Announcement

Collapse
No announcement yet.

French Guiana - Mayaro virus disease , 13 cases, Oct 2020 (WHO)

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • French Guiana - Mayaro virus disease , 13 cases, Oct 2020 (WHO)

    Mayaro virus disease - French Guiana, France


    Disease Outbreak News

    25 October 2020

    On 13 October 2020, the French health authorities officially reported 13 laboratory-confirmed cases of Mayaro fever in French Guiana, France.

    In September 2020, the Institut Pasteur de la Guyane (IPG) (member of the French National Reference Laboratory for arboviruses) identified two cases of Mayaro virus infection (MAYV) confirmed by reverse transcriptase polymerase chain reaction (RT-PCR) and one probable case found positive for Mayaro antibodies. The case-patients presented dengue-like symptoms and joint pains, and tested negative for dengue by RT-PCR.

    This unexpected diagnosis led to a further retrospective search for additional cases of Mayaro fever among patients with dengue-like symptoms who tested negative for dengue. Reverse transcriptase polymerase chain reaction was performed on samples collected between 15 July and 15 September, at laboratories mainly located in Cayenne area. These blood samples were collected from patients with dengue-like symptoms , who had tested negative for dengue within five days after the onset of symptoms. In total (including the first detections and retrospective search) IPG identified 11 cases of Mayaro fever by RT-PCR out of 79 samples tested. These cases were reported on 21 September 2020.

    On 2 October and 8 October 2020, two additional confirmed cases of Mayaro fever were reported by the Institute Pasteur de la Guyane in Cayenne, leading to a total of 13 confirmed cases among 97 tested samples between 15 July and early October. The onset of symptoms for the 13 confirmed cases ranged from 18 July to 29 September 2020. Of the 13 confirmed cases, 11 lived in the urban coastal area including nine from Cayenne area (Cayenne: 1, R?mire: 4, Matoury: 4), one from Kourou, and one from Montsinery-Tonnegrande. Only two cases lived in a rural/sylvatic area, both in Roura (including one in the village of Cacao, located further in the interior). The age of these cases ranged between 11 to 68 years old (median = 40 years old) and the male to female sex ratio was 1.2:1.

    Mayaro virus (MAYV) has been known to circulate in French Guiana since 1998, but the number of RT-PCR detections of MAYV by IPG between 2017 and 2019 added up to between 1 to 3 confirmed cases annually, detected from 150 to over 600 samples tested every year. As per the testing criteria for MAYV, blood samples were collected within 5 days of the onset of dengue-like symptoms and found negative for dengue virus.

    Detection of 13 confirmed cases within less than 3 months is thus unusual. Furthermore, MAYV is mainly transmitted through a sylvatic cycle and transmission in urban settings has been sparsely described. It is therefore atypical that 11 out of 13 (85%) identified cases of Mayaro fever resided in an urban area.

    MAYV vector (Haemagogus species mosquitoes) is also the vector of the sylvatic cycle of yellow fever virus and is present in wild or rural habitats of the region of the Americas and the Caribbean. MAYV has been isolated from other genera of mosquitoes, including Culex,Mansonia , Aedes, Psorophora , and Sabethes .

    Epidemiological investigation is ongoing in particular to document the travel history of the cases and to determine whether the infections were contracted in forest areas or if the transmission through an urban cycle may be suspected.


    READ MORE
    ?Addressing chronic disease is an issue of human rights ? that must be our call to arms"
    Richard Horton, Editor-in-Chief The Lancet

    ~~~~ Twitter:@GertvanderHoek ~~~ GertvanderHoek@gmail.com ~~~

  • #2
    See also: Emergence of recombinant Mayaro virus strains from the Amazon basin
    ?Addressing chronic disease is an issue of human rights ? that must be our call to arms"
    Richard Horton, Editor-in-Chief The Lancet

    ~~~~ Twitter:@GertvanderHoek ~~~ GertvanderHoek@gmail.com ~~~

    Comment


    • #3
      Snip from PAHO document:


      Mayaro virus (MAYV) was isolated for the first time in Trinidad and Tobago in 1954. However, a retrospective study showed evidence of infection by MAYV in sera collected during the construction of channels in Panama and Colombia between 1904 and 1914 (1, 2).

      Since then, cases have been reported in Central America and South America, particularly in the regions around the Amazon basin. Following the cases identified in Trinidad and Tobago, Mayaro fever cases were reported in Brazil (1955), Colombia (1958-1960), Bolivia (1959), Suriname (1964), Peru (1965), the United States of America (cases imported from Peru and Bolivia, 1997), Ecuador (1997), French Guiana (1998), Venezuela (2000), Mexico (2001), Panama (2010), and Haiti (2015) (3, 4). Although some studies suggest transmission in urban areas (5, 6), outbreaks described in the last decade in the Americas were reported among residents of rural communities in the Amazon region of Brazil, Bolivia, Peru, and Venezuela.

      The majority of human cases occurred among persons who work or reside in tropical rainforests. For the documented outbreaks, the vector identified was the Haemagogus mosquito found in rural and sylvatic habitats.

      The reservoir for MAYV is unknown, but some studies have reported virus isolation or high levels of antibodies in host vertebrates, such as nonhuman primates (8). In 2015, one case of Mayaro fever was reported in Haiti. The case is an 8-year-old child from a rural area who was diagnosed with a coinfection of dengue and Mayaro (15). In 2018, Peru reported 35 cases of Mayaro fever (16). In 2019, 2 cases were confirmed in Peru in the provinces of Quispicanchis (Cusco Region) and La Mar (Ayacucho Region) (16). Additionally, on 26 April 2019, Ecuador reported that of 34 samples that were negative for dengue, chikungunya, Zika, and leptospirosis, 5 were positive for Mayaro. The cases correspond to four different cantons: Guayaquil (2 cases), Portoviejo (1 case), Santo Domingo (1 case), and Babahoyo (1 case). These cantons are in the eastern part of the country, with a distance of up to 300 kilometers between them. The detection occurred through laboratory surveillance of MAYV which has been implemented in Ecuador since 2018.

      READ MORE
      ?Addressing chronic disease is an issue of human rights ? that must be our call to arms"
      Richard Horton, Editor-in-Chief The Lancet

      ~~~~ Twitter:@GertvanderHoek ~~~ GertvanderHoek@gmail.com ~~~

      Comment

      Working...
      X