Recent Research – September 2017

Surveillance

A data platform to improve rabies prevention, Sri Lanka. An electronic platform for rabies surveillance was rolled out in June 2016 in four districts of Sri Lanka, linking six rabies clinics, three laboratories and the public health inspectorate. Over 9-months, 12,121 animal bites were entered in the registry, and live information on treatment and outcomes of patients started on post-exposure prophylaxis (9,507) or receiving deferred treatment (2,614) was securely made available to clinicians. Laboratories rapidly communicated the results of rabies virus tests on dead mammals (328/907 positive). In two pilot districts SMS reminders were sent to 1,376 (71.2%) of 1,933 patients and daily SMS reports alerted 17 public health inspectors to bite incidents for investigation.

Molecular characterization of atypical antigenic variants of canine rabies virus reveals its reintroduction by wildlife vectors in southeastern Mexico. Molecular characterization of six rabies virus strains found in Yucatan and Chiapas showed four with atypical patterns after monoclonal antibody screening. Phylogenetic analyses on the RNA sequences suggested three were atypical strains from Yucatan associated with skunks, distinct from other known lineages. The Chiapas atypical strain was grouped in a lineage that was considered extinct, while the others are clustered within classic dog variants.

 

Strategic planning

The Formation of the Eastern Africa Rabies Network: A Sub-Regional Approach to Rabies Elimination. The first sub-regional Eastern Africa rabies network meeting included Kenya, Ethiopia, Tanzania, Rwanda, and Uganda. The Stepwise Approach towards Rabies Elimination and the Global Dog Rabies Elimination Pathway tool were used to stimulate discussion and planning to achieve the elimination of canine-mediated human rabies by 2030. Our analysis estimated a total dog population of 18.3 million dogs in the region and current vaccination coverage of 5%, with an estimated 4,910 vaccinators available. There is an average annual shortfall of $ 23 million USD in current spending if elimination by 2030 is to be achieved across the region.

 

Canine Vaccination

The Role of Dog Population Management in Rabies Elimination-A Review of Current Approaches and Future Opportunities. A review of dog population management (DPM) in the context of rabies control. Humane DPM tools, such as sterilization, could theoretically reduce dog population turnover and size, allowing rabies vaccination coverage to be maintained more easily. However, technical demands, costs, and the time necessary to achieve population-level impacts are major barriers, and evidence of population-wide impacts is currently scarce.

Risk factors for inadequate antibody response to primary rabies vaccination in dogs under one year of age. Rabies antibody titers were measured after primary vaccination of 8,011 dogs under one year of age whose serum was submitted for routine diagnostics, and factors associated with failure to achieve 0.5 IU/mL were identified. Dogs vaccinated at >16 weeks showed higher titres than those vaccinated at <12 weeks and at 12-16 weeks (which were equivalent). Most dogs fail to show an adequate response after 3 days, the ideal test is 8-30 days after primary vaccination, and most dogs achieved an adequate response after a repeat test (in the absence of booster vaccination). Booster vaccination after failure provided the highest probability of an acceptable response.

Dog ecology and its implications for rabies control in Gwagwalada, Federal Capital Territory, Abuja, Nigeria. Direct street counts and a house-to-house survey of city streets identified a dog-to-human ratio of 1:3.7, and a dog population estimate of 103,758. The majority of dogs in the urban (60.9%) and semiurban (82.0%) were free roaming, and most did not have vaccination certificates. The presence of a collar, region, sex, use and having ever visited a veterinarian were significantly associated with rabies vaccination and respondents with higher education were willing to pay more for the healthcare needs of their dogs than those with a lower level of education.

 

Human cases

Rabies Virus Transmission in Solid Organ Transplantation, China, 2015-2016. Two recipients of organs were confirmed to have rabies and died. The donor, a young boy, had a diagnosis of viral encephalitis, but a rabies ELISA test was negative, permitting organ donation under China’s organ transplant policy.

 

Wildlife rabies

The economic implications of sylvatic rabies eradication in Italy. After rabies’ re-appeared in Italy in 2008, from winter 2009 to autumn 2016, a total of 15 ORV campaigns (four emergency, four regular and seven preventive ORV) were implemented through aerial distribution of baits. Cumulative costs per km2 were estimated at €59.45 during emergency campaigns and ranged between €51.94 and €65.67 in the regular vaccinations. The main portion of costs for ORV programmes were related to baits supply and distribution, and reducing the density of dropped baits could potentially lead to a cost-saving of 22.81%, still maintaining a satisfactory level of bait intake by the fox population.

Natural exposure of bats in Grenada to rabies virus. Brain tissue and sera from 111 insectivorous and frugivorous bats belonging to four species were tested. Rabies virus antigen and genomic RNA were not detected in brain tissues. Rabies virus neutralizing antibodies were detected in the sera of eight A. jamaicensis in four out of six parishes. Bats in Grenada continue to show natural exposure to rabies virus, but serology alone is insufficient to determine the strain of rabies virus circulating. Dispersion of infected bats to neighboring islands is possible.