Recent Research – April 2016

A summary of recent research most relevant to GARC's mission.

PEP

Reducing Cost of Rabies Post Exposure Prophylaxis: Experience of a Tertiary Care Hospital in Pakistan. Between July 2013- June 2014, 2983 bite patients were assessed and 97% given PEP (free to the patients). The cost, per patient, of providing vaccine alone via the intradermal (ID) route was PKR 570.8 (USD 5.70) and for providing Equine RIG, PKR 1138.0 (USD11.38). The use of the ID regimen was estimated to have cost only 1/5th of the customary 5-dose Essen intramuscular regimen.

Development of broad-spectrum human monoclonal antibodies for rabies post-exposure prophylaxis. Two broadly neutralizing human monoclonal antibodies (RVC20 and RVC58) were identified as a valid and affordable alternative to RIG. The two bind to different antigenic sites, and were found to neutralize all of 35 rabies virus (RABV) and 25 non-RABV lyssaviruses tested, showing higher potency and breath than antibodies under clinical development and commercially available human RIG. In vivo, the RVC20-RVC58 cocktail protected Syrian hamsters from a lethal RABV challenge and did not affect the endogenous hamster post-vaccination antibody response.

Dog rabies control                                                                                             

Towards Canine Rabies Elimination in South-Eastern Tanzania: Assessment of Health Economic Data. The total cost per dog vaccinated ranged from $2.50 to $22.49 across districts and phases, with the cost per phase falling from $11.27 to $7.30 as efficiencies improved. The cost per human PEP course administered was approximately $24.41, with the average patient receiving 2.5 of the recommended four vaccine doses.

Intention of dog owners to participate in rabies control measures in Flores Island, Indonesia. 96% of dog owners intended to participate in a free vaccination campaign, but only 24% if they were asked to pay a vaccination fee. 81% of the dog owners intended to keep their dogs inside or to leash them if there was rabies within their village and only 40% intended to cull their dogs if this occurred. Analysis suggested useful guidance – such as education focusing on the benefits of rabies control, training on how to confine dogs, holding campaigns at weekends and creating a subsidy program for the vaccine and leash costs – that could benefit control efforts.

Size and demography pattern of the domestic dog population in Bhutan: Implications for dog population management and disease control.  Cross-sectional household surveys and mark-resight surveys were conducted to estimate dog population sizes. The dog: human ratio was 1:16.30 (urban areas) and 1:8.43 (rural areas). The total owned dog population estimated based on the mean number of dogs per household was 65,312 and based on dogs per person was 71,245 in the country. The stray dog population was estimated to be 48,379, and in the two border towns 31% of dogs were found free-roaming.

Willingness to Pay for Dog Rabies Vaccine and Registration in Ilocos Norte, Philippines (2012). Eighty-six per cent of Ilocos Norte residents were willing to pay 69.65 Philippine Pesos (PHP) (1.67 USD) for dog vaccination and 29.13PHP (0.70 USD) for dog registration each year. Willingness to pay was influenced by demographic and knowledge factors, such as income, participants' willingness to commit to pay each year, municipality, knowledge of the signs of rabies in dogs, and number of dogs owed.

Awareness and education

Dog Demography, Animal Bite Management and Rabies Knowledge-Attitude and Practices in the Awash Basin, Eastern Ethiopia. A survey of over 500 respondents from urban, pastoralists and medical personnel communities. No bite wound records were kept in medical facilities, where staff recalled around 100 bites per year. Over 90% of the respondents knew about rabies but not all knew the symptoms, and most pastoralists did not know how dogs acquired the disease, or that it was fatal if untreated in people. Over half of pastoralists visit traditional healers if bitten, despite a health extension worker program in place in the study area.

Community Health Seeking Behavior for Suspected Human and Animal Rabies Cases, Gomma District, Southwest Ethiopia. The majority of the respondents would seek treatment from modern health care facilities for human rabies exposures. However, a significant number had inappropriately managed domestic animals with rabies, including slaughtering them for human consumption, selling them immediately, visiting a traditional healer, caring for them at home, or doing nothing.

Diagnostics

Laboratory diagnostics in dog-mediated rabies-an overview of performance and a proposed strategy for various settings. A review of benefits and drawbacks of different available diagnostic assays for rabies with suggested policies for their use in different endemic settings.

Retrospective diagnosis of two rabies cases in humans by high throughput sequencing. A broad-range polymerase chain reaction analysis followed by high throughput sequencing were used to diagnose rabies in two patients who died of encephalitis of unknown origin in Russia in 2003.  The entire genome of each strain was sequenced,

Comparison of rapid immunodiagnosis assay kit with molecular and immunopathological approaches for diagnosis of rabies in cattle. Brain samples from suspected rabid cattle were screened by the FAT, Heminested RT-PCR, Immunohistochemistry (IHC), and a new rapid immunodiagnostic assay (RIDA). Despite a comparatively low-sensitivity (85.7%) and accuracy (91.6%) of RIDA, it can still be useful in screening a large number of field samples promptly. However, negative results with RIDA in cattle need to be authenticated with suitable alternative diagnostic approaches.

Epidemiology

Revealing the Micro-scale Signature of Endemic Zoonotic Disease Transmission in an African Urban Setting. Detailed epidemiological time series and viral sequence data from more than 20 years from Bangui, the capital of Central African Republic was used in mathematical models and phylogenetic analyses. Although dog rabies appears to be endemic in Bangui, in fact local chains of transmission regularly go extinct, but there are frequent introductions of new lineages. Thus rabies is not self-sustaining in Bangui, but driven by human-mediated spread of virus. Control measures should target areas neighbouring the city that are the source of frequent incursions in Bangui.

Rabies transmission risks during peripartum - Two cases and a review of the literature. Babies of two mothers with probable rabies at or near the end of pregnancy did not contract rabies after receiving PEP. A literature review revealed 14 other published cases of infants born from rabid mothers, one of which had confirmed rabies. Mother-to-child transmission of rabies is possible, but rare, since exposure of the baby's mucosa to maternal infectious fluids and tissue seems limited. Babies should be given rabies PEP, including RIG, as soon as possible. Rabies cell-culture vaccines are safe and effective and can be administered to pregnant and lactating women, as well as newborns.