Rabies: Haiti Pre-decision Brief for Public Health Action

Key recommendations

Diagnostic capacity and surveillance

Conduct community outreach to educate the public about the disease, as a means of bite prevention and enhanced local awareness for initial suspicion of cases.
Encourage health care providers and agricultural/veterinary staff to consider rabies in the differential diagnosis of any acute progressive encephalitis.
Increase the availability of ante-mortem, and post-mortem, rabies diagnostic testing in suspect human and animal cases and other potential causes of encephalopathy. Build capacity for broader, de-centralized veterinary diagnosis of rabies in suspect animals. Provide training and access to appropriate laboratory facilities, equipment, and reagents in standard confirmatory rabies diagnosis and new procedures, such as a direct rapid immunohistochemical test (dRIT), for initial presumptive diagnosis.
Create an adverse event reporting system for vaccine-preventable diseases, such as rabies.
Sustain broader de-centralized surveillance for acute progressive encephalitis in remote healthcare and agricultural facilities, monitor reports, employ GIS and related epidemiological techniques, and ensure that prevention and control measures are implemented in affected areas based upon the identification of rabies foci, together with other stake holders along the common border in the Dominican Republic.

Prevention

Inform residents to minimize contact with suspect animals such as free-ranging and ill dogs, cats, livestock, and wildlife, which may be potentially infected with rabies.
Wash all animal bites with soap and water and seek medical attention for risk assessments and the need for application of specific rabies prophylaxis.
Provide access to modern rabies biologics for prevention and control.
If working in diagnostic and clinical settings, use personal protective equipment (PPE), such as proper clothing, foot covers, and gloves, as well as pre-exposure immunization of first responders among at-risk human populations.
Establish a comprehensive animal rabies management program, and implement other environmental measures to minimize attraction of animals at or around human dwellings, such as the appropriate disposal of garbage.
Promote inter-sectoral cooperation in zoonoses in the One Health context, and in the event of an outbreak, the Haitian Ministry of Public Health and Population and the Ministry of Agriculture should coordinate activities for joint risk assessments, and consider a mass local prophylaxis of dogs.
Utilize World Rabies Day on 28 September as a means of galvanizing support for renewed health communications, surveillance, and prevention/control efforts.

Supporting Information

1. What was the situation in Haiti prior to the earthquake?

Rabies is enzootic in the New World, with few exceptions.¹ Throughout Central and South America, rabies is maintained by infected dog populations, or by wildlife reservoirs, such as other carnivores, or bats.² Factors associated with rabies perpetuation include the presence of specific variants of the virus, an adequate density of susceptible host populations, and the relative proximity of potential mammalian reservoirs to human populations.¹,³

For decades, Haiti had the highest incidence of human rabies of all Latin American and Caribbean countries.⁴ In 2005, a human case in Florida was acquired from a rabid dog exposure in Haiti.⁵ As of 2006, Haiti reported 11 of 29 dog-related human cases in the Americas. With enhanced national vaccination of nearly 200,000 dogs and control efforts, the number of reported human cases fell to five deaths in 2007.⁶ Preliminary surveillance assessments from January to May 2010, based upon clinical signs alone, suggest as many as 17 possible human rabies cases. As a whole, Latin America and the Caribbean have dramatically reduced cases of human rabies since 1983 by 90%, when PAHO member countries launched a regional effort to eliminate transmission of the disease from dogs to humans.⁴
Since a large proportion of infected animals with rabies are never tested or reported, surveillance in Haiti underestimates disease prevalence and spatio-temporal occurrence. Rabies is considered to be a top priority zoonotic disease by the Chief Veterinary Officer in the Ministry of Agriculture.

2. What is the likelihood of cases/outbreaks of this disease developing in the near future?

Rabies is enzootic in Haiti, and events since the 2010 earthquake are expected to exacerbate epidemiological conditions.⁴ Additional animal cases are likely to occur given the increased presence of risk factors which may predispose both animal and human populations to increased exposures.

3. Should an outbreak occur, how would this be detected?

As rabies is a zoonosis, increased numbers of aggressive and neurological animals, with subsequent increases in the incidence of animal bites, may be the first indication of an outbreak, with human cases to follow in approximately 1 to 3 months after exposure.
Sentinel surveillance should be established for clinical signs of encephalitis throughout Haiti, including Port-au-Prince and settlement areas. An outbreak would be suggested by an increase in the number of animal bites and cases of acute progressive fatal encephalitis.
The definitive diagnosis of rabies is the identification of viral antigens in CNS tissue by the direct fluorescent antibody test.³^,7 Human antemortem diagnosis includes the demonstration of rabies virus antigens, antibodies or amplicons in clinical samples.⁵ However, these tests require specific reagents, specialized equipment, such as a fluorescent microscope, and an electrical power supply for the laboratory. As an alternate, a new test developed by CDC, the dRIT can be performed using light microscopy alone.⁸ A single positive dRIT result supports classifying suspected cases of rabies as probable and would be considered adequate to initiate prophylaxis and public health investigations to identify additional cases. If diagnostic ability is limited or lacking, human prophylaxis may be initiated based on a history of a suspect animal bite, or clinical presentation of the animal alone.
Confirmatory testing can take place at international reference laboratories, such as CDC in Atlanta and/or the Caribbean Epidemiology Center (CAREC) of the PAHO/World Health Organization.

4. What options for public health action should be considered in the event of an outbreak?

Actions entail combined control in animals and prevention of the disease in humans.^1,^3,^9,¹⁰
There are no proven treatment modalities for patients with signs/symptoms of rabies. Avoiding exposures, and prevention of a productive viral infection after exposure, but before clinical signs, is the key to rabies management, especially during an epizootic.
Primary measures to control an outbreak of rabies include enhanced surveillance for acute progressive encephalitis in humans and animals to detect cases early, community animal management, and prophylaxis of exposed persons. Prophylaxis consists of local wound care (including tetanus immunization and antibiotic use, as warranted), administration of rabies immune globulin (RIG), infiltrated directly into the wound at a dose of 20 IU/kg, for homologous human RIG, or 40 IU/kg, of heterologous equine RIG, followed by multiple doses of modern cell culture rabies vaccine IM, on days 0, 3, 7, and 14 (a fifth dose is given to immune-compromised patients on day 28).¹⁰ The use of a reduced dose of vaccine, by intradermal application in a volume of 0.1 ml, is an alternate route that is extremely effective and highly economical in resource-limited settings.³ The use of nerve-tissue vaccines is not supported by current ACIP/WHO recommendations.³
First responders, such as agricultural workers, veterinarians, and rabies laboratory diagnostic staff, should receive rabies pre-exposure vaccination. Consideration of childhood immunization should be considered for certain high-risk settings.
Public health campaigns should be conducted to educate the public about rabies, including the likely animal sources, routes of transmission, clinical signs of infection, methods for control and prevention of disease, responsible pet ownership, and the need for medical care and prophylaxis after exposure. Promoting appropriate behavior to minimize provocation and avoiding direct contact with ill and free-ranging dogs or animals, such as cats, will decrease the risk of rabies virus exposure. Improved animal population management and more ideal environmental resource use will reduce the risk of rabies from large numbers of community animals.
Mass dog immunization with modern pure, potent, safe, and efficacious cell culture vaccines is the single most effective long term measure for public health action during a rabies outbreak, coupled with humane and novel methods of population management.^3,⁹

References

¹ Rupprecht CE, Barrett J, Briggs D, Cliquet F, Fooks AR, Lumlertdacha B, Meslin FX, Müler T, Nel LH, Schneider C, Tordo N, Wandeler AI. Can rabies be eradicated? Dev Biol (Basel). 2008;131:95-121.

² Ruiz M, Chávez CB. Rabies in Latin America. Neurol Res. 2010 Apr;32(3):272-7.

³ World Health Organization, 2005; Expert Consultation on Rabies, WHO Technical Report Series 931, Geneva.

⁴ Schneider MC, Belotto A, Adé MP, Hendrickx S, Leanes LF, Rodrigues MJ, Medina G, Correa E. Current status of human rabies transmitted by dogs in Latin America.Cad Saude Publica. 2007;23:2049-63.

⁵ Blanton JD, Robertson K, Palmer D, Rupprecht CE. Rabies surveillance in the United States during 2008. J Am Vet Med Assoc. 2009;235:676-89.

⁶ PAHO Today. The Newsletter of the Pan American Health Organization. July, 2008. Washington, D.C.

⁷ Control of Communicable Diseases Manual - 19th Ed. (2008). David Heymann, ed. Washington, DC: APHA.

⁸ Lembo T, Niezgoda M, Velasco-Villa A, Cleaveland S, Ernest E, Rupprecht CE. Evaluation of a direct, rapid immunohistochemical test for rabies diagnosis. Emerg Infect Dis. 2006;12:310-3.

⁹ Hampson K, Dushoff J, Cleaveland S, Haydon DT, Kaare M, Packer C, Dobson A. Transmission dynamics and prospects for the elimination of canine rabies. PLoS Biol. 2009;7(3):e53.

¹⁰ Rupprecht CE, Briggs D, Brown CM, Franka R, Katz SL, Kerr HD, Lett S, Levis R, Meltzer MI, Schaffner W, Cieslak PR. Evidence for a 4-dose vaccine schedule for human rabies post-exposure prophylaxis in previously non-vaccinated individuals. Vaccine. 2009;27:7141-8.

Emergency Preparedness and Response

Emergency Preparedness & Response