Human-biting activities of Anopheles species in Ethiopia

Kenea O, Balkew M, Tekie H, Gebre-Michael T, Deressa W, Loha E, Lindtjørn B, Overgaard HJ: Human-biting activities of Anopheles species in south-central Ethiopia. Parasites & vectors 2016, 9(1):1-12.

Abstract

Background    Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are the key malaria vector control interventions in Ethiopia. The success of these interventions rely on their efficacy to repel or kill indoor feeding and resting mosquitoes. This study was undertaken to monitor human-biting patterns of Anopheles species in south-central Ethiopia.

Methods   Human-biting patterns of anophelines were monitored for 40 nights in three houses using human landing catches (HLC) both indoors and outdoors between July and November 2014, in Edo Kontola village, south-central Ethiopia. This time coincides with the major malaria transmission season in Ethiopia, which is usually between September and November. Adult mosquitoes were collected from 19:00 to 06:00 h and identified to species. Comparisons of HLC data were done using incidence rate ratio (IRR) calculated by negative binomial regression. The nocturnal biting activities of each Anopheles species was expressed as mean number of mosquitoes landing per person per hour. To assess malaria infections in Anopheles mosquitoes the presence of Plasmodium falciparum and P. vivax circumsporozoite proteins (CSP) were determined by enzyme-linked immunosorbent assay (ELISA).

Results   Altogether 3,408 adult female anophelines were collected, 2,610 (76.6 %) outdoors and 798 (23.4 %) indoors. Anopheles zeimanni was the predominant species (66.5 %) followed by An. arabiensis (24.8 %), An. pharoensis (6.8 %) and An. funestus (s.l.) (1.8 %).

The overall mean anopheline density was 3.3 times higher outdoors than indoors (65.3 vs19.9/person/night, IRR: 3.3, 95 % CI: 1.1–5.1, P = 0.001). The mean density of An. zeimanniAn. pharoensis and An. funestus (s.l.) collected outdoors was significantly higher than indoors for each species (P < 0.05). However, the mean An. arabiensis density outdoors was similar to that indoors (11.8 vs 9.4/person/night, IRR: 1.3, 95 % CI: 0.8–1.9, P = 0.335). The mean hourly human-biting density of An. arabiensis was greater outdoors than indoors and peaked between 21:00 and 22:00 h. However, An. arabiensis parous population showed high indoor man biting activities during bedtimes (22:00 to 05:00 h) when the local people were indoor and potentially protected by IRS and LLINs. All mosquito samples tested for CSP antigen were found negative to malaria parasites.

Conclusions   Results show much greater mosquito human-biting activities occurring outdoors than indoors and during early parts of the night, implying higher outdoor malaria transmission potential in the area. However, high bedtime (22:00 to 05:00 h) indoor biting activities of parous An. arabiensissuggest high potential intervention impact of IRS and LLINs on indoor malaria transmission.

New information about malnutrition in Ethiopia

Seifu-thesis coverNew PhD: On September 16, Seifu Hagos Gebreyesus from Ethiopia, shall defend his PhD work at the University of Bergen:

Spatial variations in child undernutrition in Ethiopia: Implications for intervention strategies

Summary

Background: Ethiopia is one of the countries with the highest burden of undernutrition, with rates of stunting and underweight as high as 40% and 25%, respectively. National efforts are underway for an accelerated reduction of undernutrition by the year 2030. However, for this to occur, understanding the spatial variations in the distribution of undernutrition on a varying geographic scale, and its determinants will contribute a quite a bit to enhance planning and implementing nutrition intervention programmes.

Objectives: The aim of this thesis was to evaluate the large- and small-scale spatial variations in the distribution of undernutrition indicators, the underlying processes and the factors responsible for the observed spatial variations.

Methods: We used nationally available climate and undernutrition data to evaluate the macro-scale spatial pattern of undernutrition and its determinants. We applied a panel study design, and evaluated the effect of growing seasonal rainfall and temperature variability on the macro-scale spatial variations (Paper I). We conducted a repeated cross- sectional survey to assess the performance of the Household Food Insecurity Access Scale (HFIAS) developed internationally to measure household food insecurity. The results from this validation work were used to modify the HFIAS items for subsequent papers (Papers III and IV). We conducted a census on six randomly selected kebeles to evaluate the spatial patterns of undernutrition on a smaller scale (Paper III). For Paper IV, we conducted a cross-sectional survey on a representative sample, and employed a Bayesian geo-statistical model to help identify the risk factors for stunting, thereby accounting for the spatial structure (spatial dependency) of the data.

Results: In Paper I, we demonstrated spatial variations in the distribution of stunting across administrative zones in the country, which could be explained in part by rainfall. However, the models poorly explained the variation in stunting within an administrative zone during the study period. We indicated that a single model for all agro-ecologic zones may not be appropriate. In Paper II, we showed that the internal consistency of the HFIAS’ tools, as measured by Cronbach’s alpha, was adequate. We observed a lack of reproducibility in HFIAS score among rural households. Therefore, we modified the HFAIS tool, and used it for subsequent surveys in this thesis (Papers III and IV). In Paper III, spatial clustering on a smaller scale (within a kebele) was found for wasting and severe wasting. Spatial clustering on a higher scale (inter-kebele) was found for stunting and severe stunting. Children found within the identified cluster were 1.5 times more at risk of stunting, and nearly five times more at risk of wasting, than children residing outside this cluster. In Paper IV, we found a significant spatial heterogeneity in the distribution of stunting in the district. Using both the local Anselin Moran’s I (LISA) and the scan statistics, we identified statistically significant clusters of high value (hotspots) and a most likely significant cluster for stunting in the eastern part of the district. We found that the risk of stunting was higher among boys, children whose mother or guardian had no education and children who lived in a food-insecure household. We showed that including a spatial component (spatial structure of the data) into the Bayesian model improved the model fit compared with the model without this spatial component.

Conclusion: We demonstrated that stunting and wasting exhibited a spatial heterogeneity, both on a large and small scale, rather than being distributed randomly. We demonstrated that there is a tendency for undernourished cases (stunting and wasting) to occur near each other than to occur homogeneously. We demonstrated a micro-level spatial variation in risk and vulnerability to undernutrition in a district with a high burden of undernutrition. Identifying such areas where a population at risk lives is central in assisting a geographical targeting of intervention. We recommend further study, possibly using a trial design or implementation research approach, to help evaluate the feasibility and benefits of geographically targeting nutritional interventions.

The thesis can be downloaded here.

Important research on tuberculosis control

Mesay-thesis title

New PhD: On September 5, Mesay Hailu Dangisso from Ethiopia, shall defend his PhD work at the University of Bergen:

Tuberculosis control in Sidama in Ethiopia. Programme performance and spatial epidemiology

The Sustainable Development Goals are to end the TB epidemic by reducing the incidence of TB by 90 % and by reducing mortality by 95% by 2035 from what was in 2015. Globally, access to TB diagnostic and treatment facilities (DOTS) has improved, and millions of TB cases have been notified and treated, which has resulted in many lives being saved. In recent years in Ethiopia, TB control services have been substantially expanded and decentralized, which has improved access to TB care. Assessing trends in TB programme performance (case notification and treatment outcomes), as well as the spatial distribution and variations of the disease, could help in understanding the differentials in accessibility to TB control services, the distribution of disease burden and help in understanding the effectiveness of TB control programmes.

We assessed the distribution of- and accessibility to TB control facilities and trends in TB control programme performance in both urban and rural settings, by age category and by gender, and assessed the case notification rates of childhood TB over 10 years. We also assessed trends of the treatment outcomes of TB cases in order to identify high-risk groups for adverse treatment outcomes. Lastly, we explored spatial distribution and spatio-temporal clustering of the disease over 10 years to identify areas with the highest TB case notifications, and to identify the spatial variations in disease occurrence.

Over 10 years, the accessibility to- and coverage of TB control facilities has improved. Thus, TB control service coverage increased by 36%, and the proportion of locations within 10 km of the nearest TB diagnostic facility also increased. However, we noted variations in physical accessibility between areas in the study area. The mean distance from the nearest smear microscopy unit was 7.6 km in 2003 and declined to 3.2 km in 2012. The substantial expansion of primary health-care services, including TB control facilities and community-based intervention, has contributed to an increase in TB CNRs and treatment outcomes. From this finding, we suggest that a concerted effort be made to improve the accessibility to TB control facilities in areas with low case notification and poor accessibility.

An analysis of the trends of TB case notification and treatment outcomes in different settings based on the correct address, by age category and gender, and place of residence, could help understand the performance of TB control programmes and the epidemiology of TB within a community. We found that the CNRs for all forms of- and smear-positive TB increased steadily between 2003 and 2012. The CNR of smear-positive TB in the 45-year and above age groups rose by nearly fourfold. The disparity between men and women in CNR declined from 16 per 100,000 people in 2003 to eight per 100,000 people in 2012, with the male to female ratio also declining from 1.3:1 to 1.1:1. The increase in CNRs could be attributed to improved access to TB care and community-based interventions.

Over a decade, treatment success increased, whereas mortality and lost-to-follow-up declined. However, more deaths occurred among smear-negative TB cases, in children and among older patients. Targeted interventions are needed to address high-risk groups for adverse treatment outcomes.

The burden of childhood TB is one of the indicators used for assessing the ongoing transmission of the disease within a community. Assessing the case notification and treatment outcome of childhood TB could provide essential evidence to help understand the effectiveness of TB control programmes and the disease burden. Thus, we assessed childhood TB case notification and treatment outcomes over a decade. The mean CNRs for new cases of TB of all forms were 30 per 100,000 children, and no decline was observed in childhood TB cases over a 10-year study period. A community-based active case-finding intervention increased TB case notification in adults and in older children (10-14-year-olds); however, the case notification did not increase among younger children (less than five-years old). This could be explained by inadequate diagnostic facilities for childhood TB despite the community-based intervention, which focuses on symptomatic screening, followed by sputum-smear microscopy and the substantial expansion of TB control services. Better diagnostic facilities and interventions are required to increase case detection, and to improve treatment outcome among younger children.

The burden of TB varies between- and within countries because of differentials in health service performance and the varying distribution of risk factors that increase the transmission of- and susceptibility to the disease. An analysis of the disease burden in coarser geographic or administrative units could hide the burden of the disease at lower administrative units. Therefore, we assessed the distribution of the disease in different geographic settings in the study area, and looked for the pattern of the disease transmission over years, as well as for evidence of spatio- temporal clustering. We found spatial variations in both the disease distribution and spatial and space-time clustering of the disease in the central, northern and northwestern areas of the study area. This could be explained by sustained transmission, disproportionate distribution of risk factors, varying access to TB care and varying TB programme performance, all of which require targeted interventions.

In conclusion, in a population with a high prevalence of tuberculosis, we show that access to tuberculosis diagnostic and treatment facilities, in addition to the performance of TB control programmes, improved from 2003 to 2012. However, we identified areas with poor accessibility to diagnostic and treatment facilities. The low and constant case notification rate in childhood TB is an area of concern, and may indicate an underdiagnosis of childhood tuberculosis. Moreover, the distribution of tuberculosis has changed over time, and in different areas, thereby suggesting a high transmission or variable access to diagnosis and treatment. As a result, the variations in case notification rates, and in accessibility to tuberculosis control services represent challenges on how to improve the organization and performance of TB control.

To download the thesis please clic here.

Joint PhD Programme

Joint-PhDs are doctorates, which are done at two degree-awarding institutions. This doctorate means that you are fully registered in two universities, having to comply with admission requirements, and assessment regulations at both institutions, and it will result in one jointly awarded PhD (one diploma with the two university logos).

The other benefits for students are:

  • Access to complementary facilities and resources
  • Exposure to two cultural approaches to research
  • International student mobility
  • Enhanced acquisition of research and transferable skills, such as negotiation skills, use of videoconferencing, adaptability…
  • Better networking opportunities

Recently, Hawassa University and the University of Bergen agreed on such a joint PhD degree.

This programme is funded by The South Ethiopia Network of Universities in Public Health (SENUPH), and nine PhD students have been registered at the home institution which in this case is Hawassa University. The currently available financial support is for staff at Hawassa, Dilla and Wolaita Sodo universities. We plan to admit seven more students (four women and three men) in September 2016.

You can get more information about the admission requirements and about topics that this programme will prioritise by writing to Dr Eskindir Loha or to Professor Bernt Lindtjørn.

The structure of the joint PhD programme can be downloaded here.

Highland malaria in Ethiopia

Abebe Animut Ayele defenAbebe [1]ds on Friday 15 January 2016 his PhD degree at the University of Bergen with a dissertation:

“Anopheles species and malaria transmission risk in a highland area, south-central Ethiopia.” 

Anopheles arabiensis is the primary malaria vector in the lowlands of Ethiopia. In the highland Butajira area, a typical area of highland Ethiopia, the entomological aspects of the disease remain poorly described.

The study describes the entomological aspects of malaria transmission by highlighting on the abundance, host feeding preferences, entomological inoculation rates (EIRs) and risk of households’ exposure to malaria infectious Anopheles bites over two years. The study was done at three different altitudes ranging from 1800 to 2300 m.

Ten species of larval stages and nine species of adult stages of anophelines occurred in the area. The streams were the main breeding habitats of the anophelines. Anopheles arabiensis was the most prevalent species, and was found to feed on human and cattle with a similar preference. Plasmodium falciparum and Plasmodium vivax infected Anopheles arabiensis and Plasmodium vivax infected Anopheles pharoensis were caught in the low- and mid-altitude villages. Also, houses with open eaves had higher density of malaria infectious Anopheles arabiensis.

Abebe Animut Ayele was born in 1968 in Gojjam in Ethiopia. He completed his bachelor’s degree in biology and his master’s degree in medical parasitology from Addis Ababa University where he works as a lecturer. He started his PhD training at the Centre for International Health, University of Bergen in 2008 with Professor Bernt Lindtjørn as main supervisor and Associate Professor Teshome Gebre-Michael as co-supervisor.

Abebe-coverThe thesis can be downloaded here 

The publications in his thesis include:

Animut A, Gebre-Michael T, Balkew M, Lindtjorn B. Abundance and dynamics of anopheline larvae in a highland malarious area of south-central Ethiopia. Parasit Vectors. 2012;5:117.

Animut A, Balkew M, Gebre-Michael T, Lindtjorn B. Blood meal sources and entomological inoculation rates of anophelines along a highland altitudinal transect in south-central Ethiopia. Malar J 2013; 12(1): 76.

Animut A, Balkew M, Lindtjorn B. Impact of housing condition on indoor-biting and indoor-resting Anopheles arabiensis density in a highland area, central Ethiopia. Malaria journal 2013;12(1):393.

Start of PhD programme at Hawassa University

In October, the PhD programme started at Hawassa University. This is a joint programme between Hawassa University and the University of Bergen.

Nine students started, and have chosen a research topic, and are working to finalize their research plans. Some of these topics include

  1. Community-based management of acute malnutrition
  2. Measuring the occurrence of maternal, neonatal and childhood diseases, and analyze their use of health services (two students)
  3. Can an intervention to reduce the oral and physical abuse by health workers on women during labour improve the health for the mother and child?
  4. Does intimate partner violence and depression during pregnancy adversely affect maternal health during delivery, and the health of the newborn?
  5. To describe the vulnerability to food shortages by examining food insecurity, food intake and nutritional status over one year in Wolaita.
  6. Is the nutritional transition taking place in Wolaita increasing the occurrence of non-communicable diseases such as hypertension and diabetes?
  7. Can better use of the iron-rich amaranth plant reduce the occurrence of iron eficiency anaemia?
  8. School health.

2015 Ranking of Ethiopian Universities

Top 10 Ethiopian U
During the last decade there has been a great increase in the number of Ethiopian Universities.

There are several methods of ranking universities. This is a ranking system with many pitfalls, but it gives an impression about the quality of work done at the institutions.

The top 10 ranking Ethiopian Universities are seen from the table.

For more information see the following web page: http://www.webometrics.info/en/Africa/Ethiopia

Strengthening malaria and climate research in Ethiopia

Lindtjorn-Malaria conference posterLindtjorn B, Loha E, Deressa W, Balkew M, Gebremichael T, Sorteberg A, Woyessa A, Animut A, Diriba K, Massebo F, et al: Strengthening malaria and climate research in Ethiopia. Malaria Journal 2014, 13:P56.

Poster presentation

The project “Ethiopian Malaria Prediction System” implemented from 2007 to 2012 combined new population-based malaria transmission information with climate and land use variability data to develop an early warning tool to predict malaria epidemics in Ethiopia. Scientists from Ethiopia and Norway collaborated to incorporate climate variability and forecast information for malaria epidemics.

Our study shows that the association between weather and malaria is complex. Statistical models can predict malaria for large areas. However, as malaria transmission varies and depends on local environmental conditions, we need to have good and local knowledge about each area. However, weather variability is the main driver of malaria in Ethiopia.

While the generation of precipitation depends on local ascent and cooling of the air, our research provided new data on the transport of moisture into the country that may improve weather forecasting. We developed a new classification of climate zones, have mapped drought episodes in Ethiopia during the last decades, and have improved seasonal weather forecasting. Our hydrology studies show that potential climate change differs among the Ethiopian river basins, with river flows being sensitive to variations in rainfall, and less to temperature changes.

The computer model, Open Malaria Warning, incorporates hydrological, meteorological, mosquito-breeding, land-use data, and cattle densities to find out when and where outbreaks are likely to occur. We validated the model with data for malaria transmission in the highlands and lowlands, characterizing malaria transmission over some years in both highlands and lowlands. This provided us with new knowledge on malaria transmission in Ethiopia, how intense the seasonal transmission is, and how malaria occurs in different populations and areas. Our study showed that indigenous malaria transmission during a non-epidemic year takes place above 2000 m altitude. We also showed the ideal temperature for malaria transmission is about 25°C, underlining that global warming may lead to increased risk of malaria in highland areas, and less in the lowlands with already high average temperatures. However, to validate such models, there is a need for several years of active monitoring of malaria cases and mosquito densities. Unfortunately, such data is rare in Africa, and we need to invest in long-term monitoring of malaria transmission.

Lindtjorn-Malaria conference poster

The San Francisco Declaration on Research Assessment

In May 2013, more than 480 researchers and 80 scientific organisations published a declaration condemning the use of the journal impact factor to measure scholarly success.  Journals and organisations such as Science, Proceedings of The National Academy Of Sciences (PNAS), Times Higher Education, and Wellcome Trust are among the organisations backing this call.

The San Francisco Declaration on Research Assessment states the journal impact factor is misused to assess the significance of work by scientists who publish in those journals. A number of themes run through these recommendations:

  • “the need to eliminate the use of journal-based metrics, such as Journal Impact Factors, in funding, appointment, and promotion considerations;
  • the need to assess research on its own merits rather than on the basis of the journal in which the research is published; and
  • the need to capitalise on the opportunities provided by online publication (such as relaxing unnecessary limits on the number of words, figures, and references in articles, and exploring new indicators of significance and impact)”.

The first and general recommendation is:  “Do not use journal-based metrics, such as Journal Impact Factors, as a surrogate measure of the quality of individual research articles, to assess an individual scientist’s contributions, or in hiring, promotion, or funding decisions.”

The declaration concludes that we need a cultural change where papers are mainly evaluated for their own scientific merit.

A note in Nature (2005) stated that research assessment “rests too heavily on the inflated status of the impact factor”. And the biologist Stephen Curry of Imperial College London wrote in a blog post: “I am sick of impact factors and so is science”.