Se calcula que el número de víctimas de la Primera Guerra Mundial, que finalizó en 1918, fue de diez millones de personas; el mismo año, murieron el doble durante una epidemia de gripe que resultó ser más mundial todavía que el conflicto. Países neutrales como España resultaron más gravemente afectados que algunas de las naciones que participaron en la guerra. En un mapa del mundo elaborado por epidemiólogos, descubrimos focos de gripe tan diversos como Odesa en Rusia, Mashed en Persia, Bristol Bay en Alaska, Río de Janeiro (Brasil) y Zamora, a orillas del Duero. Zamora fue una de las ciudades del mundo en la que más mortífera fue la enfermedad: mató al 3 por ciento de la población.…  Seguir leyendo »

The quality of mercy is strained in the Middle East. Last week, Saudi Arabia closed off the highways, sea routes and airports in war-torn Yemen, forbidding humanitarian groups from even shipping chlorine tablets for the Yemenis suffering from a cholera epidemic. More than 500,000 Yemenis have been infected with cholera this year and nearly 2,000, mostly children, have died, according to the World Health Organization. The International Red Cross expects about a million people to be infected by cholera in Yemen by December.

The spread of cholera in Yemen glaringly illustrates how disease follows in the wake of bombs.

The seeds of the epidemic were planted in 2015, when a military coalition led by Saudi Arabia and the United Arab Emirates and backed by the United States joined the fighting in Yemen on behalf of the ousted president, Abdu Rabbu Mansour Hadi, who had been forced out by Houthi rebels.…  Seguir leyendo »

Four months ago, the situation in Yemen was dire: there had been 124,000 suspected cases of cholera, and experts were predicting that it could rise to 300,000. Urgent action was called for – from health and humanitarian actors as well as from warring parties – to allow the population better access to health care and to allow supplies to reach those in need.

These pleas have had little effect. As of 2 November, with an estimated 900,000 suspected cases, Yemen’s cholera outbreak has now surpassed that of Haiti (which has seen 815,000 cases since 2010) to become the largest recorded in recent history.…  Seguir leyendo »

Los últimos brotes de enfermedades como el ébola y el zika han demostrado la necesidad de anticiparse a las pandemias y contenerlas antes de que aparezcan. Pero la enorme diversidad, resiliencia y transmisibilidad de las enfermedades mortales también pone de manifiesto en los términos más duros las dificultades inherentes a la contención y la prevención.

Una amenaza a la capacidad de prepararnos es el grado de conexión actual. Los brotes masivos de dengue, chikungunya y zika que hubo estos años en el continente americano y el Caribe fueron posibles por la facilidad que hay hoy para los viajes internacionales, que permitió a esos virus viajar como polizones de Oriente a Occidente.…  Seguir leyendo »

Imagina que tus enemigos tuvieran un tipo de armas con las que, de vez en cuando, atacan a tu pueblo. Podrían pasar décadas sin que haya ataques, pero en algún momento volverán a suceder. También imagina que esas armas se hicieran más potentes y, los ataques, más frecuentes.

Ahora imagina que hubiera una forma de proteger a tu gente de esas amenazas. Sin embargo, generarla sería costoso y podría tomar años. Así que por eso no se fabrica.

Cada ataque provocaría muertes, pánico y una protesta: “¿Dónde está nuestra defensa? ¿Por qué no estamos protegidos?”. Pero en cuanto pasara el ataque, también se acabaría el interés por prepararse para el siguiente.…  Seguir leyendo »

From a lack of basic public services, to violations of internal humanitarian law by warring parties, Yemen’s humanitarian crisis is daunting. But infectious disease outbreaks, like the cholera currently sweeping Yemen, should not be considered inevitable. By pressuring donors to urgently deliver on pledged resources, and by supporting humanitarian advocacy efforts to protect and promote access to health and other essential commodities and services, cholera can be stopped.

The outbreak

In terms of health security risks, cholera in Yemen is a ‘known known’. We know that infectious diseases such as cholera spread in conflict zones, where there is lack of water, poor sanitation and a weak or absent health system.…  Seguir leyendo »

On 9 May, a cluster of undiagnosed illness and deaths in a remote location in the north of the Democratic Republic of Congo (DRC) was reported to the World Health Organization (WHO). Several individuals tested positive for Ebola (Zaire subtype) a few days later. As of 19 May, 29 confirmed and suspected cases, including three deaths, had been reported. With the wounds of the West African Ebola outbreak that killed more than 11,000 between 2014 and 2016 still fresh, the rapidly evolving situation in northern DRC is likely to cause unease locally, nationally and internationally.

Here are six things to understand about this new outbreak:

  1. The potential for international spread is limited.
…  Seguir leyendo »

One of the saddest stories of this year has been the death of Salome Karwah, a Liberian health worker who was featured on the cover of Time magazine as a fighter in the 2014 Ebola epidemic.

She lost most of her family to the disease. She was also infected, but she recovered to return to the clinical front lines to care for hundreds of other patients. Earlier this year in Monrovia, the capital of Liberia, she died from complications of childbirth.

Her death draws new attention to the governing structure in Liberia. The scope of the dysfunction that Ebola revealed is beyond what can be chalked up simply to being a weak state in West Africa.…  Seguir leyendo »

Liberia was finally declared Ebola-free a year ago this month. The 2013-2015 outbreak wreaked havoc on the lives of thousands of Liberians, infecting at least 10,675 and killing 4,809. Many more were affected: 4 in 10 Liberians reported having a relative or close friend die during the outbreak.

During Liberia’s epidemic, analysts pointed to multiple obstacles blocking effective response: inadequate health facilities and resources, citizens’ mistrust of government, and the slow international response. There were questions about whether the Ebola outbreak would have severe consequences for Liberia’s already embattled government, leaving citizens even more distrustful of government and its ability to protect and provide for them.…  Seguir leyendo »

The race for a Zika vaccine, one of the most pressing priorities in global health, is at full throttle. More than a dozen companies and government institutions are working to unlock the secrets of the virus, and a vaccine could be available as early as 2018.

But available to whom? If history is any guide, impoverished communities in Africa are likely to be the last in line. And this despite a mounting body of evidence that, contrary to the prevailing wisdom, poor families in Africa might bear the greatest burden of the disease.

Indeed, much of what we have taken for granted about Zika — that it is a threat unique to the Western Hemisphere; that it may only recently have evolved the ability to cause microcephaly and brain damage in babies; and that it hasn’t hurt women and children in Africa — is now in serious doubt.…  Seguir leyendo »

Scientists know that Ebola can cause anything from severe hemorrhagic fever to no symptoms at all (asymptomatic infections). What wasn’t known, until now, is the number of people who experienced asymptomatic infections during the 2013-2016 outbreak of Ebola in West Africa.

This is not the first report of potential asymptomatic cases of Ebola. About one in five people who came into contact with individuals infected during the 1976 outbreak in Sudan had detectable antibodies against Ebola but had not been ill. A 2005-2008 survey of the public in Gabon, which had its first outbreak of Ebola in 1994, suggested 15% had been infected with Ebola but did not show symptoms.…  Seguir leyendo »

With the number of suspected cases of cholera in Haiti now in the hundreds, the race is on to try to prevent further death and devastation following Hurricane Matthew.

With one million doses of cholera vaccine due to arrive this week, the hope is that we can prevent a repeat of the horrific outbreak in 2010 that infected nearly 800,000 Haitians, killing more than 9,000 people. But, even if we are successful in Haiti, the fact is for a highly preventable disease like cholera, vaccine stockpiles while certainly helpful cannot be a long-term solution.

Ten million people live in Haiti alone, and yet fewer than 6 million doses of cholera vaccine are currently produced each year, to maintain a global emergency stockpile of 2.2 million, with two doses recommended per person.…  Seguir leyendo »

Cholera patients received treatment at the St. Nicholas Hospital in St.-Marc, in 2010. Dieu Nalio Chery/Associated Press

Marseille, France In late 2010, the Haitian government asked me to investigate a cholera outbreak that struck that autumn following the arrival of a United Nations peacekeeping unit. It quickly became evident that some of the peacekeepers, who had been rotating through Haiti as part of a mission started in 2004 to provide security and stability, had introduced cholera from Nepal, where the disease had been flourishing.

By scrutinizing the most affected areas and using maps to trace the disease, I demonstrated how the epidemic originated with the peacekeepers. I published my findings in a July 2011 article, and an independent scientific team confirmed my conclusions within a few months.…  Seguir leyendo »

Don’t get pregnant.” Not now. Maybe not for two years.

This was the advice governments gave women in a number of South American countries when the connection was established between the Zika virus and microcephaly, a serious birth defect that can result in seizures and developmental delays. But details on how they were supposed to accomplish this in countries with limited access to contraception and strict abortion restrictions weren’t provided.

Now Zika has been locally transmitted in the continental United States. The Center for Disease Control and Prevention issued a similar warning, saying women and men who visit affected areas, including Wynwood in Miami, should wait at least eight weeks before trying to get pregnant.…  Seguir leyendo »

I am a millennial; half my peers are single and on Tinder, half are getting ready to start families. I’m also a scientist, working toward a master’s degree in bioethics. And I am more and more worried about Zika.

This summer, I co-wrote a guide for travelers to Rio de Janeiro about how to stay healthy in a place where Zika infection is common. After the Olympics’ closing ceremony, I worry that Americans will stop paying attention to the virus. They shouldn’t. Last month, a Miami hospital treated the first American known to have been infected locally, instead of while traveling abroad.…  Seguir leyendo »


Las amenazas biológicas naturales, relacionadas con actividades humanas o directamente intencionadas, constituyen una grave preocupación mundial que debe ser adecuadamente abordada desde una perspectiva preventiva.


Las amenazas pandémicas recientes han constituido un motivo de preocupación social internacional por encima incluso de sus daños para la salud y la vida de las personas. En casi todas ellas la respuesta ha sido o bien lenta y descoordinada o bien desproporcionada e impulsiva, desacreditándose las instituciones en su conjunto. Para controlar adecuadamente la segura aparición futura de este tipo de problemas se requiere un intenso esfuerzo de vigilancia, coordinación y actuación precoz, fundamentalmente en los lugares de origen.…  Seguir leyendo »

De vuelta a España tras ocho meses en los EE UU, me ha dejado muy desconcertado lo poco que se habla en Europa del virus del zika y de sus consecuencias. Me sorprende el poco eco que esta epidemia está recibiendo en los medios de comunicación y en el debate público. Afortunadamente, organismos tan importantes como el Center for Disease Control and Prevention americano (CDC), que trabajan continuamente para analizar la evolución de este virus, entre otros, están compartiendo públicamente cierta información que deberíamos tener en cuenta. Cuando leo, por ejemplo, que su director, el Dr. Tom Frieden, está haciendo un llamamiento de aportación masiva de fondos por parte del Gobierno americano, o que compara el estado de la epidemia con, cito textualmente, “estar al lado de una persona que se está ahogando y tener la habilidad de salvarla, pero no puedes”, ciertamente, me transmite la gravedad de la realidad a la que nos enfrentamos.…  Seguir leyendo »

Antes de que los horrores del último brote de Ébola en África occidental pudieran empezar a borrársenos de la mente, el virus Zika estalló como un riesgo importante para la salud global y hoy ocupa a investigadores y médicos en Sudamérica, América central y el Caribe. Sin embargo, la cantidad de víctimas de otro virus -la fiebre amarilla- está creciendo a pasos acelerados.

En el sudoeste de África, Angola enfrenta una epidemia seria de fiebre amarilla, la primera en ese país en 30 años. Desde que el virus apareció en Luanda, la capital y la ciudad más poblada de Angola, en diciembre pasado, le provocó la muerte a 293 personas e infectó, se sospecha, a 2.267.…  Seguir leyendo »

If I were a pregnant woman living on the Gulf Coast or in Florida, in an impoverished neighborhood in a city like Houston, New Orleans, Miami, Biloxi, Miss., or Mobile, Ala., I would be nervous right now. If mosquitoes carrying the Zika virus reach the United States later this spring or summer, these are the major urban areas where the sickness will spread. If we don’t intervene now, we could begin seeing newborns with microcephaly and stunted brain development on the obstetrics wards in one or more of these places.

There are many theories for Zika’s rapid rise, but the most plausible is that the virus mutated from an African to a pandemic strain a decade or more ago and then spread east across the Pacific from Micronesia and French Polynesia, until it struck Brazil.…  Seguir leyendo »

Genetically modified mosquitoes are in the news for good reason: They may be our best hope for controlling the mosquito-borne Zika virus. The Food and Drug Administration has issued a preliminary finding of no significant environmental impact and is seeking public comment on a plan to test them in a field trial in the Florida Keys.

So you might think this will resolve the Zika crisis, which has caught the world’s attention because of an unexpected spike in microcephaly in babies born to women infected during pregnancy and in the incidence of the paralytic Guillain-Barré syndrome in Zika-infected adults.

You’d be wrong.…  Seguir leyendo »