Mario Osava

RIO DE JANEIRO, Nov 28 2005 (IPS) – Brazil, the world s largest exporter of chicken, has been making efforts to ease fears that bird flu could spread to Latin America. But closer to home than the H5N1 virus that has decimated flocks and killed dozens of people in Asia is the scare caused by the reemergence of spotted fever, a rare tick-borne disease with a high mortality rate.
Although the disease is nothing new for doctors, many Brazilians heard of it for the first time this month when three people died after staying in a hotel in Petrópolis, a mountain retreat about an hour away from Rio de Janeiro, in October.

The incident has had repercussions for tourism in the city, the summer residence of Brazil s emperors and aristocrats in the 19th century, and the surrounding mountain region, which depends heavily on Brazilian and foreign visitors.

My first reaction was fear. I had never heard of the disease, Anderson Vieira, chief receptionist at the hotel where the three victims had stayed overnight, told IPS.

The idea that the disease represented a new public health problem, like bird flu or SARS (severe acute respiratory syndrome), was laid to rest by reports pointing out that spotted fever has been endemic in certain parts of Brazil, especially the southern state of Sao Paulo, for at least seven decades.

In Brazil, the most alarming recent outbreaks of the acute, febrile disease which is also known as Rocky Mountain spotted fever and is present in the United States, Canada, Mexico, Central America and Colombia have occurred in Piracicaba, 160 km from Sao Paulo, Brazil s biggest city.
Last August, five members of a family were killed in that city by spotted fever, which is caused by the tick-borne Rickettsia ricketsii bacterium.

The local higher school of agriculture became a high-risk zone, with the proliferation of the Amblyomma cajennense tick, the main vector of the disease. In the last three years, two people have died there of spotted fever, including the son of one of the professors, and at least three other people have caught the disease on campus.

The main carriers of the ticks in that area are capybaras, the world s largest rodent, which are sometimes raised domestically. The ticks are also carried by dogs, horses and cattle.

After the high-profile coverage given to the cases in Petrópolis, where at least two other people were infected, numerous cases of contagion by spotted fever, including deaths, began to emerge into the national spotlight. Spotted fever can be difficult to diagnose in its early stages. The initial symptoms include fever, nausea, vomiting, severe headache, muscle pain and lack of appetite. If the disease is detected early enough and treated with antibiotics, the mortality rate is significantly reduced. A 15-year-old boy died last week in Queluz, a town located between Rio de Janeiro and Sao Paulo, with the same symptoms as a friend of his who had died of spotted fever three weeks earlier.

The disease is also suspected to be the culprit in the deaths of a 43-year-old woman and her 12-year-old daughter in Sao Paulo, a city of 11 million which has barely any contact with the rural world.

Public alarm continued to grow when spotted fever was confirmed as the cause of other deaths in Guarujá, a beach city 90 km from Sao Paulo, and in the states of Minas Gerais and Espíritu Santo, to the west and north of Rio de Janeiro, respectively.

Although the attention received by the recent cases of the disease and its high mortality rate scared the public, spotted fever is not an unknown disease, said Denise Marangoni, a doctor who specialises in infectious diseases at the Federal University of Rio de Janeiro.

The difficulty of diagnosis, which leads to delayed antibiotic treatment, and the fact that the disease is rare are largely to blame for the high proportion of fatal cases, she told IPS.

A report by four professors at the Piracicaba school of agriculture revealed that from 1985 to 2004, 160 confirmed cases of spotted fever were registered in the state of Sao Paulo, 70 of which were fatal, while there was a possibility that other cases went undiagnosed.

The cases in Petrópolis were high-profile because the city is a major tourist spot, said Vieira. But activity there has now returned to normal, the hotel was allowed to reopen, and the fear has waned, now that we know what the symptoms of the disease are, he added.

The recent cases brought back memories of a spate of deaths that occurred four years ago in Nueva Iguazú, a city near Rio de Janeiro, when 19 people died of unknown causes.

According to exams carried out afterwards by a medical research institute, at least one of them was killed by the Rickettsia rickettsii bacterium.

Marangoni noted that while the latest outbreaks of spotted fever took the public by surprise, it does not form part of the wave of emerging diseases, mainly caused by new viruses, like H5N1, which causes avian influenza, and HIV, the AIDS virus.

The gravity of the current wave of new epidemics and reemergence of diseases like spotted fever is due to the greater susceptibility of the global population, which is ageing thanks to the successful fight against a number of illnesses, said Marangoni, who also pointed out that people take more medications today, which depress the immune system.

At the same time, bacteria and funguses that affect humans have become more and more antibiotic-resistant, through a process of natural selection.