To analyse the determinants of human rabies deaths in Côte d’Ivoire from 2016 to 2022.

1) Determine the socio-demographic and clinical characteristics of patients who died of human rabies from 2016 to 2022.

2) To determine the geographical distribution of human rabies cases in Côte d’Ivoire in the general population and in the population of people at risk.

3) To describe the use and compliance of post exposure prophylaxis in human rabies deaths in Côte d’Ivoire from 2016 to 2022.

The study took place at the Rabies Centre of the National Institute of Public Hygiene (NIPH) located in the Treichville Health District (Abidjan). This Centre is the reference service for the fight against human rabies in Côte d’Ivoire. It is responsible for the systematic care of people exposed to rabies, for behavior change communication about rabies and for coordinating epidemiological surveillance of human rabies throughout the country. These activities are carried out in collaboration with the health districts via the National Institute of Public Hygiene branches. In addition, the rabies center collects and analyses data from all the rabies canters (INHP branches) for dissemination at the central level.

We carried out a retrospective cross-sectional qualitative study from January to August 2023 on all the records of patients who died of human rabies at the Treichville Rabies Centre from 2016 to 2022. An analysis of the rabies center’s annual activity reports from 2016 to 2022 was also carried out in order to complete the information gathered from the files.

We carried out an exhaustive study, all records of patients who died of human rabies from January 2016 to December 2022 at the National Institute of Public Health’s rabies center were selected for our study.

Data were collected from patient files and activity reports from health centers, branches of the National Institute of Public Health and the rabies center. The following variables were selected:

· Patient’s socio-demographic data: age, sex, level of education, occupation, marital status, place of residence, vaccination status;

· Animal bites: species, breed, vaccination status, owner identified or not;

· Circumstances of the bite: location, time of day, the fate of the animal responsible for transmitting the disease;

· Post-exposure care: care-seeking circuit, time between bite and request for care.

We carried out a descriptive analysis of deaths due to human rabies. Data analysis was performed with Epi info software version 3.5.1.

The data were analyzed in terms of

· Patient profile (child/adult, male/female, rural/urban, seeking care/no seeking care after the bite);

· The profile of the biting animal and the bite: per year and from one year to the next.

The incidence of the disease in the general population was calculated using the following formula: number of cases/average general population ×100,000. The average incidence was calculated using the following formula: Average annual number of rabies deaths over the 7 years/average annual number of cases of exposure ×100,000.

The results presented are summarized in tables and figures.

Authorization was obtained from the National Institute of Public Hygiene management to access the medical records of patients who died at the anti-rabies center. The confidentiality of the data processed was respected, as was the non-disclosure of any information enabling the patients and their relatives to be identified.

The socio-demographic characteristics of patients who died of human rabies from 2016 to 2022 in Côte d’Ivoire are shown in the following table.

Children accounted for 47.97% (71) of rabies deaths and 66.22% (98) of rabies deaths were male, with a M/F sex ratio of 1.96. Of the people who died of rabies, 50 had no occupation (33.78%), 49 were students (33.11%) and 29 were farmers (19.60%). 65 people (43.92%) who died of rabies had primary education and 56 (37.84%) had secondary education (Table 1).

97.97% (145) of exposure lesions were bitten, 47.98% (71) of which were on the upper limbs and 37.16% (55) on the lower limbs. In 97.30% (144) of cases, the deceased had presented with furious rabies (Table 2).

109 rabies cases out of 148, or 73.65%, had been sampled. The results of these samples are shown in the figure below.

Analysis by the Pasteur Institute of Côte d’Ivoire laboratory confirmed 101 cases (92.66%) of human rabies, while 8 inadequate samples (7.34%) could not be analyzed (Figure 1).

Dogs accounted for 98.65% (146) of the animals that transmitted rabies to the deceased. 89.19% (132) of the biting animals were unvaccinated and 10.81% (16) had unknown vaccination status (Table 3).

Cases of human rabies were recorded in 56 health districts during the study

period (2016-2022).

· The Health Districts of Bouaké-West in the center of the country and Divo and Daloa in the south-west recorded at least 7 cases, i.e. one case a year;

· The Health Districts that have recorded at least 5 cases of human rabies are: Vavoua, San Pedro, Abobo West, Lakota and Duékoué.

94% or 63.51% of people who died of rabies lived in rural areas (Table 4).

In our study, the incidence of human rabies is estimated at 0.0714, or 0.07 cases of high-grade rabies per 100,000 inhabitants The incidence of human rabies is fluctuating. It rises to reach a peak in 2019, then falls to reach its lowest level in 2021 before rising again in 2022 (Figure 2).

The essential characteristics of human rabies cases over the period 2016-2022 are as follows:

47.97% (71) of people who died of rabies were children and 66.21% (98) were male, with a M/F sex ratio of 1.96.

In terms of occupation, 50 had no occupation (33.78%) and 49 were students (33.11%).

In addition, 65 (43.92%) of the people who died of rabies had completed primary

school and 56 (37.84%) secondary school. These data are found in most previous studies in Côte d’Ivoire [1] [9] [10] and in Africa [11] - [16] .

Dogs accounted for 99% of the animals that transmitted rabies to the deceased. 89.19% (132) of the biting animals were unvaccinated and 10.81% had rabies status vaccine unknown. In Africa, as in Asia, the dog population is the main reservoir and vector of rabies [17] .

This result confirms previous data and shows the need to implement a genuine mass immunisation plan for pets in Côte d’Ivoire, particularly dogs, in order to control the reservoir of the disease in the long term.

Although rabies is endemic in Côte d’Ivoire, cases have mainly been reported throughout the country, with a high concentration in the districts located in the western region of the country.

Cases of human rabies were recorded in 56 Health Districts, 23 (41.07%) of which were in the western part of the country during the study period.

In 2010, the geographical distribution of reported cases of human rabies showed that all cases were concentrated in the southern region of the country, where the epidemiological surveillance system was operational [4] . 63.5% of people who died of rabies lived in rural areas. These figures differ from those for Tiembré in 2010, which found that only 15.38% of human rabies cases originated in rural areas [4] . This situation may be due to improved surveillance and knowledge of the disease in rural areas.

The incidence of human rabies in our study is estimated at 0.0714, or 0.07 cases of high-grade rabies per 100,000 inhabitants. As in most countries, this incidence is underestimated. According to Dacheux, global mortality from the disease, based on data communicated to the WHO by its member states via Rabnet, is underestimated [18] . In Nigeria, Otolorin highlighted this underreporting and attributed it to misreporting of cases, cultural beliefs, misdiagnosis of the disease and poor knowledge of how the disease is transmitted and prevented [19] .

The under-reporting of cases means that the burden of rabies cannot be seen, which makes it impossible to lobby the health authorities for funding to combat the disease, perpetuating a vicious circle.

Indeed, in the absence of reliable epidemiological data, the health authorities are unable to perceive the importance of this disease in terms of public health. As a result, they pay little attention to it, and do not consider it worthwhile to allocate resources to monitoring the disease or treating the victims of bites. Many cases of rabies go unrecognised and unreported. In most cases, sufferers die at home without being diagnosed. Cases diagnosed in hospitals are rarely reported, or may be attributed to other diseases such as neuromalaria or meningitis. As a result, the number of deaths due to rabies is increasing without the authorities being alerted, since cases are not reported (Figure 1), fuelling the vicious circle that has led to the current situation [19] .

109 (73.65%) of the 148 recorded cases of rabies had been sampled, with analysis at the Pasteur Institute of Côte d’Ivoire laboratory confirming 101 cases (92.66%). However, 8 (7.34%) inadequate samples could not be analysed.

Although all the health workers had been trained, 26.35% of cases were not sampled. The reasons for this could be linked to the death of patients whose families refused to take samples or buried them very quickly. We found that 8 of the samples taken were inadequate, hence the need to train and build the capacity of our staff in view of staff changes.

Our study showed that 79.73% of people exposed to rabies had not sought medical care. Ignorance, financial hardship and negligence were also identified as key determinants of human rabies mortality among the deceased, with ignorance being the dominant factor.

According to Dodet (2009), victims of bites do not receive appropriate prophylactic care because patients do not know what to do for first aid, because health workers are not aware of the problem, because they do not have the necessary biological products, or because they do not have sufficient resources to cover the cost of preventive treatment.

In addition, the socio-economic environment of rural areas is conducive to the occurrence of cases of human rabies. This environment is characterised by low levels of education and cultural constraints, which also have a negative effect on people’s relationship with dogs, the main vector of the disease in Côte d’Ivoire.

In addition to non-use of vaccination, non-compliance with the PEP was also noted. In fact, 14 people started vaccination late and 16 did not complete it. This is a worrying situation and could be the cause of rabies, especially in children.

Because of its retrospective nature and the under-reporting of human rabies cases, our study may have limitations due to selection bias. However, this bias does not significantly alter the epidemiological characteristics of human rabies deaths in Côte d’Ivoire. We are planning an analytical study to better analyze the factors associated with human rabies deaths in Côte d’Ivoire.

Conclusion: In view of these results, control strategies and interventions need to be adapted to the epidemiological characteristics of the disease. In addition, raising awareness and communicating about the disease with the full participation of the population would enable them to take ownership of the fight against rabies, which is essential if we are to eliminate dog-transmitted rabies by 2030. Finally, stepping up the vaccination of animals, especially dogs, will help to control the animal reservoir.