Seasonal and altitudinal variations in fly density and their association with the occurrence of trachoma, in the Gurage zone of central Ethiopia

In the Gurage zone of central Ethiopia, the association between fly density and the occurrence of trachoma has been investigated across varying altitudes. The seasonal pattern of fly density in the area was also explored. When, over short sampling periods (10 min/child indoors and 10 min/child outdoors), hand nets were used to collect flies from the eyes of children aged 2-8 years, only Musca sorbens and M. domestica were caught. Almost all of the 13,147 'eye-seeking' flies collected came from villages at low (<2000 m; 40.7%) or mid altitudes (2200-2500 m; 58.6%) with only 0.7% of them caught in the high-altitude villages investigated (at >3000 m). Musca sorbens predominated outdoors and M. domestica indoors. Almost all (99.3%) of the eye-seeking M. sorbens collected were caught outdoors whereas most (76.7%) of the M. domestica were caught indoors (P<0.0001 for each). The median numbers of flies caught, per child, per 10-min collection, in the low-, mid- and high-altitude villages were 9.5, six and zero, respectively, for M. sorbens, and eight, three and zero, respectively, for M. domestica. The altitudinal trends in these numbers of 'eye-seeking' flies matched those in the prevalences of active trachoma among children aged 1-10 years, which were high in the villages at low (81.6%) and mid altitude (78.7%) but much lower (1.7%) in the high-altitude villages. In conclusion, trachoma is a common disease of public-health importance only in the low- and mid-altitude villages in the Gurage zone, where there are large numbers of eye-seeking flies, and not in the villages that lie >3000 m above sea level, where there is a dearth of such flies.     

T cell mediated immune responses in patients with tuberculous lymphadenitis from Butajira, southern Ethiopia

The control of tuberculosis (TB) requires improved vaccines in addition to chemotherapy. It is essential to understand the immune response in tuberculosis to successfully evaluate potential vaccines. Current investigations have focused on immune responses in pulmonary forms. We studied the T-cell response of peripheral blood mononuclear cells (PBMC) from HIV-infected (n=8) and non-infected patients (n=19) with lymph node tuberculosis to PPD and short-term culture filtrates (ST-CF) of M. tuberculosis. PBMC from HIV-negative TB lymphadenitis patients proliferated in response to both antigens (p<0.001) and produced variably higher levels of IFN-gamma compared to healthy controls (p=0.02) (n=19) from the same area. Such responses were suppressed in HIV co-infected subjects. The results indicate that circulating PBMC in the apparently localized form of tuberculous lymphadenitis react to mycobacterial antigens in a similar pattern as those of patients with pulmonary disease.     

Nine-year trends in HIV-1 prevalence among visa applicants in Urban Ethiopia

A retrospective study was conducted to examine trends in HIV-1 prevalence among visa applicants between the years 1993 to 2001 in Urban Ethiopia. A total of 63,869 visa applicants were screened during these nine years period. The majority of them (79.5%) were females. Their mean age was 31.6 and 25.7 years for males and females, respectively. HIV-1 prevalence ranged from 6.8% in 1993 to 10.4% in 1997 (test for trend: p<0.001), while it seems stabilized at around 11% after 1997. The overall period prevalence was 9.5%. The peak prevalence was documented in the age group 25-29 for females (12.1%) while it was in the age group 30-34 for males (11.4%). This study, therefore, confirms the severity of the HIV-1 epidemic in the country. Visa applicants can be used as a sentinel population for monitoring trends in HIV-1 prevalence in the country, although additional socio-demographic information would be useful for better interpretation of such data.     

Angio-immunoblastic lymphadenopathy with dysproteinaemia in an Ethiopian: case report and literature review

A thirty year-old man with angio-immunoblastic lymphadenopathy (AILD) is presented. This is the first case recorded from Ethiopia, and few have been reported elsewhere in Africa. The patient presented with generalized lymphadenopathy, fever, weight loss, pruritus, skin rashes, anaemia, hepatomegaly and pulmonary infiltrates. Lymph node histology was typical of AILD. The available literature on this relatively new pathologic entity reveals that little is known about the nature of AILD, and since there is no established therapy, an individualized approach to management is advisable.     

Decline in prevalence of HIV-1 infection and syphilis among young women attending antenatal care clinics in Addis Ababa, Ethiopia: results from sentinel surveillance, 1995-2001

From 1995 to 2001, five rounds of sentinel surveillance were carried out for young women attending antenatal care clinics at four health centers in Addis Ababa, the capital city of Ethiopia, to monitor trends in the prevalence of HIV infection and syphilis. Serum samples were tested for antibodies to HIV (enzyme-linked immunosorbent assay and Western blotting) and antibodies to Treponema pallidum (T. pallidum hemagglutination assay and rapid plasma reagin test). Prevalence ratios for an increase in one calendar year were estimated using log-binomial models. Between 1995 and 2001, the prevalence of HIV infection among young women (age range, 15-24 years) attending antenatal care clinics in inner city health centers declined from 24.2% to 15.1% (prevalence ratio for an increase in one calendar year, 0.91; 95% confidence interval, 0.87-0.95). No change was observed for older age groups or in outer city health centers. The decline in the prevalence of active syphilis (T. pallidum hemagglutination assay and rapid plasma reagin testing positive for antibodies to T. pallidum) was more pronounced among and also restricted to the young age groups (age range, 15-24 years) in the inner city (from 7.6% in 1995 to 1.3% in 2001; prevalence ratio, 0.69; 95% confidence interval, 0.59-0.80). The declining trends in the prevalence of HIV infection and syphilis among young women attending antenatal care clinics in the inner city are encouraging, but these findings require confirmation in future years and for other population groups.     

Plasma cholinesterase level of Ethiopian farm workers exposed to chemical pesticide

BACKGROUND: Pesticide applications can have unwanted health consequences. AIM: To study cholinesterase levels in farm workers with varying exposure to chemical pesticide. METHODS: Plasma cholinesterase (PChE) was measured in workers at two Ethiopian farms. A standard questionnaire adopted from the British Medical Research Council was used to determine the health status of the subjects. RESULTS: A total of 82 farm workers and 47 controls participated in the study. While the mean values of plasma cholinesterase were generally lower in those exposed, this difference was only significant in the sprayers at Birr farm (P<0.05). In this group, four sprayers had cholinesterase activity lower than 50%. CONCLUSION: The sprayers in both farms were the most affected groups, suggesting that improved controls on workplace exposure to pesticide is required in these groups of workers.