MercoPress. South Atlantic News Agency

Argentina and Bolivia tighten yellow fever controls

Argentina and Bolivia have taken further steps to prevent the spread of the mosquito transmitted yellow fever outbreak in neighboring Paraguay which so far has caused at least seven confirmed deaths, another 39 almost certain cases and an overall atmosphere of panic in the country with people in urban areas desperate to be vaccinated.

Argentine president Cristina Fernandez de Kirchner spent over two hours on Thursday with close aides and governor Maurice Closs of Misiones province, next to Paraguay, and instructed him to continue with the yellow fever vaccination campaign, both among Argentines and Paraguayans who are increasingly crossing over given insufficient inoculants in Paraguay. "We're not afraid of an outbreak of yellow fever (in Misiones) because we're prepared. In 2001 we had another vaccination campaign covering 70% of the Misiones population. Now we're working in the most potentially vulnerable area along the border vaccinating our Paraguayan brothers and sisters", said Closs. "President Cristina Fernandez de Kirchner told us to keep up with the good job, that we help with the vaccination of the people of Misiones and from Paraguay, so we can protect a border area which is particularly complicated", said Closs. However the governor of the rain forest covered province that borders with Paraguay and Brazil said that there was concern because of reports coming from the jungle area in Brazil. "The mosquito remains circumscribed to the jungle area but we have information that at least fourteen monkeys have died close to the Paraguayan-Brazilian border". In Bolivia, the Public health minister announced that a sanitary "red alert" had been declared all along the Brazilian and Paraguayan borders, which means reinforcing those areas and recommending people living there to be vaccinated. "We have sufficient doses for those vulnerable areas", he added. Bolivia so far has had no yellow fever cases reported or confirmed and according to official data from the Ministry of Public health, the vaccination campaign "covered 98% of the population". Meantime in Paraguay and in an attempt to calm the population of the capital Asuncion, President Nicanor Duarte announced that an additional two million doses of the yellow fever vaccine would be arriving over the weekend. The World Health Organization, working closely with the Paraguayan government has confirmed seven deaths and 39 seriously suspect cases, some of them in the outskirts of Asuncion which have caused a panic atmosphere with people violently demanding to be vaccinated. WHO describes yellow fever is a viral disease that has caused large epidemics in Africa and the Americas. Infection causes a wide spectrum of disease, from mild symptoms to severe illness and death. The "yellow" in the name is explained by the jaundice that affects some patients. Although an effective vaccine has been available for 60 years, the number of people infected over the last two decades has increased and yellow fever is now a serious public health issue again. The disease is caused by the yellow fever virus, which belongs to the flavivirus group and is mosquito transmitted. South America has two different types, but since 1974 only one has been identified as the cause of disease outbreaks. Yellow fever is difficult to recognize, especially during the early stages. It can easily be confused with malaria, typhoid, rickettsial diseases, hemorrhagic viral fevers (e.g. Lassa), arboviral infections (e.g. dengue), leptospirosis, viral hepatitis and poisoning (e.g. carbon tetrachloride). A laboratory analysis is required to confirm a suspect case. In the Americas, yellow fever is endemic in nine South American countries and in several Caribbean islands. Bolivia, Brazil, Colombia, Ecuador and Peru are considered at greatest risk. There are 200,000 estimated cases of yellow fever (with 30,000 deaths) per year. However, due to underreporting, only a small percentage of these cases are identified. Humans and monkeys are the principal animals to be infected. The virus is carried from one animal to another (horizontal transmission) by a biting mosquito (the vector). The mosquito can also pass the virus via infected eggs to its offspring (vertical transmission). The eggs produced are resistant to drying and lie dormant through dry conditions, hatching when the rainy season begins. Therefore, the mosquito is the true reservoir of the virus, ensuring transmission from one year to the next. Several different species of the Aedes and Haemogogus (S. America only) mosquitoes transmit the yellow fever virus. These mosquitoes can be domestic (i.e. they breed around houses), wild (they breed in the jungle) or semi-domestic types (they display a mixture of habits). Any region populated with these mosquitoes can potentially harbor the disease. Control programs successfully eradicated mosquito habitats in the past, especially in South America. However, these programs have lapsed over the last 30 years and mosquito populations have increased.