Measles outbreak in the Americas
THE LANCEDTWORLD REPORT| VOLUME 392, ISSUE 10145, P373, AUGUST 04, 2018 Barbara Fraser
A measles outbreak is spreading throughout the Americas, threatening local and indigenous populations that have not been vaccinated. Barbara Fraser reports.
Venezuela's ongoing health crisis is spilling over into neighbouring countries, as a year-long measles epidemic has spread to Brazil, Ecuador, Colombia, and Peru, almost 2 years after the Pan American Health Association (PAHO) declared the Americas free of measles. Measles is particularly threatening to indigenous people near the remote, heavily forested border between Venezuela and Brazil.
Spiralling inflation and political turmoil have undermined immunisation coverage, health services, and surveillance of disease, according to Venezuelan experts and a June report by PAHO. “Venezuela is a country living under a war crisis, but without a war”, said Alberto Paniz-Mondolfi, founder of the Venezuelan Science Incubator, an independent health research organisation in Barquisimeto. The crisis has caused millions of people to flee the country, including 1·6 million people in 2017 alone, according to the UN International Organization for Migration.
As a result, measles cases are on the rise in the Americas. Diphtheria has also reappeared in Venezuela, and malaria has spread throughout the country from the southeastern state of Bolívar, where illegal alluvial gold mining is rampant.
Health officials talk about a measles outbreak that started in Venezuela in mid-2017 but the situation is epidemic, with cases reported in all states and in Caracas, the capital, says José Oletta. Oletta served as Venezuelan health minister from 1997 to 1999 and now is part of a network of experts who compile health statistics to help make up for the lack of official reports.
The first suspected measles case in the Brazilian state of Roraima, which borders Venezuela, was that of a year-old Venezuelan child who had not been vaccinated. As of July 25, there were 272 cases in Roraima and 519 cases in the neighbouring state of Amazonas, according to the Brazilian health ministry. The D8 genotype of the confirmed cases in those states is the same as that identified in Venezuela when the ongoing outbreak began.
By mid-July, cases had also been reported in the Brazilian states of São Paulo, Rio de Janeiro, Rio Grande do Sul, Rondônia, and Pará, and in Colombia, Ecuador, and Peru. PAHO's Pan American Sanitary Bureau is providing immunisation, diagnostic, surveillance, and other assistance to Venezuela, Brazil, Colombia, Ecuador, and Guyana to control the spread of measles and diphtheria.
The greatest danger, however, is to indigenous people, including the Yanomami, who live in regions accessible only by river or helicopter. The first cases in Yanomami communities in Alto Orinoco, in Venezuela's Amazonas state, were reported in mid-March. By early July, the number of cases increased to 126, with 53 reported deaths. On the Brazilian side of the border, by late July, there were 77 confirmed cases among Yanomami and Ye'kuna communities in the Brazilian states of Amazonas and Roraima, according to PAHO. Many of the cases are in the Auaris region of Roraima, where indigenous people from Venezuela often cross the border to seek health care in Brazil.
Even before the economic crisis in Venezuela, the vaccination rate among the semi-nomadic Yanomami was about 45%, and it was far lower by the time the epidemic reached the indigenous communities, says María Teresa Quispe of Wataniba, a non-profit organisation that works among the Yanomami and other indigenous groups. Venezuelan health teams have been travelling by helicopter to vaccinate members of Yanomami communities, but the effort did not begin until November, 2017, 5 months after the first cases were reported in Venezuela, Quispe says.
The precise origin of the epidemic is not clear, although the D8 strain could have come from Europe or elsewhere in the world, Oletta says. “More important than where it came from is the harsh reality that conditions existed that enabled the virus to circulate”, he says.
Malnutrition due to chronic food shortages has left children, especially, with weaker immune systems. Long-running shortages of medicine and medical supplies, sporadic epidemiological surveillance, and debilitated national immunisation programmes are exacerbated by a shortage of doctors, since at least 22 000 of them have left Venezuela, by PAHO's count.
Rampant unregulated gold mining in the Venezuelan states of Bolívar and Amazonas promotes the spread of disease, as Venezuelans join the Brazilian, Guayanese, and Colombian miners working in unsafe conditions with poor sanitation. Miners who contract diseases infect others when they return home.
Paniz-Mondolfi, who studied a 2016 diphtheria outbreak in the state of Bolívar and who monitors arboviruses such as dengue, Zika, and chikungunya viruses, worries that other diseases could emerge.
Between “low vaccination coverage and explosive activity of illegal mining”, he says, “it is a recipe for disaster.”
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Published: 04 August 2018
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