Zoonotic diseases: sharing insights from interdisciplinary research

Researchers and others involved with the Zoonoses and Emerging Livestock Systems (ZELS) initiative gathered in Tanzania earlier this year to discuss progress with projects being carried out as part of the five- year programme. Mary Ryan and Sarah Cleaveland report

Implementing Pasteur's vision for rabies elimination: the evidence base and the needed policy actions

It has been 129 years since Louis Pasteur's experimental protocol saved the life of a child mauled by a rabid dog, despite incomplete understanding of the etiology or mechanisms by which the miracle cure worked (1). The disease has since been well understood, and highly effective vaccines are available, yet Pasteur's vision for ridding the world of rabies has not been realized. Rabies remains a threat to half the world's population and kills more than 69,000 people each year, most of them children (2). We discuss the basis for this neglect and present evidence supporting the feasibility of eliminating canine-mediated rabies and the required policy actions

The Burden of Rabies in Tanzania and Its Impact on Local\ud Communities

Rabies remains a major public health threat in many parts of the world and is responsible for an estimated 55,000 human deaths annually. The burden of rabies is estimated to be around US$20 million in Africa, with the highest financial expenditure being the cost of post-exposure prophylaxis (PEP). However, these calculations may be substantial underestimates because the costs to households of coping with endemic rabies have not been investigated. We therefore aimed to estimate the household costs, health-seeking behaviour, coping strategies, and outcomes of exposure to rabies in rural and urban communities in Tanzania. Extensive investigative interviews were used to estimate the incidence of human deaths and bite exposures. Questionnaires with bite victims and their families were used to investigate health-seeking behaviour and costs (medical and non-medical costs) associated with exposure to rabies. We calculated that an average patient in rural Tanzania, where most people live on less than US$1 per day, would need to spend over US$100 to complete WHO recommended PEP schedules. High costs and frequent shortages of PEP led to poor compliance with PEP regimens, delays in presentation to health facilities, and increased risk of death. The true costs of obtaining PEP were twice as high as those previously reported from Africa and should be considered in re-evaluations of the burden of rabies

Domestic dog demographic structure and dynamics relevant to rabies control planning in urban areas in Africa: the case of Iringa, Tanzania

<p>Background Mass vaccinations of domestic dogs have been shown to effectively control canine rabies and hence human exposure to rabies. Knowledge of dog population demography is essential for planning effective rabies vaccination programmes; however, such information is still rare for African domestic dog populations, particularly so in urban areas. This study describes the demographic structure and population dynamics of a domestic dog population in an urban sub-Saharan African setting. In July to November 2005, we conducted a full household-level census and a cross-sectional dog demography survey in four urban wards of Iringa Municipality, Tanzania. The achievable vaccination coverage was assessed by a two-stage vaccination campaign, and the proportion of feral dogs was estimated by a mark-recapture transect study.</p> <p>Results The estimated size of the domestic dog population in Iringa was six times larger than official town records assumed, however, the proportion of feral dogs was estimated to account for less than 1% of the whole population. An average of 13% of all households owned dogs which equalled a dog:human ratio of 1:14, or 0.31 dogs per household or 334 dogs km-2. Dog female:male ratio was 1:1.4. The average age of the population was 2.2 years, 52% of all individuals were less than one year old. But mortality within the first year was high (72%). Females became fertile at the age of 10 months and reportedly remained fertile up to the age of 11 years. The average number of litters whelped per fertile female per year was 0.6 with an average of 5.5 pups born per litter. The population growth was estimated at 10% y-1.</p> <p>Conclusions Such high birth and death rates result in a rapid replacement of anti-rabies immunised individuals with susceptible ones. This loss in herd immunity needs to be taken into account in the design of rabies control programmes. The very small proportion of truly feral dogs in the population implies that vaccination campaigns aimed at the owned dog population are sufficient to control rabies in urban Iringa, and the same may be valid in other, comparable urban settings.</p&gt

Transmission dynamics and prospects for the elimination of canine rabies

Rabies has been eliminated from domestic dog populations in Western Europe and North America, but continues to kill many thousands of people throughout Africa and Asia every year. A quantitative understanding of transmission dynamics in domestic dog populations provides critical information to assess whether global elimination of canine rabies is possible. We report extensive observations of individual rabid animals in Tanzania and generate a uniquely detailed analysis of transmission biology, which explains important epidemiological features, including the level of variation in epidemic trajectories. We found that the basic reproductive number for rabies, R<sub>0</sub>, is very low in our study area in rural Africa (∼1.2) and throughout its historic global range (<2). This finding provides strong support for the feasibility of controlling endemic canine rabies by vaccination, even near wildlife areas with large wild carnivore populations. However, we show that rapid turnover of domestic dog populations has been a major obstacle to successful control in developing countries, thus regular pulse vaccinations will be required to maintain population-level immunity between campaigns. Nonetheless our analyses suggest that with sustained, international commitment, global elimination of rabies from domestic dog populations, the most dangerous vector to humans, is a realistic goal

Plain Facts About Anthropogenic Global Climate Change and Warming: A Review

Anthropogenic global climate change (AGC) is proceeding rapidly. The proximate cause is the greenhouse effect of carbon dioxide, methane and other greenhouse gases (GHG), which have rapidly accumulated in the atmosphere from burning fossil fuels and other human activities. Measurements of incoming and outgoing radiation have verified the warming imbalance. Effects manifest themselves in accelerating sea level rise and diminishment of the cryosphere. This has already created climatic refugees and water stress, and will destroy coastal infrastructure. It also impacts ecosystems and biodiversity in many ways. To avoid catastrophic effects, fossil fuel use must cease and carbon sinks must be protected and expanded. While voluminous scientific evidence supports the need for action, the U.S.A. has not acted. A survey of manifestos of geographically diverse conservative national parties in nine industrialized democracies (US, Canada, UK, Spain, Norway, Sweden, Germany, Australia, New Zealand; Båstrand 2015) shows that eight see this as an urgent problem to be solved; the exception being the U.S. Republican Party. I explore reasons for this anomaly