Alzheimer's disease is a neurodegenerative disease that mainly affects memory but also has an impact on other cognitive functions, for example those related to language, reasoning and learning. Alzheimer's disease generally leads to a loss of independence. It is one of the leading causes of...
Amoebiasis is the third deadliest parasitic disease in the world. Around 10% of the world’s population is thought to be infected by parasitic amebae from the Entamoeba genus, the most pathogenic being Entamoeba histolytica, the agent of amebiasis . The large majority of infected persons often...
Antibiotics are drugs used to treat infections caused by bacteria. Bacteria can become resistant and no longer respond to these drugs: this phenomenon is known as antibiotic resistance and resistant bacteria. In Europe, the European Center for Disease Prevention and Control (ECDC) estimates that...
Aspergillosis is a term that refers to any infection caused by fungus (mold) belonging to the genus Aspergillus, whose spores are present in the air and breathed in by people every day. While Aspergillus is entirely harmless for most individuals, the spores can cause various...
Autism is a neurodevelopmental disorder (NDD). It appears in early childhood (before the age of 36 months) and affects children's developmental areas in different ways and to different degrees. In most cases, its effects impact on autistic individuals' level of independence and social...
Avian influenza is a viral disease that affects birds, with a very high mortality rate in farmed birds such as chickens and geese. Although most avian viruses do not infect humans, some subtypes are able to cross the species barrier, such as the H5N1 virus, which is pathogenic for humans and is...
Buruli ulcer is a disease caused by a bacterium that multiplies in skin and is currently reported in 33 countries, mostly in tropical regions. Although not fatal, it can lead to permanent disabilities, imposing a heavy burden on both patients and society.
Fungi (yeast) of the Candida genus can cause superficial infections affecting the mucous membranes or skin, and invasive infections, either localized to one organ or generalized throughout the body. Of the 200 known species of Candida, around twenty are responsible for human...
Cervical cancer is the second most common form of cancer in women worldwide. It occurs exclusively after infection with viruses belonging to the papillomavirus family. Nearly 500,000 new cases and 250,000 to 300,000 deaths are recorded each year. A preventive vaccine that offers protection...
Chagas disease is a neglected parasitic infection. It is transmitted by a hematophagous insect and mainly affects the American continent, where over 100 million people are exposed to it. In some cases, the infection takes a chronic form, causing irreversible lesions and death. Every year, Chagas...
The chikungunya virus, transmitted by Aedes mosquitoes, AKA tiger mosquitos, causes severe, and sometimes persistent, joint pain in affected patients. Both Aedes albopictus and Aedes aegypti mosquitos transmit the virus. Existing treatment options are purely...
Chlamydia is a sexually transmitted infection (STI) caused by the bacterium Chlamydia trachomatis. It is the most widespread bacterial STI, affecting both men and women, and is particularly common among young people. In many cases, the infection is asymptomatic and...
Cholera is an infectious, diarrheal, strictly human disease caused by bacteria from serogroups O1 and O139 of the species Vibrio cholerae. The bacillus was initially observed by Pacini in 1854, before being isolated in 1883 in India by Robert Koch. V. cholerae bacteria of serogroup O1, biotype...
In December 2019, an outbreak of pneumonia, then described as apparently viral and of unknown etiology emerged in the city of Wuhan, in the Chinese province of Hubei. On January 9, 2020, the Chinese health authorities and the World Health Organization (WHO) officially announced the discovery of...
Cryptococcosis is a severe fungal infection that occurs in immunocompromised patients. The most frequent clinical form of infection is meningoencephalitis, which is fatal in the absence of treatment.
Cystic fibrosis is the most common severe hereditary genetic disease in the Caucasian population. It is an autosomal recessive inherited disease of the CFTR gene. This fatal condition is characterized by respiratory impairment that affects approximately one in every 2,500 births in Europe and...
Dengue, also known as dengue fever, is a viral disease transmitted to humans by mosquitoes of the genus Aedes. The incidence of dengue is currently increasing dramatically, and it is now one of the diseases said to be re-emerging. WHO estimates the annual number of cases to be 50...
Diphtheria is a disease caused by several Corynebacterium species in the diphtheriae complex. Diphtheria typically manifests as a respiratory infection that causes impairment of the central nervous system, the throat and other organs, resulting in death by suffocation....
The Ebola virus causes high fever and bleeding that can often prove fatal. The death rate varies between 30 and 90% depending on the outbreak and virus species. Bats are believed to be the natural reservoir of the Ebola virus. The virus was first discovered in 1976 following outbreaks in Sudan...
Escherichia coli (E. coli) is a bacterium that lives in the digestive tract of humans and warm-blooded animals. Most strains of E. coli are harmless, but a small number can lead to illness for humans. One such strain is enterohemorrhagic E. coli (EHEC), which causes...
Infections with group A and B Streptococcus (respectively Streptococcus pyogenes and Streptococcus agalactiae) are frequent. The two bacteria are part of the commensal flora and they only cause symptoms in certain conditions (opportunistic pathogens) or in people at...
Hearing loss is a decrease in auditory acuity. It is the most common sensory deficit in humans and can occur at any age, and at various levels of severity. Initially a genetic approach was used to identify the genes responsible for early-onset hearing loss in humans. Studies of these genes then...
Although there have been considerable advances in treatment, HIV continues to be a serious problem, especially in the terminal phase of the disease in the absence of treatment, known as AIDS. HIV/AIDS is currently one of the leading causes of death worldwide for adolescents and women of...
HTLV-1 was the first human retrovirus to be discovered – it was isolated in 1980 by Robert Gallo's team in the United States. In 5% of cases, infected individuals go on to develop leukemia or a myeloneuropathy. Ten to twenty million people are infected by the virus worldwide. The major areas of...
Influenza is an acute contagious respiratory infection caused by influenza viruses, which are unique due to their vast genetic variability. It is a public health issue because of the annual seasonal outbreaks that affect 2 to 8 million people in France every year, with influenza-associated...
Kaposi’s sarcoma (KS) is caused by infection with human herpesvirus-8 (HHV-8). Although KS can occur independently of HIV/AIDS, it frequently develops in individuals co-infected with HIV and HHV-8. The AIDS epidemic has therefore led to a huge rise in the number of cases of Kaposi’s sarcoma,...
Lassa fever is a hemorrhagic disease caused by an arenavirus known as Lassa virus. It is endemic in several countries in West Africa, where it infects 100,000 to 300,000 people every year, claiming 5,000 to 6,000 lives. There is currently no vaccine for this virus, which represents not only a...
Legionellosis is a collective term for diseases caused by Legionella bacteria, including the potentially fatal Legionnaires' disease. The most common species, Legionella pneumophila, causes a severe lung infection. The recent emergence of the disease can be explained by the affinity of...
Leishmaniases are parasitic diseases causing severely debilitating cutaneous or visceral lesions, which can prove fatal if left untreated. They are caused by various parasites of the genus Leishmania, transmitted by bites from insects commonly known as sandflies. Every year, 700,000 to...
Leprosy is a chronic bacterial condition and a neglected tropical disease. Although effective treatment exists, thousands of new cases are recorded every year. Leprosy remains a major public health issue for several countries in Africa, Asia and Latin America.
Leptospirosis is a bacterial disease found throughout the world. Its main reservoirs are rodents, particularly rats, which excrete the bacterium in their urine. In humans the disease may lead to kidney failure, and even death in 5 to 20% of cases.
Listeriosis is a severe foodborne infection caused by the bacterium Listeria monocytogenes. It can cause septicemia and central nervous system infections. In pregnant women, it can cause miscarriage, premature delivery or serious neonatal infection. This is a relatively rare disease,...
Lyme disease, also known as Lyme borreliosis, is a tick-transmitted zoonosis. It is the most widespread vector-borne disease in the whole of the northern hemisphere. Its incidence continues to rise at global level due to myriad demographic and environmental factors, including climate change.
Malaria is a disease caused by parasites of the Plasmodium genus. According to the World Health Organisation (WHO), malaria affected approximately 241 million people worldwide in 2020 and caused 627 000 deaths. The situation is all the more worrying because of the development of parasitic...
Meningitis is an infection of the brain membranes – or meninges – caused by several types of virus, bacteria and fungi. Meningococcus (another name for the Neisseria meningitidis bacterium) is one of the main causes of acute meningitis. Despite treatment, meningococcal infections have a...
A new respiratory virus emerged in Saudi Arabia in 2012. It was named MERS-CoV, or Middle East Respiratory Syndrome Coronavirus, and it affects the respiratory tract, causing fever and a cough and proving fatal in 30% of cases. The virus has since been reported in several countries throughout...
Mitochondrial diseases are a series of genetic disorders that are often hereditary. It is thought that there are around 200 new cases in France each year. Mitochondrial diseases can be life-threatening, and there are currently no available curative treatments. The symptoms are highly...
Monkeypox is a disease that was initially present in animals, especially rodents in Africa, and now circulates among humans – it is referred to as an emerging zoonotic disease. It presents as a mild form of smallpox, with less severe symptoms and a lower case-fatality rate (the number of deaths...
Parkinson’s disease is a chronic degenerative disorder affecting almost 200,000 people in France. It is the second leading cause of motor disability in adults after strokes and is characterized by the gradual loss of certain neurons in the brain. Contrary to a common preconception, Parkinson’s...
Plague is still rife in Africa, Asia and America, is counted among the world's re-emerging diseases, and is subject to international regulations. WHO is reporting an increasing number of cases in some regions. During the 20th century, the use of antibiotic treatments and strengthening of public...
Poliomyelitis is a highly contagious disease caused by a virus (the poliovirus), which invades the nervous system and can lead to irreversible paralysis in just a few hours. This disease has been preventable since the 1960s thanks to effective vaccines. A global program, aiming to eradicate the...
Rabies remains responsible for tens of thousands of human deaths each year. The burden of the disease is borne mainly by Africa and Asia where the dog is the main vector of transmission to humans. In Europe, bats can be infected by certain lyssaviruses, different from that of the dog,...
Salmonella is a genus of the Enterobacteriaceae family that is responsible for cases of foodborne illness, also known as salmonellosis. Most Salmonella bacteria are hosted in the intestines of vertebrates. They are usually transmitted to humans through contaminated food. ...
Sanfilippo syndrome is a rare and intractable neurological disorder of genetic origin. First manifestations in children are delayed cognitive development and behavioral disturbances, which further progressively evolve towards severe psychomotor retardation and polyhandicap. The disease is...
SARS (severe acute respiratory syndrome) was the first severe transmissible disease to emerge in the 21st century. The outbreak that began in China in late 2002 spread worldwide in 2003, with more than 8,000 cases and nearly 800 deaths. Thanks to an unprecedented international response triggered...
Sepsis is the term used internationally to describe a widespread inflammatory response that occurs as a result of severe infection. Septicemia, the term coined in 1837 by French doctor Pierre Piorry from the Greek words "σήψις" (sêptikós), putrefaction, and "αίμα" (haîma), blood, refers to the...
Shigellosis is a highly contagious diarrheal disease, with outbreaks occurring throughout the world. In France, small-scale outbreaks are regularly reported in schools. A concerning increase in case numbers in the male homosexual community has also been observed in recent years. Shigellosis is...
Sleeping sickness, also known as African trypanosomiasis, is caused by the parasitic flagellate Trypanosoma brucei, which is injected into the body by the tsetse fly. The disease occurs only in the 36 sub-Saharan African countries exposed to the tsetse fly. Following efforts to combat the...
Staphylococci are pathogenic bacteria causing a broad spectrum of diseases with varying degrees of severity. They are one of the main agents of nosocomial infections (hospital-acquired infections) but can also be contracted outside of hospitals (community-acquired infections). Their natural...
Tuberculosis (TB) is an infectious disease of major global importance to public health, with more than 10 million cases and 1.4 million deaths occurring annually. The synergy between TB and HIV and the emergence of strains of Mycobacterium tuberculosis (Koch's bacillus) with multiple...
Typhoid and paratyphoid fever are infectious diseases that can be fatal if left untreated. They generally occur in regions with low standards of hygiene, especially in developing countries. In France, 100 to 150 cases are reported every year among travelers or people from endemic areas (Africa,...
Hepatitis is an inflammation of the liver caused by toxic substances or – in the majority of cases – by viruses. To date, five viruses have been identified that target the liver and cause inflammatory infection. These viruses are referred to by the letters A, B, C, D and E, and vary according to...
West Nile virus is transmitted to humans by mosquitoes. It causes sudden fever, sometimes associated with neurological complications that can be severe in many animal species. Since it was first identified in East Africa, the virus has been observed on every continent. It is currently endemic in...
Whooping cough, long thought of as a childhood illness, can actually be severe at any age. It is particularly dangerous, and sometimes even fatal, for unvaccinated or partially vaccinated infants and at-risk patients such as pregnant women and elderly people.
Yellow fever is a viral disease that was first described in the mid-sixteenth century in Yucatán, Mexico. It is caused by the yellow fever virus an arbovirus (a virus transmitted by an insect vector) isolated in 1927, simultaneously in Ghana and at the Institut Pasteur in Dakar, Senegal. The...
The Zika virus is a flavivirus transmitted by mosquitoes of the Aedes genus. It is widespread in Asia and Africa and has recently emerged in Central and South America. The disease caused by the virus develops 3 to 12 days after the vector insect bite and symptoms (which resemble those...
