acta Tropica, 1999
A total of 611 Schistosoma mansoni infected primary school children from three schools in north-e... more A total of 611 Schistosoma mansoni infected primary school children from three schools in north-east Ethiopia were treated with praziquantel at 40 mg/kg body weight in a single dose. Pre-treatment, 40.4% had no presenting symptoms and 30–40% had nausea, abdominal cramps and/or bloody-mucoid diarrhoea. None of the pre-treatment symptoms was related to nutritional status, intensity of S. mansoni egg excretion,
Tropical Medicine and International Health, 2006
Parasitology Today, 1999
Both Leishmania and the human immunodeficiency virus (HIV) can infect and multiply in macrophages... more Both Leishmania and the human immunodeficiency virus (HIV) can infect and multiply in macrophages, and both can dysregulate the immune system. Recent studies indicate that Leishmania can induce the activation of HIV in latently infected monocytic and T cells. Moreover, HIV can enhance intracellular growth of Leishmania in macrophages. Here, Dawit Wolday and colleagues examine the mechanisms that might be involved in the immunopathogenesis of Leishmania- HIV co-infection.
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1995
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1995
This communication reports 7 Ethiopian visceral leishmaniasis (VL) patients co-infected with huma... more This communication reports 7 Ethiopian visceral leishmaniasis (VL) patients co-infected with human immunodeficiency virus (HIV). The clinical and laboratory findings in 6 patients did not differ from classical VL. All patients had highly elevated anti-leishmanial antibody titres, determined by immunoglobulin G-based enzyme-linked immunosorbent assay; they most probably acquired the Leishmania infection before HIV. Amastigotes were identified in the splenic aspirates of 6 patients and in the lymph node aspirate of the 2 patients whose lymph nodes were examined. The CD4:CD8 lymphocyte ratio was depressed in those patients whose ratio was determined. Most patients showed some initial response to pentavalent antimonial therapy.
Parasites & Vectors, 2014
Inflammatory Bowel Diseases, 2004
Interferon (IFN)- gamma plays an important role during immune responses against leishmaniasis. Pr... more Interferon (IFN)- gamma plays an important role during immune responses against leishmaniasis. Production of IFN-gamma is regulated by interleukin (IL)-12, IL-18, and IL-15. Interferon-gamma-inducible protein (IP)-10 and monokine induced by IFN-gamma (Mig) are CXC chemokines, the production of which, at least in part, is IFN-gamma dependent. A follow-up study of individuals infected with Leishmania donovani was undertaken in an area of Ethiopia endemic for visceral leishmaniasis (VL). Plasma levels of IFN-gamma, IL-12p40, IL-18, IL-15, IP-10, and Mig were markedly elevated in symptomatic VL patients (n = 70) compared with individuals with asymptomatic Leishmania infections (n = 39), malaria patients (n = 13), and healthy controls from the endemic area (n = 12). A significant decrease of IFN-gamma and all mediators was observed after treatment of VL patients (n = 33). These data show that increased plasma levels of IFN-gamma, as well as the mediators involved in the production and the activity of this cytokine, are characteristic of active VL in humans, and may play an important immunopathogenic role. The data also suggest that in patients with VL, the production of type 1 cytokines is not depressed, but there appears to be an unresponsiveness to the stimuli of type 1 cytokines. The underlying causes of immunologic unresponsiveness remain a subject of further investigation.
Ethiopian medical journal
As part of an epidemiological investigation of visceral leishmaniasis, entomological surveys were... more As part of an epidemiological investigation of visceral leishmaniasis, entomological surveys were conducted in Ziway-Langano, Dimtu-Bilate and Wadjifo-Mirab Abaya areas located in the middle course of the Ethiopian Rift Valley between November 1994 and June 1996. A total of 4518 sand flies (Diptera: Psychodidae) were collected from the study areas using CDC light traps and oiled plastic sheets which were identified to nine species of Phlebotomus and 14 species of Sergentomyia. Most of the Phlebotomus species were from Ziway-Langano area and they included P. martini and P. orientalis, which are the principal vectors of visceral leishmaniasis in Ethiopia. Among 339 females of nine Phlebotomus species dissected, natural infections with flagellates were detected in 11 specimens (two P. duboscqi and nine P. rodhami) from Ziway-Langano area, but were different from mammalian Leishmania species by their position in the insect gut, morphology and behaviour in cultures. However, the reasons ...
Interferon (IFN)- plays an important role during immune responses against leishmaniasis. Producti... more Interferon (IFN)- plays an important role during immune responses against leishmaniasis. Production of IFN- is regulated by interleukin (IL)-12, IL-18, and IL-15. Interferon-�inducible protein (IP)-10 and monokine induced by IFN- (Mig) are CXC chemokines, the production of which, at least in part, is IFN- dependent. A follow-up study of individuals infected with Leishmania donovani was undertaken in an area of
Ethiopian journal of health sciences, 2014
Schistosomiasis is one of the chronic and neglected tropical diseases affecting rural communities... more Schistosomiasis is one of the chronic and neglected tropical diseases affecting rural communities. Heavy infections contribute to anemia and can retard children's growth, physical activity and cognitive function. This study was conducted in order to determine the prevalence, intensity and variation of Schistosoma mansoni infection among human subjects in geographically apart localities. The prevalence and intensity of Schistosoma mansoni infection was assessed in three geographically apart endemic areas of Ethiopia from May to August 2010 through cross-sectional approach. A total of 1073 individuals (528 males and 545 females) were found eligible for the study. Their age ranged from 5-60 years with mean age of 11 years in Wondo Genet, 22 years in Kemissie and 24 years in Sille-Elgo. Small plastic sheets were distributed to the study participants and sizable stool specimens were collected and examined using Kato-Katz method (41.7mg template). The prevalence of Schistosoma mansoni...
Ethiopian medical journal, 2011
The search for a correlation between chemokine levels in plasma or serum and protection from HIV ... more The search for a correlation between chemokine levels in plasma or serum and protection from HIV infection or progression to AIDS has been attempted by a number of workers. Chemokines are also suggested to play a role in immunity to Leishmania and Leishmania co-infection with HIV. To assess plasma level of alpha chemokine (CXCL12, formerly known as SDF-1alpha) and beta chemokines (CCL3, CCL4 and CCL5, formerly known as MIP-1alpha, MIP-1beta and RANTES, respectively) in HIV Visceral Leishmaniasis (VL) and HIV/VL coinfection. Frozen serum samples from a cross sectional study were used. The samples (n = 80) were comprised of healthy controls (n = 20), HIV patients (n = 20); Visceral Leishmaniasis (VL) patients (n = 22), and HIV/VL coinfected patients (n = 18). Chemokine levels of MIP-1alpha, MIP-1beta, RANTES, and SDF-1alpha of the serum samples were determined using ELISA. MIP-1alpha and MIP-1beta expression were significantly elevated in Leishmania infected (p < 0.001) and in HIV/...
The American journal of tropical medicine and hygiene, 2007
To elucidate determinants of morbidity in schistosomiasis mansoni, a community-based study was un... more To elucidate determinants of morbidity in schistosomiasis mansoni, a community-based study was undertaken involving 2,451 subjects (mean age, 18.8 +/- 15.3 [SD] years) from four endemic sites in Ethiopia. Overall prevalence of infection was 65.9%, reported blood in stools was 35.8%, and schistosomal periportal thickening/fibrosis (PPT/F) was 4.6%. Similarly, 43.2% were positive for at least one marker of hepatitis B virus (HBV), 5.3% were HBsAg positive, and 1.3% were anti-hepatitis C virus (HCV) positive. Prevalence of PPT/F increased significantly with increasing community prevalence and intensity of S. mansoni infection. In a multiple logistic regression analysis, intensity of egg excretion, markers of HBV infection, age, and male sex were significantly associated with PPT/F, whereas co-infection with other intestinal helminths was associated with lower odds for PPT/F. HCV was not associated with S. mansoni infection or with schistosomal PPT/F. In conclusion, integrated helminth ...
The American journal of tropical medicine and hygiene, 2008
To study outcome determinants of schistosomal periportal thickening/fibrosis (PPT/F), 199 subject... more To study outcome determinants of schistosomal periportal thickening/fibrosis (PPT/F), 199 subjects (mean age = 24.0 years, range = 7-68 years), 109 with mild (image pattern C) PPT/F, 69 with moderate (image pattern D) PPT/F, and 21 with severe (image patterns E and F) PPT/F were treated with praziquantel and evaluated every six months for a mean duration of 26 months. Subjects excreting Schistosoma mansoni eggs during any of the six-month evaluations were offered repeat treatment. Thirty-five had some improvement, and 69 had total resolution of PPT/F, of which 63.8% resolved within one year. Compared with subjects with moderate lesions, a significantly higher proportion of subjects with mild lesions had resolution/improvement of PPT/F (40.6% versus 69.7%, P < 0.001). Subjects with severe PPT/F showed no improvement. Resolution of PPT/F was significantly more frequent at a younger age, among seronegative for hepatitis B virus and among those with a lower frequency of post-treatmen...
Ethiopian medical journal, 2002
In June 1996, a study on the economic impacts of onchocercal skin disease was initiated in southw... more In June 1996, a study on the economic impacts of onchocercal skin disease was initiated in southwestern Ethiopia. We made parasitological and clinicoepidemiological investigations among 1619 workers of a coffee plantation firm in Teppi, south-western Ethiopia. Sixty percent of the workers were included in the study. The prevalence of onchocercal skin disease (OSD) was 85.3%. Severe OSD (SOSD) was found in 17.3% of the study subjects. This was 1/5 of all OSD cases. The overall nodule carrier rate was 44.2%, which differed significantly by age classes from a rate of 12.3% to 73.0%. This rate varied by sex, 51.7% in males and 22.6% in females. Microfilarial carrier rate (MFCR) was 77.6%. This rate did not vary neither with severity of disease nor with presence or absence of pruritus or onchodermatitis. Mean microfilarial count was determined to be 38.1 per mg of skin snip or 44.4 per mg of infected skin snips. The geometric mean of microfilarial load per infected skin was 23.8. The com...
Parasitology International, 1998
Parasites & Vectors, 2010
Acta Tropica, 1999
A total of 611 Schistosoma mansoni infected primary school children from three schools in north-e... more A total of 611 Schistosoma mansoni infected primary school children from three schools in north-east Ethiopia were treated with praziquantel at 40 mg/kg body weight in a single dose. Pre-treatment, 40.4% had no presenting symptoms and 30–40% had nausea, abdominal cramps and/or bloody-mucoid diarrhoea. None of the pre-treatment symptoms was related to nutritional status, intensity of S. mansoni egg excretion,
Tropical Medicine and International Health, 2006
Parasitology Today, 1999
Both Leishmania and the human immunodeficiency virus (HIV) can infect and multiply in macrophages... more Both Leishmania and the human immunodeficiency virus (HIV) can infect and multiply in macrophages, and both can dysregulate the immune system. Recent studies indicate that Leishmania can induce the activation of HIV in latently infected monocytic and T cells. Moreover, HIV can enhance intracellular growth of Leishmania in macrophages. Here, Dawit Wolday and colleagues examine the mechanisms that might be involved in the immunopathogenesis of Leishmania- HIV co-infection.
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1995
Transactions of the Royal Society of Tropical Medicine and Hygiene, 1995
This communication reports 7 Ethiopian visceral leishmaniasis (VL) patients co-infected with huma... more This communication reports 7 Ethiopian visceral leishmaniasis (VL) patients co-infected with human immunodeficiency virus (HIV). The clinical and laboratory findings in 6 patients did not differ from classical VL. All patients had highly elevated anti-leishmanial antibody titres, determined by immunoglobulin G-based enzyme-linked immunosorbent assay; they most probably acquired the Leishmania infection before HIV. Amastigotes were identified in the splenic aspirates of 6 patients and in the lymph node aspirate of the 2 patients whose lymph nodes were examined. The CD4:CD8 lymphocyte ratio was depressed in those patients whose ratio was determined. Most patients showed some initial response to pentavalent antimonial therapy.
Parasites & Vectors, 2014