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...
Amebiasis is one of the most deadly parasitic diseases in the world (after malaria and schistosomiasis). Around 10% of the global population is thought to be infected with parasitic amoebae of the genus Entamoeba, the most pathogenic of which is Entamoeba histolytica, the...
Antibiotics are drugs used to treat infections caused by bacteria. Antibiotic resistance occurs when bacteria become resistant and no longer respond to these drugs.
Aspergillosis is a general term for infections caused by a type of mold (fungus) belonging to the genus Aspergillus. The mold that causes aspergillosis can be found everywhere in the environment in the form of spores, but in certain conditions it can become pathogenic, for example in...
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...
The term avian influenza actually refers to several entities. First, it indicates infection with an influenza type A virus in birds. This infection can take various forms. Certain viruses are responsible for outbreaks in domestic poultry, with a very high...
Botulism is a severe neurological disease caused by a highly potent toxin produced by Clostridium botulinum bacteria. There are different types of botulism: foodborne botulism, infant botulism and wound botulism. Although botulism is rare, the mortality rate is high if treatment is not...
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 fourth most common form of cancer in women worldwide. Almost all cases can be attributed to chronic infection with viruses belonging to the papillomavirus family. Globally, approximately 600,000 new cases and more than 300,000 deaths are recorded every year. Cervical...
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...
Chikungunya is a viral disease transmitted to humans by the bite of Aedes albopictus and Aedes aegypti mosquitoes. Although rarely fatal, chikungunya can cause significant pain and debilitating symptoms that affect patients' quality of life. Existing treatments are solely...
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, infection is asymptomatic and is therefore...
Cholera is an epidemic acute diarrheal disease that only affects humans and is caused by serogroup O1 (and in rare cases O139) of the Vibrio cholerae bacterium. Although this infection is sometimes caused by direct contact with infected individuals (e.g. through unwashed hands, last...
The SARS-CoV-2 coronavirus, discovered in December 2019 in the province of Wuhan in China, is responsible for COVID-19. This highly contagious emerging infectious disease spreads by airborne transmission and surface contamination. Although COVID-19 can be asymptomatic, it can also cause a...
Crimean-Congo hemorrhagic fever (CCHF) is a disease caused by a virus of the same name. In most cases, the infection is mild, but it can be severe or even fatal. The main route of transmission of the virus to humans is bites from ticks of the genus Hyalomma.
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 ‘tropical flu’, is an infectious disease caused by the virus of the same name. The virus is transmitted by mosquitoes of the genus Aedes. The incidence of dengue is rising rapidly and it is currently considered a ‘re-emerging’ disease.
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...
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...
Endometriosis is a chronic gynecological condition in which the tissue that normally lines the uterus, known as the endometrium, develops outside the uterus. The condition can lead to a range of painful symptoms, affecting quality of life, as well as fertility problems.
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 cause illness in humans. One such strain is enterohemorrhagic E. coli (EHEC). EHEC strains...
Infections with group A and B Streptococcus (respectively Streptococcus pyogenes and Streptococcus agalactiae) are frequent. The two bacteria are part of the commensal flora; they are opportunistic pathogens and only cause symptoms in certain conditions 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...
Hidradenitis suppurativa is a chronic autoinflammatory skin condition. It is characterized by recurring painful nodules, abscesses and suppurative lesions in areas where the skin rubs together, mainly the armpits, the skin folds of the groin, the buttocks and under the breasts. Symptoms occur in...
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 a 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 seasonal outbreaks that affect 2 to 6 million people in France every winter, with influenza-associated excess mortality...
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 an acute viral disease belonging to the category of viral hemorrhagic fevers, similar to Ebola. It is mainly found in West Africa and is caused by the Lassa virus, which is transmitted to humans through contact with infected rodents. Although many cases of infection are...
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...
Leishmaniasis is a parasitic disease that causes severely debilitating cutaneous or visceral lesions, which can be fatal if left untreated. The plural form "leishmaniases" is sometimes used, as the disease is actually a group of diseases caused by different parasites of the genus Leishmania...
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 that occurs worldwide. It is transmitted from animals to humans via urine. The main animal reservoirs are rats, but any mammals can carry the bacteria. In humans, leptospirosis is often mild, but it can lead to kidney failure or even death in 5 to 20% of...
Listeriosis is a severe foodborne infection caused by the bacterium Listeria monocytogenes. It can cause septicemia or central nervous system infections. In pregnant women, it can lead to miscarriage, premature delivery or serious neonatal infection.
Lyme disease, also known as Lyme borreliosis, is a tick-borne disease. It is the most widespread vector-borne disease in the entire northern hemisphere. Its incidence continues to rise at global level as a result of demographic and environmental factors, including climate change.
Malaria is a disease transmitted by parasites of the genus Plasmodium. According to WHO figures, the disease caused 608,000 deaths worldwide in 2022. For several years now, parasites have been developing resistance to antimalarial drugs and mosquitoes are increasingly less susceptible...
Meningitis is an infection of the spinal cord and the brain membranes – or meninges –, caused by several types of virus, bacteria and fungi. Meningococci (another name for Neisseria meningitidis bacteria) are the main cause of acute meningitis. Despite treatment, meningococcal...
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...
Mpox is a virus that was initially present in animals, especially rodents in Africa, and now circulates among humans – it is referred to as an emerging zoonotic disease. The disease caused by this virus is also known as mpox (formerly monkeypox), and presents as a mild form of smallpox, with...
Parkinson’s disease is a degenerative disorder affecting almost 200,000 people in France. It is the second leading cause of motor disability in adults after stroke and is characterized by the gradual loss of certain neurons in the brain. Although current treatments may alleviate symptoms, they...
Plague is still rife in Africa, Asia and America. It is considered as one of 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...
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. It mostly affects children under the age of five. The disease has been preventable since the 1960s thanks to effective...
Rabies is a severe viral infection that can be transmitted to humans by certain mammals. The disease is almost always fatal once symptoms appear, and today rabies is still responsible for tens of thousands of human deaths every year. Africa and Asia have the highest rabies burden, and dogs are...
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, also known as bacillary dysentery, is an infectious bowel disease caused by a group of bacteria known by the name of Shigella. Infection is mainly characterized by severe diarrhea, often containing blood, together with abdominal cramps and fever. It mainly affects preschool...
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 responsible for a broad spectrum of diseases with varying degrees of severity. They are one of the main causes of nosocomial infections (hospital-acquired infections) but can also be acquired outside hospitals. They are part of the natural skin flora,...
The bacterium Helicobacter pylori (H. Pylori) is the causative agent of stomach diseases in humans, including chronic gastritis, gastric ulcers (open sores that develop on the mucosa lining the stomach) and duodenal ulcers. It also plays a major role in stomach cancer genesis (...
Tuberculosis (TB) is an infectious disease that generally affects the lungs, caused by the Mycobacterium tuberculosis bacterium. It is highly contagious and is spread through the air when infected people cough or sneeze. Although tuberculosis can be fatal, it is often treatable and can...
Typhoid and paratyphoid fever are infectious diseases that can be fatal if left untreated. They generally occur in regions with low standards of hygiene and particularly affect low- and middle-income countries. In France, 100 to 250 cases are reported every year among travelers or people from...
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 be severe at any age. This bacterial infection is particularly dangerous, and sometimes even fatal, for unvaccinated or partially vaccinated infants and at-risk individuals 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 yellow fever virus, an arbovirus (a virus transmitted by an insect vector) isolated in 1927, simultaneously in Ghana and at the Institut Pasteur de Dakar, Senegal. The...
The Zika virus is a Flavivirus mainly transmitted by the bite of infected mosquitoes of the genus Aedes. It causes Zika virus disease.
