From Chikungunya to COVID-19
When I reflect on nearly six years of training and practice as an infectious disease doctor, one of the most natural ways I divide that time is by the series of outbreaks that have caused great human suffering but also inspired extraordinary efforts in research and innovation to alleviate that suffering. As I interact with colleagues and leadership in my hospital and city I again see a heroic response to the current threat that has occupied the majority of my thoughts for the past month. Five outbreaks stand out to me as especially definitive of my brief career as a doctor:
The first was a new infection reported in December of 2013 on the island of St. Martin in the Caribbean. Although the infection was new in the Americas, it had first been identified in Africa in southeastern Tanzania in 1952. It was from that location that it got its name — chikungunya, a word from the language of the Makonde people meaning roughly, “that which bends up.” In December 2013 my thoughts were far from the Caribbean and I doubt I’d ever heard of chikungunya. I was in my third year of internal medicine residency in Tacoma, Washington and I’d just submitted my applications for infectious disease fellowship. That was also the month that I came out to my mom, on the car ride back from our church’s Christmas Eve service, and told her I’d been dating Alex for four months. Eight months later, at the very beginning of my ID fellowship, there was probably nothing I thought about more than chikungunya.
Chikungunya is a disease caused by a virus of the same name. It’s part of an interesting group of viruses called the “arthritogenic alphaviruses,” — arthritogenic because they can cause severe joint inflammation and pain, thus the name: “that which bends up.” These viruses have all kinds of interesting names like Ross River Virus, Mayaro and o’nyong-nyong. They fall into a group called “Arboviruses” — arbovirus an amalgamation of “arthropod-borne virus.” Arthropods are insects and the insects that transmit chikungunya are mosquitos, specifically Aedes mosquitoes — Aedes aegypti, the yellow fever mosquito, and Aedes albopictus, the Asian tiger mosquito. While the Americas had long had abundant populations of both of these mosquitos, they had never had chikungunya, at least not in recent history. The virus first landed in the Western Hemisphere in an interesting location — St. Martin, an island divided between France and the Netherlands since 1648. It was likely brought to the northern French half of St. Martin by a traveler from Africa or Asia and by the end of December 2013, 66 cases on the island had been confirmed. From St. Martin it rapidly spread throughout the islands of the Caribbean. By May 2014 the first cases were confirmed in Florida.
It was at the height of this epidemic that I began my infectious disease fellowship at Walter Reed National Military Medical Center. As a new infectious disease fellow in August 2014 I saw the first confirmed chikungunya case at my hospital, a patient who had returned from a mission trip in Haiti. She had had a fever, a rash and joint pains, all the classic signs and symptoms of the illness and had a positive antibody test, confirming she had recently been infected. Thankfully, her symptoms were already improving by the time I evaluated her.
A big part of any medical training program, residencies and fellowships, are presentations on interesting cases given to peers and superiors. So I took the chikungunya case I’d seen and ran with it, presenting it at my fellowship’s weekly Friday conference. Subsequently I would present it to the Greater Washington Infectious Disease Society, GWIDS, at Washington Hospital Center in the District of Columbia. I followed with interest the work on vaccine development that some of my attendings were involved in at the Walter Reed Army Institute of Research. On a personal level, reminiscing on my interactions with chikungunya take me back to the first few months that Alex and I lived together, just after arriving in Washington, DC. Alex suffered through being an audience of one as I practiced my presentations multiple times and will still sometimes jokingly rattle off the name “Aedes albopictus.” The chikungunya outbreak would eventually affect 43 countries and territories in the Americas, infecting more than 2.9 million people and killing 296 by the end of 2016. The virus continues to circulate in the Americas.
Chikungunya was not the only pestilence that passed into the human species in December 2013. In the small village of Méliandou in the West-African nation of Guinea an 18-month-old boy fell ill and died. Soon his mother, sister and grandmother became ill and also died. It is thought that perhaps the source of the virus were Angolan free-tailed bats which were common in the area. The outbreak simmered along and it was not until March that Guinean health officials first announced the outbreak of a mysterious hemorrhagic fever. The cause was later confirmed as Ebola. Later in March the first Ebola cases were confirmed in Liberia. By the end of the month the WHO announced that there had been 112 cases and 70 deaths. In May the first cases and deaths were reported in Sierra Leone. In late summer the number of cases began to increase drastically and on August 8th the WHO declared the Ebola outbreak a Public Health Emergency of International Concern. September saw the first Ebola case diagnosed in the U.S. at a Dallas hospital although a handful of evacuated Ebola patients had already received care in American hospitals prior to the Dallas case.
While chikungunya defined the beginning of my infectious disease fellowship, my thoughts rapidly turned to Ebola. I remember sitting outside, having dinner with Alex on a warm evening in D.C., talking about the fact that I expected to see an Ebola case in the coming months. Ebola held something of a mystique for me as I had read Richard Preston’s “The Hot Zone,” while in middle school about Ebola and closely-related viruses and it was that book which piqued an early curiosity about infectious diseases for me. Caring for an Ebola patient was something I never would have expected prior to the West African outbreak. The closest I ever ended up getting was looking across Rockville Pike from Walter Reed to the National Institutes of Health hospital where a nurse who had been infected in Dallas was hospitalized. In early October U.S. troops began deploying to Liberia in Operation United Assistance to help combat the outbreak. Alex will never let me live down the fact that without first talking to him I sent an email to a higher-up begging to be sent to Liberia to be part of the operation. I don’t think I really expected to get an affirmative answer and I was correct — I was advised to continue my training in the U.S. By October the number of new cases began to decline in Liberia. New cases began to decline in Guinea and Sierra Leone by December. The outbreak was not declared over until June 2016 with 28,616 cases and 11,310 deaths eventually reported. In May of 2017, during the month I spent rotating at a hospital in the Ghanaian capital, Accra, I had the pleasure of meeting Liberian doctors who had cared for patients in the midst of the epidemic years earlier — after hearing their stories I could not help but view these men as true heroes. Looking back on the epidemics I’ve encountered in recent years, Ebola stands out to me as being the most horrific, at least until COVID-19.
Next came a virus with a number of similarities to chikungunya which was first reported to be circulating in northern Brazil in March 2015. This was also an arbovirus, transmitted by the same mosquitoes that transmit chikungunya, it was also first described in Africa after being isolated from a rhesus monkey in a forest in Uganda in 1947 and in most people the illness it caused was characterized by a fever and a rash. But some important differences also existed. While chikungunya is an alphavirus, this was a flavivirus, the same family of viruses to which the yellow fever and dengue viruses belong. This virus was quite unique being the only arbovirus, a group of greater than 500 viruses, which could be transmitted sexually. Most importantly and devastatingly, this virus could cause severe birth defects in babies born to mothers who had been infected. The virus was Zika, named after the forest in Uganda where it was discovered. While for decades Zika was a rather obscure virus circulating in parts of Africa, in 2007 the first major outbreak outside of that continent occurred in Micronesia on the Island of Yap. Subsequent outbreaks occurred in French Polynesia, New Caledonia and the Cook and Solomon Islands. Within months after this new illness was described in northern Brazil, a spike in cases of microcephaly (babies born with an abnormally small head size due to abnormal brain development) were reported among women who had been afflicted with Zika during their pregnancies. During the remainder of 2015 the virus spread throughout many other countries in South and Central America and the Caribbean. In July 2016 the first cases of locally-transmitted Zika occurred in Florida. I never saw a patient with Zika. In travel clinics I counseled many patients to avoid conception during and in the months after returning from areas with Zika transmission. Between May 2015 and December 2016 just over 700,000 cases of Zika were reported in the Americas. Interestingly, a later study on the genetic diversity of Zika in the Americas suggested that the virus likely arrived in Brazil between May and December of 2013. So it’s possible that all three of the major outbreaks that defined my time as an infectious disease fellow started in December 2013.
In August 2017 I arrived in El Paso, Texas to begin work at my current hospital. I made it through nearly two years without any direct interaction with a new outbreak or epidemic other than seasonal influenza. That all changed the week of Independence Day 2019. That week I evaluated a patient who had had high fevers, a runny nose, a cough and diarrhea for a few days before developing a rash with reddish spots starting on the face and trunk and spreading to the extremities. I performed a test on this patient, confirming the first measles case in El Paso in a quarter century. The last case of measles in the El Paso area had been diagnosed in 1993. This was the first completely preventable outbreak I had ever dealt with. From the beginning of the outbreak I assumed that it might not be all that bad as most of the El Pasoans I knew seemed to be reasonable people (read not anti-vaxxer) and immunizations are mandatory for members of the U.S. military. This assessment turned out to be correct with only six cases in total diagnosed prior to the outbreak being declared over. Our very small outbreak in El Paso allowed me to get a taste of what was going on on a much larger scale throughout the U.S. in 2019, with 1282 cases of measles confirmed, the greatest number of cases since 1992.
Which brings me to the current pandemic with Johns Hopkins University currently reporting 2,240,191 confirmed cases and 153,822 deaths from COVID-19 worldwide. Our current situation seems worse by orders of magnitude compared to everything else I’ve seen during my short career. But my experience working with dedicated doctors, nurses, researchers, epidemiologists and public health experts, and many other ancillary medical staff, gives me great hope that humanity will overcome this as well.
