Epidemiological characteristics of rabies in Zambia: A retrospective study (2004–2013)

Rabies Realities: Navigating Barriers to Rabies Control in Rural Zambia-A Case Study of Manyinga and Mwansabombwe Districts

Rabies persists as a longstanding issue in Zambia, despite being preventable. The current control measures, including dog vaccination, population control, and movement restriction, guided by 'The Control of Dogs Act Chapter 247 of the Laws of Zambia', have not yielded the desired impact in many areas of the country including Manyinga and Mwansabombwe districts. These two districts continue to report low dog vaccination rates, unrestricted dog movements, and escalating cases of animal and human rabies, along with dog bites. Aligned with global aspirations to achieve zero human rabies cases by 2030, this study scrutinizes the determinants and obstacles hampering the execution of rabies control initiatives in Manyinga and Mwansabombwe. Spanning approximately 11 months, this cross-sectional study gathered pre- and post-vaccination data from 301 households in Manyinga and 100 households in Mwansabombwe. Questionnaires probed knowledge, attitudes, and practices related to rabies prevention and control. A transect survey, key informant interviews, and assessment of rabies vaccination and dog bite records complemented the data collection. Findings revealed that 88.0% of respondents from both districts possessed knowledge about rabies, confirming affected species and transmission. Moreover, 76.8% in Manyinga and 88.6% in Mwansabombwe were acquainted with rabies prevention and control methods. Concerning dog owners, 89.0% were aware of rabies, 66.0% understood its prevention and control, and the majority identified bites as the primary mode of transmission. Despite the high level of knowledge recorded during the survey, the implementation of preventive measures was low, which was attributed to low levels of law enforcement by the local government authority, inadequate staffing in the veterinary department, unwillingness to pay for dog vaccinations, and unavailability of rabies vaccine at the veterinary office in both districts. Vaccination coverage stood at 64.0% in Manyinga and 21.0% in Mwansabombwe. Notably, education and occupation exhibited a positive significant association with rabies knowledge. In terms of dog bite cases, Manyinga recorded 538 dog bite cases from 2017 to June 2022, while Mwansabombwe recorded 81 dog bite and 23 jackal bite cases from 2021 to June 2022. The study underscores critical knowledge gaps in rural areas and emphasizes the imperative for enhanced public education and awareness programs, improved rabies surveillance, free mass vaccination campaigns, and community engagement to augment vaccination coverage and knowledge about rabies.

Patterns of Animal Rabies Prevalence in Northern South Africa between 1998 and 2022

Rabies is endemic in South Africa and rabies cycles are maintained in both domestic and wildlife species. The significant number of canine rabies cases reported by the World Organization for Animal Health Reference Laboratory for Rabies at Onderstepoort suggests the need for increased research and mass dog vaccinations on specific targeted foci in the country. This study aimed to investigate the spatiotemporal distribution of animal rabies cases from 1998 to 2017 in northern South Africa and environmental factors associated with highly enzootic municipalities. A descriptive analysis was used to investigate temporal patterns. The Getis-Ord Gi statistical tool was used to exhibit low and high clusters. Logistic regression was used to examine the association between the predictor variables and highly enzootic municipalities. A total of 9580 specimens were submitted for rabies diagnosis between 1998 and 2022. The highest positive case rates were from companion animals (1733 cases, 59.71%), followed by livestock (635 cases, 21.88%) and wildlife (621 cases, 21.39%). Rabies cases were reported throughout the year, with the majority occurring in the mid-dry season. Hot spots were frequently in the northern and eastern parts of Limpopo and Mpumalanga. Thicket bush and grassland were associated with rabies between 1998 and 2002. However, between 2008 and 2012, cultivated commercial crops and waterbodies were associated with rabies occurrence. In the last period, plantations and woodlands were associated with animal rabies. Of the total number of municipalities, five consistently and repeatedly had the highest rabies prevalence rates. These findings suggest that authorities should prioritize resources for those municipalities for rabies elimination and management.

Spatiotemporal heterogeneity and determinants of canine rabies evidence at Local Government Area Level in Nigeria: Implications for rabies prevention and control

Canine rabies poses a significant risk to humans and animals in Nigeria. However, the lack of reliable tools to evaluate the performance of existing canine rabies control programs to inform public health policy decisions poses a severe obstacle. We obtained canine rabies surveillance data from the National Veterinary Research Institute (NVRI) and supplemented these data with rabies diagnoses reported in the published studies from Nigeria. To uncover contextual factors (i.e., environmental and sociodemographic) associated with canine rabies evidence at the Local Government Area (LGA) level, we classified LGAs in Nigeria into four categories based on evidence availability (i.e., LGAs with NVRI data or published studies, both, or no evidence). We described the geographical and temporal variation in coverage. We fitted a multinomial regression model to examine the association between LGA level canine rabies evidence and potential sociodemographic and ecological determinants of canine rabies evidence. The effective annual testing during the 19 years was less than one dog/100,000 Nigerian resident-year. Our results showed that 58% of Nigerian LGAs (450/774) had not been targeted by the existing national rabies surveillance or studies on rabies, including ten states capitals with high human populations. While 16% (122/774) of Nigerian LGAs concentrated in Taraba, Adamawa, and Abia had canine rabies evidence from published studies, none of these LGAs was represented in the NVRI rabies surveillance data. We also observed an increasing trend in rabies evidence over time towards the eastern part of Nigeria. Our multinomial regression model indicated that education level, poverty, population density, land use and temperature were significantly associated with canine rabies evidence at the LGA level. This study underscores the value of combining canine rabies evidence from different sources to better understand the current disease situation for targeted intervention.

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This study shows the value of combining different evidence sources to advocate for public health interventions.

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Educational level, poverty, population density, land use and temperature were determinants of evidence of canine rabies.

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Such evidence demonstrates the need to expand Nigeria's rabies laboratory-based surveillance to support rabies prevention.

Immunization Coverage and Antibody Retention against Rabies in Domestic Dogs in Lusaka District, Zambia

Rabies remains endemic in Zambia. Despite conducting canine vaccinations in Lusaka district, the vaccination coverage and actual seropositivity in the dog population in Lusaka district are rarely evaluated. This study estimated the seropositivity-based immunization coverage in the owned dog population in Lusaka district using the expanded program on immunization cluster survey method. The time-series trend of neutralizing antibodies against rabies in vaccinated dogs was also evaluated. Of 366 dogs in 200 dog-owning households in Lusaka district, blood samples were collected successfully from 251 dogs. In the sampled dogs, 42.2% (106/251) had an antibody titer ≥0.5 IU/mL. When the 115 dogs whose blood was not collected were assumed to be seronegative, the minimum immunization coverage in Lusaka district's owned dog population was estimated at 29.0% (95% confidence interval: 22.4-35.5). It was also found that a single vaccination with certified vaccines is capable of inducing protective levels of antibodies. In contrast, higher antibody titers were observed in multiple-vaccinated dogs than in single-vaccinated dogs, coupled with the observation of a decline in antibody titer over time. These results suggest the importance of continuous booster immunization to maintain herd immunity and provide useful information to plan mass vaccination against rabies in Zambia.

Domestic dog demographics and estimates of canine vaccination coverage in a rural area of Zambia for the elimination of rabies

Background

An estimated 75% or more of the human rabies cases in Africa occur in rural settings, which underscores the importance of rabies control in these areas. Understanding dog demographics can help design strategies for rabies control and plan and conduct canine mass vaccination campaigns effectively in African countries.

Methodology/Principal findings

A cross-sectional survey was conducted to investigate domestic dog demographics in Kalambabakali, in the rural Mazabuka District of Zambia. The population of ownerless dogs and the total achievable vaccination coverage among the total dog population was estimated using the capture-recapture-based Bayesian model by conducting a canine mass vaccination campaign. This study revealed that 29% of the domestic dog population was under one year old, and 57.7% of those were under three months old and thus were not eligible for the canine rabies vaccination in Zambia. The population growth was estimated at 15% per annum based on the cross-sectional household survey. The population of ownerless dogs was estimated to be small, with an ownerless-to-owned-dog ratio of 0.01–0.06 in the target zones. The achieved overall vaccination coverage from the first mass vaccination was estimated 19.8–51.6%. This low coverage was principally attributed to the owners’ lack of information, unavailability, and dog-handling difficulties. The follow-up mass vaccination campaign achieved an overall coverage of 54.8–76.2%.

Conclusions/Significance

This paper indicates the potential for controlling canine rabies through mass vaccination in rural Zambia. Rabies education and responsible dog ownership are required to achieve high and sustainable vaccination coverage. Our findings also propose including puppies below three months old in the target population for rabies vaccination and emphasize that securing an annual enforcement of canine mass vaccination that reaches 70% coverage in the dog population is necessary to maintain protective herd immunity.

Because dogs are the main transmitter of rabies to humans, controlling rabies in dogs is essential for preventing rabies in humans. Canine vaccination is well-known as the most effective measure for controlling rabies in dogs. Understanding the demographics and dynamics of dog populations is important when designing efficient canine vaccination strategies. Furthermore, protective herd immunity in the total dog population should be attained through the vaccination of owned dogs since ownerless dogs are not usually covered in such campaigns. This study investigated domestic dog demographics and estimated the number of ownerless dogs to finally estimate the vaccination coverage among the overall dog population achievable through a mass vaccination campaign in a rural setting in Mazabuka District, Zambia. The target domestic dog population was young, and population growth was estimated at 15% annually based on the cross-sectional survey. The vaccination coverage attained by providing free canine mass vaccination campaigns was eventually estimated as 54.8–76.2% in the overall dog population, coupled with the estimate that the ownerless dog population was quite small. Our findings emphasize the necessity of conducting annual canine mass vaccinations, including puppies, that target 70% coverage in the dog population to maintain protective herd immunity.

An assessment of risk factors for contracting rabies among dog bite cases recorded in Ward 30, Murewa district, Zimbabwe

BACKGROUND

Zoonoses are a major threat to human health. Worldwide, rabies is responsible for approximately 59 000 deaths annually. In Zimbabwe, rabies is one of the top 5 priority diseases and it is notifiable. It is estimated that rabies causes 410 human deaths per year in the country. Murewa district recorded 938 dog bite cases and 4suspected rabies deaths between January 2017 and July 2018, overshooting the threshold of zero rabies cases. Of the 938dog bite cases reported in the district, 263 were reported in Ward 30 and these included all the 4suspected rabies deaths reported in the district. This necessitated a study to assess risk factors for contracting rabies in Ward 30, Murewa.

METHODOLOGY/ PRINCIPAL FINDINGS

A descriptive cross sectional survey was used for a retrospective analysis of a group of dog bite cases reported at Murewa Hospital, in Ward 30. Purposive sampling was used to select dog bite cases and snowball sampling was used to locate unvaccinated dogs and areas with jackal presence. The dog bite cases and relatives of rabies cases were interviewed using a piloted interviewer-administered questionnaire. Geographical Positioning System (GPS) coordinates of dog bite cases, vaccinated and unvaccinated dogs and jackal presence were collected using handheld GPS device. QGIS software was used to spatially analyse and map them. Dog owners were 10 times more likely to contract rabies compared to non-dog owners (RR = 10, 95% CI 1.06-93.7). Owners of unvaccinated dogs were 5 times more likely to contract rabies compared to owners of vaccinated dogs (RR = 5.01, 95% CI 0.53-47.31). Residents of the high density cluster (area with low cost houses and stand size of 300 square meters and below) were 64 times more likely to contract rabies compared to non-high density cluster residents (RR = 64.87, 95% CI 3.6039-1167.82). Participants who were not knowledgeable were 0.07 times more likely to contract rabies, compared to those who had knowledge about rabies. (RR = 0.07, 95% CI 0.004-1.25). Our study shows that the risk factors for contacting rabies included; low knowledge levels regarding rabies, dog ownership residing in the high density cluster, owning unvaccinated dogs and spatial overlap of jackal presence with unvaccinated dogs.

Epidemiological Patterns of Animal Bites in the Najafabad, Center of Iran (2012-2017)

Background:

Animal bite due to the risk of rabies is a major public health problem. Rabies is of great importance because of fatalities and economic damage.

Objective:

This study was conducted to investigate the epidemiological patterns of animal bite in Najaf Abad during the years of 2012 to 2017.

Methods:

This is a cross-sectional study. All records (4,104) were registered in the registration offices of animal bites during the years of 2012 to 2017 at the rabies treatment centres of Najafabad by census method. Demographic characteristics, animal type and sometime clinical patterns of the wounded were examined.

Results:

The mean age of the injured was 31.28 ± 15.28 years. Of the 4,104 injured, 3648 (88%) were male and the rest of them were women. In terms of residential area, 3645 people (88%) were in urban areas and the rest were in rural areas in the place of occurrence of bites. Most cases of animal biting occurred in dogs (70.9%) and then cat (24.3%). The most affected part was 51% with shoulder and hand. In this study, the incidence of animal bites is estimated as 100,000 people per year in Najaf Abad in in 2012 it was 206.4, with an increasing trend to 212.9 in 2019 (P < 0.001).

Conclusion:

The results of the study showed that most cases of animal bites were related to dogs, urban areas and male sex variables. The incidence of animal bites was also increasing. Due to the importance of this disease and its financial losses, it is recommended that prevention methods should be used to control stray dogs, vaccination of domesticated dogs and to raise awareness of the people.

Insights and efforts to control rabies in Zambia: Evaluation of determinants and barriers to dog vaccination in Nyimba district

BACKGROUND

The current rabies control strategy in Zambia is based on dog vaccination, dog population control and dog movement restrictions. In Nyimba district of Zambia, dog vaccination coverage is low but the incidence of dog bites is high which places the community at risk of rabies infection. The renewed global interest eliminating rabies in developing countries has spurred interest to identify determinants and barriers of dog vaccination in an effort to reduce the overall disease burden.

METHODOLOGY

A mixed methods cross sectional design was used in the study. This consisted of three parts: Evaluation of medical records regarding dog bite injuries, implementation and analysis of a household survey and in-depth review of key informant interviews. Data was collected into a Microsoft Excel database and subsequently transferred to STATA for descriptive, inferential and thematic analysis.

RESULTS

Dog vaccination coverage overall was 8.7% (57/655), with 3.4% (22/655) in urban areas, 1.8% (12/655) in peri-urban and 3.5 (23/655) in the rural regions. Financially stable households were more likely to have their dogs vaccinated. Only 10.3% (31/300) of the respondents had vaccinated their dogs and these had a reliable source of income as 6% (18/300) were peasant farmers, 2% (6/300) were dependants whose guardians were financially stable and 2.3% (7/300) were in steady employment. Important barriers to dog vaccination included cost, limited awareness of vaccination program and access.

CONCLUSION

Current rabies control strategies in Nyimba district, Zambia, appear quite limited. Improvements in the regional dog vaccination program may provide benefits. Enhancement of educational efforts targeting behavioural factors may also prove useful. Finally, the cost of dog vaccination can be reduced with scaled up production of a local vaccine.