LABORATORY NETWORK FOR HIV INFECTION IN ETHIOPIA

ABSTRACT: One of the main objectives of the Short Tern Plan of the Ethiopian AIDS Control Programme was the establishment of screening laboratories in blood banks in the country and strengthening the Immunology Laboratory of the National Research Institute of Health. As a result, HIV screening laboratories were established in all five blood banks and the National Referral Laboratory for AIDS (NRLA) was established during the first half of the short tenn plan. Based on the Medium Term Plan of the programme which envisaged establishment of HIV screening laboratories in all regional hospitals where a substantial amount of blood transfusion took place, HIV screening laboratories were established. To date there are 24 HIV screening laboratories throughout the country .Nineteen of these laboratories use ELISA tests and 5 use simple/rapid assays. There is a well established quality control and supervision system where each laboratory is visited twice a year and characterized panels of sera are sent to each laboratory three times a year from the NRLA. The plan of the National AIDS Control Programme is to establish screening laboratories in all establishments where blood transfusion is carried out

ELISA FALSE POSITIVITY IN RELATION TO HIV -1 PREVALENCE IN ETHIOPIA

ABSTRACT: A close investigation of data accumulated over several years at the National Referral Laboratory for AIDS (NRLA), revealed a certain pattern in the number of false positive results that occur in population groups with a given prevalence of HIV -1 infection. To provide more accurate information regarding this observation 8850 serum samples from females with multi-partner sexual contact (MPSC) residing in different regions of Ethiopia with varying HIV -1 prevalence rates, were collected and tested using 1st and 2nd generation enzyme immunoassays (EIA) and a western blot. The results obtained from this study suggest that the rate of the occurrence of false positive enzyme linked imrnuno-sorbent assay (ELISA) results during laboratory testing for HIV -1 antibody is (regardless of the quality of antigen used) inversely proportional to the prevalence of HIV-l in a given population group

HIV-1 INFECTION AMONG EMPLOYEES OF THE ETHIOPIAN FREIGHT TRANSPORT CORPORATION

SUMMARY: In the study on HIV-l infection conducted in July 1988, 995 long distance truck drivers, their assistants, and lorry technicians employed by the Ethiopian Freight Transport Corporation (EFTC) were enrolled. 89.4% of trips made by the drivers were along the Addis Ababa -Assab road. The HIV prevalence rates were 13% among 468 drivers, 12.9% among 209 drivers assistants, and 4.1% among 318 technicians. The prevalence rate among those who served for < 5 yrs was 4.7% (n = 297) .Those who served longer in the Corporation (82.9% of whom are drivers) had a mean prevalence rate of 12.5% (n=698). Drivers had more sexual partners and more frequently experienced sexually transmitted diseases than the technicians. The study indicated that the long distance truck drivers in Ethiopia practiced frequent contacts with female sex workers. They were at a significantly higher risk to acquire HIV infection than the technicians employed at the same corporation

Interaction of Dendritic Cells with Skin Endothelium: A New Perspective on Immunosurveillance

The goal of this study was to determine the mechanisms by which dendritic cells (DCs) in blood could interact with endothelium, a prerequisite to extravasation into tissues. Our results indicate that DCs express both HECA-452–reactive and nonreactive isoforms of P-selectin glycoprotein ligand 1 (PSGL-1) and can tether and roll efficiently on E- and P-selectin under flow conditions in vitro. Freshly isolated blood DCs were further observed to roll continuously along noninflamed murine dermal endothelium in vivo. This interaction is strictly dependent on endothelial selectins, as shown by experiments with blocking antibodies and with E- and P-selectin–deficient mice. We hypothesize that DCs in blood are constitutively poised at the interface of blood and skin, ready to extravasate upon induction of inflammation, and we showed that cutaneous inflammation results in a rapid recruitment of DCs from the blood to tissues. We propose that this is an important and previously unappreciated element of immunosurveillance

Chip-based human liver-intestine and liver-skin co-culture : A first step toward systemic repeated dose substance testing in vitro

Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called “human-on-a-chip” concepts are aiming to replace respective animals and humans in substance evaluation with miniaturized functional human organisms. The major technical hurdle toward success in this field is the life-like combination of human barrier organ models, such as intestine, lung or skin, with parenchymal organ equivalents, such as liver, at the smallest biologically acceptable scale. Here, we report on a reproducible homeostatic long-term co-culture of human liver equivalents with either a reconstructed human intestinal barrier model or a human skin biopsy applying a microphysiological system. We used a multi-organ chip (MOC) platform, which provides pulsatile fluid flow within physiological ranges at low media-to-tissue ratios. The MOC supports submerse cultivation of an intact intestinal barrier model and an air–liquid interface for the skin model during their co-culture with the liver equivalents respectively at 1/100.000 the scale of their human counterparts in vivo. To increase the degree of organismal emulation, microfluidic channels of the liver–skin co-culture could be successfully covered with human endothelial cells, thus mimicking human vasculature, for the first time. Finally, exposure routes emulating oral and systemic administration in humans have been qualified by applying a repeated dose administration of a model substance – troglitazone – to the chip-based co-cultures.BMBF/0315569/GO-Bio 3: Multi-Organ-Bioreaktoren für die prädiktive Substanztestung im Chipforma

HIV-1 INFECTION AND RELATED RISK FACTORS AMONG FEMALE SEX WORKERS IN URBAN AREAS OF ETHIOPIA

SUMMARY: A total of 6234 female sex workers practicing multi-partner sexual contacts (MPSC) from 23 urban areas of the country were tested for Human Immuno deficiency Virus type 1 (HIV1) infection, in 1988. The sample size ranged from 99 persons in Moyale, to 386 in Asmara. The mean age of the individuals studied was 24.2 years (ranging from 21.5 years to 27.1 years in the different towns). The HIV-1 prevalence rates varied from 1.3% (n=318) in Massawa, to 38.1% (n=312) in Dessie town; the mean for all towns being 17%. The highest prevalence rates were found in the towns along the road from Addis Ababa to Assab, in Bahr-Dar , Dessie and Mekele. The lowest prevalence rates were recorded in three towns of northern Ethiopia. This study indicated that Hiv-1 is widely spread in the urban areas of Ethiopia affecting female sex workers mainly in the 15-29 years age group. Previous episodes of other sexually transmitted diseases, and frequent change of sexual partners were identified as possible risk factors for HIV infection. Frequent mobility of these females may have played a significant role in HIV transmission between the towns

HIV -1 INFECTION AND SOME RELATED RISK FACTORS AMONG FEMALE SEX WORKERS IN ADDIS ABABA

SUMMARY: A sero-epidemiological survey on HIV-l infection was carried out in July 1989, among four groups of female sex workers randomly selected in Addis Ababa. The four groups were comprised of: bar girls, tej (traditional wine) sellers, tella (traditional beer) sellers and females in red light houses. Sera were tested by ELISA and confirmed y western blot. The mean age of the 2617 females studied was 31.2 years, and the prevalence rate for HIV-1 was 24.7%. Persons in the 15-24 age group were affected more frequently. The highest prevalence (43.8%) was found among the females in red light houses. Females with relatively larger number of sexual partners and those who had previous exposure to STDs, had a higher prevalence of the infection. The survey revealed that HIV-1 is highly prevalent among females practicing multi-partner sexual contact (MPSC) in Addis Ababa, and the infection concentrates in the central areas of the city

Hyperosmolal vaginal lubricants markedly reduce epithelial barrier properties in a three-dimensional vaginal epithelium model

Most of the widely used vaginal lubricants in the U.S. and Europe are strongly hyperosmolal, formulated with high concentrations of glycerol, propylene glycol, polyquaternary compounds or other ingredients that make these lubricants 4 to 30 times the osmolality of healthy vaginal fluid. Hyperosmolal formulations have been shown to cause marked toxicity to human colorectal epithelia in vivo, and significantly increase vaginal transmission of genital herpes infections in the mouse/HSV model. They also cause toxicity to explants of vaginal epithelia, to cultured vaginal epithelial cells, and increase susceptibility to HIV in target cells in cell cultures. Here, we report that the osmolality of healthy vaginal fluid is 370 ± 40 mOsm/Kg in women with Nugent scores 0–3, and that a well-characterized three-dimensional human vaginal epithelium tissue model demonstrated that vaginal lubricants with osmolality greater than 4 times that of vaginal fluid (>1500 mOsm/Kg) markedly reduce epithelial barrier properties and showed damage in tissue structure. Four out of four such lubricants caused disruption in the parabasal and basal layers of cells as observed by histological analysis and reduced barrier integrity as measured by trans-epithelial electrical resistance (TEER). No epithelial damage to these layers was observed for hypo- and iso-osmolal lubricants with osmolality of <400 mOsm/Kg. The results confirm extensive reports of safety concerns of hyperosmolal lubricants and suggest the usefulness of reconstructed in vitro vaginal tissue models for assessing safety of lubricants in the absence of direct clinical tests in humans. Keywords: Vaginal lubricant, Osmolality, EpiVaginal tissue, Epithelial damag

Activated CD34-Derived Langerhans Cells Mediate Transinfection with Human Immunodeficiency Virus▿

Langerhans cells (LCs) are a subset of dendritic cells (DCs) that reside within epidermal and mucosal tissue. Because of their location, LCs are potentially the first cells to encounter human immunodeficiency virus (HIV) during sexual transmission. We report that LCs purified from CD34+-derived DCs can facilitate the transinfection of target cells but only after activation. Virions were observed in an intracellular compartment that contains several tetraspanins, in addition to the unique LC markers langerin and CD1a. This reveals that the trafficking of HIV within LCs is reminiscent of that which occurs in mature monocyte-derived DCs and that it varies with the activation state of the cell. The observation that activated LCs can mediate transinfection suggests a potential role for these cells in the known increase in HIV transmission associated with sexually transmitted infections that would cause inflammation of the genital lining