Fabiana Frayssinet
RIO DE JANEIRO, May 15 2009 (IPS) – The H1N1 flu virus has begun its southward march in Latin America, carried by passengers travelling from areas hit by the outbreak. But the mortality rate is much lower than in Mexico, and there are no signs of sustained domestic transmission in the rest of the region.
According to infectious disease expert Dr. Gabriel Levy at the Durand Hospital in Buenos Aires, who is the coordinator of the Infectious Disease Network in the Argentine capital, the new H1N1 influenza A virus popularly known as swine flu got off to a ferocious start in Mexico, but its impact has gradually weakened as it moves southward.
Brazilian President Luiz Inácio Lula da Silva drew angry reactions when he said the flu outbreak is serious, but it does not have the magnitude that it appeared to have at first.
In Brazil, eight cases have been confirmed so far, none of them serious.
Dr. Alberto Chebabo, an expert in infectious diseases, told IPS in Brazil that most of the cases involved young adults who had travelled to the United States or Mexico, while others had arrived from other infected areas, such as a woman who returned from Europe, where she had visited several countries.
Two of the patients did catch the H1N1 virus in Brazil. But Chebabo, who works at the Clementino Fraga Filho Hospital in Rio de Janeiro, said there is no epidemic in Brazil, pointing out that the two cases in question were the friend of one of the patients who had travelled to Mexico, and the patient s mother.
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Of the 34 countries around the world that have reported laboratory-confirmed cases, nine have involved isolated in-country transmission : Brazil, Canada, Germany, Italy, Mexico, Panama, Spain, the United Kingdom and the United States.
But only three of them have sustained community-level human-to-human transmission : Mexico, the United States and Canada.
The flu has behaved in a similar manner in other Latin American countries, like Colombia, where the Social Protection Ministry confirmed one new case, which brought the total there to seven.
The latest case is a man who had travelled to Mexico City, and like the rest of the cases in Colombia, he has completely recovered, the ministry reported.
Brazil, like other countries in the region, has stepped up airport controls, while putting an emphasis on follow-up of everyone who has come into close contact with the patients.
Neighbouring Argentina took a more radical approach, cancelling all flights from Mexico after the first, and so far only, case of H1N1 virus in Argentina a man who returned from Mexico on Apr. 24 and has already recovered. Another 100 cases are under study.
Argentina lifted the suspension of flights to and from Mexico on Friday.
In Brazil, the cases have been relatively mild, with the exception of one woman who had pneumonia but is in stable condition, said Chebabo.
But the expert did not rule out the possibility of the virus evolving into a more virulent strain, which means the mortality rate could still rise.
In Costa Rica, the situation is similar to the rest of the region: there are nine confirmed cases and five probable cases still awaiting the results of the lab tests. The cases involved people who either travelled to Mexico or came into contact with people from Mexico or the United States.
Like in Brazil, health authorities in Costa Rica say there is no evidence of sustained community-level human-to-human transmission. However, one of the cases was fatal: a 53-year-old man who suffered from diabetes and chronic lung disease.
As of Friday, the World Health Organisation (WHO) reported a total of 7,520 laboratory-confirmed cases around the world.
Mexico, where the first cases appeared, had reported 2,446 confirmed cases, including 66 deaths; the United States, 4,298 cases, including three deaths; and Canada, 449 cases, including one death.
Costa Rica was the only other country that had reported a fatal case.
Mexico reported Friday that the number of cases there had risen to 2,895.
The Latin American countries where cases have been confirmed so far are Argentina (one), Brazil (eight), Colombia (seven), Costa Rica (eight), Cuba (one), El Salvador (four), Guatemala (three), and Panama (29).
Experts say the most vulnerable population group is young adults, and that there have been few cases among children or the elderly, although they admit that they cannot yet explain the phenomenon. In addition, they say, the virus appears to be mild but highly contagious.
It is still early, but the virus would appear to be easily transmitted. On the other hand, the cases (in Latin America) appear to be less severe than what was initially observed in Mexico, said Chebabo.
Outside of Mexico, cases have been mild and the deaths were in patients who were at risk due to complications and underlying health conditions, he added.
However, the experts have not ventured to predict what might happen. Virologist Marilda Siqueira with the Oswaldo Cruz Foundation, a Brazilian government institute, said the virus could continue to circulate simultaneously with seasonal flu viruses, making the genetic exchange between them possible.
A milder (or more virulent) strain could emerge as a result of that combination. For example, the virus could circulate for a few months and later mutate into a more severe form, as has been observed on other occasions, she said.
Chebabo said that more virulent strains of the virus have not been observed. But he did not rule out the possibility, because the influenza virus undergoes frequent mutations which could lead the A/H1N1 virus to become more severe in the next waves of the epidemic.
For now it has been contained, virologist Laya Hun Opfer, at the University of Costa Rica Microbiology Faculty, told IPS. But the flu virus is unpredictable, and could mutate into a totally new form, she acknowledged.
In any of the possible future scenarios, say experts, the important thing is not to let down the guard and to stay alert, for example by preparing the public health system for an eventual epidemic.
Keeping mortality down depends on other factors, such as the hospital network s response capacity.
The question is whether the countries of Latin America, several of which are currently suffering from epidemics of dengue fever, and a number of which have health systems with serious shortcomings, would be able to deal with a severe flu outbreak.
Dr. Hun Opfer said that because Costa Rica has a first world health system, it will not see a mortality rate like that of Mexico. Besides, the virus is being kinder for the moment, she added.
The prevention measures taken by the authorities in Costa Rica have been praised by the WHO, she pointed out. The Costa Rican social security institute announced a 700,000 dollar investment in health equipment to confront the flu outbreak.
In addition, 3,500 government health agents are dedicated to searching out suspected cases in that small Central American country of 4.5 million people known as the Switzerland of Central America .
And in Argentina, said Levy, the response capacity is strong; there is good information and organisation.
Because of the swift response by authorities in Argentina, there should be no mortality along the lines of what has been seen in Mexico, he said.
In addition, there is always a major impact at the start of an epidemic, but later the impact declines, he added. Indeed, in Mexico, the infection rate has declined sharply since late April, he noted.
Chebabo, by contrast, has doubts with respect to the Brazilian health system s response capacity.
If the cases remain mild, like the ones seen so far, there won t be major problems in care. But if the number of hospitalisations goes up, we will likely have problems, because the health network is already overburdened, he warned.
According to the Brazilian Health Ministry, 800 beds have been set aside for H1N1 flu cases in 54 hospitals, and nine million doses of antiviral drugs have been stockpiled in this country of 189 million people.
Chebabo said that an overlapping of epidemics, like dengue fever and the flu, is unlikely. The mosquito-transmitted dengue is more common in summer, and influenza is more common in winter, he pointed out.
But the Health Ministry in Costa Rica is worried about such a scenario, with the arrival of the rainy season, which could bring other threats, like dengue or malaria, on top of the H1N1 influenza virus.
Another concern in Latin America is the availability of laboratories and materials to test suspected cases.
In Costa Rica and Colombia, for example, samples from suspected cases have been sent to labs in the United States up to now.
But according to authorities in Colombia, the test kits will arrive by the end of the month. And Costa Rican Deputy Health Minister Ana Morice reported Friday that her country had received a shipment of test kits that would soon be available for use.
In Brazil, the tests are carried out in three national laboratories with kits provided by the WHO. Other labs are interested in working with their own diagnostic kits, which have been developed on the basis of international protocols.
In Mexico, which accounts for more than 90 percent of the flu deaths, the last death occurred on May 10.
In Mexico City, people have largely stopped wearing surgical masks and day-to-day life is returning to normal, said Miguel Ángel Lezana, director of the National Centre for Epidemiological Surveillance and Disease Control. But we insist that although the figures are positive, because of the reduction in the number of cases, we must remain on epidemiological alert as long as this new virus continues to circulate.
Everything is like it was before; luckily the paranoia has resided and business is rallying, Jaime Cabrera, the owner of a small restaurant that serves typical Mexican food in the capital, told IPS.
In Brazil, all patients with possible symptoms are being tested so far, since the number of cases is still small. But, said Chebabo, if an outbreak occurs, the routine will probably be like in Mexico and the United States, with random samplings or tests on seriously ill patients.
* With additional reporting from Marcela Valente (Buenos Aires), Daniel Zueras (San José) and Diego Cevallos (Mexico City).
