Giving the Plague no Quarter in Madagascar

Plague, for very good reasons, is something that will always capture headlines and panic individuals. It is an infectious disease that entirely disrupted civilization on multiple occasions and has become the stuff of legends involving everyone from Roman emperors to Nostradamus. Indeed for most of human history plague, caused by a bacteria that spreads from rodents via the bite of flea, was an existential threat, until it was tamed by scientific discoveries that discovered its origin and its susceptibility to antibiotic therapy. In many parts of the world, this taming of plague has made it a non-issue but a new outbreak on the African island nation of Madagascar has some worrying characteristics that merit swift action to extinguish what could become a larger problem. 

In Madagascar, close to 700 individuals have been infected with 57 succumbing to the infection. What makes this outbreak particularly notable, despite occurring in a country that has hundreds of annual plague cases, is that many of the cases are of the pneumonic form. This form of plague, which involves infection of the lungs, is the form that can be transmitted between humans through coughs and sneezes in little droplets that travel about 3 feet. Also, cases are occurring in urban areas giving the bacteria more opportunity to find new hosts. 

These factors have prompted public health agencies to take prompt actions including the creation of a treatment center and the delivery of antibiotics. So far, the risk of international spread is low -- despite an importation to the Seychelles. However, in the wake of Ebola it is crucial, even in low international risk situations and with effective antibiotic therapies, to not allow infectious diseases to any breathing room 

The Mystery of Malaria in Italy

It's said that half of all humans have died from one infection -- malaria. But today in many parts of the developed world malaria is just a travel or global health concern. However, it must be remembered that relegating malaria to such a status was a great human achievement as malaria had a much bigger planetary profile in the past -- indeed Washington DC was literally, at one time, a malarious swamp. 

A new case of fatal cerebral malaria in northern Italy is a stark reminder that this disease can have a much bigger impact if it is allowed to. Italy was freed of malaria in only 1970 the result of strong eradication campaigns that beat the mosquito back. However, there have been reports of recent possible local transmission in the southcentral part of the country. It is unclear, at this time, how the disease was contracted as the patient had not traveled abroad. An unknown pool of possibly Italian Anopheles mosquitoes is infected with the parasite and just found the right opportunity to transmit to the now deceased four year old child. There is some question whether a contaminated needle may have played a role as well as travel related malaria cases were treated around the same time at the same hospital.

Malaria is a complex infectious disease that has marked the human race and provided a tremendous evolutionary pressure on our species. Alarming rates of drug resistance to artemesinin, if they spread to Africa, could be catastrophic.

The disease, however, can be defeated --but only if humans put all the resources of their mind into the fight. Bed nets, insecticides, vaccines, antimalarials, and genetically modified mosquitoes should all have major roles in this fight for the best chance at success. 

A Little Blue in the Face over Yellow Fever Vaccination

To many people, yellow fever is a disease from a bygone era in which giants like Benjamin Rush and Walter Reed roamed. Indeed, since yellow fever was beaten back from the United States and many other areas of the world and an effective vaccine was developed (and resulted in a Nobel Prize) yellow fever is largely thought of as a travel-related disease. However, new and recent outbreaks of the disease in various countries -- including its first ever Asian appearance in China  -- and poor vaccine supply chains and logistics have increased the threat level posed by this virus. As the virus is spread by the Aedes aegypti mosquito (aka the yellow fever mosquito) to which half the human population is exposed to yellow fever has the capacity to roar back. With a penchant for severe disease and death, such an event would be majorly disruptive. 

Yellow fever outbreaks are managed by effective vector control and vaccination campaigns. However as the frequency of these outbreaks occurs and the population sizes involved increase, it is increasingly likely that vaccine supply issues will constrain the ability to respond. Coupled to that supply issue -- which is even impacting the US -- is the logistical issues that constrain vaccine administration. 

Yellow fever was one of the original infectious disease covered by the International Health Regulations (IHR) given its high consequence nature. As part of the IHR framework, yellow fever vaccines have to be administered by certified vaccine centers in every country, including the United States. In the US, certification is done on a state level.

While all this may just seem like a minor hurdle to overcome, my experience last week procuring vaccine for myself and a couple of others left me wondering if this regulatory framework could hamper response efforts in an emergency situation that is already compromised by vaccine supply issues. Suffice it to say arranging a vaccination for a pediatric patient in Pennsylvania -- even when you are an infectious disease physician -- was daunting and really frustrating. The amount of paperwork the vaccinator has to fill out and the consequent amount of time one must wait for vaccination was almost prohibitive to someone as pathologically impatient as me.

In emergency infectious disease situations, bureaucratic inertia can rapidly make a tenuous situation worse and delays only benefit pathogen spread. If a yellow fever outbreak took hold in the US vaccination would be increasingly demanded and, just like during a flu pandemic, easily accessible vaccination points employing physicians, nurses, pharmacists, and other health care workers would be ideal in order to maximize vaccination coverage.

Relying exclusively on certified yellow fever vaccinators, to comply with IHR stipulations, could prove difficult in such a situation. In addition, state laws -- such as exist in Pennsylvania -- artificially restricting the age limits a pharmacist can vaccinate (because 17 year olds are somehow magically different than 18 year olds) will also pose problems as it does in every outbreak situation in which pharmacist-administered pediatric vaccination stipulations have to be waived.

I understand the real problem posed by fake yellow fever vaccinators and the black market in counterfeit yellow fever vaccination certificates, but a one-size-fits-all approach that could hamper the US ability to fortify itself against yellow fever is not optimal.

Old Viruses Never Die: A Spate of Hepatitis A

A virus has been grabbing headlines in the west coast the past several weeks and it one that is usually not on anyone's lists anymore: hepatitis A. Hepatitis A outbreaks in San Diego, Santa Cruz, and Los Angeles have garnered a lot of attention and public health authorities are stepping up measures to contain the fecal-oral spreading virus with emergencies declared in Los Angeles and San Diego. There is also concern of another outbreak in Utah.

Like I discuss in this video and this podcast, hepatitis A was a near ubiquitous virus that everyone contracted during childhood, sometimes with no to minimal symptoms. Others might experience nausea, vomiting, abdominal pain, and jaundice. However, unlike other viral hepatitis viruses (hepatitis B, hepatitis C), this virus does not have a chronic phase of infection that confers risks of cirrhosis and liver cancer. The introduction of the vaccine in 1995 and its adoption as a universal childhood vaccine in the US has dramatically reduced its incidence. However, there are segments of the population that are not vaccinated and were not naturally infected who remain susceptible. Of those susceptible, those with preexisting liver disease because of alcohol, hepatitis C (20% of those tested in the San Diego outbreak), and/or hepatitis B are particularly at risk for having a fulminant infection with hepatitis A. At least 16 people have died during the San Diego outbreak. 

Because hepatitis A  spreads through the fecal-oral route and has a 28 day incubation period it can cause large outbreaks -- the largest one occurred in 2003 in the Pittsburgh area and was linked to the now defunct Chi Chi's restaurant chain.

I would suspect that it is no accident that the San Diego outbreak has its epicenters within homeless populations. Homeless populations will, by definition, have less access to sanitary facilities for bodily functions as well as for handwashing. They also are likely of an age that did not have the ability to be vaccinated against the virus as children. Additionally, they often cluster together in shelters, encampments, or in enclaves within a city, allowing more opportunity for viral exchange. Medical interventions are also much more difficult to implement with populations that are transitory, mobile, and otherwise hard to reach.

Vaccination, immunoglobulin and sanitation are the two most important tools to end these outbreaks. The US had just 1234 cases of hepatitis A in 2014 -- a 95% decline from the pre-vaccine era -- so it is clear that humans have the capacity to put this virus down. Aggressive case finding coupled with vaccination, immunoglobulin use, and infection control -- all of which are occurring now -- to prevent further spread are what will ultimately prevail. 

Pasteurization is Still a Thing

I always say that Louis Pasteur invented pasteurization for a reason -- his reason was to prevent the hijacking and ruining of the fermentation process necessary to make alcohol. Of course, pasteurization has had a much broader application and impact than that. 

By making products safe for consumption, pasteurization is a cornerstone of food safety and a great example of how the human mind could solve a problem that was historically regarded as a mysterious fact of life. Pasteurization involves heating a substance to a degree to kill potentially harmful bacteria that may be present (either intrinsically or from later contamination). 

In recent years, there has been a (misguided, in my estimation) demand for unpasteurized products and hand-in-hand with this return to the primitive, almost as if pasteurization was designed for this very reason, have been reports of infections linked to consumption of these products. 

Once, as a fellow, I took care of a person who bought and consumed unpasteurized milk voluntarily, contracted a bacterial diarrheal illness (Campylobacter), developed Guillain-Barre Syndrome, and ended up on a mechanical ventilator with a tracheostomy. I thought the events were totally predictable and must've been something he thought about when he bought the milk but obviously the patient and his lawyer thought differently, filing a lawsuit accusing those involve with selling a "defective product" -- to me unpasteurized milk is, by definition, a "defective product."

Fast forward to last week and there were an important two items related to unpasteurized products consumption that illustrate the value of pasteurization: The first is the report of a Texas woman contracting the somewhat rare (because of pasteurization) brucellosis after drinking unpasteurized milk. In this case the strain of Brucella contracted was drug resistant making treatment more difficult. Brucellosis is a serious infection and it will be important to determine how many other preventable infections could have occurred.

The second is a Rhode Island warning about Listeria infections tied to consumption of queso fresco cheese. This type of soft cheese can be found in an unpasteurized, unsafe form and the risk of Listeria is real and can be devastating to pregnant women.

I can't fathom why people would knowingly expose themselves to unpasteurized products when other safer alternatives are readily available. I do, however, believe it is an adult's right to knowingly eat dangerous substances and face the consequences that Louis Pasteur has spared most of us from.