Dengue Vaccine Gone Wrong?

A Dengue vaccine program was recently suspended in the Philippines due to concerns that the “vaccine could worsen the potentially deadly disease in people not previously infected.” The vaccine, known as Dengvaxia, has been given to over 830,000 children. It’s the first-ever approved dengue vaccine, produced by the French pharmaceutical company Sanofi. While it appears to be effective in people who have already had the virus, given the results of the study, the vaccine program has been suspended pending a review.

Dengue is an infection caused by mosquitoes. It’s a flu like illness found in tropical and sub-tropical climates and can be deadly. It’s the leading cause of serious illness and death among children in these areas. Infection rates have grown globally in recent decades and half the worlds’ population is at risk. Early detection and access to proper medical care dramatically lowers fatality rate.

Did a researcher foresee this problem?

Four decades ago, Dr. Scott Halstead, a leading figure in dengue research, first proposed that antibodies from an initial exposure to one of four types of the disease could increase the risk of a potentially lethal complication called severe dengue when a person was infected a second time, a process know as antibody-dependent enhancement or ADE.

This phenomenon could make development of a dengue vaccine tricky.

Rather than being protective, a shot given to someone who had never had dengue could act like a first infection, increasing their risk of severe dengue when they were exposed a second time.

 

Uganda Avoids Marburg Virus Disaster

Uganda has successfully contained an outbreak of Marburg virus, just weeks after it was first detected. Within 24 hours of being notified of the first confirmed death, the WHO deployed a rapid response team to the area:

Marburg is a highly fatal disease caused by a virus from the same family as that of Ebola. It can be transmitted from person to person by bodily fluids, and can cause bleeding, fever, vomiting, diarrhea and other symptoms.

This was the fifth outbreak of Marburg virus in a decade, and lessons have been learned from those outbreaks, as well as from the West African Ebola epidemic that killed more than 11,000 people.

Surveillance and contact tracing are critical in containing the virus:

“The response to the Marburg virus disease outbreak demonstrates how early alert and response, community engagement, strong surveillance and coordinated efforts can stop an outbreak in its tracks before it ravages communities,” said Dr Peter Salama, executive director of the WHO Health Emergencies Programme.

A Way to Predict Ebola Outbreaks?

Researchers have identified a possible link between deforestation and the emergence of Ebola outbreaks. There is evidence that Ebola outbreaks are likely to occur within 2 years of forest loss.

This new research also suggests that preventing the loss of forests could reduce the likelihood of future outbreaks. “We have accumulated knowledge that removing forests causes problems not just to the functioning of the climate and ecosystems but also to humans, then we must see it as a threat to human livelihoods, health, security and everything else,” said Fa – a Senior Associate at CIFOR and a Professor of Human Development and Biodiversity at Manchester Metropolitan University in the United Kingdom.

When forests are destroyed, the animals that live in them are displaced. The Ebola virus is transmitted from wild animals, such as fruit bats or apes.

The forests should not be protected for the sake conservation alone but also for health reasons, according to Lutwama, a Virologist at the Uganda Virus Institute. “People should keep the forests,” he said.

 

 

The Worst Cholera Outbreak in History

The size of the cholera epidemic in Yemen is hard to grasp. According to an article in the Guardian in October:

The World Health Organization has reported more than 815,000 suspected cases of the disease in Yemen and 2,156 deaths. About 4,000 suspected cases are being reported daily, more than half of which are among children under 18. Children under five account for a quarter of all cases.

Those statistics, which are really thousands upon thousands of helpless people and children dying terribly tragic deaths, are sobering.

The spread of the outbreak, which has quickly surpassed Haiti as the biggest since modern records began in 1949, has been exacerbated by hunger and malnutrition. While there were 815,000 cases of cholera in Haiti between 2010 and 2017, Yemen has exceeded that number in just six months.

Save the Children has warned that, at the current rate of infection, the number of cases will reach seven figures before the turn of the year, 60% of which will be among children.

Tamer Kirolos, Save the Children’s country director for Yemen, said an outbreak of this scale and speed is “what you get when a country is brought to its knees by conflict, when a healthcare system is on the brink of collapse, when its children are starving, and when its people are blocked from getting the medical treatment they need”.

Kirolos said: “There’s no doubt this is a man-made crisis. Cholera only rears its head when there’s a complete and total breakdown in sanitation.

There is perhaps a glimmer of optimism, however small, as the rate of new cases have started to slow, and the mortality rate has begun to decline. Cholera is easily preventable and treatable with access to clean water and oral re-hydration salts, but in a war ravaged country like Yemen, those things are often insurmountable challenges.

“Whatever decline we’re seeing now is due to the heroic efforts of workers at the scene,” said Sherin Varkey, the officiating representative of Unicef Yemen.

Varkey said the situation would not be solved until there was peace in the country.

“There are no signals that give us any reason for optimism. We know that both parties to the conflict are continuing with their blatant disregard of the rights of children,” he said. “We’re at a cliff and we’re staring down and it is bottomless. There seems to be no hope.

California’s Hepatitis A Outbreak and the Importance of Bathrooms

Access to safe and clean bathrooms is important for several reasons, one of which is disease prevention. Lack of access to safe and clean bathrooms is a major reason the hepatitis A outbreak in California has been quick to spread and hard to halt.

Hepatitis A is a liver disease transmitted through ingestion of contaminated food and water or through direct contact with an infectious person, according to the WHO. The risk of hepatitis A is strongly associated with lack of safe water, and poor sanitation and hygiene.  Although California’s hepatitis A outbreak has been linked to the transient homeless population, according to the WHO the virus is also “one of the most frequent causes of foodborne infection.” So nothing is safe, as usual.

As of November 10, San Diego had reported 546 cases of the disease and 20 deaths. There are signs the outbreak is slowing and efforts to vaccinate the homeless population against hepatitis A are proving effective. According to The San Diego Tribune:

Last week…local health providers forwarded only eight possible hepatitis A cases to the health department for further investigation. There have been no new deaths, leaving the outbreak total at 20 for the second straight week.

It’s the lowest weekly new case total since the outbreak began, eventually launching a vast, multmilllion-dollar campaign to improve sanitation and housing conditions for the homeless.

What could still go wrong? The physician noted that the outbreak could still jump into another demographic population such as gay men who are considered at an elevated risk of hepatitis A infection. Because the virus’s incubation period can last up to 50 days, there is still a chance, he added, that an infected person could have exposed a large number of people who simply have not started to show symptoms yet.

In addition to the homeless and drug users, high-risk groups are those with compromised immune systems, existing liver disease and gay men. Public-facing job classifications also recommended for vaccination include food handlers, first responders and health care workers.

 

Another article in The San Diego Tribune notes that the city built a 2 million dollar restroom in 2014, “designed by an artist to invoke “Jonathan Livingston Seagull,” the popular 1970 novella about a seagull who wanted to be special.” While the restroom building looks pretty, many point out that the money could have been better spent on more restrooms to serve the city’s large homeless population, potentially avoiding such a massive outbreak. According to the article:

The city was warned repeatedly as far back as 2000 that human waste on city streets was a problem that threatened public health, and that there was a shortage of 24-hour public restrooms available to the city’s growing homeless population downtown.

In 2005, city officials shot down a grand jury recommendation calling for more toilets to address the shortage. City officials said the facilities could cost up to $250,000 each to buy and install, plus another $65,000 per year to maintain, and the city did not have “the resources to execute a project of this magnitude.”

Based on those cost estimates, the $2 million spent on the seagull-themed restroom could have paid for four such facilities and operated them for 16 years.