Effective Surveillance Strategies for Human and Canine Rabies

Elimination ProgramsMary Elizabeth Miranda

Field Epidemiology Training Program Foundationand Research Institute for Tropical Medicine

Philippines

Endemicity of canine rabies in Asia

• Canine RABV - zoonotic infection that invariably spill over into non-reservoir hosts (humans, cats , bovines etc)

• Onward transmission within these dead-end hosts is not sustained

• estimated 96% of documented human cases are from an infected dog bite

Table 1. Regional human and animal rabies occurrence and status of certain animal disease control measures, 2011 (Data sources: Ministries of Health, WHO SEARO, OIE WAHID)

Country Reported

Number of Human Cases

Rate Per Million

Population Per Year

Presence of Dog Rabies

Rabies Notifiable to the OIE General

Surveillance and Monitoring

Dog Vaccination Programme

Dog Cat Wildlife Brunei 0 0 No Yes Yes Yes Yes No

Cambodia 800* 56 Yes No No No No No

Indonesia 116 0.48 Yes Yes No Yes Yes Yes

Lao PDR 1 0.16 Yes Yes Yes No Yes Yes

Malaysia 0 0 No Yes Yes Yes Yes Yes

Myanmar 1000* 21 Yes Yes Yes No Yes Yes

The Philippines 208 2 Yes No No No Yes Yes

Singapore 0 0 No Yes Yes Yes Yes ** Yes

Thailand 8 0.12 Yes Yes Yes Yes Yes Yes

Vietnam 89 1 Yes Yes No No Yes Yes

*estimate only **targeted surveillance only

Burden on human and animal health

Molecular epidemiologyAnalysis of phylogeographic structure of canid RABV revealed only limited

viral movement among geographical localities- Philippine samples are distinct and divergent from other Southeast Asian

countries (export cases could be readily identified from the Philippines)- Laos - three viral lineages are currently circulating in the country; related to

those of neighboring countries, indicating shared ancestry but no recent viral invasion

- China being a big country, some samples cluster with those from the Mekong River Subregion (Malaysia, Laos, Vietnam and Thailand)

- Indian isolates – dog rabies variants major circulating viruses and are related geographically

- Korean isolates form a monophyletic group closely related to the Arctic strains but distant from other Asian strains

Most Asian strains are within genotype 1 thereforecurrent vaccine works for strains circulating in the region

Spread across mainland Asia

- widespread RABV infection in dog populations

- movement of animals across borders thru formal and informal entry points

- role of illegal dog trade- Illegal dog trade for food

sensitive issue although no one can deny that it exists

Spread among island countries

Indonesia and Philippines

- archipelagos with islands endemic and sporadic cases

- numerous islands rabies-free

- Incursion of cases in rabies-free areas

Spread to rabies-free areas

• Only Malaysia, Singapore and Brunei free• Constant risk of reintroduction or re-

emergence of animal rabies cases

• Incursions of dog rabies cases in some Indonesian territories historically disease free – Bali, Nias, Flores, Maluku

Rabies incidence and spread in Bali prior to island-wide mass vaccination.

Townsend SE, Sumantra IP, Pudjiatmoko, Bagus GN, Brum E, et al. (2013) Designing Programs for Eliminating Canine Rabies from Islands: Bali, Indonesia as a Case Study. PLoS Negl Trop Dis 7(8): e2372. doi:10.1371/journal.pntd.0002372http://127.0.0.1:8081/plosntds/article?id=info:doi/10.1371/journal.pntd.0002372

Incursion in mid- 2008

Rapid spread across the island

>150 human rabies deaths

$ 2M / yr postexposurevaccinations

Example of Bali

Disease Surveillance

• critical component of disease control and elimination programmes but is often poorly resourced, particularly in developing countries lacking good infrastructure

• especially for zoonoses which require combined veterinary and medical capacity and collaboration

• allows early detection and reporting of cases, initiating timely responses and enabling informed decisions about when and where to intensify control efforts

• once interventions implemented – also essential to generate data on the progress and cost-effectiveness of such sustainable implementation of programmes

As human or animal health professionals –

an improved understanding of the history, techniques and contemporary tools of disease surveillance important to surveillance efforts in

your own country and community, leading to improved prevention, control

and eventual elimination of rabies

Traditional disease surveillance• The purpose is to understand the ongoing patterns of

disease in a population so that control and prevention measures can be applied efficiently and effectively.

• accomplished through the systematic collection, evaluation and analysis of health information

• Traditional sources Official Ministry reportsHospital records Veterinary surveillance recordsLaboratory results – public & private

Can be passive or routine surveillance

• Key sources of data in passive surveillance are monthly/annual disease surveillance reports

• Primary healthcare facilities and laboratories required to notify health authorities about any patient presenting with a notifiable disease

• Veterinary services, facilities and laboratories required to submit reports to national authorities

Traditional disease surveillance

Zoonotic Disease Dynamics

To effectively put zoonoses surveillance data into action for disease control, need information on:

• Context (environment)– available prevention and treatment resources;

urban, rural and remote areas affected; general perceptions of people around this disease

• Dynamics of disease transmission (including host, agent and vectors)– infectious period; clinical signs and symptoms;

antimicrobial resistance patterns; disease vector like an animal or insect; role of wildlife

Surveillance in Animal Populations: The One Health Concept

• The one health concept recognizes the important links between human, animal and environmental health

• It is estimated that 75 percent of emerging infectious diseases in humans are zoonoses, and that more than 70 percent of these zoonoses come from wildlife. Surveillance of diseases in domestic animals and wildlife is vital.

Image Source: Thompson, A. R. C. (2013) Parasite zoonoses and wildlife: One health, spillover and human activity. International Journal for Parasitology, 43:1079-1088.

Pros and Cons of Traditional SurveillancePROS CONS

Accurate information from credible sources

Slow detection

Opportunity to provide incentives to overcome non-reporting

May miss novel diseases or those with vague case definitions

Able to access detailed, protected information from government and healthcare facilities

Uses only confirmed information, from a limited number of sources

Source: Tephinet Epicore lecture

Improving Disease Surveillance

Gaps that need to be addressed: – Delays in official reporting– Capturing unusual disease events– Limited reach of traditional systems

Innovative surveillance efforts that leverage non-traditional information sources can help address some of these gaps in order to find outbreaks faster

Innovative surveillance platforms

• Despite these challenges, innovative surveillance approaches continue to demonstrate an ever-increasing potential to help us detect outbreaks faster and with greater sensitivity.

• Innovative platforms need the participation of human and animal health professionals on the ground to validate informal surveillance data and to harness the full potential of innovative surveillance systems

Pros and Cons of Innovative Surveillance

PROS CONSFast detection and reporting Information captured might not

be accurate or significant*

Not constrained to certain events

Sources may present biased information

Multiple sources of information (e.g., clinicians, labs, media reports, internet blogs)

Uses broad case definitions

Leverages publicly available information, increasing transparency

No standard data format, takes additional time to synthesize

Source: Tephinet Epicore lecture

Challenges in Using Non-Traditional Sources of Disease Information

Innovative surveillance and the use of non-traditional sources can provide additional disease surveillance information. However this requires

– Basic IT skills and Internet access – Data management skills– Planning of human resources– Adequate knowledge of source and its quality– Transdiscplinary expertise

Relevant applications for rabies

• One Health approach among surveillance professionals sharing disease data from public health and veterinary services at sub-national, national & regional level

• Improving laboratory-based surveillance by increasing diagnostics with support of OIE and WHO reference labs

• Community-led reporting / participatory surveillance– Examples of mobile phone-based reporting that support rabies

control programs• Joint investigations of unusual occurrence of animal

cases or any report of suspect human case

Fig. 2 Simulation scenario indicating the critical time points from an incursion to the declaration of freedom from rabies. An example simulation illustrated as a time series and as the spatial occurrence of cases on an island grid (circular, 500 km loc="p...

Sunny E. Townsend , Tiziana Lembo , Sarah Cleaveland , François X. Meslin , Mary Elizabeth Miranda , Anak Agung Gde...

Surveillance guidelines for disease elimination: A case study of canine rabies

Comparative Immunology, Microbiology and Infectious Diseases, Volume 36, Issue 3, 2013, 249 - 261

http://dx.doi.org/10.1016/j.cimid.2012.10.008

Surveillance guidelines for disease elimination – case study for rabies

Regional Rabies EliminationCrossborder Strategies

• challenge of implementing dog rabies elimination program in contiguous and cross border areas -constant risk of re-introduction of cases from neighboring endemic areas

• mutually agreed strategies must be in place to have a harmonized institutional operational framework

• cross border rabies control once successful will geographically expand rabies-free areas

Regional Rabies Elimination

• Obvious benefits of regional efforts– reduce cross border transmission– control canine rabies introduction to rabies-free areas– prevent further exporting human cases

• Regional responsibilities to be shared to achieve the common goals of rabies freedom across Asia

• Each country expected to systematically implement rabies control and elimination programme in accordance with set international standards

“Unless an effective reporting and surveillance programme is developed, there is no prospect

whatsoever for a successful eradication programme”

D.A. HendersonEpidemiologist who led the international effort during the

1960s to eradicate smallpox