Outbreak of meningoencephalitis in Seville puts 16 people in hospital, five in the ICU

An outbreak of viral meningitis in the Seville municipalities of Puebla del Río and Coria del Río have led to the hospitalization of 16 people, of whom five were in intensive care on Wednesday. Both of the areas in question are located close to the Guadalquivir River, and mosquitoes are common there. The Andalusian regional government has identified 18 cases in total of viral meningoencephalitis, which is a condition that simultaneously resembles meningitis and encephalitis. Tests are being carried out on the people who have been infected in a bid to identify the source of the outbreak.

While this research is being carried out, the Andalusian health department has recommended that 42,000 residents of the areas in question take measures to avoid mosquitoes, such as the use of repellents and nets. They are also advised to cover their skin with clothing, to not go outside at dawn or dusk, to turn off unnecessary lights and to avoid strong perfumes or colognes.

The suspicion, in an area close to the marshland of the Guadalquivir, is that we would have to think about mosquitos, although we will have to extend the search to other pathogens

Jesús Rodríguez Baño, head of infectious diseases service at the Virgen de Macarena hospital

So far, the regional government has the results of analysis on four of the infected patients, who tested negative for the main bacteria and viruses, as well as West Nile virus, Toscana virus and lymphocytic choriomeningitis, it announced via a press release. However, despite the four negative tests the main suspect to have caused the meningoencephalitis continues to be the West Nile virus, which is transmitted by a type of mosquito that is common to the area.

“The etiology [study of the causes of the disease] is complicated and requires repetitions of the samples,” explained José Miguel Cisneros, the secretary of the Spanish Society of Infections Diseases and Clinical Microbiology and the head of service at the Virgen del Rocío Hospital in Seville, where several of the patients have been admitted. “This is a complicated and laborious task. Even if someone is negative in the preliminary tests this does not determine the final result.”

There are no vaccines or drugs to treat the 16 hospitalized patients – a particularly high number given that previous outbreaks identified in the region have not exceeded three infections due to the illness, which cannot be transmitted from person to person.

“The suspicion, in an area close to the marshland of the Guadalquivir, is that we would have to think about mosquitoes, although we will have to extend the search to other pathogens,” explained Jesús Rodríguez Baño, the head of the infectious diseases service at the Virgen de Macarena hospital in Seville.

For Salvador Oyonarte, the general director of the Andalusian network for Transfusional Medicine, Tissue and Cells, the outbreak in Seville “does not look good.” He added that he was “surprised by the high number of infections. In 2016 we had three cases and in 2010 another two. We will talk to the Health Ministry about this [on Thursday] but it seems very strange to me. We usually detect cases in September or October [...]. When the migratory birds leave, the virus replicates in birds and mosquitoes transmit it to us and to horses.”

The mayor of Coria del Río, Modesto González, called on residents to remain calm, avoid risk areas and protect themselves from possible bites

In 2020 so far, there have been 12 West Nile virus infections detected: 10 in Greece and two in Romania, with just one fatality in Greece, according to the European Centre for Disease Prevention and Control. Also this year there has only been one outbreak among horses, which was detected in Portugal, and none among birds.

The mayor of Coria del Río, Modesto González, called on residents to remain calm, avoid risk areas and protect themselves from possible bites. “Between all of us, residents, and the local and regional governments, we will take the appropriate actions to deal with and overcome the situation as soon as possible,” he said in a statement. The mayor of Puebla del Río, Manuel Bejarano, also called on citizens to act with “prudence and to avoid scaremongering.”

English version by Simon Hunter.