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.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.     

Species Richness and Habitat Use of Small Carnivores in the Arusha National Park (Tanzania)

The carnivore community of Arusha National Park, Tanzania, was monitored using live trapping and diurnal and nocturnal visual counts and recording of tracks and signs along line transects. Nine carnivore species were recorded. Hyena (Crocuta crocuta), the most common large species, leopard (Panthera pardus) and African civet (Civettictis civetta) were detected along line transects, while the smaller species were counted and/or captured. Mungos mungo, Galerella sanguinea, and Genetta maculata were the most prevalent at transect counts, while G. sanguinea, Bdeogale crassicauda, and G. maculata were most frequently captured. Ichneumia albicauda and Ictonyx striatus were captured at only a single site. Carnivores selected natural habitat types, multilayered forest, open shrubs and herbaceous savannah, and were absent, or tended to avoid disturbed (man-made) habitats. Species of which sufficient data were gathered seemed to behave as habitat generalists (C. crocuta, G. sanguinea, G. maculata, M. mungo and I. striatus). The need for more detailed studies on small carnivore ecology and the importance of smaller protected areas for their conservation are discussed.     

Ecosystem Management in the Context of Large, Infrequent Disturbances

Large, infrequent disturbances (LIDs) can have significant impacts yet seldom are included in management plans. Although this neglect may stem from relative unfamiliarity with a kind of event that rarely occurs in the experience or jurisdiction of individual managers, it may also reflect the assumption that LIDs are so large and powerful as to be beyond the ability of managers to affect. However, some LIDs can be affected by management, and for many of those that cannot be affected, the resilience or recovery of the system disrupted by the disturbance can be influenced to meet management goals. Such results can be achieved through advanced planning that allows for LIDs, whether caused by natural events, human activities, or a combination of the two. Management plans for LIDs may adopt a variety of goals, depending on the nature of the system and the nature of the anticipated disturbance regime. Managers can choose to influence (a) the system prior to the disturbance, (b) the disturbance itself, (c) the system after the disturbance, or (d) the recovery process. Prior to the disturbance, the system can be managed in ways that alter its vulnerability or change how it will respond to a disturbance. The disturbance can be managed through no action, preventive measures, or manipulations that can affect the intensity or frequency of the disturbance. Recovery efforts can focus on either managing the state of the system immediately after the disturbance or managing the ongoing process of recovery. This review of the management implications of LIDs suggests that management actions should be tailored to particular disturbance characteristics and management goals. Management actions should foster survival of residuals and spatial heterogeneity that promote the desired recovery pattern and process. Most importantly, however, management plans need to recognize LIDs and include the potential for such disturbances to occur. Received 14 July 1998; accepted 16 September 1998     

Transition of Mountain Pastoralism: An Agrodiversity Analysis of the Livestock Population and Herding Strategies in Southeast Tibet,China

Vertical mobile grazing is typical in undulating mountain landscapes. However, recent social, economic, and political changes in China are impacting these traditional practices. This paper presents findings of a study conducted in the Tibetan communities of southwest China to assess the current status of mountain pastoralism and its future viability. Rangeland environment, livestock variety, and grazing form were found to be significantly related factors, which made it possible to analyze livestock distribution. The yak population—the main mobile grazer in alpine pasture— is currently stagnating while the population of cattle raised around settlements is steadily increasing. This situation is likely closely related to labor shortages in households, which have triggered the imbalanced distribution of livestock. The fact that the key to rangeland sustainability is to stimulate mobile grazing runs counter to current privatization policies.     

Behavioral Responses to Mammalian Blood Odor and a Blood Odor Component in Four Species of Large Carnivores

Only little is known about whether single volatile compounds are as efficient in eliciting behavioral responses in animals as the whole complex mixture of a behaviorally relevant odor. Recent studies analysing the composition of volatiles in mammalian blood, an important prey-associated odor stimulus for predators, found the odorant trans-4,5-epoxy-(E)-2-decenal to evoke a typical “metallic, blood-like” odor quality in humans. We therefore assessed the behavior of captive Asian wild dogs (Cuon alpinus), African wild dogs (Lycaon pictus), South American bush dogs (Speothos venaticus), and Siberian tigers (Panthera tigris altaica) when presented with wooden logs that were impregnated either with mammalian blood or with the blood odor component trans-4,5-epoxy-(E)-2-decenal, and compared it to their behavior towards a fruity odor (iso-pentyl acetate) and a near-odorless solvent (diethyl phthalate) as control. We found that all four species displayed significantly more interactions with the odorized wooden logs such as sniffing, licking, biting, pawing, and toying, when they were impregnated with the two prey-associated odors compared to the two non-prey-associated odors. Most importantly, no significant differences were found in the number of interactions with the wooden logs impregnated with mammalian blood and the blood odor component in any of the four species. Only one of the four species, the South American bush dogs, displayed a significant decrease in the number of interactions with the odorized logs across the five sessions performed per odor stimulus. Taken together, the results demonstrate that a single blood odor component can be as efficient in eliciting behavioral responses in large carnivores as the odor of real blood, suggesting that trans-4,5-epoxy-(E)-2-decenal may be perceived by predators as a “character impact compound” of mammalian blood odor. Further, the results suggest that odorized wooden logs are a suitable manner of environmental enrichment for captive carnivores.     

Cercopithecine and Colobine Abundance Across Protected and Unprotected Land in the Greater Mahale Ecosystem,Western Tanzania

International Journal of Primatology - Most primates live in unprotected land where abundances and threats may differ from those in protected areas. We therefore need to establish population...     

Inter-epidemic Transmission of Rift Valley Fever in Livestock in the Kilombero River Valley,Tanzania: A Cross-Sectional Survey

Background

In recent years, evidence of Rift Valley fever (RVF) transmission during inter-epidemic periods in parts of Africa has increasingly been reported. The inter-epidemic transmissions generally pass undetected where there is no surveillance in the livestock or human populations. We studied the presence of and the determinants for inter-epidemic RVF transmission in an area experiencing annual flooding in southern Tanzania.

Methodology

A cross-sectional sero-survey was conducted in randomly selected cattle, sheep and goats in the Kilombero river valley from May to August 2011, approximately four years after the 2006/07 RVF outbreak in Tanzania. The exposure status to RVF virus (RVFV) was determined using two commercial ELISA kits, detecting IgM and IgG antibodies in serum. Information about determinants was obtained through structured interviews with herd owners.

Findings

An overall seroprevalence of 11.3% (n = 1680) was recorded; 5.5% in animals born after the 2006/07 RVF outbreak and 22.7% in animals present during the outbreak. There was a linear increase in prevalence in the post-epidemic annual cohorts. Nine inhibition-ELISA positive samples were also positive for RVFV IgM antibodies indicating a recent infection. The spatial distribution of seroprevalence exhibited a few hotspots. The sex difference in seroprevalence in animals born after the previous epidemic was not significant (6.1% vs. 4.6% for females and males respectively, p = 0.158) whereas it was significant in animals present during the outbreak (26.0% vs. 7.8% for females and males respectively, p<0.001). Animals living >15 km from the flood plain were more likely to have antibodies than those living <5 km (OR 1.92; 95% CI 1.04–3.56). Species, breed, herd composition, grazing practices and altitude were not associated with seropositivity.

Conclusion

These findings indicate post-epidemic transmission of RVFV in the study area. The linear increase in seroprevalence in the post-epidemic annual cohorts implies a constant exposure and presence of active foci transmission preceding the survey.     

Tracks,Trails and Trampling by Large Vertebrates in a Rift Valley Paleo-Wetland,Lowermost Bed II,Olduvai Gorge,Tanzania

The impact of large vertebrates on the sedimentary record in an East African groundwater-fed wetland in Ngorongoro Crater, Tanzania, is used as a modern analog to interpret an ancient (Plio-Pleistocene) wetland record in Olduvai Gorge, Tanzania. The 3 km² wetland at Olduvai is characterized by massive silty claystones produced by intense vertebrate trampling, as well as trails by vertebrates frequenting the wetlands and isolated footprints that represent a “snapshot in time.” Based on modern analogs, a paleo hippo trail (1.2 m wide and 0.6 m deep) in the Plio-Pleistocene wetlands is interpreted as a frequently used corridor between hippo pools (days) and grazing meadows (nights). Groundwater-fed wetlands are low energy environments where the physical record appears to be dominated by plant and animal activity. The bioturbation record reflects a number of interacting factors such as substrate texture, moisture content, sedimentation rate, frequency of flooding, type of animals present, trampling rate, and post-depositional changes (compaction). Lithofacies in both the modern and ancient wetlands include muddy sandstone (drainage channels) and silty claystone (vegetated and nonvegetated mud flats). Organic-rich sediments eventually oxidize, eliminating most evidence of the habitat. Modern wetlands have organic-rich mud and peat, whereas the ancient analog has siliceous earthy claystones that contains plant remains, bone fragments, pollen, phytoliths, and localized beds of diatomite. Thus, the physical record of vertebrate bioturbation in conjunction with paleontological and lithological records provides crucial information on the ecology of ancient wetland environments.     

Herding and snaking by the harem stallion in domestic herds

Four herds of pony mares, each consisting of a stallion and six mares, were used to characterize the nature of herding by the stallion and the factors that induced the herding behavior. Herding behaviors were compared among four successive treatments (six mares alone, stallion added, two new mares added, and entire herd moved to a new pasture). A new treatment was initiated every 7 days and behavior was studied for 5 consecutive days (Days 1-5) for each treatment. Observations were made every 10 min during a 2-h period for each day. The extent of herding was quantitated by the mean distances between mares. The extent of snaking (herding with the head and neck extended and ears held back) was scored 0, 1, 2, or 3 (nil, minimal, intermediate, and maximal, respectively). The mean distance among the original mares on Day 1 when the mares were alone was 5.0 mare lengths and was reduced (P < 0.05) to 1.9 mare lengths when the stallion was added. The mean distance among the original mares of an established stallion/mare herd (3.8 mare lengths) was reduced (P < 0.05) on the day the herd was moved to a new pasture (1.9 mare lengths), similar to the effect of the introduction of the stallion. Scores for the extent of snaking, as well as the extent of herding, were highest (P < 0.05) on Day 1 when the stallion was added or the stallion/mare herd was moved to a new pasture. The extent of herding and snaking decreased (P < 0.05) by Day 2 and was seen only occasionally on Days 3-5. The addition of new mares to the herd did not induce herding of the original mares. However, the new mares maintained mean distances of 8-12 mare lengths from the original mares, resulting primarily from chasing by the stallion. By Day 4, the distances between the new and original mares were not different (P > 0.05) from the distances among the original mares.     

Epidemiology and Molecular Characterization of Cryptosporidium spp. in Humans,Wild Primates,and Domesticated Animals in the Greater Gombe Ecosystem,Tanzania

Cryptosporidium is an important zoonotic parasite globally. Few studies have examined the ecology and epidemiology of this pathogen in rural tropical systems characterized by high rates of overlap among humans, domesticated animals, and wildlife. We investigated risk factors for Cryptosporidium infection and assessed cross-species transmission potential among people, non-human primates, and domestic animals in the Gombe Ecosystem, Kigoma District, Tanzania. A cross-sectional survey was designed to determine the occurrence and risk factors for Cryptosporidium infection in humans, domestic animals and wildlife living in and around Gombe National Park. Diagnostic PCR revealed Cryptosporidium infection rates of 4.3% in humans, 16.0% in non-human primates, and 9.6% in livestock. Local streams sampled were negative. DNA sequencing uncovered a complex epidemiology for Cryptosporidium in this system, with humans, baboons and a subset of chimpanzees infected with C. hominis subtype IfA12G2; another subset of chimpanzees infected with C. suis; and all positive goats and sheep infected with C. xiaoi. For humans, residence location was associated with increased risk of infection in Mwamgongo village compared to one camp (Kasekela), and there was an increased odds for infection when living in a household with another positive person. Fecal consistency and other gastrointestinal signs did not predict Cryptosporidium infection. Despite a high degree of habitat overlap between village people and livestock, our results suggest that there are distinct Cryptosporidium transmission dynamics for humans and livestock in this system. The dominance of C. hominis subtype IfA12G2 among humans and non-human primates suggest cross-species transmission. Interestingly, a subset of chimpanzees was infected with C. suis. We hypothesize that there is cross-species transmission from bush pigs (Potaochoerus larvatus) to chimpanzees in Gombe forest, since domesticated pigs are regionally absent. Our findings demonstrate a complex nature of Cryptosporidium in sympatric primates, including humans, and stress the need for further studies.     

Seabird diversity hotspot linked to ocean productivity in the Canary Current Large Marine Ecosystem

Upwelling regions are highly productive habitats targeted by wide-ranging marine predators and industrial fisheries. In this study, we track the migratory movements of eight seabird species from across the Atlantic; quantify overlap with the Canary Current Large Marine Ecosystem (CCLME) and determine the habitat characteristics that drive this association. Our results indicate the CCLME is a biodiversity hotspot for migratory seabirds; all tracked species and more than 70% of individuals used this upwelling region. Relative species richness peaked in areas where sea surface temperature averaged between 15 and 20°C, and correlated positively with chlorophyll a, revealing the optimum conditions driving bottom-up trophic effects for seabirds. Marine vertebrates are not confined by international boundaries, making conservation challenging. However, by linking diversity to ocean productivity, our research reveals the significance of the CCLME for seabird populations from across the Atlantic, making it a priority for conservation action.     

Black and Hispanic Men Perceived to Be Large Are at Increased Risk for Police Frisk,Search, and Force

Social justice issues remain some of the most pressing problems in the United States. One aspect of social justice involves the differential treatment of demographic groups in the criminal justice system. While data consistently show that Blacks and Hispanics are often treated differently than Whites, one understudied aspect of these disparities is how police officers'' assessments of suspects'' size affects their decisions. Using over 3 million cases from the New York Police Department (NYPD) Stop, Question, and Frisk (SQF) Database, 2006–2013, this study is the first to explore suspects'' race, perceived size, and police treatment. Results indicate that tall and heavy black and Hispanic men are at the greatest risk for frisk or search. Tall and heavy suspects are at increased risk for experiencing police force, with black and Hispanic men being more likely to experience force than white men across size categories.     

Comparison of Closed-Ended,Open-Ended,and Perceived Informed Consent Comprehension Measures for a Mock HIV Prevention Trial among Women in Tanzania

Verifying participant comprehension continues to be a difficult ethical and regulatory challenge for clinical research. An increasing number of articles assessing methods to improve comprehension have been published, but they use a wide range of outcome measures including open-ended, closed-ended, and self-perceived measures of comprehension. Systematic comparisons of different measures have rarely been reported. This study evaluated the likely direction of bias observed when using open-ended, closed-ended, and perceived ease of comprehension measures among women administered a mock informed consent process in Mwanza, Tanzania. Participants were randomized to either a closed-ended or an open-ended assessment of comprehension, administered the consent process for a hypothetical HIV prevention trial in Kiswahili, and then administered a comprehension assessment, per their randomization. They were then asked how easy or hard it was to understand each of the informed consent components measured in the comprehension assessment. Women in the closed-ended arm had significantly higher overall comprehension scores than in the open-ended arm. Perceived scores were significantly higher when compared to both open-ended and close-ended scores within arms but were similar between arms. Findings highlight the importance of comprehension assessments in complex clinical trials that go beyond asking participants if they understand or have any questions. They also indicate the need for continued exploration of objective measures of comprehension in international clinical research settings, so that points in need of clarification can be efficiently and effectively identified and addressed. Such measures would reduce burdens on both staff and participants that result from well-intentioned but potentially unnecessary time spent explaining in unwarranted detail things already understood.     

Zooplankton and salinity in the Rufiji River delta,Tanzania

A comparative analysis of the zooplankton from different salinities was carried out in the Rufiji River delta system, located on the mid Tanzanian coastline opposite Mafia Island (7° 45 S, 39° 20 W).Zooplankton samples were collected by vertical, oblique and horizontal surface tows (250 µm mesh) at three sites, namely at the river mouth (salinity = 20–25), in the estuary (salinity = 12–14), and in the upper reaches of the river (salinity = 0). Samples taken in the river mouth and estuary were collected at two times of the day, which coincided approximately with midday and sunset.A comparison of zooplankton diversity and abundance at the three sites showed that a much richer, more diverse fauna existed at the river mouth and estuary compared to the upper reaches. The zooplankton collected both at the mouth and in the estuary were very abundant at certain times of the day, although differences in faunal composition were found between the two sites.