Date: Thu, 3 Oct 2019 03:41:42 +0200 (METDST)
By Allison JACKSON

Rio de Janeiro, Oct 3, 2019 (AFP) - Dengue-resistant mosquitoes breed in a Rio de Janeiro laboratory, producing offspring infected with bacteria packing a punch in the fight against the deadly virus, which is exploding across Brazil this year.   Scientists are using Wolbachia, a bacteria common among insects except the dengue-transmitting Aedes aegypti mosquito, to dent the spread of the debilitating virus and other illnesses including Zika and chikungunya.

Since 2015, the Fiocruz institute in Rio has been producing mosquitoes infected with Wolbachia and releasing their dengue-hardened offspring into the densely populated city and neighboring Niteroi.   The hope is they will spread the bacteria by reproducing with wild mosquitoes.   Wolbachia works in two ways: it boosts a mosquito's immune system, making it less likely to contract dengue.   But if the mosquito does get dengue, Wolbachia makes it harder for the virus to grow inside the insect and be transmitted to humans.   So far, results are promising.    Scientists involved in the trial report a "significant reduction" in cases of dengue and chikungunya in targeted neighborhoods.   Tests show more than 90 percent of mosquitoes in areas where the first infected insects were released more than three years ago have the bacteria.

But Wolbachia is not the silver bullet for eliminating dengue, Luciano Moreira, head of the project in Brazil, tells AFP in a lab as workers walk around waving electrified mosquito racquets to zap insects that have escaped from test tubes.    "Where there are people, there are mosquitoes," Moreira explains, surrounded by hundreds of tubes holding thousands of Wolbachia-infected mosquitoes.    "We always say we are not the solution, it has to be an integrated process done together.   "People still have to destroy breeding sites at home. You want to have less mosquitos, but mosquitoes with Wolbachia.   "If there is a vaccine you can use it in conjunction with that ... it has to be a combination."

Brazil is one of several countries holding trials of the so-called Wolbachia method, which began in Australia in 2011, to tackle the virus that infects tens of millions around the world every year.    The self-sustaining process does not involve genetic modification (GM), which has been tested in Brazil and elsewhere.   In one GM trial, thousands of male mosquitoes carrying a "self-limiting gene" designed by British biotech company Oxitec were released in the eastern Brazilian state of Bahia between 2013 and 2015.   The number of viable offspring fell dramatically, suppressing the wild mosquito population by an average of 70 percent compared with before the release, Oxitec found.   But mosquito numbers rebounded after the project ended.    Moreira says previous attempts to wipe out mosquito populations have failed.   "There are too many (mosquitoes)," he says.

- Fresh blood is best -
Thousands of bacteria-carrying mosquitoes at Fiocruz institute are the descendants of insects originally infected with Wolbachia at Australia's Monash University.    Researchers there took the bacteria from fruit flies and injected it into mosquito eggs using a very fine needle.   The Brazilian insects are kept in small boxes in a temperature- and humidity-controlled room.   During their brief lives, which can be as long as 100 days in the lab, females have sex with their male counterparts multiple times.   After mating, the females dine on human blood supplied by a blood bank, and then deposit their eggs on the surface of water held in plastic containers.   The eggs, which inherit Wolbachia from the female, are harvested and transferred to large test tubes.

Only female mosquitoes consume blood, which they need to produce eggs, Catia Cabral, supervisor of the insectary, tells AFP during a recent visit.    Any blood type is ok, but fresh is always best.    "She is going to prefer 1,000 times more the blood from my arm, but she can't choose here so she has to eat this blood," says Cabral, showing AFP a bag of blood from a bank.   Within two weeks, the infected offspring have grown into adults and are ready for release.   Brazil's health ministry plans to expand the program to municipalities in other parts of the country to see if similar results can be produced in different environments.   But state and federal government budget cuts mean no more Wolbachia-carrying mosquitoes will be released in Rio or Niteroi after December, Moreira says.    He is lobbying authorities to keep the program going.   "Rio (state) has had quite large financial problems in recent years and for that reason cannot invest in this project," Moreira explains.

The decision comes as Brazil sees a spike in the number of cases of dengue, which causes fever, rash, nausea and -- in some cases -- death.   More than 1.4 million cases were registered in the first eight months of this year, health ministry figures show, up 600 percent on the same period in 2018.    Nearly 600 people have died so far.   Moreira blames this year's surge on the return of type two dengue, which has not been seen in Brazil for years, meaning many people have no resistance.   Unseasonal rain and high temperatures are also fueling the outbreak, the health ministry says.   A vaccination for the four types of dengue was in the "final stage of tests," Health Minister Luiz Henrique Mandetta announced last month.    Mandetta hopes it will be ready next year. In the meantime, he said, Brazilians should brace for a "very tough summer."
Date: Thu 29 Aug 2019
Source: Yahoo News [abridged, edited]
<https://uk.news.yahoo.com/brazil-confirms-first-measles-death-174356272.html?guccounter=1>

Brazil's Health Ministry said Thursday [29 Aug 2019] that a 42-year-old man died from measles in Sao Paulo. He was not vaccinated against the disease.

Nearly all the measles cases recorded this year [2019] in Brazil are in the state of Sao Paulo, where health authorities have confirmed 2457 cases.

Brazil received a measles eradication certificate from the Pan American Health Organization in 2016, but the disease returned in January 2018 from people immigrating from Venezuela.

Measles cases also have surged in Europe and parts of the United States. Health authorities blame that on people refusing vaccines.

The Pan American Health Organization says Brazil recorded more than 10 000 cases of measles with 12 deaths last year [2018].
Date: Fri 9 Aug 2019
Source: Folha de S. Paulo [trans. Kiratiana Freelon; abridged, edited]
<https://www1.folha.uol.com.br/internacional/en/scienceandhealth/2019/08/mutated-measles-virus-is-responsible-for-new-outbreak-in-sao-paulo.shtml>

A mutated measles virus is responsible for the recent outbreak of the virus that has led to 1000 cases in the the Sao Paulo area, according to Edison Luiz Durigon, a professor at USP's Institute of Biomedical Sciences and one of the country's most respected virologists.

The previous outbreak of the disease, which was considered eradicated in Brazil in the past decade, occurred in 1999. The current version of the virus, however, is another.

Still, the vaccine protects against this type of measles virus, the D-8. But the amount of antibodies in the body of an immunized person (made with the type A virus) drops after 15 years of application. Therefore, anyone who has never been immunized or injected for a long time should be vaccinated. WHO estimates that from 2000-2017, 21 million measles deaths were prevented by the vaccine.

With the amount of antibodies generated by someone who recently took the vaccine, the body can neutralize viruses of various types (8 in all, from A to H) and subtypes (24, distributed between types).

D-8 viruses circulated generally in Europe and began to pop up about a year ago in Venezuela and the northern part of the country. "Because there were a few cases, we thought the disease was spreading among unvaccinated people."  [Byline: Gabriel Alves]
Date: Thu 25 Jul 2019
Source: Teresina Prefecture [in Portuguese, trans. ProMED Mod.TY, edited]
<https://pmt.pi.gov.br/2019/07/25/fms-lanca-nota-informativa-sobre-investigacao-e-acompanhamento-de-casos-de-febre-do-nilo/>

PI [Piaui state] has been following with attention and care the developments regarding the 3rd confirmed case of West Nile fever in Piaui. Since 2013, all suspected cases admitted to the municipal public network have been subjected to an investigation protocol implemented by the FMS [Fundacao Municipal de Saude de Teresina; Teresina Municipal Health Foundation] that includes West Nile virus, among several others of important relevance.

The patient in question, a victim of encephalitis, coming from Piripiri in Piaui, received all possible assistance in the intensive care unit of the Teresina Emergency Hospital, but suffered several clinical complications that, due to her advanced age and the presence of comorbidities, led to her death.

The coast and the interior of the state of Piaui are located on migratory bird routes, identified as important links in the spread of the disease [virus], according to the National Center for Research for the Conservation of Wild Birds (CEMAVE / ICMBIO). The virus was also detected in the state of Espirito Santo in 2018 and in the state of Ceara in 2019.

From 2014 to 2019, the FMS investigated 399 suspected human cases of severe West Nile fever disease from various cities in Piaui and neighbouring states: 319 were discarded, 35 had "undetermined" results, and 42 remain under investigation. All hospitals in the municipality are trained to investigate and treat any new suspicious cases.  [Byline: Amariles de Souza Borba]
=======================
[West Nile virus transmission has been active in several spots in Brazil this year [2019]. There have been recent equine cases in Ceara and Espirito Santo states, so it is not surprising that a human case has occurred in Piaui state as well. As ProMED Mod.CRD noted in a previous ProMED-mail post (West Nile virus (19): Americas (Brazil) horse, OIE; archive no. http://promedmail.org/post/20190725.6586397), "West Nile fever is a mosquito-borne viral disease that can affect birds, humans, and horses causing inapparent infection, mild febrile illness, meningitis, encephalitis, or death. West Nile virus (WNV) is a member of the genus _Flavivirus_ in the family Flaviviridae. The arbovirus is maintained in nature by cycling through birds and mosquitoes; numerous avian and mosquito species support virus replication" (see  Source:<http://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/3.01.24_WEST_NILE.pdf>).

Hosts are birds, some of which may succumb to fatal systemic illness. Among mammals, clinical disease is primarily exhibited in horses and humans, but they are dead-end hosts and cannot infect mosquitoes. There is a vaccine available for equine animals but not for humans. The best preventive measure is to avoid mosquito bites. - ProMED Mod.TY]

[HealthMap/ProMED-mail map:
Piaui, Brazil: <http://healthmap.org/promed/p/9666>]
Date: Mon 1 Jul 2019
Source: EurekAlert!, American Association for the Advancement of Science (AAAS) [edited]
<https://www.eurekalert.org/pub_releases/2019-07/fda-yfv070119.php>

The origin of the virus responsible for the ongoing yellow fever epidemic in Brazil, the worst for 40 years, has just been identified by scientists affiliated with 2 Brazilian institutions: Adolfo Lutz Institute (IAL) and the University of Sao Paulo (USP).

By means of a molecular study of yellow fever viruses found in dead monkeys and in mosquitoes, the group discovered that the strain behind the current epidemic originated in Para state in North Brazil in 1980.

The virus infected monkeys in Para and spread from there throughout the Amazon region until it reached Venezuela and Suriname. From 2000 on, always via infection of monkeys, the disease migrated to the Center-West and Southeast of Brazil, finally reaching Sao Paulo state in 2013. The 1st deaths of humans in Sao Paulo occurred in 2016.

Findings of the study, which was supported by Sao Paulo Research Foundation - FAPESP, are published in Scientific Reports [see reference below].

The investigation was led by Mariana Sequetin Cunha, a researcher in IAL's Vector-Borne Disease Group. Scientists at the University of Sao Paulo's Tropical Medicine Institute (IMT-USP), the Federal University of Para (UFPA) and the Federal University of Sao Paulo (UNIFESP) also took part. The project was also funded by Brazil's National Council for Scientific and Technological Development (CNPq).

Since mid-2016, when the ongoing yellow fever epidemic began, 2245 cases of the disease have been confirmed, with 764 deaths, according to the Health Ministry. The largest number of cases since 1980, when the government made notification mandatory, had previously been reported in 2000. In that year, 40 people died from yellow fever.

Another face of the problem is the infection of monkeys by the same mosquitoes that transmit the virus to humans. Since 2016, public health authorities responsible for epidemiological surveillance in the Center-West, Southeast, and South, where the epidemic is concentrated, have collected the carcasses of more than 10 000 monkeys found in forests and parks, mainly howler monkeys (_Alouatta_ spp.), marmosets (_Callithrix_ spp.) and capuchins (_Sapajus_ spp). Yellow fever virus was detected in 3403, according to the Health Ministry (Boletim Epidemiologico de Febre Amarela/Yellow Fever Epidemiological Bulletin).  "More than 90% of the dead monkeys are believed to be _Alouatta guariba_ [brown howler monkey]. The species is extremely susceptible to yellow fever," said Ester Sabino, Director of IMT-USP.  "Troops of more than 80 monkeys were entirely destroyed," Cunha said, referring to the deaths of howler monkeys from yellow fever in Horto Florestal, a nature reserve in the north of Sao Paulo city in late 2017.

Yellow fever is an acute disease caused by a virus transmitted to monkeys and humans through the bites of infected mosquitos. The symptoms include jaundice, a yellowish or greenish pigmentation of the skin and whites of the eyes due to high bilirubin levels, reflecting liver damage.

In the sylvatic (wild) transmission cycle, the yellow fever virus circulates between mosquitoes of the genera _Haemagogus_ and _Sabethes_ and monkeys. Humans are considered incidental hosts in the sense that people are infected only if they happen to live or work in tropical forests or travel on land through such areas. In the urban transmission cycle, the virus is transmitted to humans (the main host in this case) by the mosquito _Aedes aegypti_.

Yellow fever was endemic in the South and Southeast of Brazil in the early 20th century. Urban transmission has been eradicated thanks to vaccination and action against _Ae. aegypti_ breeding sites.

In the last 2 decades, transmission to humans has occurred outside the Amazon region, where yellow fever is still endemic. Cases have been reported in humans and monkeys in Bahia, Goias, Minas Gerais, Sao Paulo, Parana, and Rio Grande do Sul [states].

Since late 2016, the disease has spread faster and farther, reaching the Atlantic Rainforest biome, with all its extraordinary biodiversity, which includes many species of monkey. Yellow fever had not occurred in these areas for decades.

In search of the yellow fever virus, Cunha and her group investigated samples of brain, liver, and spleen tissue from dead monkeys found by state public health workers and compulsorily sent for analysis to IAL, the state reference laboratory. Samples from 430 dead monkeys were tested between July 2016 and March 2017. Most were _Alouatta_, _Callithrix_, and _Sapajus_, but there were some specimens of black-fronted titi (_Callicebus nigrifrons_) and golden lion tamarin (_Leontopithecus rosalia_), an endangered species.

Investigation in search of the yellow fever virus was carried out in each one of the species. The published study contributes to a better understanding of the biotic pathways involved in the virus's spread from the Amazon to the Southeast. "The study describes the evolution of the virus in different species. The disease is milder in capuchins than in howler monkeys and marmosets," Sabino said.

Not all the dead monkeys sent to IAL died from yellow fever. "Some had been run over and others electrocuted, for example," Cunha said. "The protocol requires analysis by the reference lab of tissue samples from all dead monkeys found, whatever the circumstances."

The presence of the virus was ruled out in most cases, and even in the minority in which it was confirmed, it was not always possible to be sure that death was due to yellow fever. The disease is practically a death sentence for howler monkeys. Marmosets are susceptible but do not always die. Capuchins are considered resistant.

By mid-2017, the epidemic that began in the north of Sao Paulo state in 2016 had spread to the Campinas region, not far from the state capital. "Yellow fever virus hadn't circulated in Campinas since the early 20th century," Cunha said.

The 1st infected monkey was confirmed by IAL in July 2016. It was a capuchin from the Ribeirao Preto region. The species is resistant, so the cause of death was not reported as having been caused by yellow fever, although the virus was found in its tissue.  "The animal came into contact with the pathogen via a mosquito bite but died from other causes. We wanted to find out if capuchins were acting as natural reservoirs of the virus precisely because they're resistant," Cunha said.

Yellow fever virus was found in 67 out of the 430 samples analyzed by Cunha and colleagues at IMT-USP; 30 were from howler monkeys, 9 from marmosets, and 7 from capuchins. The rest were from monkeys of unidentified genera.  "In these 21 cases, the material didn't indicate the genus, but we suspect they were _Alouatta_ owing to the high viral loads in the tissues analyzed," Cunha said.

40-year-old strain
------------------
The researchers isolated the virus from each of the 67 confirmed samples, sequenced the genomes, and compared the genomes with those (available online) of viruses from the outbreaks of yellow fever that occurred between 1980 and 2015 in Brazil and neighboring countries.

They discovered that the strain responsible for the current epidemic originated in Venezuela and in Roraima state and Para State in Brazil. This is in line with prior research suggesting that the 2016-17 epidemic began in the North region and spread to the Southeast by means of a long and continuous sylvatic cycle involving mosquitoes and monkeys.

The results of the study reveal an evolutionary journey of sizable proportions in both time and space. In 1980, yellow fever virus was endemic in Para. In 2000, it reached Mato Grosso do Sul, Goias, and Minas Gerais in the Center-West. By 2004, it had crossed into Venezuela, and by 2009, it had reached Trinidad and Tobago in the Caribbean. In 2010, it was present in Roraima in the [Brazilian] far North, while one strain was found in Rio Grande do Sul in the far South. The virus arrived in Sao Paulo state in 2013.

The molecular analyses performed by Cunha and colleagues showed that the virus was fully disseminated in most Brazilian states and in Suriname by 2017.

Other researchers at IAL and IMT-USP are now conducting similar studies involving the dead monkeys collected in Sao Paulo State during the 2nd wave of the epidemic, in July 2017-June 2018, and during the 3rd wave, which began in July 2018 and will fizzle out this year [2019] with the end of the rainy season and the advent of winter, when the mosquitoes practically stop reproducing.

Depending on the results of these forthcoming studies, it may be possible to determine whether the current epidemic in Sao Paulo state is on the wane. Alternatively, despite mass vaccination the virus could still be spreading through the monkey population and fresh outbreaks may be in the offing.
========================
[Reference
---------
Cunha MS, da Costa AC, de Azevedo Fernandes NCC, et al. Epizootics due to yellow fever virus in Sao Paulo state, Brazil: viral dissemination to new areas (2016-2017). Sci Rep. 2019; 9(1): 5474. doi: 10.1038/s41598-019-41950-3;  <https://www.nature.com/articles/s41598-019-41950-3>

The report above provides a fascinating account of the recent yellow fever (YF) outbreaks and traces the movement of the virus in Brazil over time. Fortunately, in none of the widely dispersed outbreaks were there any reports of urban (people-_Aedes aegypti_-people) transmission of YF virus.

The Brazil Ministry of Health has embarked on an ambitious effort to vaccinate everyone, starting with areas of highest risk. Although that should eliminate human cases, it will not affect the sylvan (forest) cycle involving non-human primates. Meanwhile, human YF cases continue to occur in several states in Brazil this year (2019) (See Yellow fever - Americas (09): Brazil, official summary http://promedmail.org/post/20190627.6541056). An official 8 Jun 2019 report stated that confirmed human yellow fever cases were registered in the states of Sao Paulo (68 cases), Parana (13), and Santa Catarina (1) this year (2019). Most of the cases were rural workers or those exposed in forested areas. The 1st case of yellow fever was confirmed in Santa Catarina state. Cases in non-human primates continue to be reported also. Confirmed epizootics in non-human primates were registered in Sao Paulo (13 cases), Rio de Janeiro (1), Parana (32), Para (1), and Santa Catarina (1). Most of the confirmed epizootics were registered in the southern region (69%; 33/48) with the majority of the epizootics occurring in Parana state.

Continued YF surveillance will be essential to track YF movement in nature over time. - ProMED Mod.TY]

[Maps of Brazil:
<https://www.mapsland.com/maps/south-america/brazil/large-brazil-regions-map.jpg>
and <http://healthmap.org/promed/p/6>]
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