Southwest Tanzania Research Articles

Impact of climate change on the ecology of the Kyambangunguru crater marsh in southwestern Tanzania during the Late Holocene

Instrumental records of temperature and hydrological regimes in East Africa evidence frequent droughts with dramatic effects on population and ecosystems. Sources of these climatic variations remain largely unconstrained, partly because of a paucity of Late Holocene records. Here, we present a multi-proxy analysis of a 4-m continuous sediment core collected in the Kyambangunguru crater marsh, in southwest Tanzania, covering the last 4000 yrs (cal. BP). We used microscopic (macro-remains, microfossils, palynofacies, pollen), elemental (carbon, nitrogen contents), molecular (br GDGTs, n-alkanes) and compound-specific isotopic (δ2H n-alkanes) investigations to reconstruct the environmental history of the marsh. The multi proxy record reveals that, 2500 years ago, the marsh underwent a major ecological transition from a lake to a peatland. Temperature and hydrological reconstructions evidence warmer and drier conditions between 2200 and 860 cal. BP, which probably triggered the establishment of a perennial peatland. This study is one of the first combined temperature and precipitation record of Late Holocene in the region and highlights changes in the spatial distribution of the East African climate regimes. Several cold periods are observed, between 3300 and 2000 cal. BP and since 630 cal. BP, the latter corresponding to the Little Ice Age. Moreover, wetter conditions are reported during the Medieval Climate Anomaly in contrast to other north-eastern African records suggesting that Tanzania is located at the transition between two hydro-climatic zones (north-eastern versus southern Africa) and has experienced variable contributions of these two zones over the last millennium.

Evaluation of branched GDGTs and leaf wax n-alkane δ2H as (paleo) environmental proxies in East Africa

The role of mountain evolution on local climate is poorly understood and potentially underestimated in climate models. One prominent example is East Africa, which underwent major geodynamic changes with the onset of the East African Rift System (EARS) more than 250Myr ago. This study explores, at the regional East African scale, a molecular approach for terrestrially-based paleo-climatic reconstructions that takes into account both changes in temperature and in altitude, potentially leading to an improved concept in paleo-climatic reconstructions. Using surface soils collected along pronounced altitudinal gradients in Mt. Rungwe (n=40; Southwest Tanzania) and Mt. Kenya (n=20; Central Kenya), we investigate the combination of 2 terrestrial proxies, leaf wax n-alkane δ2H (δ2Hwax) and branched glycerol dialkyl glycerol tetraether (br GDGT) membrane lipids, as (paleo) elevation and (paleo) temperature proxies, respectively. At the mountain scale, a weak link between δ2Hwax and altitude (R2=0.33) is observed at Mt. Kenya, but no relationship is observed at Mt. Rungwe. It is likely that additional parameters, such as decreasing relative humidity (RH) or vegetation changes with altitude, are outcompeting the expected 2H-depletion trend along Mt. Rungwe. In contrast, br GDGT-derived absolute mean annual air temperature (MAAT) and temperature lapse rate (0.65°C/100m) for both mountains are in good agreement with direct field measurements, further supporting the robustness of this molecular proxy for (paleo) temperature reconstructions. At the regional scale, estimated and observed δ2H data in precipitation along 3 mountains in East Africa (Mts. Rungwe, Kenya and Kilimanjaro) highlight a strong spatial heterogeneity, preventing the establishment of a regional based calibration of δ2Hwax for paeloaltitudinal reconstructions. Different from that, an improved regional soil calibration is developed between br GDGT distribution and MAAT by combining the data from this study (Mts. Rungwe and Kenya) with previous results from East African surface soils along Mts. Kilimanjaro (Tanzania) and Rwenzori (Uganda). This new regional calibration, based on 105 samples, improves both the R2 (0.77) and RMSE (root mean square error; 2.4°C) of br GDGT-derived MAAT over the global soil calibrations previously established (R2=0.56; RMSE=4.2°C) and leads to more accurate (paleo) temperature reconstructions in the region.

Effect of Wuchereria bancrofti infection on HIV incidence in southwest Tanzania: a prospective cohort study

The past decades have seen an ongoing controversial debate about whether the immune activation induced by helminths has an effect on the susceptibility of individuals to HIV. In view of this, we assessed the effect of lymphatic filariasis, a chronic helminth disease elicited by Wuchereria bancrofti, on HIV incidence in southwest Tanzania. In this population-based cohort study, we enrolled a geographically stratified randomly chosen sample of about 10% of the households in nine distinct sites in southwest Tanzania. All household members present were followed up and tested for HIV and circulating filarial antigen, an indicator of W bancrofti adult worm burden. Our main outcome of interest was HIV incidence in participants with or without lymphatic filariasis. Between May 29, 2006, and June 16, 2011, we enrolled 4283 households with roughly 18 000 participants. Of these, 2699 individuals from Kyela district participated in at least one round of the EMINI study. In the 1055 initially HIV-negative adolescents and adults with clearly defined lymphatic filariasis status, 32 new HIV infections were observed in 2626 person-years. HIV incidence in lymphatic filariasis-positive participants (1·91 cases per 100 person-years) was significantly higher than the incidence in lymphatic filariasis-negative participants (0·80 cases per 100 person-years). The age-adjusted and sex-adjusted incidence rate ratio was 2·17 (95% CI 1·08-4·37, p=0·0300). Lymphatic filariasis status remained an independent and significantly relevant risk factor for HIV infection when controlled for other known risk factors such as sexual behaviour and socioeconomic factors. To our knowledge, this is the first prospective study demonstrating a significantly increased risk of acquiring HIV for lymphatic filariasis-infected individuals. Immunological studies and interventional treatment studies that eliminate the adult worms and not only the microfilariae are needed to follow up on the results presented. European Union as part of EuropAid; German Federal Ministry of Education and Research; German Center for Infection Research.

Prevalence of Lymphatic Filariasis and Treatment Effectiveness of Albendazole/ Ivermectin in Individuals with HIV Co-infection in Southwest-Tanzania.

BackgroundAnnual mass treatment with ivermectin and albendazole is used to treat lymphatic filariasis in many African countries, including Tanzania. In areas where both diseases occur, it is unclear whether HIV co-infection reduces treatment success.MethodologyIn a general population study in Southwest Tanzania, individuals were tested for HIV and circulating filarial antigen, an indicator of Wuchereria bancrofti adult worm burden, before the first and after 2 consecutive rounds of anti-filarial mass drug administration.Principle FindingsTesting of 2104 individuals aged 0–94 years before anti-filarial treatment revealed a prevalence of 24.8% for lymphatic filariasis and an HIV-prevalence of 8.9%. Lymphatic filariasis was rare in children, but prevalence increased in individuals above 10 years, whereas a strong increase in HIV was only seen above 18 years of age. The prevalence of lymphatic filariasis in adults above 18 years was 42.6% and 41.7% (p = 0.834) in HIV-negatives and–positives, respectively. Similarly, the HIV prevalence in the lymphatic filariasis infected (16.6%) and uninfected adult population (17.1%) was nearly the same. Of the above 2104 individuals 798 were re-tested after 2 rounds of antifilarial treatment. A significant reduction in the prevalence of circulating filarial antigen from 21.6% to 19.7% was found after treatment (relative drop of 8.8%, McNemar´s exact p = 0.036). Furthermore, the post-treatment reduction of CFA positivity was (non-significantly) larger in HIV-positives than in HIV-negatives (univariable linear regression p = 0.154).Conclusion/SignificanceIn an area with a high prevalence for both diseases, no difference was found between HIV-infected and uninfected individuals regarding the initial prevalence of lymphatic filariasis. A moderate but significant reduction in lymphatic filariasis prevalence and worm burden was demonstrated after two rounds of treatment with albendazole and ivermectin. Treatment effects were more pronounced in the HIV co-infected subgroup, indicating that the effectiveness of antifilarial treatment was not reduced by concomitant HIV-infection. Studies with longer follow-up time could validate the observed differences in treatment effectiveness.

Butterfly communities in miombo woodland: Biodiversity declines with increasing woodland utilisation

ABSTRACT Deforestation and degradation are threatening forests and woodlands globally. The deciduous miombo woodlands of sub-Saharan Africa are no exception, yet little is known about the flora and fauna they contain and the implications of their loss. Butterflies are recognised as indicators of environmental change; however the responses of butterflies in miombo woodlands have received little attention. This paper describes butterfly assemblages and their response to woodland utilisation in an understudied area of miombo woodland in south-west Tanzania. This is an area representative of miombo woodlands throughout sub-Saharan Africa, where woodland is utilised by local communities for a range of products, and is being rapidly converted to agriculture. Baited canopy traps and sweep nets were used to sample frugivorous and nectarivorous butterfly communities at different vertical stratifications in nine different study sites. 104 species were recorded, of which 16 are miombo specialists that have been recorded in Tanzania to the west of the country only. Indicator species were identified for three different levels of utilisation, with species from the sub-family Satyrinae indicating moderate utilisation. Generalised linear mixed effects models showed that butterfly species richness, diversity and abundance all decreased in response to increasing agriculture and anthropogenic utilisation. The loss of miombo woodlands is likely to result in declines in butterfly diversity. However, there was evidence of an intermediate disturbance effect for butterfly species richness, diversity and abundance with one utilisation variable, suggesting that a miombo woodland management plan that allows moderate sustainable utilisation in a heterogeneous landscape of mature miombo woodland and agriculture will simultaneously maintain butterfly communities and enable agricultural production.

Official invitation letters to promote male partner attendance and couple voluntary HIV counselling and testing in antenatal care: an implementation study in Mbeya Region, Tanzania.

BackgroundThe benefits of male partner involvement in antenatal care (ANC) and prevention of mother-to-child transmission of HIV (PMTCT) for maternal and infant health outcomes have been well recognised. However, in many sub-Saharan African settings, male involvement in these services remains low. Previous research has suggested written invitation letters as a way to promote male partner involvement.MethodsIn this implementation study conducted at three study sites in southwest Tanzania, acceptability of written invitation letters for male partners was assessed. Pre-study CVCT rates of 2–19 % had been recorded at the study sites. Pregnant women approaching ANC without a male partner were given an official letter, inviting the partner to attend a joint ANC and couple voluntary counselling and testing (CVCT) session. Partner attendance was recorded at subsequent antenatal visits, and the invitation was repeated if the partner did not attend. Analysis of socio-demographic indices associated with male partner attendance at ANC was also performed.ResultsOut of 318 women who received an invitation letter for their partner, 53.5 % returned with their partners for a joint ANC session; of these, 81 % proceeded to CVCT. Self-reported HIV-positive status at baseline was negatively associated with partner return (p = 0.033). Male attendance varied significantly between the rural and urban study sites (p < 0.001) with rates as high as 76 % at the rural site compared to 31 % at the urban health centre. The majority of women assessed the joint ANC session as a favourable experience, however 7 (75 %) of women in HIV-positive discordant or concordant relationships reported problems during mutual disclosure. Beneficial outcomes reported one month after the session included improved client- provider relationship, improved intra-couple communication and enhanced sexual and reproductive health decision-making.ConclusionOfficial invitation letters are a feasible intervention in a resource limited sub-Saharan African context, they are highly accepted by couple members, and are an effective way to encourage men to attend ANC and CVCT. Pre-intervention CVCT rates were improved in all sites. However, urban settings might require extra emphasis to reach high rates of partner attendance compared to smaller rural health centres.

Two decades of temporal change of Earth's inner core boundary

AbstractWe report two decades of changing behavior of the Earth's inner core boundary (ICB), which provides the simplest explanation for the observed temporal change of the compressional seismic waves that are reflected from the ICB (PKiKP) and refracted in the inner core (PKIKP), from earthquake doublets occurring in South Sandwich Islands between 1993 and 2013. In the early period (before 2003), the ICB is enlarged beneath the western coast of Gabon, Republic of Congo, and southwest Tanzania in the reflected points of the PKiKP observed at seismic stations OBN, AAK, and ARU, while it experiences little change beneath Zimbabwe or/and Kenya, and beneath west Angola or/and north Central African Republic, in the PKIKP entry or/and exit points of AAK and ARU observations, respectively. In the later period (after 1998), the ICB regions beneath the western coast of Gabon, Republic of Congo, and southwest Tanzania either shrink or remain unchanged, and the temporal change migrates to beneath Zimbabwe or/and Kenya, and beneath west Angola or/and north Central African Republic, with a decrease of inner core surface by 5.59 km between 1998 and 2009 beneath Zimbabwe or Kenya and by 1.73 km beneath west Angola or north Central African Republic between 1998 and 2013. These results indicate that ICB temporal change occurs in localized regions and is episodic, rapidly migrating, and alternately enlarged and shrunk.

Eriospermum adpressifolium (Asparagaceae) and Emilia blittersdorffii (Asteraceae) — two new species from Tanzania with nearly identical leaves

Summary. Two new species from southwest Tanzania are described, illustrated and their conservation status evaluated. Emila blittersdorffii Beentje and Eriospermum adpressifolium O. Weber are a striking example of convergent evolution with their leaves indistinguishable to the naked eye. Their vegetative habit has been observed in a number of other taxa.

Predominant leptospiral serogroups circulating among humans, livestock and wildlife in Katavi-Rukwa ecosystem, Tanzania.

BackgroundLeptospirosis is a worldwide zoonotic disease and a serious, under-reported public health problem, particularly in rural areas of Tanzania. In the Katavi-Rukwa ecosystem, humans, livestock and wildlife live in close proximity, which exposes them to the risk of a number of zoonotic infectious diseases, including leptospirosis.Methodology/Principal FindingsA cross-sectional epidemiological study was carried out in the Katavi region, South-west Tanzania, to determine the seroprevalence of Leptospira spp in humans, domestic ruminants and wildlife. Blood samples were collected from humans (n = 267), cattle (n = 1,103), goats (n = 248), buffaloes (n = 38), zebra (n = 2), lions (n = 2), rodents (n = 207) and shrews (n = 11). Decanted sera were tested using the Microscopic Agglutination Test (MAT) for antibodies against six live serogroups belonging to the Leptospira spp, with a cutoff point of ≥ 1:160. The prevalence of leptospiral antibodies was 29.96% in humans, 30.37% in cattle, 8.47% in goats, 28.95% in buffaloes, 20.29% in rodents and 9.09% in shrews. Additionally, one of the two samples in lions was seropositive. A significant difference in the prevalence P<0.05 was observed between cattle and goats. No significant difference in prevalence was observed with respect to age and sex in humans or any of the sampled animal species. The most prevalent serogroups with antibodies of Leptospira spp were Sejroe, Hebdomadis, Grippotyphosa, Icterohaemorrhagie and Australis, which were detected in humans, cattle, goats and buffaloes; Sejroe and Grippotyphosa, which were detected in a lion; Australis, Icterohaemorrhagie and Grippotyphosa, which were detected in rodents; and Australis, which was detected in shrews. Antibodies to serogroup Ballum were detected only in humans.ConclusionsThe results of this study demonstrate that leptospiral antibodies are widely prevalent in humans, livestock and wildlife from the Katavi-Rukwa ecosystem. The disease poses a serious economic and public health threat in the study area. This epidemiological study provides information on circulating serogroups, which will be essential in designing intervention measures to reduce the risk of disease transmission.

First-class health: amenity wards, health insurance, and normalizing health care inequalities in Tanzania.

In 2008, a government hospital in southwest Tanzania added a "first-class ward," which, unlike existing inpatient wards defined by sex, age, and ailment, would treat patients according to their wealth. A generation ago, Tanzanians viewed health care as a right of citizenship. In the 1980s and 1990s, structural adjustment programs and user fees reduced people's access to biomedical attention. Tanzania currently promotes "amenity" wards and health insurance to increase health care availability, generate revenue from patients and potential patients, and better integrate for-profit care. In this article, I examine people's discussions of these changes, drawing on ethnographic fieldwork in the 2000s and 1990s. I argue that Tanzanians criticize unequal access to care and health insurance, although the systemic structuring of inequalities is becoming normalized. People transform the language of socialism to frame individualized market-based care as mutual interdependence and moral necessity, articulating a new biomedical citizenship.

Re-Os GEOCHRONOLOGY OF QUARTZ-ENCLOSED ULTRAFINE MOLYBDENITE: IMPLICATIONS FOR ORE GEOCHRONOLOGY

Re-Os molybdenite geochronology relies on the aliquant analysis taken from a mineral separate. Although suitable for coarse-grained molybdenite samples, traditional mineral separation techniques are not ideally suited for samples possessing fine-grained molybdenite ( μ m) and thus hamper the application of Re-Os geochronology for such samples. Here, we demonstrate a room-temperature hydrofluoric acid (HF) chemical separation technique that is capable of isolating ultrafine molybdenite (i.e., μ m) for Re-Os geochronology. Six Re-Os molybdenite model ages from four molybdenite in-house control and NIST reference material (RM8599) samples exposed to concentrated HF are indistinguishable from the Re-Os molybdenite model ages for aliquants not exposed to HF. Thus, HF exposure at room temperature has no effect on Re-Os molybdenite systematics. Our HF chemical separation technique was then applied to six ultrafine molybdenite samples from the Lupa goldfield, southwest Tanzania. Three samples from the Kenge deposit provide a weighted average Re-Os molybdenite model age of 1953 ± 5 Ma (MSWD = 0.6; n = 3), whereas three samples and one repeat analysis from the Porcupine deposit provide a weighted average Re-Os molybdenite model age of 1886 ± 5 Ma (MSWD = 1.5; n = 4). Our proposed analytical protocol has allowed us to determine reproducible ages from ultrafine molybdenite samples within the Lupa goldfield that were previously unsuitable for molybdenite Re-Os geochronology using conventional mineral separation techniques.

Low Specificity of Determine HIV1/2 RDT Using Whole Blood in South West Tanzania

ObjectiveTo evaluate the diagnostic performance of two rapid detection tests (RDTs) for HIV 1/2 in plasma and in whole blood samples.MethodsMore than 15,000 study subjects above the age of two years participated in two rounds of a cohort study to determine the prevalence of HIV. HIV testing was performed using the Determine HIV 1/2 test (Abbott) in the first (2006/2007) and the HIV 1/2 STAT-PAK Dipstick Assay (Chembio) in the second round (2007/2008) of the survey. Positive results were classified into faint and strong bands depending on the visual appearance of the test strip and confirmed by ELISA and Western blot.ResultsThe sensitivity and specificity of the Determine RDT were 100% (95% confidence interval = 86.8 to 100%) and 96.8% (95.9 to 97.6%) in whole blood and 100% (99.7 to 100%) and 97.9% (97.6 to 98.1%) in plasma respectively. Specificity was highly dependent on the tested sample type: when using whole blood, 67.1% of positive results were false positive, as opposed to 17.4% in plasma. Test strips with only faint positive bands were more often false positive than strips showing strong bands and were more common in whole blood than in plasma. Evaluation of the STAT-PAK RDT in plasma during the second year resulted in a sensitivity of 99.7% (99.1 to 99.9%) and a specificity of 99.3% (99.1 to 99.4%) with 6.9% of the positive results being false.ConclusionsOur study shows that the Determine HIV 1/2 strip test with its high sensitivity is an excellent tool to screen for HIV infection, but that – at least in our setting – it can not be recommended as a confirmatory test in VCT campaigns where whole blood is used.

Liquid bread: beer and brewing in cross-cultural perspective

List of Figures List of Tables Preface List of Contributors Introduction Helen Macbeth and Wulf Schiefenhovel Chapter 1. Natural Ingestion of Ethanol by Animals: Why? W.C.McGrew Chapter 2. Healthy or Detrimental? Physiological, Psychiatric and Evolutionary Aspects of Drinking Beer Peter Kaiser, Gerhard Medicus and Martin Brune Chapter 3. Beer: How it's made - the Basics of Brewing Keith Thomas Chapter 4. Interdisciplinary Investigations into the Brewing Technology of the Ancient Near East and the Potential of the Cold Mashing Process Martin Zarnkow, Adelheid Otto and Berthold Einwag Chapter 5. Beer in Prehistoric Europe Hans-Peter Stika Chapter 6. Beer and Beer Culture in Germany Franz Meussdoerffer Chapter 7. Europe North and South, Beer and Wine: Some Reflections about Beer and Mediterranean Food F. Xavier Medina Chapter 8. Living in the Streets: Beer Acceptance in Andalusia during the Twentieth Century Isabel Gonzalez Turmo Chapter 9. The Thirst for Tradition: Beer Production and Consumption in the United Kingdom Paul Collinson and Helen Macbeth Chapter 10. Beer in the Czech Republic Jana Parizkova and Martina Vlkova Chapter 11. Alcohol Consumption and Binge Drinking in German Fraternities: Anthropological and Social Psychological Aspects Gerard Dammann Chapter 12. Rugby, Racing and Beer in New Zealand: Colonising a Consuming Culture Nancy J. Pollock Chapter 13. Beer, Ritual and Conviviality in Northern Cameroon Igor de Garine Chapter 14. The Gender of Beer: Beer Symbolism among the Kapsiki/Higi and the Dogon Walter van Beek Chapter 15. Ritual Use of Beer in South West Tanzania Ruth Kutalek Chapter 16. Brewing Sorghum Beer in Burkina Faso: a Study in Food Technology from the Perspective of Anthropological Linguistics Francois Belliard Chapter 17. Rice Beer and Social Cohesion in the Kelabit Highlands, Sarawak Monica Janowski Chapter 18. Tradition and Change: Beer Consumption in Northeast Luzon, Philippines Dante Aquino and Gerard Persoon Chapter 19. Culture, Market and Beer Consumption Mabel Gracia Arnaiz Chapter 20. Beer and European Media: Global vs. Local Luis Cantarero and Monica Stacconi Glossary Index

Performance of ParaHit and OptiMAL tests in the diagnosis of Malaria in Mwanza, Southwest Tanzania.

Malaria rapid diagnostic tests (RDTs) are non microscopic tests that provide a rapid detection of malaria infections in infected individuals. The objective of this study was to evaluate the performance of ParaHit and OptiMAL tests for detection of malaria infections as compared with routine microscopy. This facility-based study was carried out in Mwanza, north-western Tanzania and involved outpatients attending Igoma Health Centre. Blood samples were tested for malaria infection using the two RDTs and compared with Giemsa stained blood films examined using microscope. A total of 243 individuals (median age= 22 years) were involved in the study. Microscopy had a higher detection rate of 19.7% (48/243) as compared to ParaHit (4.5%) and OptiMAL (3.7%). Low sensitivity of 21.2% and 17%, but high specificity of 99.4% for ParaHit and OptiMAL, respectively was observed. Of all positive blood slides for Plasmodium falciparum, 78.7% had low parasite density (80 -720 parasite/microl of blood). These slides were negative for malaria parasite for both RDTs. Over 80% of study participants who reported fever had negative blood slides for malaria parasites by microscopy. On the other hand, 44.7% of those who reported no fever had positive blood slides for P. falciparum. Study participants who reported to have fever and high parasite density above 720 parasite/ microl were likely to be positive by both RDTs (OR= 6.8; P= 0.031529). In conclusion, the overall performance of both RDTs in detecting asexual P. falciparum was low as compared to microscopy and their performance were highly affected by parasite density. This calls for further evaluation studies before RDTs are widely used in peripheral health facilities in order to minimize potential severe consequences.

Impact of non‐livelihood‐based land management on land resources: the case of upland watersheds in Uporoto Mountains, South West Tanzania

Various land management strategies are used to prevent land degradation and keep land productive. Often land management strategies applied in certain areas focus on the context of the physical environment but are incompatible with the social environment where they are applied. As a result, such strategies are ignored by land users and land degradation becomes difficult to control. This study observes the impacts of land management in the upland watersheds of the Uporoto Mountains in South West Tanzania. In spite of various land management practices used in the area, 38% of the studied area experienced soil fertility loss, 30% gully erosion, 23% soil loss, 6% biodiversity loss and drying up of river sources. Land management methods that were accepted and adopted were those contributing to immediate livelihood needs. These methods did not control land resource degradation, but increased crop output per unit of land and required little labour. Effective methods of controlling land degradation were abandoned or ignored because they did not satisfy immediate livelihood needs. This paper concludes that Integrating poor people's needs would transform non-livelihood-based land management methods to livelihood-based ones. Different ways of transforming these land management methods are presented and discussed.

Home range, core areas and movement in the ‘critically endangered’ kipunji (Rungwecebus kipunji) in southwest Tanzania

AbstractUnderstanding how threatened forest primates use a heterogeneous landscape is essential to ensuring their survival. Kipunji (Rungwecebus kipunji) are ‘critically endangered’, arboreal monkeys restricted to two sites in Tanzania. Over 90% of the population lives in the degraded Rungwe‐Kitulo forests of the Southern Highlands. In this study, we present the first comprehensive investigation into daily path length and home range size of kipunji, based on data from four groups followed simultaneously over 70 consecutive days on Mt. Rungwe. The mean daily distance travelled was 1293 m (SE 150.82), and daily distance was not significantly correlated to group size. Using fixed kernel density estimation, an area enclosing 90% of the home range calculated using the ‘reference’ method as a smoothing parameter, measured a mean of 306.18 ha (SE 67), and the core area (50% use) was 86.55 ha (SE 18.73). Using the ‘least‐squares cross validation’ method, the mean home range and core area were 205.45 ha (SE 57.02) and 55.45 ha (SE 14.23) respectively. Home range overlap was extensive, although contact between groups was rare, with &gt;97.30% of all observations within 20 min separated by &gt;250 m. The data strongly suggest that kipunji are not territorial.

Onchocerciasis situation in the Tukuyu focus of southwest Tanzania after ten years of ivermectin mass treatment

A purposive cross-sectional epidemiological study was conducted in the Tukuyu Onchocerciasis focus in south-western Tanzania in 2004, ten years after launching the ivermectin mass treatment programme, and 23 years after establishing focal parasite prevalence. The objective was to assess contemporary Onchocerciasis clinical and parasitological situation and assess community knowledge about the disease and its control. From historical data, five villages with high parasite prevalence were selected, two each on the Lufilyo and Kiwira Rivers and one on lower Lumbira River. Skin biopsies were taken from the iliac crest on the left and right buttocks, for examination of Onchocerca volvulus microfilariae. Onchocercal skin lesions were checked using natural light, while nodules were palpated from head to ankles and scored. A structured questionnaire was administered to participants. A total of 438 persons (age=16-99 years) were examined. No skin microfilariae (mf) were detected. Onchocercal skin symptoms were found in 170 (38.8%), of which 30 (6.9%) had nodules, 48 (11.0%) chronic onchodermatitis and 92 (21%) itching. One-third (34.5%) had correct knowledge that black flies ("tusunya") are vectors of onchocerciasis. Half of the respondents (n=217) confirmed taking ivermectin for onchocerciasis treatment, and 428 (97.7%) were willing to continue for any duration. It is concluded that the undetectable skin microfilariae in the study sample was partly attributable to the consequences of ongoing ivermectin mass treatment. It is recommended that the control efforts, as well as monitoring and evaluation be sustained to determine its long term impact, and that a more sensitive technique be used to check O. volvulus skin mf prevalence.

Reproduction and population dynamics of Mastomys natalensis Smith, 1834 in an agricultural landscape in the Western Usambara Mountains, Tanzania

The multimammate rat, Mastomys natalensis Smith 1834, is a dominant species in agro-ecosystems in Sub-Saharan Africa, but adapts quickly to changes in non-agricultural landscape, particularly woodlands and forests. In this study we report on reproduction and population dynamics of M. natalensis in deforested high elevation localities in the Usambara Mountains, north-east Tanzania. We conducted Capture-Mark-Recapture studies in 2002-2004, and established that reproduction of M. natalensis takes place in the extended wet season between February and June, and the population density peaks in June-August. Reproduction cease in July to January and population density drops from July onwards. Reproduction and population density fluctuations are linked to the duration and amount of rainfall. In years when rainfall was below average and the wet season was short, the population density was significantly lower (below 10 animals/ha and 60 animals/ha in 2003 and 2004 respectively, compared to >100 animals/ha in 2002 when rainfall was above the seasonal average) (F(df 2,13)= 9.092, p < 0.01 for in between years variations and F(df 12,15)= 5.389, p < 0.01 for effect of cumulative annual rainfall on population density). These densities were much lower than in the lowland savannah habitats in central and southwest Tanzania. A comparison between the farmland/fallow mosaic fields and agro-forestry areas showed higher population densities in the former, which have similarities to the preferred habitats in the lowland savannahs. The increasing abundance of M. natalensis in the Usambara could have some consequences: M. natalensis is major pest and is involved in the plague cycle in the western Usambara Mountains. Mastomys natalensis is also a strong competitor and the impact on endemic rodent species, e.g. Lophuromys flavopunctatus and Praomys delectorum is unknown.

Susceptibility of &lt;i&gt;Simulium damnosum&lt;/i&gt; complex larvae to temephos in the Tukuyu onchocerciasis focus, southwest Tanzania

Tukuyu onchocerciasis focus was earmarked for vector control using insecticide against larval stages. Susceptibility tests of mature larvae of Simulium damnosum s.l. vectors to temephos insecticide were carried out before and after two years of insecticide treatment of rivers within Tukuyu onchocerciasis focus, south-western Tanzania. The tests were done in 1999/2000 and 2004 using WHO standard methods. Mature larvae were exposed to 9 concentrations of temephos active ingredient, from the weakest 0.00975mg/litre to the strongest of 2.5mg/l. Each test concentration and control was run in duplicates of 25 larvae each, set for three hours in a cool temperature. After incubation, test solution was discarded and larval condition checked. Numbers of larvae in each category were recorded and used to determine mortality rate for each concentration as well as for the LC50 and LC95. A total of 1,666 larvae were tested, 942 during the pre- and 724 post-treatment. Results showed that both pre and post-treatment samples were susceptible, attaining 100% mortality at the diagnostic dose of 1.25mg/l, and LC50 between 0.129-0.34mg/l pre - and 0.144-0.211 mg/l (95% CI, P < 0.05) post- treatment. These values fall within the standard diagnostic dose of < or = 0.4mg/l for susceptible S. damnosum s.l populations. It was concluded that the endemic S. damnosum population was susceptible to temephos before and after two years of intermittent field application. Temephos was thus recommended for continued use in onchocerciasis vector control in the Tukuyu focus, to complement Community Directed Treatment with Ivermectin, but close monitoring of vector susceptibility should be done.

Molecular surveillance of drug-resistance associated mutations of Plasmodium falciparum in south-west Tanzania

BackgroundIn Tanzania, drug-resistant malaria parasites are an increasing public health concern. Because of widespread chloroquine (CQ) resistance Tanzania changed its first line treatment recommendations for uncomplicated malaria from CQ to sulfadoxine-pyrimethamine (SP) in 2001. Loss of SP sensitivity is progressing rapidly. SP resistance is associated with mutations in the dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes.MethodsIn samples from 86 patients with uncomplicated Plasmodium falciparum malaria from Mbeya and Matema, Mbeya region, south-western Tanzania, the occurrence of mutations was investigated in the pfcrt and pfmdr1 genes which are associated with CQ resistance and in pfdhfr and pfdhps, conferring SP resistance, as well in cytb which is linked to resistance to atovaquone.ResultsPfcrt T76 occurs in 50% and pfmdr1 Y86 in 51.7%. Pfdhfr triple mutations coexisting with pfdhps double mutations were detected in 64.3% of the P. falciparum isolates. This quintuple mutation is seen as a possible predictive molecular marker for SP treatment failure. Mutations of the cytb gene were not detected.ConclusionThese findings of a high prevalence of mutations conferring SP resistance correspond to data of in vivo SP efficacy studies in other regions of Tanzania and underline the recommendation of changing first-line treatment to artemisinin-based combination therapy.