There are five hepatitis viruses (designated A, B, C, D & E) and they all share two things in common:
And that's where the similarities end. In the family tree of all the viruses that exist on the whole planet, these 5 viruses are barely even related to each other! In fact, hepatitis C virus is more closely related to Dengue Virus and Zika Virus then it is to hepatitis B virus! Hepatitis A virus is more closely related to poliovirus (the virus that causes polio) then it is to either hepatitis B or C viruses. Hepatitis D virus can only infect people who are already infected with hepatitis B virus (it piggybacks on to hepatitis B virus to infect the cells of humans). Hepatitis E virus is a distant relative of hepatitis A virus, but it is more closely related to the virus that causes Rubella then it is to hepatitis A virus. And things don't get any simpler after this...
There are vaccines available against hepatitis A and B, but none against hepatitis C virus. There is treatment for hepatitis C virus infection that is very effective at curing the infection, however there is no cure for hepatitis B virus infection. The current treatments for hepatitis B virus infection are similar to HIV antiretroviral drugs, in that they just 'lock up' the virus, they don't eradicate it from the infected persons system, meaning that, like for HIV infection, life long disease monitoring and therapy is neccessary. Without treatment, hepatitis B and C cause a chronic infection that leads to severe liver damage, ultimately causing liver failure and liver cancer. Viral hepatitis is now the seventh leading cause of death world wide, and hepatitis C virus alone kills more people annually than HIV/AIDS.
So, I guess the title above is probably a little misleading, because the hepatitides (plural of hepatitis) are really not that easy at all...
The first of the hepatitis viruses I will discuss in more detail is hepatitis C virus (HCV). HCV is of the family Flaviviridae, (this family also contains members West Nile Virus, Dengue Virus, Zika Virus & Yellow Fever virus) in the genus Hepacivirus. HCV is a bloodborne virus and it can be transmitted through unsafe medical procedures (e.g. using unsterilised equipment or unscreened blood products), unsafe tattooing or piercing (e.g. in prison or other places where needles or ink pots may be reused), sharing drug injecting equipment (e.g. using a needle or syringe after someone else has already used it, using the same spoon as someone else to mix up, etc) and it may also be transmitted sexually, but this is much less common, is not fully understood and is related to specific sexual practises or circumstances (e.g. sexual transmission is more likely between men who have sex with men, if another sexually transmitted infection (STI) is present, if recreational drugs have been taken or when sex may involve mucosal trauma). Depending on the exact population of people (i.e. the genetic make-up, gender & age of the group), for roughly 25% of people who become infected with HCV, they will naturally clear the infection on their own, within 6 months of being infected, without any treatment. However, for the other 75%, they develop a chronic infection that, withouth treatment, slowly causes damage to the liver ('fibrosis') which eventually causes liver failure and liver cancer.
The best estimates are that there are 130–150 million people infected with HCV around the world at the moment, which compared to only 36.7 million people infected with HIV, gives you an idea of how prevalent this disease is. The infection caused by HCV was known as "Non-A, Non-B hepatitis" up till 1989, when HCV was first discovered. HCV isn't commonly sexually transmitted, like HIV is, yet there are four times as many people infected with HCV then there are with HIV. The prevalence of HCV, along with the fact it was only discovered in 1989, raises a few questions. First, how did so many people become infected with HCV? For how long was HCV spreading, unknown, through populations of humans before it was discovered? And where did this virus first come from? I hope you are as intrigued by these questions as I am, because I will begin answering them in subsequent posts, so stay tuned for the next instalment!
Many people are aware that Human Immunodeficiency Virus (HIV) originated in monkeys, however there is much more to this fascinating and deadly story of transmission. This was a situation where the ‘perfect storm’ was created, and it allowed this virus, which is almost harmless to monkeys, to become one of the deadliest viruses in human history. It’s now widely agreed by scientists that the origin of the HIV epidemic was a place in the Democratic Republic of Congo, called Kinshasa (Worobey, 2008), which at the time was the capital of Belgian Congo, in Central Western Africa. However this story really began further up the Sangha River system in Cameroon, where sometime between 1900 and 1920, a monkey virus, called Simian Immunodeficiency Virus (SIV), was first transmitted from a monkey to a human, from what is probably the result of hunting and eating Pan troglodytes troglodytes chimpanzees (Gao, 1999, pictured above).
SIV had probably been infecting these chimps for a long time, in the order of hundreds of years (Sharp, 2011), before it jumped to humans. But it’s estimated only 6% of the chimps were infected with it, and it doesn’t affect their health significantly. Humans didn’t start hunting these chimps to eat their meat until guns were easily accessible (Peeters, 2002), which was only at the beginning of the 20th century for people in Cameroon. These two facts explain why SIV didn’t jump from chimps to humans until before the 1910’s or 1920’s. There is strong evidence to suggest that SIV was only transmitted from chimp to human on four single occasions, which is a scary prospect when we think of all the damage those four single events caused! After SIV made the leap from chimp to human, it adapted itself to taking over its human host's immune system and also became able to be transmitted from human to human. One of these adapted SIVs became what we now call HIV-1, group M, and it’s the virus that spread around the world, eventually infecting 70 million people and killing 35 million people so far (WHO). Between 1920 and 1940, HIV crept up the Sangha River system with the ferries that moved workers harvesting rubber from Cameroon to Belgian Congo, eventually making it to Kinshasa.
HIV transmission started to take off during the 1940’s and 1950’s, when the Belgian Congo and neighbouring French Middle Congo underwent extensive urbanisation and various development programs initiated by the colonial administrations, such as extensive construction of railways across the countries (Faria et al, 2014). The populations of both Kinshasa and neighbouring Brazzaville underwent rapid expansion at this time, with people from the surrounding areas flocking to the capitals to work on the urbanisation projects. With more human hosts to infect in the form of population growth, and the ease of mobility afforded by the construction of railways and river ferries, HIV began to spread far and wide across the Belgian Congo (Faria et al, 2014). During this period, it’s likely that sexual transmission between humans accounted for some of the spread of HIV in Kinshasa and the Congo, however it was most probably boosted by things like the advent of machine-made glass syringes that happened at this time, which allowed affordable mass administration of medicines (Drucker, 2001). These syringes were used repeatedly and weren’t sterilized properly, if at all. The French and Belgian colonial administrations both tackled many diseases in their colonies by administering medicines in these syringes, which although was a nice gesture, probably significantly expedited the spread of HIV at that time.
In 1960 both French Middle Congo and Belgian Congo gained full independence, becoming the Republic of the Congo (RC) and the Democratic Republic of the Congo (DRC) respectively. Very shortly after the DRC and RC gained independence, the United Nations (UN) created the United Nations Operation in the Congo (ONUC). Due to a scarcity of university educated native Congalese people to take up professional positions in ONUC, the UN recruited French speaking professionals from all over the world, and in particular Haitians heeded this call. There was a large movement globally of black African expatriates and activists returning to Africa during this period of decolonization. This movement, coupled with French being the main language spoken in Haiti, and many Haitians being well educated, vastly explains the influx of Haitians to the DRC that began in 1958 (Jackson, 2014). Throughout the 1960’s, many Haitians who had been working for ONUC in the DRC returned to Haiti. And they had bought a deadly passenger back with them; HIV (Gilbert, 2007).
There are still a few conflicting theories as to how HIV spread from Haiti to the rest of the world and when this spread occurred. There was a rather brutal theory that was perpetuated in the media for a long time that a man called Gaétan Dugas (pictured), who was an international flight attendant and allegedly ‘a promiscuous gay man’, was the Patient Zero who introduced HIV to the United States, however this has been totally ruled out since then by testing a blood sample collected from him before he passed away. Haitian migrants to Miami in the 1960’s were also initially blamed for the spread of HIV to the US (CDC, 1982), however the study that ruled Dugas out as Patient Zero identified New York City as the earliest location in the United States where HIV landed and was spread. So the Haitian migrants to Miami could have bought HIV with them, but they probably weren’t responsible for the first transmission in the United States. Many more gay men (and Men Who Have Sex with Men [MSM]) like Gaetan Dugas were blamed and vilified for bringing HIV to the United States from Haiti as well. It had been quite common for MSM in the US to go on holidays to Haiti during the 1960’s and 70’s. In Haiti, many American men had sexual relations with local Haitian men (Farmer, 1999), so it’s likely that multiple men from the US did bring HIV home with them from Haiti in the 1960’s. However sex tourism in Haiti wasn’t just limited to MSM, so it’s possible that heterosexual people also bought HIV home with them from Haiti. In any case, none of these people knew HIV existed, much less that they were at risk of infection and potentially transmitting it to other people. To attempt to pin point and blame particular people for bringing HIV in to the United States is both unfair and pointless, however studying the patterns of how HIV was transmitted on a population level does help to understand how the epidemic spread. Regardless of how HIV got to the United States, it had well and truly arrived and was spreading locally throughout the 1960’s and 1970’s, especially among MSM. HIV was also starting to become transmitted among people who inject drugs (Masur, 1981) and people who required blood products such as haemophiliacs (CDC, 1982).
In 1981, the first cases of rare lung infections (what is now recognized as a sign of AIDS) were reported in Los Angeles among previously healthy gay men (CDC, 1981). For most people who become infected with HIV, if they don’t receive treatment, AIDS develops between 10 and 15 years after they first became infected with HIV. This is one of the reasons it is known that the people who first developed AIDS symptoms in 1981 in the US would have probably been infected with HIV in the early 1970’s or late 1960’s. In 1982, the term AIDS was first used to describe the syndrome characterized by these rare infections and rare cancers (CDC, 1982), and cases of AIDS were reported in Europe (Francioli, 1982) and Uganda (Serwadda, 1982). In 1983, they identified HIV as the probable cause of AIDS (Barre-Sinoussi, 1983), and all the major routes of transmission had been identified (in 1983 the CDC listed the routes as mother to child before during or shortly after child birth, sexual contact, blood transfusion/blood products, and sharing of injecting equipment). In 1985, a commercial blood test was first licensed by the FDA in the US which could detect signs of HIV infection (antibodies against the virus) in people’s blood (Roberts, 1994). Blood banks began to screen the US blood supply from this time. By the end of 1985, HIV was truly global, as every region in the world had reported at least one case by that time (Veronika, 2003), and its global conquest still continues today.
In 1985 when the world finally became aware of this virus that had been spreading unnoticed among humans for more than 80 years, people rushed to find the source of the outbreak. Due to the large number of people infected with HIV in Haiti, Haitian people were demonized and blamed for HIV in the US, as were gay men and MSM, sex workers and people who inject drugs. In the overall story of the spread of HIV, not only is this blame and demonization unhelpful, it’s also really unfair. None of these people knew HIV or AIDS even existed, much less that they were infected with it. And little did the French & Belgian colonialists realize, when they took up residence in the Congo, that they were about to set off a chain of events that would lead to one of the deadliest pandemics in human history!
In the big picture, it’s arguable that the single largest factor that contributed to the explosion of HIV globally was the failure of leaders and policy makers to introduce prevention measures when they first found out how HIV was being transmitted (Australia was one of the exceptions to this, and as a result had many fewer HIV infections than in the rest of the world, detailed in the documentary Rampant). In 1983, all the routes of transmission were known, and in 1985 a commercial test was available for HIV detection. However, the majority of prevention measures implemented at that time consisted of simply telling people not to inject drugs or have sex, which we now can see was unrealistic and totally useless. It’s been proposed by several academics, researchers and field workers (notably Elizabeth Pisani in her book Wisdom of Whores) that ideology & bureaucracy were the biggest reasons that the two simplest things that stop HIV from spreading (supplying condoms and clean injecting equipment) were not made widely and easily available straight away when the HIV/AIDs epidemic was first discovered. Pisani posits that had these two things been handed out en masse from 1983 onwards, HIV would have been but a blip on the global health radar. We’ll never know if she was right, and if that was why HIV became the global issue that it still is today. But we do know that we can learn lessons from these events and hopefully not repeat the same mistakes again in the future, when the next deadly virus comes along!
This blog is written by Sofia Bartlett; scientist and curious human being. Her bio can be viewed here.
© Sofia Bartlett and Rogue Transmissions, 2017. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author is strictly prohibited.