Recent Research - September 2016

Economic Impacts

Incidence and economic impact of rabies in the cattle population of Ethiopia.  532 cattle-owning households were surveyed and average economic losses per herd due to rabies were estimated at 49 and  52 USD per year for different farming systems. In affected herds the average losses per year were 228 USD and 477 USD.

Rabies in Kazakhstan. From 2003 to 2015, a mean of 7.1 people died due to rabies per year and a mean of 64,289 individuals per annum underwent PEP. Rabies costs Kazakhstan $20.9 million per annum, nearly half attributed to PEP and the loss of income whilst being treated. Life time loss of income for fatal cases was valued at $5.4 million per annum and animal vaccination programmes and animal control programmes also contributed substantially to the economic losses.

Epidemiology

Human Rabies in China, 1960-2014: A Descriptive Epidemiological Study. From 1960 to 2014, 120,913 human rabies cases were reported in mainland China, with peaks in 1981and  2007 Cases are more common in August and most victims are farmers with a male-to-female ratio of 2.4:1. Since 2004, the number of cases has decreased by 65.2%, but the area of risk is expanding.

Rabies awareness and dog ownership among rural northern and southern Chadian communities - Analysis of a community-based, cross-sectional household survey.  A community-based survey in 40 villages in two southern and two northern regions of Chad was carried out to prepare for mass vaccination campaigns. Dog:human ratio of 1:5.2 in the south and 1:16.4 in the north were found and  only 76% of the respondents had heard of rabies. Differences in rabies knowledge were identified between regions, and across religions and education backgrounds. 11% of respondents reported a family member being bitten by a dog in the past year, 31% of respondents knew someone who had died of rabies and 58% had encountered a rabid animal.

Dog vaccination

The Vaccination of 35,000 Dogs in 20 Working Days Using Combined Static Point and Door-to-Door Methods in Blantyre, Malawi. Vaccination was conducted at 44 static point stations at weekends, followed by door-to-door vaccination sessions in the areas surrounding them. 23,442 dogs were vaccinated at static point stations and 11,774 dogs were vaccinated door-to-door. After the 20 day vaccination programme, vaccination coverage through door-to-door surveys estimated that 79.3% of 10,919 observed dogs were vaccinated. The human:dog ratio for the city was estimated at 18.1:1. Mobile technology facilitated the collection of data as well as efficient direction and coordination of vaccination teams in near real time.

Human Exposures, Cases and PEP

Post-Marketing Surveillance of Human Rabies Diploid Cell Vaccine (Imovax) in the Vaccine Adverse Event Reporting System (VAERS) in the United States, 1990‒2015. A 25-year review of the US Vaccine Adverse Event Reporting System (VAERS) revealed 1,611 adverse reports after HDCV; 93 (5.8%) were serious. The three most common adverse events were pyrexia (18.2%), headache (17.9%), and nausea (16.5%). Four deaths appeared unrelated to vaccination. The study did not identify new or unexpected adverse reactions compared to pre-licencing studies.

Human Rabies Survivors in India: An Emerging Paradox? Survival from human rabies (although with severe residual deficits) has been reported in 6 patients in the last 6 years from India, and between 2012 and 14, a further 6 patients have been reported to have lived  from 2 weeks to 3 months after onset of illness. Increases in access to intensive care and doctor’s willingness to try to save patients may be responsible. However, treatment should not distract from prevention and India needs to scale up indigenous production of modern cell culture vaccines and promote the intradermal regimen.

A Systematic Review of Human Bat Rabies Virus Variant Cases: Evaluating Unprotected Physical Contact with Claws and Teeth in Support of Accurate Risk Assessments. A systematic review to understand the risk of infection for individuals who have been potentially exposed to a suspect or confirmed rabid bat. A total of 41 verified human bat-rabies cases between 1990 and 2015 were all fatal. Seven (17.1%) reported a bite from a bat, Ten (24.3%) cases had unprotected physical contact (UPC) such as a bat landing on them or touching a bat's teeth. Seven (17.1%) cases had probable UPC. Questioning individuals about contact with bat teeth and claws may help identify additional exposures.

Misdiagnosis of cerebral malaria initially as acute psychotic disorder and later as human rabies: a case report. A 17-year-old school girl presented with agitation and over talkativeness and was diagnosed as having an acute psychotic state. She later became drowsy and developed recurrent seizures and marked phobic spasms which prompted a diagnosis of rabies. However, later tests revealed cerebral malaria, which was treated with intravenous quinine  and she was discharged with no residual neurological deficit.

Diagnosis

Development of Primer Pairs from Molecular Typing of Rabies Virus Variants Present in Mexico. A total of 158 sequences of N gene from RABV were used to design primers for typing the four different RABV variants (dog, skunk, vampire bat, and non-hematophagous bat) which are most common in Mexico. Used in nested and/or real-time PCR, these provide an alternative technique for variant RABV typing.

Localization of the rabies virus antigen in Merkel cells in the follicle-sinus complexes of muzzle skins of rabid dogs. Tactile hairs abundant in the muzzle skin are equipped with more than 2,000 sensory nerve endings. Muzzle skins were obtained from 60 rabid dogs diagnosed with rabies by dFAT and virus antigen was clearly detected in a part of the outer root sheath of hairs from each dog. The results suggest that hair follicles from muzzle skin could serve as a useful alternative specimen source for diagnosis of rabies.