The fly that Brazil can’t swat

. Sep 17, 2019
aedes aegypti dengue mosquito

Every year it’s the same story. The Ministry of Health releases TV advertisements with advice on how to prevent the proliferation of Aedes aegypti, the mosquito that causes dengue fever and transmits the Zika virus. The pests like clean, standing water, which can easily accumulate in gardens, potted plants, and the like. Yet, every summer inevitably sees a rise in the number of dengue fever cases in the country’s warmest areas, such as Rio de Janeiro and the Northeast. This year, however, things have gotten even worse.

</p> <p>The number of probable cases of dengue fever in Brazil spiked in 2019—way before the usual season has begun—after two years of low levels of infections. Between January and August, authorities recorded 599 percent more cases than in the same period of last year, leading the government to bring forward its summertime anti-mosquito campaigns.&nbsp;</p> <p>In the first 34 weeks of 2019, over 1.4 million cases of dengue infection have been reported, against 206,000 in 2018. Meanwhile, cases of Zika and chikungunya have also spiked, by 44 and 47 percent, respectively.&nbsp;</p> <p>The Zika virus created panic worldwide in 2016, as it is linked to microcephaly in babies when mothers are infected during pregnancy. These babies’ skulls have circumferences smaller than normal and will likely suffer brain and eye damage.</p> <p>Also fresh in the memory was one of Brazil&#8217;s deadliest-ever yellow fever outbreaks, another disease transmitted by the <em>Aedes aegypti</em> mosquito. Between July 2017 and February 2018, 237 people died from yellow fever. And there were a further 37 confirmed cases of <a href="">between July 2018 and February 2019</a>, with nine deaths.&nbsp;</p> <p>Faced with numbers like these, we tried to grasp exactly why Brazil seems unable to eradicate the <em>Aedes aegypti </em>mosquito, responsible for so many pressing diseases.</p> <h2>Anti-mosquito campaigns never much of a priority</h2> <p>Most dengue-endemic countries, Brazil included, have “poorly-defined goals and are unwilling to commit resources except during epidemics,” according to a paper published by the <a href=""><em>PLOS Medicine</em> journal</a>. In recent years, the budget dedicated to eradicating the mosquito was cut by 10 percent, according to Brazilian newspaper <em>Folha de S.Paulo</em>.</p> <p>Authorities seem to only be able to respond to crises, instead of avoiding them. After the surge of the Zika virus in 2016, many efforts were put in place. But, as infections dropped in 2017 and 2018, so did public administrators&#8217; worries about mosquito-borne diseases. Hence the recent spike in the numbers.</p> <h2>Lack of information</h2> <p>In a recent survey amid the 2016 Zika virus outbreak, 92 percent of Brazilians interviewed by pollster Datafolha wanted more information about mosquito-borne diseases. Also, 20 percent said they didn’t understand the severity of a Zika infection, and another 20 percent said Zika infections were not that serious. Forty-two percent of the interviewees weren’t even aware that the disease was transmitted by <em>Aedes aegypti</em>.</p> <h2>Brazilians don’t do their part</h2> <p>Complaining about government ineptitude is a national sport in Brazil. Citizens, however, must shoulder part of the blame for the recent dengue fever and Zika outbreaks. While Brazilians expect the government to eradicate <em>Aedes aegypti</em>, the accumulation of standing water in households is still prevalent. This could be down to the lack of information explained previously. Forty-five percent of survey respondents, however, admitted that they had done nothing to help prevent breeding sites.</p> <h2>Mistrust gets in the way of health agents</h2> <p>When the government began sending health inspectors to examine houses and help eliminate mosquito breeding sites, they encountered an obstacle: people wouldn&#8217;t let them in to their homes. Fears that inspectors could actually be burglars in disguise meant many government health workers were left at the front door.</p> <p>In 2016, the Ministry of Health had to join forces with the Ministry of Defense to make the health inspectors’ job possible. Inspectors were escorted by soldiers to help garner public trust. This joint effort was referred to as the National Plan to Fight the Aedes Mosquito and Microcephaly.</p> <h2>Brazil already eliminated the dengue mosquito before</h2> <div class="wp-block-image"><figure class="aligncenter"><img src="" alt="ddt american soldier" class="wp-image-24221" srcset=" 640w, 300w, 610w" sizes="(max-width: 640px) 100vw, 640px" /><figcaption>American soldier applies DDT in the 1940s. Photo: Wikicommons</figcaption></figure></div> <p>Between the 1930s and 1950s, a program financed by the Rockefeller Foundation all but eradicated <em>Aedes aegypti</em> in Brazil, as a bid to get rid of yellow fever. Strictly-trained health inspectors applied DDT to the streets and were easily able to enter any private property suspected of mosquito breeding sites. Back then, Brazil was under a dictatorship and state agents had enormous powers.</p> <p>Some researchers believe that Latin America eradicated the mosquito after similar efforts in other countries. But it was in the Southern U.S. states that the Aedes aegypti remained alive, according to Brazilian researcher Rodrigo Cesar Magalhães. As American laws prevented health officials from having access to many private lands, the mosquito was able to continue breeding. His Ph.D. thesis from the Oswaldo Cruz Foundation, in association with the University of Maryland, analyzes the efforts to eradicate the mosquito in the Americas between 1918 and 1968.</p> <h2>More resistant mosquitoes</h2> <p>The massive use of insecticides, as efficient as it was at the time, ultimately helped make the mosquito stronger. It not only became more resistant, but also more adaptable, as it can now breed even in unclean water. The mosquito has also adapted to live in urban environments. Furthermore, its daily habits make it even more difficult to detect.</p> <div class="wp-block-image"><figure class="aligncenter"><img src="" alt="paho where zika was detected" class="wp-image-24220" srcset=" 640w, 300w, 610w" sizes="(max-width: 640px) 100vw, 640px" /><figcaption>Countries where Zika virus infections were registered. Pan American Health Organization</figcaption></figure></div> <p>Singapore is a more modern example of how to deal with the mosquito. The Asian city-state spends an average of USD 12 per inhabitant each year to fight <em>Aedes aegypti</em>, an unrealistic amount for most countries. Brazil, for instance, is home to 200 million people. Keeping up with Singapore’s standards would require a budget of USD 2.4 billion.&nbsp;</p> <p>But it is not only the money that helps Singapore fight the mosquito. The city has also implemented strict laws to punish those unwilling to cooperate, and teams of researchers permanently monitor suspected breeding spots. Brazil wants to make the entrance of health officials compulsory, with the government signaling it will dedicate more money to the effort.</p> <p>Former president Dilma Rousseff once declared that “Brazil will not be defeated by a mosquito.” Let’s hope she was right.

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