The acceptability of rat trap use over pesticides for rodent control in two poor urban communities in South Africa

Knowledge and practices related to plague persistence in plague-endemic foci, Mbulu District, Tanzania

INTRODUCTION

Plague continues to be a major public health concern in African countries. Several social practices and environmental conditions have been associated with the reoccurrence of bubonic plague, especially in places where the disease is prevalent. Therefore, it remains important to understand people knowledge, behavior and practices related to disease risks in order to identify factors that may hinder prevention and control strategies in the foci.

METHODS AND RESULTS

A study survey of 100 households was conducted in Mbulu district to assess plague knowledge, factors that influence flea bite and measures used for rodent and flea control. Majority of participants (86%) were familiar with the plague disease and about (50%) mentioned swelling lymph nodes as a common symptom. Most of the participants (62%) claimed to observe human plague cases during the long rain season. The majority of participants (97%) reported to experience flea bite in their domestic settings, with most stating that they experienced more flea bites during the dry season. Houses with livestock had a greater likelihood of flea bite (OR = 2.7; 95% CI: 0.36-18.80, p = 0.267) compared to houses with no livestock. Furthermore, residents reported using both local and chemical methods to control rodents and flea inside houses. Most respondents preferred using local methods in flea control. Respondents stated that the efficacy of flea control methods being applied ranged from few days to several months. There was limited knowledge of the residual effects of the agricultural chemicals being used to control fleas among the surveyed community.

CONCLUSION

Our study highlights the importance of raising awareness and adopting effective control methods for controlling fleas and lower the risk of plague transmission and other flea borne diseases in the local communities. Sensitization of the local community on the use of appropriate chemicals for flea control is urgent to avoid any potential long-term impacts of the residual effects on the health of the local communities.

Organophosphate pesticide exposure as a risk factor for attempted suicide in Cape Town, South Africa: A case-control study

Pesticides are a commonly used agent for suicide in many Low- and Middle-Income countries (LMICs). However, accumulating evidence suggests that exposure to organophosphate (OP) pesticide may also increase the risk of suicide. We conducted a hospital-based case-control study to investigate whether prior household, garden or occupational OP exposure were associated with attempted suicide using conditional logistic regression modeling. Participants who attempted suicide with any means and were admitted to two Western Cape Province hospitals in South Africa were compared to a sample of controls matched by age, sex and time of admission with unrelated conditions, between August 2015 and August 2017. The means of attempted suicide was not recorded. OP exposure was determined by dialkyl phosphate (DAP) metabolites detected in hair and by environmental and occupational history. Approximately 85% of participants reported using pesticides in the home or garden and 15% of participants reported current or past occupational exposure while working on a farm. Attempted suicide was not associated with reported home or garden OP use (Odds ratio [OR] = 0.59, 95%CI 0.33-1.04), hair DAP metabolites (OR = 1.00, 95%CI 0.98-1.02) or current or past agricultural work (OR = 1.08, 95%CI 0.62-1.87), but was associated with hazardous drinking and unemployment with no household income. We found no evidence that attempted suicide was associated with environmental or occupational pesticide use in an urban South African population attending an emergency center.

Rat Infestation in Gauteng Province: Lived Experiences of Kathlehong Township Residents

Background: Rat infestation is a major public health issue globally, and particularly in poor urban communities in South Africa. Rats pose significant threats to residents in the form of disease spread and sustained physical injuries. The dearth of knowledge about the experiences of affected residents may curtail the initiation of rat control programs. This study aimed to explore the lived experiences of rat infestation among residents of Katlehong Township in Gauteng Province. Methods: This was a qualitative research study where data were gathered from selected community participants from Katlehong Township in Gauteng Province. A semi-structured interview guide was used to collect data through in-depth interviews. The interviews were digitally recorded and transcribed verbatim, and thematic data analysis was conducted using NVivo12 data processing software. The data were presented in themes and quotations that reflect the views of the participants. Results: Exactly 20 community members aged between 18 and 56 years participated in the study, 80% being females. Over half of the participants were unemployed (60%), inclusive of students. Majority of the participants were either Zulu or Xhosa speakers. Several themes emerged from the data, which included the residents’ experiences of rat infestation, troublesome rats, dirty rats, reasons for rat infestation, and sustained physical injuries. Participants intimated that waste in the environment and overcrowding in homes contributed to rodent infestation. Conclusion: Rat infestation remains a problem that causes severe distress among the residents of Katlehong Township. The experiences reported varied from psychological trauma to bite injuries and destruction of household property. Effective rodent control strategies need to be put in place to manage both the physical and mental risks posed by rat infestation in socially underprivileged communities.

Modeling the strategies to eradicate rats introduced in the Galapagos Islands

The Galapagos Islands are well known for their incredible biodiversity and the inspiration for Charles Darwin's natural evolution theory. It is an ecosystem that has evolved without predators, so their native species are unfit for competition. As a result, this biodiversity has been threatened by invasive species like rats (Black and Norwegian). Nowadays, the primary strategy to control rats is by having drones that disperse a unique poisoned bait. Our study aims to mathematically model the strategies to eradicate rats in islands, based on previously reported processes. As a result, we are obtaining the approximated time to reduce its population as much as being eradicated, without threatening the coexisting species. We also propose a suitable alternative to be applied in the Galapagos Islands to recover their biodiversity richness. We find that rats' introduction has caused a decrease in the native species due to having specific traits that make them fitter in different situations. The best method to control species in such a sensitive environment is by the use of anticoagulant rodenticides. The current method used for eradicating rats seems to be the most profitable even though there is not enough information to see the collateral consequences of the poison technique. Furthermore, we propose this theoretical study complemented with in situ samplings to corroborate our hypothesis and improve our prediction model.

Assessing the potential impacts of non-native small mammals in the South African pet trade

The pet trade is one of the most important pathways by which small mammals are introduced to non-native areas. To prevent the introduction and invasion of non-native pets, an impact assessment protocol is useful in understanding which pets might have potential negative impacts should they escape or be released from captivity. In this study, we used the Generic Impact Scoring System (GISS) to assess the potential effects associated with 24 non-native small mammal species sold in the South African pet trade. European rabbits Oryctolagus cuniculus, house mice Mus musculus, Norwegian rats Rattus norvegicus and eastern grey squirrels Sciurus carolinensis had the highest potential impacts for both socio-economic and environmental categories. We found no statistically significant difference between the overall environmental and socio-economic impact scores. Impacts on agricultural and animal production (livestock) were the main mechanisms in the socio-economic category, while the impacts on animals (predation), competition and hybridisation prevailed for environmental impacts. The non-native mammal pet species with high impacts should be strictly regulated to prevent the potential impacts and establishment of feral populations in South Africa.

Need for preventive and control measures for Lassa fever through the One Health strategic approach

Lassa virus (LASV) has increasingly been recognised as a significant public-health pathogen transmitted by rodents. LASV infection leads to life-threatening Lassa fever, which has high potential for severe morbidity and mortality. There have been several scientific efforts to understand the genomics and ecological epidemiology of Lassa. However, very limited studies have focused on the short- and long-term impacts of environmental factors, human behaviours and rodent activities on LASV transmission dynamics and control. Recently, a very plausible and ideal way to address the Lassa epidemic has been considered through the One Health approach. The One Health system of intervention is capable of providing better and comprehensive information necessary to address the complex interplay between human, ecological, and environmental determinants of LASV transmission, persistence and re-emergence. Thus, the aim of this article was to review critically the impacts of various environmental factors on rodent infestations, LASV transmission and how human activities contribute to the persistence of Lassa with regard to exploring how they could be harnessed for better understanding of Lassa prevention and control through a concerted One Health approach.

Animal welfare and ecology in the contested ethics of rodent control in Cape Town

There is growing concern globally about the inhumane treatment of ‘pest’ animals, including rodents, and about the ecological consequences of rodenticides, notably the poisoning of non-target wildlife like raptors and scavengers. Recent contestation between Environmental Health (EH) officials in Khayelitsha, Cape Town’s largest African township, and the National Council for Societies for the Prevention of Cruelty to Animals (NSPCA) illustrates the tension that can arise between innovative ecologically-focused strategies and existing legislation and animal protection practices. In 2013/14 EH officials introduced a job-creation project to trap and drown rats, describing it as ‘humane’ because it avoided poison thereby posing no danger to wildlife such as owls. The NSPCA, however, halted the project, arguing that drowning was both inhumane and illegal. Death by poison is also inhumane but the South Africa’s Animals Protection Act (1962) allows it (and trapping and hunting) to be used against ‘pests’/‘vermin’. The NSPCA, which has never challenged the Act for allowing the inhumane treatment of these animals, used it to trump local preferences. A representative survey from Khayelitsha showed that there was some support for an NSPCA-like position (14% thought that drowning was cruel and that workers should not be allowed to trap and drown rats) but that the majority (70%) indicated that they were both concerned about the poisoning of non-target animals and supported the continuation of the trapping and drowning project. This was not a contestation over whether animals should be protected, but over how to do this, and which animals to include.

Rodent control to fight Lassa fever: Evaluation and lessons learned from a 4-year study in Upper Guinea

Lassa fever is a viral haemorrhagic fever caused by an arenavirus. The disease is endemic in West African countries, including Guinea. The rodents Mastomys natalensis and Mastomys erythroleucus have been identified as Lassa virus reservoirs in Guinea. In the absence of a vaccine, rodent control and human behavioural changes are the only options to prevent Lassa fever in highly endemic areas. We performed a 4 year intervention based on chemical rodent control, utilizing anticoagulant rodenticides in 3 villages and evaluating the rodent abundance before and after treatment. Three additional villages were investigated as controls. Analyses to assess the effectiveness of the intervention, bait consumption and rodent dynamics were performed. Anthropological investigations accompanied the intervention to integrate local understandings of human–rodent cohabitation and rodent control intervention. Patterns of bait consumption showed a peak at days 5–7 and no consumption at days 28–30. There was no difference between Bromadiolone and Difenacoum bait consumption. The main rodent species found in the houses was M. natalensis. The abundance of M. natalensis, as measured by the trapping success, varied between 3.6 and 16.7% before treatment and decreased significantly to 1–2% after treatment. Individuals in treated villages welcomed the intervention and trapping because mice are generally regarded as a nuisance. Immediate benefits from controlling rodents included protection of food and belongings. Before the intervention, local awareness of Lassa fever was non-existent. Despite their appreciation for the intervention, local individuals noted its limits and the need for complementary actions. Our results demonstrate that chemical treatment provides an effective tool to control local rodent populations and can serve as part of an effective, holistic approach combining rodent trapping, use of local rodenticides, environmental hygiene, house repairs and rodent-proof storage. These actions should be developed in collaboration with local stakeholders and communities.

In the absence of a Lassa fever vaccine, rodent control is the primary prevention option. An effective rodent control intervention must understand human behaviour towards the rodent such as: human–rodent interactions, cohabitation, and local rodent control measures. We conducted a rodent control intervention at community level in a Lassa Virus endemic area in Upper Guinea (Guinea) accompanied by an anthropological study on people’s perceptions and recommendations on the intervention. Based on our results we seek to broaden the rodent control intervention by including environmental hygiene, house repairs and rodent-proof storage. Chemical treatment has proven effective for rodent control but other factors involved in human-rodent interactions should also be addressed. Our findings highlight the need for Lassa fever prevention and rodent control initiatives to work in collaboration with communities and undertake a holistic approach towards rodent control.

An Evaluation of Removal Trapping to Control Rodents Inside Homes in a Plague-Endemic Region of Rural Northwestern Uganda

Rodents pose a significant threat to human health, particularly in rural subsistence farming communities in Africa, where rodents threaten food security and serve as reservoirs of human pathogens, including the agents of plague, leptospirosis, murine typhus, rat-bite fever, Lassa fever, salmonellosis, and campylobacteriosis. Our study focused on the plague-endemic West Nile region of Uganda, where a majority of residents live in Uganda government-defined poverty, rely on subsistence farming for a living, and frequently experience incursions of rodents into their homes. In this study, we show that rodent removal was achieved in a median of 6 days of intensive lethal trapping with multiple trap types (range: 0-16 days). However, rodent abundance in 68.9% of homesteads returned to pretreatment levels within a median of 8 weeks (range 1-24 weeks), and at least a single rodent was captured in all homesteads by a median of 2 weeks (range 1-16 weeks) after removal efforts were terminated. Results were similar between homesteads that practiced rodent control whether or not their neighbors implemented similar strategies. Overall, intensive lethal trapping inside homes appears to be effective at reducing rodent abundance, but control was short lived after trapping ceased.

Pesticide Vendors in the Informal Sector: Trading Health for Income

South African low-income communities face many challenges (e.g., insufficient housing, poor service delivery, and abject poverty); additionally, a silent challenge of pest infestation plagues these areas resulting in disease risks, nuisances, and stigma. Consequently, an enterprising urban informal sector business has emerged providing residents with highly toxic, effective, cheap, and illegal "street pesticides." These pesticides pose acute and chronic health risks for vendors and residents. The economic opportunity provided by the high demand for effective and cheap pest control results in the high risk of health effects being traded for income. Current measures to control and "regulate" the massive street pesticide sales result in toxic stockpiles and government's "turning a blind eye." Solutions will only be achieved through open dialog identifying and developing non-toxic pest control strategies while ensuring vendors' income; and relevant stakeholder recognition that pest infestation is a social and environmental health determinant needing acknowledgement in different government policies.

Range Measurement and a Habitat Suitability Map for the Norway Rat in a Highly Developed Urban Environment

Studies of habitat suitability (HS) are essential when animals' habitats have been altered or when animals migrate to a habitat different from their natural habitat. This study assessed HS and used an integrated geographic information system in the assessment of Rattus norvegicus in a highly developed urban environment. Using data from the Campbell market and the police quarters of George Town, Malaysia, home range (through the use of 100% Minimum Convex Polygon [MCP], 95% MCP and 95% Harmonic Mean [HM]) was estimated. Home range for male rats at Campbell market reached an asymptote, with a slight increase, at 96 radio fixes (home range = 133.52 m(2); core area = 29.39 m(2)). Female rats reached an asymptote at 62 radio fixes (home range = 13.38 m(2); core area = 9.17 m(2)). At Campbell market, male rats emerged at 1900 hours every day, whereas females emerged at 2000 hours; at police quarters, the most common time of emergence for males was 2000 hours and for females was 2200. Raster charts of R. norvegicus showed that rat hot spots can be grouped into 4 zones (market, shop houses, settlement and general places). The standardised raster chart isolated the market as the major rallying points of the rats (hot spots) by producing the highest rats frequencies of 255. All of the habitat suitability thresholds, including the built-up points, skip bins, water source and nature of the site explored in this study, produced a structural pattern (monotonic increase or decrease) of habitat suitability.

Development of a community-based intervention for the control of Chagas disease based on peridomestic animal management: an eco-bio-social perspective

Background

Integrated vector management strategies depend on local eco-bio-social conditions, community participation, political will and inter-sectorial partnership. Previously identified risk factors for persistent Triatoma dimidiata infestation include the presence of rodents and chickens, tiled roofs, dirt floors, partial wall plastering and dog density.

Methods

A community-based intervention was developed and implemented based on cyclical stakeholder and situational analyses. Intervention implementation and evaluation combined participatory action research and cluster randomized pre-test post-test experimental designs. The intervention included modified insecticide application, education regarding Chagas disease and risk factors, and participatory rodent control.

Results

At final evaluation there was no significant difference in post-test triatomine infestation between intervention and control, keeping pre-test rodent and triatomine infestations constant. Knowledge levels regarding Chagas disease and prevention practices including rodent control, chicken management and health service access increased significantly only in intervention communities. The odds of nymph infection and rat infestation were 8.3 and 1.9-fold higher in control compared to intervention communities, respectively.

Conclusion

Vector control measures without reservoir control are insufficient to reduce transmission risk in areas with persistent triatomine infestation. This integrated vector management program can complement house improvement initiatives by prioritizing households with risk factors such as tiled roofs. Requirement for active participation and multi-sectorial coordination poses implementation challenges.

Rats: if you can't beat them eat them! (Tricks of the trade observed among the Adi and other North-East Indian tribals)

BACKGROUND

Since outside the tribal areas of North-East India it is not widely known, neither in the world nor in India itself, that rats are considered a delicious food item, this was one of several reasons why we decided to present this ethnographic account of rat procurement and preparation (together with some additional comments on the cultural role that rats have especially amongst members of the Adi tribe). Consumption of rats by humans as a biological control method far superior to the use of rodenticide poisoning and rat consumption as a way to reduce hunting pressure on rare wild animals were further considerations to publish this account.

METHODS

Semi-structured interviews were conducted with male and female members of eight tribal communities in Arunachal Pradesh (North-East India) on the uses of rats as food and as cultural objects. The construction of rat traps as well as the preparation of rat dishes were observed and recorded photographically.

RESULTS

Numerous species of small rodents, collectively called "rats" by the locals of North-East Indian tribes and comprising the species Rattus rattus Linnaeus, R. nitidus Hodgson, R. burrus Miller, R. tanezumi Temminck as well as Bandicota bengalensis Gray and Hardwicke, B. indica Bechstein, and Mus musculus Linnaeus, are regularly trapped and consumed in roasted, cooked or smoked form. In this well-illustrated report the kinds of devices used to catch these animals are described and information is provided on how to prepare rats for human consumption. The role that rats as food and gift-exchange items play in the context of local culture is explained and the locals' most highly appreciated meat dish, known as bule-bulak oying and consisting of boiled rat's tail, legs and inner organs, is introduced.

CONCLUSION

Given the need to meet the world's future food demands and the environmental consequences of an expanding livestock production with regard to global warming, water availability, deforestation, soil erosion etc., rats as a food item, as our example shows, should not be overlooked. Using rats as food reduces hunting pressures on other wild and often already rare animals. It is a far superior method to control rat populations than poisoning the rodents and the artisanal construction of rat traps by local menfolk helps maintaining traditional skills and knowledge.

Communicating pesticide neurotoxicity research findings and risks to decision-makers and the public

The extensive research findings on neurotoxic risks of pesticides tend to remain in academic publications rather than being comprehensibly communicated to decision-makers and the public. Protecting health and promoting risk reduction, particularly in developing countries, requires access to current findings in a format that can inform policy, regulations, behaviour change and risk reduction. Successfully communicating research findings may require multiple strategies depending on the target audience's varying comprehension skills (e.g., numeracy literacy, visual literacy) and ability to interpret scientific data. To illustrate the complexities of risk communication, a case study of exposure to neurotoxic street pesticides amongst poor, urban South African communities attempting to control poverty related pests, is presented. What remains a challenge is how to communicate neurotoxicity research findings consistently and in a meaningful manner for a lay audience, consisting of both the general public and decision makers. A further challenge is to identify who will monitor and evaluate the ways in which these findings are communicated to ensure quality is maintained. Ultimately, researchers should carry the responsibility of knowledge translation and engaging with communication specialists when appropriate. Additionally, institutions should reward this as part of promotion and academic accolade systems, and funders should fund the translational process. Ethics review boards should also play an instrumental role in ensuring that knowledge translation is part of the ethics review requirement, while professional societies should take more responsibility for disseminating research findings to non-academics.