Holoendemic

Last updated

A disease is holoendemic when essentially every individual in a population is infected. [1] [2]

Although the infection is ubiquitous, symptoms of disease do not appear equally across age groups. The young are more likely to express pathogenic responses, whilst the older hosts will carry the disease asymptomatically, or with reduced damage, due to adaptive immunity. Therefore, holoendemic diseases differ from hyperendemic [3] diseases, of which symptoms are expressed equally by members across all age groups of a population. [4] [5]

Holoendemicity is frequently seen with malaria, specifically the strain caused by Plasmodium falciparum , in several regions of sub-Saharan Africa (one study found that 98.6% of the population had traces of the pathogen within a 4 month period [6] ). While individuals of all ages risk exposure to malaria, those under the age of five are particularly susceptible to the disease. Children account for the majority of both local and global malaria cases [7] because they lack the adaptive immunity that comes with repeated exposure. [8] Other examples of holoendemic diseases include ocular trachoma in certain areas in sub-Saharan Africa, where virtually all children in those populations have been infected, [9] and hepatitis B in areas of the Marquesas Islands. [10]

Related Research Articles

<span class="mw-page-title-main">Malaria</span> Mosquito-borne infectious disease

Malaria is a mosquito-borne infectious disease that affects humans and other vertebrates. Human malaria causes symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. Symptoms usually begin 10 to 15 days after being bitten by an infected Anopheles mosquito. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria.

<i>Plasmodium falciparum</i> Protozoan species of malaria parasite

Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of Plasmodium that causes malaria in humans. The parasite is transmitted through the bite of a female Anopheles mosquito and causes the disease's most dangerous form, falciparum malaria. It is responsible for around 50% of all malaria cases. P. falciparum is therefore regarded as the deadliest parasite in humans. It is also associated with the development of blood cancer and is classified as a Group 2A (probable) carcinogen.

<span class="mw-page-title-main">Proguanil</span> Chemical compound

Proguanil, also known as chlorguanide and chloroguanide, is a medication used to treat and prevent malaria. It is often used together with chloroquine or atovaquone. When used with chloroquine the combination will treat mild chloroquine resistant malaria. It is taken by mouth.

<i>Plasmodium vivax</i> Species of single-celled organism

Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria. Although it is less virulent than Plasmodium falciparum, the deadliest of the five human malaria parasites, P. vivax malaria infections can lead to severe disease and death, often due to splenomegaly. P. vivax is carried by the female Anopheles mosquito; the males do not bite.

<i>Plasmodium ovale</i> Species of single-celled organism

Plasmodium ovale is a species of parasitic protozoon that causes tertian malaria in humans. It is one of several species of Plasmodium parasites that infect humans, including Plasmodium falciparum and Plasmodium vivax which are responsible for most cases of malaria in the world. P. ovale is rare compared to these two parasites, and substantially less dangerous than P. falciparum.

Plasmodium chabaudi is a parasite of the genus Plasmodium subgenus Vinckeia. As in all Plasmodium species, P. chabaudi has both vertebrate and insect hosts. The vertebrate hosts for this parasite are rodents.

<i>Laverania</i> Subgenus of single-celled organisms

Laverania is a subgenus of the parasite genus Plasmodium. Infection with these species results in malaria. The subgenus was first described in 1958.

Malaria vaccines are vaccines that prevent malaria, a mosquito-borne infectious disease which annually affects an estimated 247 million people worldwide and causes 619,000 deaths. The first approved vaccine for malaria is RTS,S, known by the brand name Mosquirix. As of April 2023, the vaccine has been given to 1.5 million children living in areas with moderate-to-high malaria transmission. It requires at least three doses in infants by age 2, and a fourth dose extends the protection for another 1–2 years. The vaccine reduces hospital admissions from severe malaria by around 30%.

<span class="mw-page-title-main">History of malaria</span> History of malaria infections

The history of malaria extends from its prehistoric origin as a zoonotic disease in the primates of Africa through to the 21st century. A widespread and potentially lethal human infectious disease, at its peak malaria infested every continent except Antarctica. Its prevention and treatment have been targeted in science and medicine for hundreds of years. Since the discovery of the Plasmodium parasites which cause it, research attention has focused on their biology as well as that of the mosquitoes which transmit the parasites.

<span class="mw-page-title-main">Mosquito-borne disease</span> Diseases caused by bacteria, viruses or parasites transmitted by mosquitoes

Mosquito-borne diseases or mosquito-borne illnesses are diseases caused by bacteria, viruses or parasites transmitted by mosquitoes. Nearly 700 million people get a mosquito-borne illness each year resulting in over 725,000 deaths.

Human genetic resistance to malaria refers to inherited changes in the DNA of humans which increase resistance to malaria and result in increased survival of individuals with those genetic changes. The existence of these genotypes is likely due to evolutionary pressure exerted by parasites of the genus Plasmodium which cause malaria. Since malaria infects red blood cells, these genetic changes are most common alterations to molecules essential for red blood cell function, such as hemoglobin or other cellular proteins or enzymes of red blood cells. These alterations generally protect red blood cells from invasion by Plasmodium parasites or replication of parasites within the red blood cell.

Bertielliasis is the infection of Bertiella, a cestode tapeworm parasite that primarily infects nonhuman primates, rodents and Australian marsupials. Occasionally, human infections have been documented by one of two species: Bertiella studeri, or Bertiella mucronata. Of 29 different Bertiella species, only these two can infect humans.

Pregnancy-associated malaria (PAM) or placental malaria is a presentation of the common illness that is particularly life-threatening to both mother and developing fetus. PAM is caused primarily by infection with Plasmodium falciparum, the most dangerous of the four species of malaria-causing parasites that infect humans. During pregnancy, a woman faces a much higher risk of contracting malaria and of associated complications. Prevention and treatment of malaria are essential components of prenatal care in areas where the parasite is endemic – tropical and subtropical geographic areas. Placental malaria has also been demonstrated to occur in animal models, including in rodent and non-human primate models.

<span class="mw-page-title-main">Duffy binding proteins</span>

In molecular biology, Duffy binding proteins are found in Plasmodium. Plasmodium vivax and Plasmodium knowlesi merozoites invade Homo sapiens erythrocytes that express Duffy blood group surface determinants. The Duffy receptor family is localised in micronemes, an organelle found in all organisms of the phylum Apicomplexa.

Plasmodium coatneyi is a parasitic species that is an agent of malaria in nonhuman primates. P. coatneyi occurs in Southeast Asia. The natural host of this species is the rhesus macaque and crab-eating macaque, but there has been no evidence that zoonosis of P. coatneyi can occur through its vector, the female Anopheles mosquito.

Rickettsia massiliae is a tick-borne pathogenic spotted fever group Rickettsia species.

Sanaria is a biotechnology company developing vaccines protective against malaria and other infectious diseases as well as related products for use in malaria research. Sanaria's vaccines are based on the use of the sporozoite (SPZ) stage of the malaria parasite, Plasmodium, as an immunogen, and as a platform technology for liver-vectored gene delivery. SPZ are normally introduced into humans by mosquito bite where they migrate to the liver and further develop to liver stages, and eventually back into the blood stream where the parasite infects red blood cells (RBC) and causes malaria. Plasmodium falciparum is the species responsible for more than 95% deaths caused by malaria. The WHO estimates there were 249 million clinical cases and 608,000 deaths in 2022 alone.

Moses R Kamya, is a Ugandan physician, academic, researcher and academic administrator, who serves as Professor and Chair of the Department Medicine, Makerere University School of Medicine, a component of Makerere University College of Health Sciences.

Lyda Elena Osorio Amaya is a Colombian physician, epidemiologist and infectious disease specialist. She is an associate professor at the Universidad del Valle, and a researcher at the Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM) in Cali, Valle del Cauca. Osorio's research has focused mainly on vector-borne diseases like malaria, leishmaniasis, Zika and dengue fever. She has also played a role in Colombia's response against COVID-19.

In epidemiology, the term hyperendemic disease is used to refer to a disease which is constantly and persistently present in a population at a high rate of incidence and/or prevalence (occurrence) and which equally affects all age groups of that population. It is one of the various degrees of endemicity.

References

  1. "Holoendemic definition". Miriam Webster's Medical Dictionary. Retrieved 2009-04-19.
  2. "Holoendemic disease". Mondofacto. 2008. Retrieved 2009-04-19.
  3. "Medical Definition of Hyperendemic". www.merriam-webster.com. Retrieved 2017-11-07.
  4. "Endemic Diseases". www.ncbi.nlm.nih.gov. Retrieved 2017-11-07.
  5. Stich, August; Oster, N.; Abdel-Aziz, I.Z.; Stieglbauer, G.; Coulibaly, B.; Wickert, H.; McLean, J.; Kouyaté, B.A.; et al. (2006). "Malaria in a holoendemic area of Burkina Faso: a cross-sectional study". Parasitology Research. 98 (6): 596–599. doi:10.1007/s00436-005-0104-9. PMID   16416123. S2CID   27192358. Note:"In the study area, like other holoendemic areas, youth is a risk factor for malaria. In comparison, adults in such areas have acquired permunition and can more readily resist infection and tolerate various symptoms associated with malaria."
  6. Trape, Jean-Francois; Rogier, Christophe; Konate, Lassana; Diagne, Nafissatou; Bouganali, Hilaire; Canque, Bruno; Legros, Fabrice; Badji, Assane; Ndiaye, Gora (1994-08-01). "The Dielmo Project: a Longitudinal Study of Natural Malaria Infection and the Mechanisms of Protective Immunity in a Community Living in a Holoendemic Area of Senegal". The American Journal of Tropical Medicine and Hygiene. 51 (2): 123–137. doi:10.4269/ajtmh.1994.51.123. ISSN   0002-9637. PMID   8074247. Notes: "The incidence of malaria attacks was 40 times higher in children 0--4 years of age than in adults more than 40 years old. Our findings suggest that sterile immunity and clinical protection are never fully achieved in humans continuously exposed since birth to intense transmission."
  7. World Malaria Report 2015. World Health Organization. December 2015. ISBN   978-92-4-156515-8. Retrieved November 6, 2017.
  8. Rogier, Christophe; Trape, Jean-Francois; Commenges, Daniel (1996-06-01). "Evidence for an Age-Dependent Pyrogenic Threshold of Plasmodium falciparum Parasitemia in Highly Endemic Populations". The American Journal of Tropical Medicine and Hygiene. 54 (6): 613–619. CiteSeerX   10.1.1.887.5845 . doi:10.4269/ajtmh.1996.54.613. ISSN   0002-9637. PMID   8686780. Note: "From then on, it decreased with age (P < 0.001), first rapidly in children, then slowly in adults, as is classically observed in areas of malaria holoendemicity."
  9. Lewallen, Susan; Courtright, Paul (2001). "Blindness in Africa: present situation and future needs". British Journal of Ophthalmology. 85 (8): 897–903. doi:10.1136/bjo.85.8.897. PMC   1724094 . PMID   11466240. Notes: "Although the prevalence of active disease is similar for boys and girls, adult women tend to have more active disease than adult men, probably due to their more frequent interaction with children. In some areas trachoma is holoendemic—every child acquires active trachoma and every adult shows evidence of conjunctival scarring."
  10. Chanteau, S.; Sechan, Y.; Moulia-Pelat, J. P.; Luquiaud, P.; Spiegel, A.; Boutin, J. P.; Roux, J. F. (June 1993). "The blackfly Simulium buissoni and infection by hepatitis B virus on a holoendemic island of the Marquesas archipelago in French Polynesia". The American Journal of Tropical Medicine and Hygiene. 48 (6): 763–770. doi:10.4269/ajtmh.1993.48.763. ISSN   0002-9637. PMID   8333570.