Drowned in the din of the incessant political chatter and finger-pointing is a critical health crisis. The rapidly burgeoning hepatitis A epidemic in California is unprecedented and underreported.
Scope of the Problem
I would like to define the scope of the problem before explaining the virus. This way if your interest is not piqued, you can stop reading.
The largest number of Hepatitis A cases in the United States occurred in 1971, almost 60,000 cases reported
Widespread vaccination for specific populations was recommended in 1996 by the CDC. As a result by 2010, 1670 cases were reported to the CDC. Basically the incidences went from 60,000 to 1600 give or take a few.
This data is taken directly from CDC website, in 2011 1398 cases of Hepatitis A were reported for all of United States
Here is exactly the same information but graphically represented
Fast forward 2017, a large unprecedented outbreak of hepatitis A is ongoing in California. As of the last update dated October 27, 2017 California Department of Public Health has reported 633 cases, 416 hospitalizations and 21 people have died from hepatitis A. putting it into perspective almost 1400 cases of hepatitis A were reported in 2011 for the entire country, in 2017 633 cases were reported in California alone. Mind you this is a vaccine preventable disease and vaccination caused impressive declines as you can see in the graph above.
Current data can be accessed at this website
Here is the breakdown by California jurisdiction of hepatitis A cases
To summarize, a vaccine preventable disease that was declining in incidence throughout the nation is making resurgence in California. The numbers are impressive.
The Hepatitis A virus
I will try not to get too technical here and only provide context for the next section. For those whose curiosity can’t be satiated by this brief description Google is your best friend.
Hepatitis A is acquired through the mouth, replicates in the liver and is spread all over the body within 10-14 days. The word hepatitis simply means inflammation of the liver. The virus has a proclivity to living and replicating within the liver cells and is named appropriately. Within the first 2 weeks the virus has replicated to large numbers, is circulating in the blood and is excreted via bile into the feces. Massive numbers of virus, several times more than the bloodstream are present in the feces. The virus in the feces can then be acquired by another human being through the mouth, thus completing the cycle of transmission.
In most cases individuals who were symptomatic exhibited jaundice or dark urine fever decreased appetite abdominal discomfort. Most individuals do not have illness lasting greater than 2 months although 10-15% could have relapsing illness for up to 6 months. This infection can have rare but severe clinical complications including life-threatening liver failure and kidney failure.
So what is happening in California?
The spread of this infection requires one critical element. It requires availability of infected feces from a patient to be transmitted to an uninfected individual via oral route. This can be through ingestion of contaminated food or water or by contact with objects that have infected feces.
Increasing homelessness leads to decreasing sanitary facilities. Homeless people do not have access to adequate toilet facilities or handwashing. This is the crux of the problem in California. Without access to toilet facilities and handwashing the spread of this infection continues to other individuals that have not been vaccinated. A lot of homeless people have underlying liver disease on account of alcohol and drug use. In individuals who have underlying liver disease having hepatitis A is like pouring gasoline on a fire. These individuals have a higher risk of severe inflammation and consequently death.
In addition homeless people may or may not have mental illness, many suffer from distrust of government and public health authorities. Routine vaccination of all homeless individuals is hoped to stop the spread of this disease process, however this is an uphill battle. Reaching the entirety of the homeless population which is typically transient renders any outreach efforts even more difficult.
The burgeoning hepatitis A outbreak in California leads me to draw a few rational conclusions that are grounded in epidemiology.
The outbreak has occurred because of the breakdown of public health infrastructure, an ever increasing homeless and transient population and decreased focus on public health measures designed to prevent spread of communicable diseases such as hepatitis A. The incidence of homelessness and illicit drug use is directly proportional to the risk for transmission. The only way to stop the spread of this disease is to get enough individuals vaccinated so that the high risk population is very low. Provision of sanitary toilet facilities with handwashing readily available to homeless individuals is also critical. Decreasing homelessness and drug use although great in theory is unlikely to actually happen. The epidemic probably highlights an increased homeless population, none of which have received the hepatitis A vaccine. Intravenous drug users and men who have sex with men are more likely to be exposed to infected feces and also have more underlying risk factors such as chronic liver disease.
I expect this outbreak to continue unabated until the public health measures, sanitary facilities, widespread vaccination, effective outreach all reach critical mass to stop the transmission of this disease process.
The changing demographic in California makes implementation of all these measures very challenging. Although this is a public health issue, the underlying shifting political focus away from public health towards other priorities has contributed in no small measure.
This is the second largest outbreak of hepatitis A since the vaccine was approved in 1996 leading to the governor finally declaring a state of emergency. Having to declare a state of emergency for a vaccine preventable illness in a first world country should really bring all of us pause for thought as to how we came to this point.
The hepatitis A strain circulating in San Diego, Los Angeles and Santa Cruz Counties is unique and is different from that found elsewhere in the country. This allows authorities to pinpoint the spread of this unique strain to rest of the Counties and evaluate if the epidemic is spreading geographically. As of November 01, 2017, one individual in Riverside County was confirmed to have this unique strain of hepatitis A and this individual had no risk factors, was not homeless and did not use injection drugs. This means that the penumbra of infection is likely to spread to individuals that do not have risk factors and will spread beyond what we are seeing currently.
In conclusion, the state of California needs to pay more attention to its specific social and demographic issues and apply concentrated public health measures to better control this epidemic. The Department of Public Health themselves have admitted this is likely to take a long time. I suspect that in the meantime it will continue to spread to other unaffected Counties and to individuals that do not have easily perceivable risk factors. Public health resources in California have been stretched to breaking point and putting Humpty Dumpty back together again will take more than optimism.