The case is an 83-year-old male with no known vaccination history for yellow fever. He had onset of symptoms on 30 January 2020 and presented to a health facility on 2 February 2020 with abdominal pain and jaundice. Between 2 February and 9 April, he consulted the Urban Health Centre in Tchibanga, the Christian Alliance Hospital in Bongolo and the University hospital in the capital Libreville where the case received anti-malarial treatment and remained hospitalized until his death on 9 April 2020. On 14 April 2020, the laboratory results received from the WHO Regional Reference Laboratory at the Institute Pasteur in Dakar, Senegal, confirmed yellow fever infection, by seroneutralisation test. The additional differential diagnostic tests performed were negative for dengue, West Nile fever, chikungunya, Crimean-Congo Haemorrhagic fever, Zika and Rift Valley fever.
The case is a 55-year-old woman with no vaccination history for yellow fever. She had onset of symptoms on 31 January 2020 and presented to a health facility on 3 February 2020 with fever and aches. The following day she developed jaundice and a blood sample was taken. On 7 February , the blood sample was transported to the national laboratory. On 10 February , the sample from the case was received at the national laboratory and test results on 17 March were Immunoglobulin M (IgM) positive for yellow fever. The positive yellow fever result was confirmed by the Institute Pasteur in Dakar Senegal, a yellow fever reference laboratory on 14 April 2020 by seroneutralisation.
The outbreak was identified when suspected measles cases had been reported by the local residents in the surrounding areas, highlighting pockets of under-vaccinated populations. According to WHO/UNICEF 2018 estimates, measles first dose vaccination coverage is relatively high (88%), and slightly lower for the second dose (77%). However, this does not reflect the vaccination coverage of incoming refugees.
The link below provides details of the 15 reported cases.
Of the 124 confirmed cases, 105 were in Mexico City, 18 in Mexico State, and one in Campeche State; the following is a summary of the epidemiological situation in each:
In response to the positive RT-PCR results, the EPHI and Ministry of Health performed an in-depth investigation and response, supported by partners including WHO.
The cases were identified through a cross-border rapid response team investigation mounted in response to the recently declared outbreak in bordering Moyo district, Uganda. During the investigation, the team collected 41 blood samples from five villages which were in close proximity to the bordering Moyo district, Uganda. Of the 41 individuals whose samples were collected, nine (22%) had history of fever, but none had history of jaundice. The individuals represented a spectrum of occupations typical for the area (farming, forestry, homemaker, soldier). Most of the individuals investigated were between 20-45 years of age, and 18 (44%) of these individuals were female.
Dengue epidemics in these territories usually occur when there is a shift in the predominant circulating DENV serotype, and non-immune populations (e.g., tourists, new immigrants, or people not previously exposed to the circulating serotypes) are exposed to the new serotype through human movements within the territories or across neighboring countries. Local transmission occurs through the Aedes mosquito vector present on the islands and in French Guiana.