WHO | Yellow fever – Senegal

From October to December 2020, a complete of seven confirmed instances of yellow fever (YF) have been reported from 4 well being districts in three areas in Senegal. The outbreak consists of a cluster of 4 confirmed instances from three well being zones in Kidira well being district, Tambacounda area; one case within the neighbouring Kedougou well being district, Kedougou area; one case in Saraya well being district, Kedougou area; and one case in Thilogne well being district, Matam area.

In Tambacounda area, on 18 October 2020, a pattern was collected from a 40 year-old feminine dwelling in Kidira district throughout an investigation for West Nile virus an infection. On 29 October, Institut Pasteur de Dakar (IPD) confirmed the case as yellow fever. On 31 October, IPD reported outcomes of a second confirmed case of YF to nationwide well being authorities, following a notification by Bakel well being zone, Kidira well being district. The case was an eight year-old boy whose sickness started in Kidira well being district and died on 31 October. On 12 November, IPD notified nationwide well being authorities a couple of third confirmed case, a 23 year-old male, who was detected by routine surveillance and died on 5 November. On 16 November, a fourth confirmed case, a 15 year-old boy from Kidira well being district, was reported to nationwide well being authorities. The 2 deaths among the many 4 instances reported in Kidira well being district occurred at two hospitals: one on the Matam regional hospital and the opposite on the Tambacounda regional hospital.

In Kedougou and Matam areas, three confirmed instances had been reported in December 2020, whose samples had been collected throughout numerous investigations. In Kedougou area, laboratory assessments carried out by IPD revealed that out of the 16 samples acquired from area, there have been:

• one confirmed case [polymerase chain reaction (PCR) and IgM positive] dwelling in Saraya district;
• one confirmed case [IgM positive and confirmed by plaque reduction neutralization test (PRNT)] dwelling in Kedougou district; and
• two presumptive instances (IgM constructive and PRNT in progress).

In Matam area, one case was confirmed as YF by IgM and PRNT. The case is a 90-year-old male from Thilogne well being district, who’s hospitalized in a personal clinic in Dakar.

The Strategic Software for Assessing Dangers (STAR), which was used previous to notification of the third case in Kidira well being district, categorized YF as “low”, the place small outbreaks will be noticed however doubtless not a big outbreak.

Public well being response

The Ministry of Well being is coordinating a speedy response. Really useful response actions embrace immunization of the native inhabitants, enhanced surveillance, threat communication, neighborhood engagement and vector management. Extra potential assist for vaccines and operational prices could also be requested by the nation.

WHO threat evaluation

The detection of YF instances within the Tambacounda and Kedougou areas demonstrates the potential for sylvatic unfold of YF to unvaccinated individuals in a rural space and emphasizes the significance of sustaining excessive inhabitants immunity in all nations positioned in areas at excessive threat for YF. Latest epidemiological research have reported that the villages are in a savanna space with non-human primates. Everlasting or short-term swimming pools of water are noticed on the outskirts of residential areas.

Though mass vaccination occurred in Senegal in 2007, the japanese a part of the nation is taken into account to be at excessive threat of endemic YF transmission. Unvaccinated people stay susceptible to an infection with YF because of the persistence of the illness in primates (sylvatic cycle), particularly in rural areas. The 2 affected areas are additionally tough to succeed in, making vaccination efforts difficult. Intensive care models within the areas are removed from the district (186 km) with poor street circumstances. Affected districts are rural, largely consisted of forests, making it tough to regulate the vector and mitigate the mixed sylvatic-urban cycle.

The COVID-19 pandemic poses a threat of disruption to routine immunization actions because of the burden on well being methods and declining immunization uptake as a consequence of bodily distancing or neighborhood reluctance. Disruption of immunization providers, even for temporary durations, will improve the variety of prone people and improve the probability of outbreaks of vaccine-preventable ailments. As of 27 December 2020, there have been 18 523 confirmed instances of COVID-19 and 387 deaths reported in Senegal.

WHO recommendation

YF is an acute viral haemorrhagic illness transmitted by contaminated mosquitoes and has the potential to unfold quickly and have critical public well being penalties. There isn’t any particular therapy, though the illness will be prevented with a single dose of YF vaccine, which confers lifelong immunity. Supportive care to deal with dehydration, respiratory failure and fever, and antibiotic therapy for related bacterial infections are really helpful.

Senegal is taken into account a excessive precedence nation by the Remove Yellow Fever Epidemics (EYE) technique. The introduction of YF vaccination into routine vaccination occurred in January 2005. Vaccination is the first technique of stopping and controlling YF. In city centres, focused vector management measures are additionally helpful to cease transmission. WHO and companions will proceed to assist native authorities in implementing these interventions to regulate the present epidemic.

WHO recommends YF vaccination for all worldwide vacationers aged 9-months or older touring to Senegal. Senegal additionally requires a YF vaccination certificates for vacationers aged 9-months or older from nations prone to YF transmission and vacationers who’ve transited greater than 12 hours at an airport of a rustic that’s prone to transmitting YF.

YF vaccination is secure, extremely efficient and affords safety for all times. In accordance with the Worldwide Well being Regulaions (2005), third version, the validity of the worldwide YF vaccination certificates extends to the lifetime of the particular person vaccinated. A booster dose of YF vaccine can’t be required from worldwide vacationers as a situation of entry.

WHO has revealed pointers for vaccination actions in the course of the COVID-19 pandemic and is at the moment growing particular operational pointers for conducting mass vaccination campaigns within the context of COVID-19. The place circumstances allow, the EYE technique will assist the speedy resumption of YF prevention actions.

WHO encourages Member States to take all needed measures to maintain vacationers properly knowledgeable of dangers and preventive measures, together with vaccination. Vacationers also needs to concentrate on the indicators and signs of YF and may seek the advice of a doctor promptly when exhibiting indicators. Returning viremic vacationers could pose a threat to the institution of native YF transmission cycles in areas the place the competent vector is current.

WHO doesn’t advocate any restrictions on journey and commerce to Senegal primarily based on the data obtainable on this outbreak.

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