Human rabies in Côte d'Ivoire 2014-2016: Results following reinforcements to rabies surveillance

Abstract

In Côte d'Ivoire, rabies is endemic and remains largely uncontrolled. The numbers of human exposures and rabies cases are unknown and are probably much higher than reported. Data on human rabies cases are collected by the National Institute of Public Health (NIPH) Anti-rabies Center in Abidjan through a network of 28 NIPH local units, which cover the population of the entire country. During 2014, the NIPH initiated a program to reinforce the human rabies surveillance system in those 28 NIPH local units, with specific goals of improving the infrastructure, training, communication, and government involvement. Here, we report the progress and findings during 2014-2016. The reinforced system recorded 50 cases of human rabies (15-18 cases/year; annual incidence = 0.06-0.08 per 100,000) and more than 30,000 animal exposures (annual incidence = 41.8-48.0 per 100,000). Almost one-half of the human rabies cases were in children ≤15 years old. All were fatal and dog bites were the most common route by which rabies virus was transmitted. In the 32 cases where samples of sufficient quality for analysis were available, rabies was confirmed by reverse transcription-polymerase chain reaction RT-PCR. Post-exposure prophylaxis with rabies vaccine was administered to all animal exposure victims presenting at the NIPH local units, although only about 57% completed the full immunization schedule. All available reports were provided by the NIPH local units, indicating effective communication between them and the NIPH Anti-rabies Center. These findings indicate that the reinforcements resulted in highly specific detection of human rabies, provided detailed epidemiological data about these cases, and improved estimates of animal exposure numbers. These represent substantial advances, but further improvements to the surveillance system are needed to increase disease awareness and capture cases that are currently missed by the system. In the future, better communication between local health centers and the NIPH units, surveillance at the local health center level, and increased veterinarian engagement will help provide a more complete picture of the rabies burden in Côte d'Ivoire.

Fig 1. The reinforced National Institute of Public Health (NIPH) rabies surveillance network in Côte d’Ivoire.

Exposed individuals presenting at local health centers received immediate wound care and were referred to a NIPH local unit for PEP with rabies vaccine. Suspected human rabies cases were also referred to the nearest NIPH local unit for diagnosis and treatment. Exposed individuals could also present directly at a NIPH local unit or at the Anti-rabies Center in Abidjan. Individuals choosing to present at a NIPH local unit or the Anti-rabies Center received rabies vaccine and additional wound care as necessary. At the 28 NIPH local units, animal exposure data were collected from the individuals presenting there and were transmitted weekly to the Anti-rabies Center located within the NIPH Central Unit in Abidjan. NIPH units that did not comply were systematically contacted by the Anti-rabies Center to collect the information. The Anti-rabies Center was immediately notified about clinically diagnosed or suspected cases of human rabies. In addition, samples and information about the case were collected and shipped to the Anti-rabies Center through the rural bus system as an unaccompanied package, which was retrieved by Anti-rabies Center personnel in Abidjan and directly transferred to the Pasteur Institute of Côte d’Ivoire, also in Abidjan. The Anti-rabies Center collaborated with the Pasteur Institute for laboratory confirmation of rabies virus by RT-PCR [NB: give a citation for the specific sop or provide a brief, accurate description]. Rabies case information from the surveillance network was transmitted to the NIPH Central unit where it was combined with other national surveillance data and disseminated in weekly bulletins to the Anti-rabies Center, NIPH local units, and the Ministry of Health and HIV Control, as well as national veterinary authorities, and district and national health authorities.

Fig 2. NIPH units and numbers of suspected or probable human rabies cases by region in Côte d’Ivoire during 2014–2016.

Numbers of suspected or probable human rabies cases reported by the reinforced surveillance system are shown by the districts in which they occurred. Districts with NIPH units are shown in underlined text. Districts without names or shading had no rabies cases that were recorded by the surveillance program.