For there to be hepatitis D, there must also be an infection with the virus that causes hepatitis B. Coinfection with both viruses (HBV and HDV), which currently affects 5% of people with hepatitis B, according to data from According to the WHO, it is considered the most serious form of chronic viral hepatitis due to its rapid progression to liver cancer or death due to liver causes. And it is picking up.
“Hepatitis delta virus (HDV) requires the envelope of a part of the structure of hepatitis B virus (HBV) and, therefore, if there is no active infection by hepatitis B virus, there is no infection. there may be a superinfection or a coinfection by delta virus ”, explains Dr. Federico García, head of microbiology at the San Cecilio hospital in Granada and spokesman for the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC).
Although it is true that hepatitis D is not unknown at all, since it hit hard in the 1980s, affecting patients with hepatitis B with a prevalence of 20%, mainly due to injecting drug use, there is currently an unexpected worldwide rebound after being considered almost eradicated in the 1990s.
Hepatitis D is "the great forgotten", regrets the microbiologist. "This hepatitis is forgotten because until now there have been no effective treatments for it, as there have been for other hepatitis," explains the doctor, who considers that "efforts have been more focused" on hepatitis C and B, than on these moments "cure 95% of patients."
HDV infection, recalls the WHO, can be prevented by vaccination against hepatitis B, but therapeutic success rates "are low."
"Until now, the only treatment available for delta hepatitis was one based on interferon, with many adverse effects and very little efficacy compared to others," says the microbiologist. However, there is already a new drug with greater efficacy against the disease. This was also pointed out by the Spanish Society of Digestive Pathology at the end of July after one of its congresses in León.
Interferon “is successful in suppressing viral and hepatic activity only in a minority of treated patients. However, there are new pharmacological advances with greater efficacy and tolerance against the disease, as is the case with bulevirtide”. This medicine, the note stated, is already authorized by the European Medicines Agency (EMA) and by the American Medicines Agency (FDA), but not by the Spanish Agency for Medicines and Health Products (AEMPS). "It is urgently needed that Spain approve new therapeutic options against hepatitis D and that the new generations of gastroenterologists begin to look for it in all patients with B virus infection", settled the note.
In Spain, as confirmed by the AEMPS to this newspaper, this antiviral is already authorized, since once the EMA authorizes it, it is automatically authorized in all the Member States, but it has not yet passed the pricing process and that is why that, until now, has not been marketed. For the fixing of prices in new drugs, sources from the agency explain, therapeutic positioning reports have to be carried out, which normally take between six and twelve months to do. The EMA authorized the antiviral last October.
"As soon as this happens, the drug will be available for use in all the autonomous communities," recalls Dr. García.
The vaccine against the virus that causes hepatitis B is very effective, but the degree of protection "is insufficient" in Spain, says a SEIMC report, since "systematic vaccination of the population did not begin until the 1990s and a significant portion of those over 30 are not immune.”
The same report estimates that more than 250 million people worldwide are chronically infected with the virus that causes hepatitis B. Hepatitis B is transmitted through blood, saliva, or semen. “In Spain, the prevalence of active infection is currently estimated to be between 0.2% and 0.5%” with a much higher proportion among migrants, people who inject drugs, relatives of carriers and people with HIV. This means that, in our country, there are between 90,000 and 200,000 people infected with this virus. "Superinfection with the virus that causes hepatitis D is observed in 4% of carriers of chronic HBV infection." The same document notes that there is "enormous variability between countries" in the rate of superinfection, "reaching up to 70% in Nigeria."
One of the main reasons, according to García, is that "much more is being diagnosed." “Because there are effective treatments, much more work is being done to diagnose patients who are infected,” she notes. The other reason has to do with migrations. "In Spain, the vast majority of cases that are diagnosed are imported cases," she confirms. Since injecting drug use was reduced in the 1980s, "virtually new delta hepatitis cases are very limited."
Diagnosing all patients who are infected, treating and curing them is the main way to prevent transmission and eradicate it again. According to a SEIMC report on the future of infectious diseases and its presence in the year 2050, if specific measures such as screening, vaccines and treatments are implemented, it is very possible that type A, B and C hepatitis, and therefore type D, will disappear in Spain.
Hepatitis caused by emerging viruses, however, are the most worrying. “We are seeing more and more new agents that have never been diagnosed or that have not been related to hepatitis and that, in the end, are responsible for these viral hepatitis symptoms,” adds García. “Recently in Spain the first three cases of hepatitis due to a new virus called Orthohepevirus C have been described and this is an example of what can happen, especially with zoonotic viruses. Viruses that infect animals and adapt to humans”, she concludes.
However, the emergence of new viruses has nothing to do with the cases of childhood hepatitis, which have recently claimed two lives in Spain. “The hypothesis that it is a zoonosis or a new virus is ruled out. There are other hypotheses, such as the role of SARS-CoV-2, the role of adenovirus F41, or the role of other adeno-associated viruses”, concludes the expert.