Hominid cranial bone structure: a histological study of Omo 1 specimens from Ethiopia using different microscopic techniques.
(57/1130)The microstructure of a hominid cranial vault has not previously been studied to determine its tissue histology, and differences in comparison with that of modern humans. We selected the parietals of Omo-Kibish 1, regarded as one of the oldest (about 130,000 years old) anatomically modern humans, and Omo 1 (Howell), which is a very recent human (about 2,000 years old)-both from the same area of Ethiopia. A combination of macrophotography, polarizing microscopy in the incident and transmission illumination mode, and confocal laser scanning microscopy (CLSM) was employed to examine thin sections, as well as polished and unpolished block faces of unembedded bone fragments, to minimize specimen destruction as much as possible. The methods enabled remarkably detailed information on bone microstructure and remodeling to be gleaned from tiny fragments of bone. The best method for examining fossilized human bones was shown to be that of incident light microscopy, which was the least destructive while producing the most amount of information. Unless the above methods are used, bone-filling minerals, such as calcite, can cause erroneous estimations of bone thickness, as observations with the naked eye or even a magnifying glass cannot determine the limit between the cortex and the diploe. This is particularly important for sciences such as paleoanthropology, in which, for instance, a thick cranial bone of Homo erectus may be confused with a pathological one of H. sapiens and vice versa. Cross sections of parietal bones revealed differences between Omo-Kibish 1 and Omo 1 (Howell) in diploic histology and in the relative thickness between the cortex and diploe, with the former specimen having an H. erectus ratio despite its H. sapiens gross anatomy. Omo-Kibish 1 may still retain some affinities with H. erectus despite its being classified as H. sapiens. Newly described histological structures, such as the reverse type II osteons, the multicanalled osteons, and the osteocytomata are presented here. A modern human skeletal anatomy does not necessarily imply a modern human cranial bone histology. The outer circumferential lamellae of cranial bones are in essence growth lines. Cranial histology of hominids may provide useful information concerning their taxonomy and life history, including such factors as growth rate, developmental stress, and diet. (+info)
Dark adaptation pattern of pregnant women as an indicator of functional disturbance at acceptable serum vitamin A levels.
(58/1130)BACKGROUND: As a result of lack of precise guidelines, nutritional surveys on adults and high-risk groups are using diverse reference values as a dividing line between normal and deficient vitamin A status. OBJECTIVE: To investigate whether pregnant women at marginally normal serum retinol status exhibit functional alteration that are characteristic of a deficiency state. SETTING: Antenatal clinic, Gondar teaching hospital. SUBJECTS: Ninety-six healthy pregnant women were recruited for the study at the antenatal clinic. INTERVENTION: The dark adaptation time was tested in 48 pregnant women with marginal serum retinol level. The time lapse to see successive light stimuli of diminishing luminescence grade and change in retinal sensitivity pattern was measured using dark adaptometer. Results were compared with the results of a control group of women of similar age, parity and gestational period but with serum retinol values above 35 microg/dl. RESULTS: The mean serum retinol levels of cases and controls were 23.35 microg/dl and 40.47 microg/dl respectively (P<0.008). Cases have a lower dark adaptation than their controls, shown by their remarkably reduced sensitivity to light. For instance at mean final light threshold was -2.20+/-0.11 log cd/m(2) in cases as compared to -2.88+/-0.1 log cd/m(2) in the normal group (P<0.001). CONCLUSION: During pregnancy, dark adaptation was strongly associated with serum retinol concentration and women with marginal vitamin A concentration had lower dark adaptation. Hence marginally normal serum retinol levels should be categorized as a deficiency state, at least in pregnant women. (+info)
Prevalence of and risk factors for HIV infection in blood donors and various population subgroups in Ethiopia.
(59/1130)The aim was to determine the prevalence of HIV infection and risk factors for HIV infection in various population subgroups in Ethiopia. Serum panels from blood donors (n = 2610), from various population subgroups in Ethiopia were tested for anti-HIV-1/2 by ELISA. All ELISA repeatedly reactive samples were subjected for confirmation by immunoblot (IB) and anti-HIV-1 and anti-HIV-2 specific ELISAs. 155/2610 (5.9%) blood donors were HIV-1 infected. Of pregnant women, 84/797 (10.5%) were HIV-1 infected, and 1/797 (0.1%) was HIV-2 infected. 1/240 (0.4%) individuals from the rural population were HIV-1 infected. 198/480 (41.3%) female attendees, and 106/419 (25.3%) male attendees at sexual transmitted disease (STD) clinics were HIV-1 infected. One (0.2%) male, and 2 (0.4%) female STD patients were infected with both HIV-1 and HIV-2. It was concluded that the prevalence of HIV-1 infection varied from 0.4% among urban residents to 25.3-41.3% among STD attendees. There is a low prevalence of HIV-2 present in Ethiopian subjects. Risky sexual behaviour is significantly associated with HIV-infection in Ethiopia. (+info)
Evaluation of a whole-blood interferon-gamma release assay for the detection of Mycobacterium tuberculosis infection in 2 study populations.
(60/1130)A whole-blood interferon-gamma release assay (IGRA) is being evaluated for its potential to replace the tuberculin skin test (TST) for detecting Mycobacterium tuberculosis infection. To test the assay in a population in which tuberculosis is highly endemic and in another population that is representative of an urban United States population, 253 volunteers from Ethiopia and 175 volunteers from Baltimore were studied for responsiveness on IGRA compared with a simultaneously performed TST. The agreement between the 2 tests, beyond that due to chance, was 68% among subjects from Baltimore and only 35% among those from Ethiopia. IGRA had a sensitivity of 71%, compared with 95% sensitivity for the TST, among 21 subjects who had undergone treatment for culture-confirmed tuberculosis. The specificity was 85% for IGRA and 96% for TST among 52 subjects with no known history of exposure to tuberculosis. In its current form, with purified protein derivative used as the stimulation antigen, the IGRA was found to perform poorly in comparison to the TST in diagnosing M. tuberculosis infection. (+info)
Low incidence of syphilis among factory workers in Ethiopia: effect of an intervention based on education and counselling.
(61/1130)BACKGROUND: The prevalence and incidence of syphilis infection were examined in a cohort study of factory workers in Ethiopia. METHOD: Between February 1997 and March 1999, 409 men and 348 women were enrolled and followed in the cohort study. RESULTS: The prevalence (95% CI) of past/current syphilis (positive TPPA serology) was 28.9% (25.7% to 32.3%), and factors associated with past/current syphilis were markers of risky sexual behaviours including HIV infection. In this cohort of factory workers subject to public information/education meetings, testing for HIV antibodies, and individual counselling, the incidence (97.5% one sided CI) of new syphilis infections was 0/691 = 0 (0 to 0.5) per 100 person years. CONCLUSION: This study has documented a reduction in risky sexual behaviours and a low syphilis incidence among factory workers participating in a cohort study on HIV infection progression in Addis Ababa. (+info)
The new middle level health workers training in the Amhara regional state of Ethiopia: students' perspective.
(62/1130)BACKGROUND: Following health sector reform, Ethiopia started training new categories of health workers. This study addresses students' perspectives regarding their training and career plans. METHODS: A cross sectional questionnaire was administered to 145 students in the three schools of the Amhara regional state of Ethiopia. RESULTS: The majority of students were male (62%) and originally from urban areas (76%). Job search was the most common reason for enrolling in the training for almost half (48%) of the respondents, followed by a desire to help the sick (46%). Once trained, the majority (98%) of graduates preferred to serve in the government sector and in rural health institutions (84%). Females were more willing to work in rural settings [chi2 (df 1)= 7.37; P = 0.007]. The majority (98%) of students felt the training period should be extended. 12% of graduates lacked confidence in their competencies after completing the training. A substantial proportion of the respondents (29%) did not feel the social science courses (Anthropology, Ecology and Psychology) were useful. CONCLUSIONS: This study demonstrates that mid-level health professional students are highly motivated, wish to address the health needs of rural communities, and are interested in professional development. However, students do not feel the training programs are fully addressing their needs. The students found that the duration of the training, the time for theory and practice, the availability of teaching materials, the course contents and their teachers were inadequate. This study suggests that the current training programs have serious inadequacies that need to be addressed. (+info)
Patient and health service delay in the diagnosis of pulmonary tuberculosis in Ethiopia.
(63/1130)BACKGROUND: Delay in the diagnosis of tuberculosis may worsen the disease, increase the risk of death and enhance tuberculosis transmission in the community. This study aims to determine the length of delay between the onset of symptoms and patients first visit to health care (patient delay), and the length of delay between health care visit and the diagnosis of tuberculosis (health service delay). METHODS: A cross sectional survey that included all the public health centres was conducted in Addis Ababa from August 1 to December 31 1998. Patients were interviewed on the same day of diagnosis using structured questionnaire. RESULTS: 700 pulmonary TB patients were studied. The median patient delay was 60 days and mean 78.2 days. There was no significant difference in socio-demographic factors in those who delayed and came earlier among smear positives. However, there was a significant difference in distance from home to health institute and knowledge about TB treatment among the smear negatives. The health service delay was low (median 6 days; mean 9.5 days) delay was significantly lower in smear positives compared to smear negatives. Longer health service delay (delay more than 15 days) was associated with far distance. CONCLUSIONS: The time before diagnosis in TB patients was long and appears to be associated with patient inadequate knowledge of TB treatment and distance to the health centre. Further decentralization of TB services, the use of some components of active case finding, and raising public awareness of the disease to increase service utilization are recommended. (+info)
Forecasting malaria incidence from historical morbidity patterns in epidemic-prone areas of Ethiopia: a simple seasonal adjustment method performs best.
(64/1130)The aim of this study was to assess the accuracy of different methods of forecasting malaria incidence from historical morbidity patterns in areas with unstable transmission. We tested five methods using incidence data reported from health facilities in 20 areas in central and north-western Ethiopia. The accuracy of each method was determined by calculating errors resulting from the difference between observed incidence and corresponding forecasts obtained for prediction intervals of up to 12 months. Simple seasonal adjustment methods outperformed a statistically more advanced autoregressive integrated moving average method. In particular, a seasonal adjustment method that uses mean deviation of the last three observations from expected seasonal values consistently produced the best forecasts. Using 3 years' observation to generate forecasts with this method gave lower errors than shorter or longer periods. Incidence during the rainy months of June-August was the most predictable with this method. Forecasts for the normally dry months, particularly December-February, were less accurate. The study shows the limitations of forecasting incidence from historical morbidity patterns alone, and indicates the need for improved epidemic early warning by incorporating external predictors such as meteorological factors. (+info)