Health and labor productivity : the economic impact of onchocercal skin disease

Teams from two institutions studied the economic impact of health status on productivity and income. They studied whether onchocercal skin disease caused economic damage to the labor force at a coffee plantation in southwest Ethiopia, and how much. The research team estimated the daily wage equation for wage employees. Empirical analysis revealed that permanent male employees, the core of the plantation labor force, suffer significant losses in economic productivity (in the form of lower daily wages earned) as a result of onchocercal skin disease. Depending on the severity of onchocercal skin disease, and controlling for such factors as age, daily wages were 10 to 15 percent lower among those exhibiting skin-related problems.Environmental Economics&Policies,Disease Control&Prevention,Labor Policies,Health Economics&Finance,Public Health Promotion,Economic Theory&Research,Banks&Banking Reform,Environmental Economics&Policies,Youth and Governance,Health Monitoring&Evaluation

Infection Site Dependent Progression of Cutaneous Lesions in African Green Monkeys (Cercopithecus aethiops) Experimentally Infected with Leishmania aethiopica Promastigotes

Studies on experimental infection of Leishmania aethiopica are very limited due to lack of laboratory animal models. It was previously reported that the African green monkey (grivet monkey) could serve as a non–human primate model of L. aethiopica infection. This report provides preliminary data on the development and progression of skin lesions in grivet monkeys when infected with L. aethiopica either in the eye lids or the tip of nose. A total of 22 African green monkeys were inoculated subcutaneously on the eye lid (n=14) or the tip of nose (n=8) with 5 x 106 stationary phase promastigotes of L. aethiopica. No lesions developed on the eye lids. Lesions of various stages of cutaneous leishmaniasis were observed at the tip of nose. The outcome of L. aethiopica infection in African green monkeys and possibly humans could be infection-site dependent. Further studies are needed to examine and understand the immunopathogenetic processes

Development and evaluation of Indirect Hemagglutination Antibody Test (IHAT) for serological diagnosis and screening of bovine cysticercosis in Ethiopia

The study was conducted to develop and evaluate an Indirect Hemagglutination Antibody Test (IHAT) for the serological diagnosis of Cysticercus bovis in live animals. IHAT was set-up in-house and used to test serum samples of cattle against sheep red blood cell (SRBC) coated with crude extracts of C. bovis cyst. Serum samples for screening were collected from Addis Ababa abattoir (n=522), a dairy farm from the suburbs of Addis Ababa (n=101), and a traditional extensive farm (n=109). Postmortem inspection was conducted on a total of 522 animals slaughtered in Addis Ababa Abattoir, out of which 39 (7.5%) were positive for C. bovis.  Thirty-seven of these had viable C. bovis cysts. IHAT titres were determined from serially diluted sera, with a cut-off value set at a titre of 1:64. Cross reaction with other helminths was either absent or very low.  Sensitivity and specificity of the IHAT were 100% and at least 90%, respectively. Based on this test, 149 cattle (28.5%) from the Abattoir, 33 cattle (30.3%) from the extensive farm and 8 cattle (7.9%) from the dairy farm were positive for C. bovis. The difference in prevalence between the dairy farm and extensive farm was significant (

Immunity to Visceral Leishmaniasis

Leishmaniasis is a major vector-borne parasitic disease affecting 12 million people worldwide. With a broad range of clinical manifestations, ranging from self-healing skin ulcers to disfiguring mucosal lesions to life-threatening infections of visceral organs (liver and spleen), the disease has become a serious human health issue, particularly in developing countries. Among all of its forms, visceral leishmaniasis (VL, also known as kala-azar), caused by the Leishmania donovani complex (i.e., L. donovani and L. infantum in Old World and L. chagasi in New World), is often fatal in the absence of treatment. Although humans are the principal hosts for L. donovani, canine species are the main reservoirs of L. infantum. Canine VL affects millions of dogs and is associated with outbreaks of human VL and hence has become a major public health issue. The lack of vaccines to prevent and/or treat these infections, as well as the emergence of drug resistant parasites, is serious impediments to control leishmaniasis. Therefore, developing new prophylactic and therapeutic strategies against this disease is urgently required. However, for this to occur, a better understanding of the complex immune mechanisms generated in response to infection and defining those involved in resistance to infection is required. In this special issue on “Immunity to visceral leishmaniasis”, several selected papers will discuss these issues.Peer reviewe

Molecular surveillance of mutations in the cytochrome b gene of Plasmodium falciparum in Gabon and Ethiopia

BACKGROUND: Atovaquone is part of the antimalarial drug combination atovaquone-proguanil (Malarone(®)) and inhibits the cytochrome bc(1 )complex of the electron transport chain in Plasmodium spp. Molecular modelling showed that amino acid mutations are clustered around a putative atovaquone-binding site resulting in a reduced binding affinity of atovaquone for plasmodial cytochrome b, thus resulting in drug resistance. METHODS: The prevalence of cytochrome b point mutations possibly conferring atovaquone resistance in Plasmodium falciparum isolates in atovaquone treatment-naïve patient cohorts from Lambaréné, Gabon and from South Western Ethiopia was assessed. RESULTS: Four/40 (10%) mutant types (four different single polymorphisms, one leading to an amino acid change from M to I in a single case) in Gabonese isolates, but all 141/141 isolates were wild type in Ethiopia were found. CONCLUSION: In the absence of drug pressure, spontaneous and possibly resistance-conferring mutations are rare

A zoonotic focus of cutaneous leishmaniasis in Addis Ababa, Ethiopia

<p>Abstract</p> <p>Background</p> <p>Cutaneous leishmaniasis (CL) is endemic in the highlands of Ethiopia, and almost always caused by <it>Leishmania aethiopica</it>. Hitherto, Addis Ababa (the capital city of Ethiopia) was not considered endemic for CL, mainly due to absence of epidemiological and field ecological studies. This report summarizes the preliminary epidemiological investigation that proved the existence of active transmission in southeastern Addis Ababa.</p> <p>Results</p> <p>Active case finding surveys were conducted in 3 localities, Saris, Kality, and Akaki, which are found in and around Bulbula-Akaki river gorges. During the surveys conducted in January 2005 - May 2006, a total of 35 cases with 9 active and 26 healed skin lesions were identified. Eighteen of the cases (51.4%) were found in Saris; while 10 (28.6%) and 7 (20%) cases were from Kality and Akaki respectively.</p> <p>Ten colonies of rock hyraxes (<it>Heterohyrax brucei</it>) were identified in the vicinities of the 3 localities. Three of the 48 hyraxes (6.3%) trapped from the surroundings harbored natural infections of <it>Leishmania aethiopica</it>. Confirmation of the <it>Leishmania </it>species of the 3 isolates was achieved by PCR amplification and RFLP analysis of the ribosomal DNA internal transcribed spacer (ITS) sequences. Based on sandfly species composition and proximity of resting sites to human settlements, <it>Phlebotomus longipes </it>is circumstantially proven to be the vector of CL in south east Addis Ababa.</p> <p>Conclusion</p> <p>The study proves the existence of isolated zoonotic foci of CL in south eastern Addis Ababa, with <it>P. longipes </it>as the likely vector and <it>H. brucei </it>as the natural reservoir host.</p

Multilocus sequence and microsatellite identification of intra-specific hybrids and ancestor-like donors among natural Ethiopian isolates of Leishmania donovani.

Protozoan parasites of the genus Leishmania (Kinetoplastida: Trypanosomatidae) cause widespread and devastating human diseases. Visceral leishmaniasis is endemic in Ethiopia where it has also been responsible for fatal epidemics. It is postulated that genetic exchange in Leishmania has implications for heterosis (hybrid vigour), spread of virulent strains, resistance to chemotherapeutics, and exploitation of different hosts and vectors. Here we analyse 11 natural Ethiopian Leishmania donovani isolates consisting of four putative hybrids, seven parent-like isolates and over 90 derived biological clones. We apply a novel combination of high resolution multilocus microsatellite typing (five loci) and multilocus sequence typing (four loci) that together distinguish parent-like and hybrid L. donovani strains. Results indicate that the four isolates (and their associated biological clones) are genetic hybrids, not the results of mixed infections, each possessing heterozygous markers consistent with inheritance of divergent alleles from genetically distinct Ethiopian L. donovani lineages. The allelic profiles of the putative hybrids may have arisen from a single hybridisation event followed by inbreeding or gene conversion, or alternatively from two or more hybridisation events. Mitochondrial sequencing showed uniparental maxicircle inheritance for all of the hybrids, each possessing a single mitochondrial genotype. Fluorescence activated cell sorting analysis of DNA content demonstrated that all hybrids and their associated clones were diploid. Together the data imply that intra-specific genetic exchange is a recurrent feature of natural L. donovani populations, with substantial implications for the phyloepidemiology of Leishmania

Bacteremic community-acquired pneumonia in Ethiopian children : etiology, antibiotic resistance, risk factors, and clinical outcome

Background: Community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality. We sought to determine the magnitude, etiology, and risk factors of CAP in children 5 years after introduction of pneumococcal conjugate vaccine (PCV) 10 in Ethiopia. Methods: We conducted a prospective observational study on the bacterial etiology and risk factors of CAP among children aged 0–15 years in 2 pediatric emergency departments in Addis Ababa, Ethiopia. Blood culture, antibiotic susceptibility testing, and amplification of pneumococcal lytA and cpsB genes were performed. Serotypes of Streptococcus pneumoniae were determined by Quellung reaction and sequencing the cpsB gene. Results: Out of 643 eligible children, 549 were enrolled. The prevalence of bacteremic pneumonia was 5.6%. Staphylococcus aureus (26.5%) was the predominant pathogenic species, followed by Enterococcus faecium (11.8%), Escherichia coli (11.8%), and Klebsiella pneumoniae (11.8%). In univariate analysis, parental smoking and nonvaccination with PCV10 were associated with bacteremic CAP. In multivariable analysis, female sex (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.1–4.9), weight-for-age z-score (WAZ) <–2 SDs (aOR, 2.2; 95% CI, 1.1–4.8), and lower chest indrawing (aOR, 0.44; 95% CI, 0.2–0.95) were independently associated with bacteremic CAP. The overall in-hospital case fatality rate was 2.37% (13/549), and WAZ <–3 SDs (OR, 13.5; 95% CI, 3.95–46.12) was associated with mortality. Conclusions: Five years after the introduction of PCV10 in Ethiopia, S. aureus was the main cause of bacteremic CAP in children, the contribution of S. pneumoniae was low, and there was a high level of antibiotic resistance among isolates