South Ethiopia Network of Universities in Public Health

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The Norwegian Programme for Capacity Development in Higher Education and Research for Development (NORHED) recently told us that we have been awarded the project:  South Ethiopia Network of Universities in Public Health (SENUPH): improving women’s participation in post-graduate education. 

The vision of this project is to enhance the capacity of universities in south Ethiopia to train sufficient staff for the Region to carry out essential public health work, and do essential research to improve the health of the people living in South Ethiopia. This will be carried out by:

  • Establishing, and strengthening a network of the main universities in south Ethiopia doing teaching so the universities can increase their teaching capacity and train enough staff to meet the demands within the public health sector.
  • Substantially increasing the number of women with postgraduate education
  • Increasing the number of teachers at the universities in public health.
  • Strengthening the research capacity through PhD and Master’s programme so the research done in the region will aid in defining the future health policy.

This project has four integrated parts:

  • A PhD programme for all universities and located at Hawassa University
  • A master programme in Maternal and Reproductive health at Dilla University
  • A master programme in Nutrition at Wolaita Soddo University and
  • A master programme in medical entomology (malaria control) at Arba Minch University).

By developing a network of the main universities in south Ethiopia we will address several important areas such as staff development, and enhance the human capacity in higher education, in public health, reproductive health, and nutrition and malaria control.

The Southern Nations, Nationalities  and Peoples Region in Ethiopia has a population of about 16 million people, representing  more than 50 ethnic groups that live in a variety of geographic and socioeconomic areas. The area is typical of Ethiopia with high population densities, high fertility and child mortality rates, and high maternal death rates.

Detecting P. falciparum and P. vivax

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This paper reviews the sensitivity and specificity of RDTs for detecting P. falciparum and P. vivax in two different settings ¿ at health centres and in a household survey. The study includes a large number of patients (2,394 participants) and provides useful additional information about the performance of these RDTs.

Woyessa A, Deressa W, Ali A, Lindtjørn B. Evaluation of CareStartTM malaria Pf/Pv combo test for Plasmodium falciparum and Plasmodium vivax malaria diagnosis in Butajira area, south-central Ethiopia. Malaria Journal 2013, 12:218 doi:10.1186/1475-2875-12-218

Ethiopian community health workers improve TB Care

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Some years ago we did two trials [1 2] to improve case finding of tuberculosis in South Ethiopia. Our study from Sidama in South Ethiopia showed that involving Health Extension workers in Tuberculosis control improved the case detection (from 69 to 122 %) for smear-positive patients and females in particular [1]. We advised that this intervention could be used as an option to improve case detection and provide patient-centred services in high-burden countries. In a later study, we showed that this intervention is a cost-effective treatment alternative to the health service and to the patients and their caregivers [3].

We advised there is both an economic and public health reason to consider involving HEWs in TB treatment in Ethiopia.

Now a large consortium (Stop TB Partnership’s TB REACH initiative and implemented by the Southern Region Health Bureau and the Liverpool school of Tropical Medicine in collaboration with the Ministry of Health and the Global Fund) has scaled up this intervention in Sidama [4]. Their findings are similar to our earlier research: “Community-based interventions made TB diagnostic and treatment services more accessible to the poor, women, elderly and children, doubling the notification rate (from 64 to 127%) and improving treatment result. They advise that this approach could improve TB diagnosis and treatment in other high burden settings”.

I hope that they also present some findings on how this good intervention can be made sustainable in settings such as Sidama.

References

1. Datiko DG, Lindtjørn B. Health extension workers improve tuberculosis case detection and treatment success in southern Ethiopia: a community randomized trial. PLoS One 2009;4(5):e5443 doi: 10.1371/journal.pone.0005443[published Online First: Epub Date]|.

2. Shargie EB, Morkve O, Lindtjorn B. Tuberculosis case-finding through a village outreach programme in a rural setting in southern Ethiopia: community randomized trial. Bull World Health Organ 2006;84(2):112-9 

3. Datiko DG, Lindtjorn B. Cost and cost-effectiveness of smear-positive tuberculosis treatment by Health Extension Workers in Southern Ethiopia: a community randomized trial. PLoS One 2010;5(2):e9158 doi: 10.1371/journal.pone.0009158[published Online First: Epub Date]|.

4. Yassin MA, Datiko DG, Tulloch O, et al. Innovative Community-Based Approaches Doubled Tuberculosis Case Notification and Improve Treatment Outcome in Southern Ethiopia. PLoS ONE 2013;8(5):e63174 doi: 10.1371/journal.pone.0063174[published Online First: Epub Date]|.

Cattle (and mosquitoes) in Africa

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New research uses almost 50 years of data to investigate how climate has affected cattle holdings in Africa since 1961. Such research is important also to understand the distribution of mosquitoes that transmit malaria.

Lunde TM and Lindtjørn B. Cattle and climate in Africa: How climate variability has influenced national cattle holdings from 1961–2008. PeerJ 2013; 1:e55 

The role of cattle in developing countries is as a source of high-quality food, as draft animals, and as a source of manure and fuel. Cattle represent important contribution to household incomes, and in drought prone areas they can act as an insurance against weather risk. So far, no studies have addressed how historical variations in temperature and rainfall have influenced cattle populations in Africa.

The focus of this study is to assess the historical impact of climate variability on national cattle holdings. We reconstruct the cattle density and distribution for two time periods; 1955–1960 and 2000–2005. Based on estimates from FAO and official numbers, we generated a time series of cattle densities from 1961–2008, and compared these data with precipitation and temperature anomalies for the same period.

We show that from 1961–2008 rainfall and temperature have been modulating, and occasionally controlling, the number of cattle in Africa.

Model to validate species distribution and seasonal variation

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This article is a validation of a mathematical model described earlier.Overall, the model gives a realistic representation of seasonal and year-to-year variability in mosquito densities and it can accurately predict the distribution of An. gambiae s.s. and An. arabiensis in sub-Saharan Africa. It may be used for seasonal and long-term predictions of changes in the burden of malaria.

Lunde TM, Balkew M, Korecha D, Gebre-Michael T, Massebo F, Sorteberg A and Lindtjørn B. A dynamic model of some malaria-transmitting anopheline mosquitoes of the Afrotropical region. II. Validation of species distribution and seasonal variations. Malaria Journal 2013, 12:78

Background  The first part of this study aimed to develop a model for Anopheles gambiae s.l. with separate parametrization schemes for Anopheles gambiae s.s. and Anopheles arabiensis. The characterizations were constructed based on literature from the past decades. This part of the study is focusing on the model’s ability to separate the mean state of the two species of the An. gambiae complex in Africa. The model is also evaluated with respect to capturing the temporal variability of An. arabiensis in Ethiopia. Before conclusions and guidance based on models can be made, models need to be validated.

Methods  The model used in this paper is described in part one (Malaria Journal 2013, 12:28). For the validation of the model, a data base of 5,935 points on the presence of An. gambiae s.s. and An. arabiensis was constructed. An additional 992 points were collected on the presence An. gambiae s.l.. These data were used to assess if the model could recreate the spatial distribution of the two species. The dataset is made available in the public domain. This is followed by a case study from Madagascar where the model’s ability to recreate the relative fraction of each species is investigated. In the last section the model’s ability to reproduce the temporal variability of An. arabiensis in Ethiopia is tested. The model was compared with data from four papers, and one field survey covering two years.

Results  Overall, the model has a realistic representation of seasonal and year to year variability in mosquito densities in Ethiopia. The model is also able to describe the distribution of An. gambiae s.s. and An. arabiensis in sub-Saharan Africa. This implies this model can be used for seasonal and long term predictions of changes in the burden of malaria. Before models can be used to improving human health, or guide which interventions are to be applied where, there is a need to understand the system of interest. Validation is an important part of this process. It is also found that one of the main mechanisms separating An. gambiae s.s. and An. arabiensis is the availability of hosts; humans and cattle. Climate play a secondary, but still important, role.

Anopheles mosquitoes in three villages

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This is a report on the Anopheles fauna found in three different villages located at three different altitudes ranging from 1,800 meters to 2,200 metres, showing the human/cattle blood meal preference for each species and the sporozoite rate and entomological inoculation rate for the vectors.

Animut A, Balkew M, Gebre-Michael T and Lindtjørn B. Blood meal sources and entomological inoculation rates of anophelines along a highland altitudinal transect in south-central Ethiopia. Malaria Journal 2013, 12:76 doi:10.1186/1475-2875-12-76

Background The role of anophelines in transmitting malaria depends on their distribution, preference to feed on humans and also their susceptibility to Plasmodium gametocytes, all of which are affected by local environmental conditions. Blood meal source and entomological inoculation rate of anophelines was assessed along a highland altitudinal transect in south- central Ethiopia.

Methods Monthly adult anopheline sampling was undertaken from July 2008 to June 2010 in Hobe (low altitude), Dirama (mid altitude) and Wurib (high altitude) villages located at average elevations of 1800 m, 2000 m and 2200 m, respectively. Anophelines were collected using CDC light trap, pyrethrum space spray catches (PSC) and artificial pit shelter methods. Upon collection, females were categorized according to their abdominal status and identified to species. Their human blood index, sporozoite rate and entomological inoculation rate was determined.

Results A total of 4,558 female anophelines of which Anopheles arabiensis was the most prevalent (53.3%) followed by Anopheles demeilloni (26.3%), Anopheles christyi (8.9%), Anopheles pharoensis (7.9%) and Anopheles cinereus (3.6%) were caught and tested for blood meal source or sporozoite infection depending on their abdominal status. The proportions of human fed and bovine fed An. arabiensis were generally similar. In the low altitude village, there were 0.3% (1/300) and 0.2% (1/416) Plasmodium falciparum infected An. arabiensis among the CDC trap catches and PSC respectively. The percentage of Plasmodium vivax infected An. arabiensis were 3% (9/300) and 0.7(3/416) among the CDC and PSCs respectively in the village. In addition, there were 1.4% (1/71) and 50% (1/2) P. vivax infected An. pharoensis from the CDC light trap and PSCs, respectively. In the mid altitude village, 2.5% (1/40) and 1.7% (1/58) from among the CDC and PSCs of An. arabiensis respectively carried P. vivax sporozoites. Among the CDC light trap catches; there were 3.7 and 0 P. falciparum infective bites per year per household for An. arabiensis in the years July 2008 to June 2009 and July 2009 to June 2010 respectively in the low altitude village. The corresponding numbers for P. vivax infective bites for An. arabiensis were 33 and 14.5 in the same village. Space spray catches revealed 0.32 P. vivax infective bites per household for An. pharoensis during the first year in the low altitude village.

Conclusion Anopheles arabiensis was the most prevalent vector of P. vivax and P. falciparum malaria in the low and mid altitude villages followed by An. pharoensis. Annual entomological inoculation rates showed that vivax malaria transmission was higher than that of the falciparum and both decreased with increase in altitude.

Insecticide resistance in Southwest Ethiopia

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The greater tendency of An. arabiensis to feed on cattle justifies the application of insecticides on cattle to provide a significant protection from malaria infection. But, An. arabiensis has already developed resistance to the available insecticides, and alternative insecticides are needed.

Massebo F, Balkew M, Gebre-Michael T and Lindtjørn B. Blood meal origins and insecticide susceptibility of Anopheles arabiensis from Chano in South-West Ethiopia. Parasites & Vectors 2013, 6:44 doi:10.1186/1756-3305-6-44

Background  Anopheles arabiensis, the main malaria vector in Ethiopia, shows both anthropophilic and zoophilic behaviours. Insecticide resistance is increasing, and alternative methods of vector control are needed. The objectives of this study were to determine the blood meal origins and the susceptibility to insecticides of An. arabiensis from Chano village near Arba Minch in South-West Ethiopia.

Methods  Blood meal sources of anopheline mosquitoes collected using Centers for Disease Control and Prevention (CDC) light traps and pyrethrum spray catches (PSC) from human dwellings, and hand-held mouth aspirators from outdoor pit shelters were analysed using a direct enzyme-linked-immunosorbent assay (ELISA). The susceptibility of An. arabiensis to pyrethroid insecticides (alphacypermethrin, lambdacyhalothrin, deltamethrin, and cyfluthrin) and DDT was assessed using females reared from larval and pupal collections from natural breeding sites.

Results  The blood meal origins of 2967 freshly fed Anopheles mosquitoes were determined. An. arabiensis was the predominant species (75%), and it fed mainly on cattle. The densities of both freshly fed An. arabiensis and those fed on human blood followed similar seasonal patterns. The overall human blood index (HBI) of An. arabiensis, including mixed blood meals, was 44% and the bovine blood index (BBI) was 69%. The HBI of An. arabiensis from CDC light trap collections was 75% and this was higher than those for PSC (38%) and outdoor pit shelter collections (13%), while the BBI was 65% for PSC, 68% for outdoor pit shelters and 72% for CDC light traps. More freshly fed and human blood-fed An. arabiensis were sampled from houses close to the shore of Lake Abaya (the major breeding site). A high proportion of An. arabiensis was resistant to the pyrethroid insecticides, with a mortality rate of 56% for lambdacyhalothrin, 50% for cyfluthrin and alphacypermethrin, 47% for deltamethrin, and 10% for DDT.

Conclusion  Anopheles arabiensis is the predominant species of anopheline mosquito in this region, and cattle are the main source of its blood meals. The greater tendency of this species to feed on cattle justifies the application of insecticides on cattle to control it. However, An. arabiensis has already developed resistance to the available pyrethroid insecticides, and alternative insecticides are needed for malaria vector control.

Malaria model

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This study highlights some of the assumptions commonly used when constructing mosquito-malaria models and presents a realistic model of Anopheles gambiae s.s. and Anopheles arabiensis, and their interaction.

We make a case that this new mosquito model, OMaWa, may improve the understanding of vector dynamics, which in turn can be used to better understand the dynamics of malaria.

Lunde TM, Korecha D, Loha E, Sorteberg A and Lindtjørn B. A dynamic model of some malaria-transmitting anopheline mosquitoes of the Afrotropical region. I. Model description and sensitivity analysis. Malaria Journal 2013, 12:28

Background: Most of the current biophysical models designed to address the large-scale distribution of malaria assume that transmission of the disease is independent of the vector involved. Another common assumption in these type of model is that the mortality rate of mosquitoes is constant over their life span and that their dispersion is negligible. Mosquito models are important in the prediction of malaria and hence there is a need for a realistic representation of the vectors involved.

Results: We construct a biophysical model including two competing species, Anopheles gambiae s.s. and Anopheles arabiensis. Sensitivity analysis highlight the importance of relative humidity and mosquito size, the initial conditions and dispersion, and a rarely used parameter, the probability of finding blood. We also show that the assumption of exponential mortality of adult mosquitoes does not match the observed data, and suggest that an age dimension can overcome this problem.

Conclusions: This study highlights some of the assumptions commonly used when constructing mosquito-malaria models and presents a realistic model of An. gambiae s.s. and An. arabiensis and their interaction. This new mosquito model, OMaWa, can improve our understanding of the dynamics of these vectors, which in turn can be used to understand the dynamics of malaria.