A modelling framework for predicting the optimal balance between control and surveillance effort in the local eradication of tuberculosis in New Zealand wildlife.

Bovine tuberculosis (TB) impacts livestock farming in New Zealand, where the introduced marsupial brushtail possum (Trichosurus vulpecula) is the wildlife maintenance host for Mycobacterium bovis. New Zealand has implemented a campaign to control TB using a co-ordinated programme of livestock diagnostic testing and large-scale culling of possums, with the long-term aim of TB eradication. For management of the disease in wildlife, methods that can optimise the balance between control and surveillance effort will facilitate the objective of eradication on a fixed or limited budget. We modelled and compared management options to optimise the balance between the two activities necessary to achieve and verify eradication of TB from New Zealand wildlife: the number of lethal population control operations required to halt the M. bovis infection cycle in possums, and the subsequent surveillance effort needed to confidently declare TB freedom post-control. The approach considered the costs of control and surveillance, as well as the potential costs of re-control resulting from false declaration of TB freedom. The required years of surveillance decreased with increasing numbers of possum lethal control operations but the overall time to declare TB freedom depended on additional factors, such as the probability of freedom from disease after control and the probability of success of mop-up control, i.e. retroactive culling following detection of persistent disease in the residual possum population. The total expected cost was also dependent on a number of factors, many of which had wide cost ranges, suggesting that an optimal strategy is unlikely to be singular and fixed, but will likely vary for each different area being considered. Our approach provides a simple framework that considers the known and potential costs of possum control and TB surveillance, enabling managers to optimise the balance between these two activities to achieve and prove eradication of a wildlife disease, or the pest species that transmits it, in the most expedient and economic way. This cost- and risk-evaluation approach may be applicable to other wildlife disease problems where limited management funds exist.

Costs and benefits of trap-neuter-release and euthanasia for removal of urban cats in Oahu, Hawaii.

Our goal was to determine whether it is more cost-effective to control feral cat abundance with trap-neuter-release programs or trap and euthanize programs. Using STELLA 7, systems modeling software, we modeled changes over 30 years in abundance of cats in a feral colony in response to each management method and the costs and benefits associated with each method . We included costs associated with providing food, veterinary care, and microchips to the colony cats and the cost of euthanasia, wages, and trapping equipment in the model. Due to a lack of data on predation rates and disease transmission by feral cats the only benefits incorporated into the analyses were reduced predation on Wedge-tailed Shearwaters (Puffinus pacificus). When no additional domestic cats were abandoned by owners and the trap and euthanize program removed 30,000 cats in the first year, the colony was extirpated in at least 75% of model simulations within the second year. It took 30 years for trap-neuter-release to extirpate the colony. When the cat population was supplemented with 10% of the initial population size per year, the colony returned to carrying capacity within 6 years and the trap and euthanize program had to be repeated, whereas trap-neuter-release never reduced the number of cats to near zero within the 30-year time frame of the model. The abandonment of domestic cats reduced the cost effectiveness of both trap-neuter-release and trap and euthanize. Trap-neuter-release was approximately twice as expensive to implement as a trap and euthanize program. Results of sensitivity analyses suggested trap-neuter-release programs that employ volunteers are still less cost-effective than trap and euthanize programs that employ paid professionals and that trap-neuter-release was only effective when the total number of colony cats in an area was below 1000. Reducing the rate of abandonment of domestic cats appears to be a more effective solution for reducing the abundance of feral cats.

The construction of a "population problem" in colonial India, 1919-1947.

This article examines the construction of a "population problem" among public health officials in India during the inter-war period. British colonial officials came to focus on India's population through their concern with high Indian infant and maternal mortality rates. They raised the problem of population as one way in which to highlight the importance of dealing with public health at an all-India basis, in a context of constitutional devolution of power to Indians where they feared such matters would be relegated to relative local unimportance. While they failed to significantly shape government policy, their arguments in support of India's 'population problem' nevertheless found a receptive audience in the colonial public sphere among Indian intellectuals, economists, eugenicists, women social reformers and birth controllers. The article contributes to the history of population control by situating its pre-history in British colonial public health and development policy and outside the logic of USA's Cold War strategic planning for Asia.

Contraceptive vaccines for wildlife: a review.

Wildlife, free-ranging and captive, poses and causes serious population problems not unlike those encountered with human overpopulation. Traditional lethal control programs, however, are not always legal, wise, safe, or publicly acceptable; thus, alternative approaches are necessary. Immunocontraception of free-ranging wildlife has reached the management level, with success across a large variety of species. Thus far, the immunocontraceptive research and management applications emphasis have been centered on porcine zona pellucida and gonadotropin-releasing hormone vaccines. Contraceptive success has been achieved in more than 85 different wildlife species, at the level of both the individual animal and the population. At the population management level with free-ranging species, the primary focus has been on wild horses, urban deer, bison, and African elephants. The challenges in the development and application of vaccine-based wildlife contraceptives are diverse and include differences in efficacy across species, safety of vaccines during pregnancy, the development of novel delivery systems for wild and wary free-ranging animals, and the constraints of certain non-contraceptive effects, such as effects on behavior. Beyond the constraints imposed by the public and a host of regulatory concerns, there exists a real limitation for funding of well-designed programs that apply this type of fertility control.

Contraceptive vaccines based on the zona pellucida glycoproteins for dogs and other wildlife population management.

Zona pellucida (ZP) glycoproteins, by virtue of their critical role in fertilization, have been proposed as candidate antigens for the development of contraceptive vaccines. In this review, the potential of a ZP-based contraceptive vaccine for the management of wildlife population, with special reference to street dogs, is discussed. Immunization of various animal species, including female dogs, with native porcine ZP led to inhibition of fertility, which was associated with the ovarian dysfunction. Immunization of female dogs with Escherichia coli-expressed recombinant dog ZP glycoprotein-3 (ZP3) either coupled to diphtheria toxoid or expressed as fusion protein with 'promiscuous' T non-B-cell epitope of tetanus toxoid also led to inhibition of fertility. To improve the contraceptive efficacy of ZP-based contraceptive vaccine, various groups are working on improving the immunogen, use of DNA vaccine as prime-boost strategy, and delivering the zona proteins/peptides presented on either virus-like particles or entrapped in microsphere. Host-specific live vectors such as ectromelia virus and cytomegalovirus have also been used to deliver mouse ZP3 in mice. Various studies show the enormous potential of the ZP-based vaccine for the management of wildlife population, where permanent sterilization may be desirable.

Contraceptive vaccines for the humane control of community cat populations.

Free-roaming unowned stray and feral cats exist throughout the world, creating concerns regarding their welfare as well as their impact on the environment and on public health. Millions of healthy cats are culled each year in an attempt to control their numbers. Surgical sterilization followed by return to the environment is an effective non-lethal population control method but is limited in scope because of expense and logistical impediments. Immunocontraception has the potential to be a more practical and cost-effective method of control. This is a review of current research in immunocontraception in domestic cats. Functional characteristics of an ideal immunocontraceptive for community cats would include a wide margin of safety for target animals and the environment, rapid onset and long duration of activity following a single treatment in males and females of all ages, and sex hormone inhibition. In addition, product characteristics should include stability and ease of use under field conditions, efficient manufacturing process, and low cost to the user. Two reproductive antigens, zona pellucida and GnRH, have been identified as possible targets for fertility control in cats. Zona pellucida, which is used successfully in multiple wildlife species, has achieved little success in cats. In contrast, immunization against GnRH has resulted in long-term contraception in both male and female cats following a single dose. GnRH is an ideal contraceptive target because it regulates pituitary and gonadal hormone responses in both males and females, thus suppressing nuisance behaviors associated with sex hormones in addition to preventing pregnancy. The responsiveness of cats to fertility control via GnRH suppression should encourage researchers and cat control stakeholders to continue efforts to optimize vaccines that induce multiyear contraception following a single dose in a high proportion of treated cats.

Socio-cultural aspects of the high masculinity ratio in India.

The paper aims to explicate those factors accountable for the continuing imbalance in the sex ratio and its further masculinization over the whole of the 20th century. Here it is contended that the traditional practice of female infanticide and the current practice of female foeticide in the contemporary period, especially in the north-west and Hindi-speaking states, have significantly contributed to the high masculinity ratio in India. In addition, increasingly higher survival ratios of male children, particularly from the 1951 census onward, have been the prime reason for a declining proportion of females in the Indian population. As the Indian value system has been imbued with a relatively higher preference for sons, improvements in health facilities have benefited males more than females, giving rise to a highly imbalanced sex ratio in the country. This scenario, however, has steadily tended to alter in favour of greater balance in sex ratio.

The limits of scientific planning: Doxiadis and the Tehran Action Plan.

Tehran after the Second World War experienced a modernization drive and rapid population growth. In 1972, the Greek planner, Constantinos Doxiadis, who had already undertaken major housing and planning projects in Iran, was invited to prepare an action plan for the city, to guide the future investment for easing the city's problems. Doxiadis saw cities as nightmares, but advocated that a holistic scientific analysis and a naturalist approach to urban growth management could address their problems. In applying his ideas to Tehran, however, the limits of his ideas of scientific planning became evident, not only through contextual pressures, such as lack of time and data, but also through the planning consultant's approach, in which commercial considerations and the application of readymade solutions could shape the outcome. Rather than working with the context, Doxiadis followed the modernist tenet of breaking with the past, proposing the creation of West Tehran, an alternative to the city where all future growth should take place on a utopian basis. The radical nature of his proposals, his death, and a turbulent revolution aborted the impact of his action plan on Tehran, while faith in modernist scientific planning was widely being abandoned.

Population policies, programmes and the environment.

Human consumption is depleting the Earth's natural resources and impairing the capacity of life-supporting ecosystems. Humans have changed ecosystems more rapidly and extensively over the past 50 years than during any other period, primarily to meet increasing demands for food, fresh water, timber, fibre and fuel. Such consumption, together with world population increasing from 2.6 billion in 1950 to 6.8 billion in 2009, are major contributors to environmental damage. Strengthening family-planning services is crucial to slowing population growth, now 78 million annually, and limiting population size to 9.2 billion by 2050. Otherwise, birth rates could remain unchanged, and world population would grow to 11 billion. Of particular concern are the 80 million annual pregnancies (38% of all pregnancies) that are unintended. More than 200 million women in developing countries prefer to delay their pregnancy, or stop bearing children altogether, but rely on traditional, less-effective methods of contraception or use no method because they lack access or face other barriers to using contraception. Family-planning programmes have a successful track record of reducing unintended pregnancies, thereby slowing population growth. An estimated $15 billion per year is needed for family-planning programmes in developing countries and donors should provide at least $5 billion of the total, however, current donor assistance is less than a quarter of this funding target.

Results of a free spay/neuter program in a Hispanic colonia on the Texas-Mexico border.

The purpose of this study, conducted in a small, impoverished Hispanic community on the Texas-Mexico border, was to evaluate the level of participation in a bilingual spay/neuter program offered free of charge to residents with companion animals. Prior to the sterilization project, approximately 11% of dogs and about 27% of cats with guardians underwent surgical sterilization. Over an 8-month period, the spay/neuter program sterilized about 47% of dogs and 38% of cats who had guardians in the community. In spite of residents' early reluctance to neuter their dogs, the project sterilized nearly equal numbers of male and female dogs (200 male; 201 female).

Allee effect and control of lake system invasion.

We consider the model of invasion prevention in a system of lakes that are connected via traffic of recreational boats. It is shown that in presence of an Allee effect, the general optimal control problem can be reduced to a significantly simpler stationary optimization problem of optimal invasion stopping. We consider possible values of model parameters for zebra mussels. The general N-lake control problem has to be solved numerically, and we show a number of typical features of solutions: distribution of control efforts in space and optimal stopping configurations related with the clusters in lake connection structure.

Considerations for determining optimal mouse caging density.

At the 2006 National Meeting of the American Association of Laboratory Animal Science, a panel discussed the question of what constitutes optimal or acceptable housing density for mice. Though there is a consensus that present guidelines are somewhat arbitrarily defined, scientific research has not yet been able to provide clear recommendations for amending them. Speakers explored the many factors that influence decisions on mouse housing, including regulatory requirements, scientific data and their interpretation, financial considerations and ethical concerns. The panel largely agreed that animal well-being should be the measure of interest in evaluating housing density and that well-being includes not only physical health, but also animals' behavior, productivity and preference.

Impact of a bilingual mobile spay/neuter clinic in a U.S./Mexico border city.

There are between 4 and 10 million dogs and cats killed annually in the United States. Although there are no accurate national estimates of the number of companion animals who are sterilized surgically. Approximately 26,000 companion animals are euthanized annually in El Paso County, Texas, located on the U.S./Mexico border. In an effort to determine if a readily available spay/neuter program would be cost effective and eventually help to lower the county's euthanasia rate, a mobile spay/neuter clinic began operation for a 5-month period in 2004, using a volunteer veterinarian and paid staff. Sterilizations performed totaled 1,108: 959 dogs (372 males and 587 females) and 149 cats (50 males and 99 females). The per companion animal sterilization cost of 15.13 dollars (27.83 dollars had the veterinarian been paid) was considerably cheaper than the rate of 57 dollars per companion animal achieved by a local voucher program contracting with private veterinarians to perform reduced-cost sterilizations.

Dinâmica populacional canina no Município de Ibiúna-SP: estudo retrospectivo / Canine population dynamics in Ibiúna-SP: retrospective study

Foram estimados, neste estudo, parâmetros relacionados à dinâmica populacional canina no Município de Ibiúna, Estado de São Paulo, para animais domiciliados, recolhidos e eutanasiados, no período de 1998 a 2002. Os dados foram obtidos a partir de fichas de cães recolhidos e eutanasiados junto ao Departamento de Zoonoses do município e também através de censos da população canina domiciliada, com levantamentos feitos casa a casa, durante as campanhas anti-rábicas. Foi observado um aumento progressivo tanto do número de cães recolhidos quanto do número de cães eutanasiados. Os valores para a razão habitante/cão média no período foram 3,16:1, 7,67:1, e 3,91:1 para a zona rural, urbana e o município todo, respectivamente, com predominância de cães machos (70,10%) e sem raça definida (80,71 %), na população canina domiciliada. O crescimento anual médio da população canina domiciliada foi de 16,69%, e a maioria dos cães encontrava-se na zona rural (82,93%). A eutanásia e o recolhimento de cães não se mostraram efetivos, nos moldes em que foram aplicados, como mecanismos de controle populacional canino em Ibiúna. Os parâmetros da população canina estimados neste estudo servirão de auxílio para a elaboração de programas de controle tanto da população canina quanto de zoonoses, neste município. Os resultados observados chamam a atenção para aspectos relacionados à posse responsável, e sobre a importância do papel dos proprietários de animais na solução do problema do abandono de cães.

In this study, we estimated parameters related to the dog population dynamics in Ibiúna, a town in the state of São Paulo, regarding household, sheltered and euthanized dogs, in the period from 1998 to 2002. Sheltered and euthanized dogs data were obtained from Ibiúna Zoonosis Department records, and also from household dogs population census, through surveys conducted using a questionnaire to interview household members, during rabies vaccination campaigns. Both the number of sheltered and euthanized dogs increased progressively in the studied period. The values for the human to dog mean ratio were 3.16:1, 7.67:1, and 3.91:1 for the rural area, theurban area, and the whole town, respectively, with predominance of male (70.10%) and mixed breed (80.71%) dogs, in the household dog population. A 16.69% mean annual rate of increase was observed for the dog population, and most of the dogs lived in the rural area (82.93%). Euthanasia and sheltering of dogs did not show to be effective, in the way they were applied, as methods of dog population control in Ibiúna. The dog population parameters estimated in this study will help the health authorities from Ibiúna to design control programmes for both dog population and zoonosis. The results observed call our attention to some aspects related to responsible ownership and to the importance of the animal owner's role for the solution of the abandoned dogs problem.