Migration Of Human Populations Research Articles

Early twenty-first-century droughts during the warmest climate

The first 13 years of the twenty-first century have begun with a series of widespread, long and intensive droughts around the world. Extreme and severe-to-extreme intensity droughts covered 2%–6% and 7%–16% of the world land, respectively, affecting environment, economies and humans. These droughts reduced agricultural production, leading to food shortages, human health deterioration, poverty, regional disturbances, population migration and death. This feature article is a travelogue of the twenty-first-century global and regional droughts during the warmest years of the past 100 years. These droughts were identified and monitored with the National Oceanic and Atmospheric Administration operational space technology, called vegetation health (VH), which has the longest period of observation and provides good data quality. The VH method was used for assessment of vegetation condition or health, including drought early detection and monitoring. The VH method is based on operational satellites data estimating both land surface greenness (NDVI) and thermal conditions. The twenty-first-century droughts in the USA, Russia, Australia and Horn of Africa were intensive, long, covered large areas and caused huge losses in agricultural production, which affected food security and led to food riots in some countries. This research also investigates drought dynamics presenting no definite conclusion about drought intensification or/and expansion during the time of the warmest globe.

Tracing Arab-Islamic Inheritance in Madagascar: Study of the Y-chromosome and Mitochondrial DNA in the Antemoro

Madagascar is located at the crossroads of the Asian and African worlds and is therefore of particular interest for studies on human population migration. Within the large human diversity of the Great Island, we focused our study on a particular ethnic group, the Antemoro. Their culture presents an important Arab-Islamic influence, but the question of an Arab biological inheritance remains unresolved. We analyzed paternal (n=129) and maternal (n=135) lineages of this ethnic group. Although the majority of Antemoro genetic ancestry comes from sub-Saharan African and Southeast Asian gene pools, we observed in their paternal lineages two specific haplogroups (J1 and T1) linked to Middle Eastern origins. This inheritance was restricted to some Antemoro sub-groups. Statistical analyses tended to confirm significant Middle Eastern genetic contribution. This study gives a new perspective to the large human genetic diversity in Madagascar.

Identification of three new Alu Yb subfamilies by source tracking of recently integrated Alu Yb elements

BackgroundAlu elements are the most abundant mobile elements in the human genome, with over 1 million copies and constituting more than 10% of the genome. The majority of these Alu elements were inserted into the primate genome 35 to 60 million years ago, but certain subfamilies of Alu elements are relatively very new and suspected to be still evolving. We attempted to trace the source/master copies of all human-specific members of the Alu Yb lineage using a computational approach by clustering similar Yb elements and constructing an evolutionary relation among the members of a cluster.ResultsWe discovered that one copy of Yb8 at 10p14 is the source of several active Yb8 copies, which retrotransposed to generate 712 copies or 54% of all human-specific Yb8 elements. We detected eight other Yb8 elements that had generated ten or more copies, potentially acting as 'stealth drivers’. One Yb8 element at 14q32.31 seemed to act as the source copy for all Yb9 elements tested, having producing 13 active Yb9 elements, and subsequently generated a total of 131 full-length copies. We identified and characterized three new subclasses of Yb elements: Yb8a1, Yb10 and Yb11. Their copy numbers in the reference genome are 75, 8 and 16. We analysed personal genome data from the 1000 Genome Project and detected an additional 6 Yb8a1, 3 Yb10 and 15 Yb11 copies outside the reference genome. Our analysis indicates that the Yb8a1 subfamily has a similar age to Yb9 (1.93 million years and 2.15 million years, respectively), while Yb10 and Yb11 evolved only 1.4 and 0.71 million years ago, suggesting a linear evolutionary path from Yb8a1 to Yb10 and then to Yb11. Our preliminary data indicate that members in Yb10 and Yb11 are mostly polymorphic, indicating their young age.ConclusionsOur findings suggest that the Yb lineage is still evolving with new subfamilies being formed. Due to their very young age and the high rate of being polymorphic, insertions from these young subfamilies are very useful genetic markers for studying human population genetics and migration patterns, and the trend for mobile element insertions in the human genome.

Using HSV-1 Genome Phylogenetics to Track Past Human Migrations

We compared 31 complete and nearly complete globally derived HSV-1 genomic sequences using HSV-2 HG52 as an outgroup to investigate their phylogenetic relationships and look for evidence of recombination. The sequences were retrieved from NCBI and were then aligned using Clustal W. The generation of a maximum likelihood tree resulted in a six clade structure that corresponded with the timing and routes of past human migration. The East African derived viruses contained the greatest amount of genetic diversity and formed four of the six clades. The East Asian and European/North American derived viruses formed separate clades. HSV-1 strains E07, E22 and E03 were highly divergent and may each represent an individual clade. Possible recombination was analyzed by partitioning the alignment into 5 kb segments, performing individual phylogenetic analysis on each partition and generating a.phylogenetic network from the results. However most evidence for recombination spread at the base of the tree suggesting that recombination did not significantly disrupt the clade structure. Examination of previous estimates of HSV-1 mutation rates in conjunction with the phylogenetic data presented here, suggests that the substitution rate for HSV-1 is approximately 1.38 × 10(-7) subs/site/year. In conclusion, this study expands the previously described HSV-1 three clade phylogenetic structures to a minimum of six and shows that the clade structure also mirrors global human migrations. Given that HSV-1 has co-evolved with its host, sequencing HSV-1 isolated from various populations could serve as a surrogate biomarker to study human population structure and migration patterns.

Population Migration: Implications for Lymphatic Filariasis Elimination Programmes

Human population migration is a common phenomenon in developing countries. Four categories of migration—endemic to nonendemic areas, rural to urban areas, non-MDA areas to areas that achieved lymphatic filariasis (LF) control/elimination, and across borders—are relevant to LF elimination efforts. In many situations, migrants from endemic areas may not be able to establish active transmission foci and cause infection in local people in known nonendemic areas or countries. Urban areas are at risk of a steady inflow of LF-infected people from rural areas, necessitating prolonged intervention measures or leading to a prolonged “residual microfilaraemia phase.” Migration-facilitated reestablishment of transmission in areas that achieved significant control or elimination of LF appears to be difficult, but such risk can not be excluded, particularly in areas with efficient vector-parasite combination. Transborder migration poses significant problems in some countries. Listing of destinations, in endemic and nonendemic regions/countries, and formulation of guidelines for monitoring the settlements and the infection status of migrants can strengthen the LF elimination efforts.

Migration, immobility and displacement outcomes following extreme events

There is growing international concern at an apparent rise in the severity and frequency of extreme environmental events as a manifestation of global environmental change, and that this could be linked with a future rise in the migration or displacement of human populations. However, recent approaches to migration influenced by environmental change call into question the notion that migration can be ascribed in a singular way to particular environmental causes or events. This paper undertakes a systematic review of evidence on population movements associated with weather-related extreme events. The paper demonstrates that in the face of extreme environmental events, it is important to distinguish between three outcomes migration, displacement, and immobility each of which interact and respond to multiple drivers. A narrow focus on any one of these misses the point: both those who move, and those who do not move, may find themselves trapped and vulnerable in the face of such extreme events; short-term displacement that goes hand-in-hand with loss of life, destruction of property and economic disruption poses significant risks not because it is 'environmental migration', but because it represents a failure of adaptation to environmental change.

Human JCV Infections as a Bio-Anthropological Marker of the Formation of Brazilian Amazonian Populations

JC polyomavirus (JCV) is a member of the Polyomaviridae family. It presents a tropism to kidney cells, and the infection occurs in a variety of human population groups of different ethnic background. The present study investigated the prevalence of JCV infection among human populations from the Brazilian Amazon region, and describes the molecular and phylogenetic features of the virus. Urine samples from two urban groups of Belém (healthy subjects), one Brazilian Afro-descendant “quilombo” from the Rio Trombetas region, and native Indians from the Wai-Wai, Urubu-Kaapor, Tembé, Assurini, Arara do Laranjal, Aukre, Parakanã, Surui and Munduruku villages were investigated for the presence of the virus by amplifying VP1 (230 bp) and IG (610 bp) regions using a polymerase chain reaction. Nucleotide sequences (440 nucleotides, nt) from 48 samples were submitted to phylogenetic analysis. The results confirmed the occurrence of types A (subtype EU), B (subtypes Af-2, African and MY, Asiatic) and C (subtype Af-1) among healthy subjects; type B, subtypes Af-2 and MY, among the Afro-Brazilians; and type B, subtype MY, within the Surui Indians. An unexpected result was the detection of another polyomavirus, the BKV, among Afro-descendants. The present study shows, for the first time, the occurrence of JC and BK polyomaviruses infecting humans from the Brazilian Amazon region. The results show a large genetic variability of strains circulating in the region, infecting a large group of individuals. The presence of European, Asiatic and African subtypes associated to the ethnic origin of the population samples investigated herein, highlights the idea that JCV is a fairly good marker for studying the early migration of human populations, reflecting their early and late history. Furthermore, the identification of the specific mutations associated to the virus subtypes, suggests that these mutations have occurred after the entrance of the virus in the Amazon region of Brazil.

Risks of endemicity, morbidity and perspectives regarding the control of Chagas disease in the Amazon Region

Chagas disease, in the Amazon Region as elsewhere, can be considered an enzootic disease of wild animals or an anthropozoonosis, an accidental disease of humans that is acquired when humans penetrate a wild ecosystem or when wild triatomines invade human dwellings attracted by light or searching for human blood. The risk of endemic Chagas disease in the Amazon Region is associated with the following phenomena: (i) extensive deforestation associated with the displacement of wild mammals, which are the normal sources of blood for triatomines, (ii) adaptation of wild triatomines to human dwellings due to the need for a new source of blood for feeding and (iii) uncontrolled migration of human populations and domestic animals that are already infected with Trypanosoma cruzi from areas endemic for Chagas disease to the Amazon Region. Several outbreaks of severe acute cases of Chagas disease, as well as chronic cases, have been described in the Amazon Region. Control measures targeted to avoiding endemic Chagas disease in the Amazon Region should be the following: improving health education in communities, training public health officials and communities for vector and Chagas disease surveillance and training local physicians to recognise and treat acute and chronic cases of Chagas diseases as soon as possible.

Drought is a recurring challenge in the Middle East

Climate change and water availability in the Middle East are important in understanding human adaptive capacities in the face of long-term environmental changes. The key role of water availability for sedentary and nomad populations in these arid to semiarid landscapes is understood, but the millennium-scale influence of hydrologic instability on vegetation dynamics, human occupation, and historic land use are unknown, which has led to a stochastic view of population responses and adaptive capacities to precipitation anomalies. Within the time-frame of the last two global climate events, the Medieval Climate Anomaly and the Little Ice Age, we report hydrologic instability reconstructed from pollen-derived climate proxies recovered near Tell Leilan, at the Wadi Jarrah in the Khabur Plains of northeastern Syria, at the heart of ancient northern Mesopotamia. By coupling climate proxies with archaeological-historical data and a pollen-based record of agriculture, this integrative study suggests that variability in precipitation is a key factor on crop yields, productivity, and economic systems. It may also have been one of the main parameters controlling human settlement and population migrations at the century to millennial timescales in the arid to semiarid areas of the Middle East. An abrupt shift to drier conditions at ca. AD 1400 is contemporaneous with a change from sedentary village life to regional desertion and nomadization (sheep/camel pastoralists) during the preindustrial era in formerly Ottoman realms, and thereby adds climate change to the multiple causes for Ottoman Empire "decline."

Wicked Social-Ecological Problems Forcing Unprecedented Change on the Latitudinal Margins of Coral Reefs: the Case of Southwest Madagascar

Bruggemann, J. H., M. Rodier, M. M. M. Guillaume, S. Andréfouët, R. Arfi, J. E. Cinner, M. Pichon, F. Ramahatratra, F. Rasoamanendrika, J. Zinke, and T. R. McClanahan. 2012. Wicked social-ecological problems forcing unprecedented change on the latitudinal margins of coral reefs: the case of southwest Madagascar. Ecology and Society 17(4): 47. https://doi.org/10.5751/ES-05300-170447

Serological survey for Chagas disease in the rural areas of Manaus, Coari, and Tefé in the Western Brazilian Amazon

Deforestation, uncontrolled forest, human population migration from endemic areas, and the large number of reservoirs and wild vectors naturally infected by Trypanosoma cruzi promote the endemicity of Chagas disease in the Amazon region. We conducted an initial serological survey (ELISA) in a sample of 1,263 persons; 1,095 (86.7%) were natives of the State of Amazonas, 666 (52.7%) were male, and 948 (75.1%) were over 20 years old. Serum samples that were found to be reactive, indeterminate, or inconclusive by indirect immunofluorescence (IFI) or positive with low titer by IFA were tested by Western blot (WB). Serologically confirmed patients (WB) were evaluated in terms of epidemiological, clinical, ECG, and echocardiography characteristics. Fifteen patients had serologically confirmed T. cruzi infection, and 12 of them were autochthonous to the state of Amazonas, for an overall seroprevalence of 1.2% and 0.9% for the state of Amazonas. Five of the 15 cases were males, and the average age was 47 years old; most were farmers with low education. One patient who was not autochthonous, having originated from Alagoas, showed right bundle branch block, bundle branch block, and anterosuperior left ventricular systolic dysfunction with an ejection fraction of 54%. The results of this study ratify the importance of monitoring CD cases in Amazonia, particularly in the state of Amazonas.

Coastal Resource Management

This article highlights some salient ecological features of Indian coastal resources and the need for a viable coastal resources management plan. The transition between the land and the sea is one of the most fragile, complex and a productive ecosystem. It is bestowed with enormous resources, both - living, non-living and is a potential area for recreation and harnessing non-conventional energy resources (wave and wind energy). This is the zone of dynamic activity, constantly transforming itself to maintain equilibrium, under the varying intensity of the natural processes operating here Coastal zone of India has diverse ecosystems like mangroves, corals, beaches, wetlands, estuaries, lagoons and backwaters harboring many ecologically and economically important fauna and flora and also serves as a barrier against many destructive natural hazards. Coastal zone is a region of diverse activity, both complementary and conflicting to each other. Accelerated and unscientific developmental activities have induced catastrophic consequences. In order to optimally utilize&reap the benefits, without hampering the fragile balance, it is necessary to adopt coastal management strategies based on solid scientific foundation that allow for multiple use of the resources without causing serious damage to the environment. Indian seas are witnessing increased anthropogenic activities like marine fishing, off-shore oil and gas, marine transport, dumping ground for waste disposals, etc all of which have been bringing about changes in the coastal environment. Increasing stress due to development of industries, trade and commerce, tourism and resultant human population growth and migration towards coastal cities and urban centers pose a serious threat to the to the health of these coastal ecosystems and to lives and livelihoods of coastal communities. The industrial development of coast has resulted in degradation of coastal ecosystems and diminishing the living resources of Exclusive Economic Zone (EEZ) in the form of coastal and marine biodiversity and productivity. Municipal sewage, land use, tourism, maritime transport, offshore oil exploration and production, dumping at sea degrade the marine environment. Felling of mangroves and clearing of forests increase the sedimentation rate affecting the live coral and species diversity. Mangroves are a crucial component deserving high priority in any coastal zone management plan as they are degraded and destroyed due to conversion into agriculture, aquaculture and industrial land. Fishery and fishery resources are another major component in coastal resource management. Preliminary efforts to develop a model coastal zone plan in three different stretches refined our skills to expand the plan at country level. As a result, an exhaustive management plan is being implemented at three different coastal states of the country. It is strongly hoped that many maladies afflicting coastal environment could be effectively addressed by formulating and actively adopting an all encompassing and exhaustive coastal zone management plan. Options to tide over this persistent issue is being debated at national and even international levels and some suggestions consistently made by public interest groups and NGOs includes: Earmarking exclusive zone for fishery, mangroves and other coastal biodiversity and for settlement for fishing communities. All fishery development recommendations suggest that Integrating fishing community with the ongoing development could be initiated to reverse their poverty. It could be done only through long term planning to enhance their special skills which will make them employable and eventually integrate them with the ongoing developmental process. It is also to be remembered that downslide in economic returns of fishing sector is a global phenomenon and Indian fishermen are no exception to this. It is strongly hoped that many maladies afflicting coastal environment could be effectively addressed by formulating and actively adopting an all encompassing and exhaustive coastal resource management plan.

Forty years of visceral leishmaniasis in the State of Piaui: a review

Visceral leishmaniasis (VL) has been known to occur in the state of Piauí since 1934. The typically rural disease began to appear in urban areas over time, being concentrated mainly in Teresina, the capital of Piauí. Teresina was also affected by the first urban epidemic of VL in Brazil. Over 1,000 cases of the disease were reported during urbanization (1981-1986). Human population growth and migration led to land occupation on the outskirts of Teresina. These factors have contributed to vector proliferation, increasing the incidence of VL. At present, the incidence of human and canine disease is quite high and uncontrolled in Piauí. It seems that some measures, such as the elimination of seropositive dogs, failed to significantly reduce the number of new VL cases in Teresina. Despite previously conducted studies, little is known about VL epidemiology in urban areas. The aim of this review is to reveal the situation of VL in Teresina during the last 40 years, focusing on the major factors that may contribute to the high incidence and persistence of VL infection.

Prevalence of Mycobacterium tuberculosis in Taiwan: A Model for Strain Evolution Linked to Population Migration

The global evolution and spread of Mycobacterium tuberculosis (MTB), one of the most successful bacterial pathogens, remain a mystery. Advances in molecular technology in the past decade now make it possible to understand MTB strain evolution and transmission in the context of human population migration. Taiwan is a relatively isolated island, serving as a mixing vessel over the past four centuries as colonization by different waves of ethnic groups occurred. By using mycobacterial tandem repeat sequences as genetic markers, the prevalence of MTB strains in Taiwan revealed an interesting association with historical migrations of different ethnic populations, thus providing a good model to explore the global evolution and spread of MTB.

Impacts of human activity on the late-Holocene development of the subaqueous Yangtze delta, China, as shown by magnetic properties and sediment accumulation rates

Development of the Yangtze delta during the late Holocene, and its relationship to human activities in the drainage basin, was analyzed using data from 16 cores collected from distributaries to the prodelta. We used AMS 14C dating and digital elevation model (DEM) data from marine charts from 1864 through 2005 to determine ages and estimate sediment accumulation rates. The results demonstrate that the latest major subaqueous delta front formed within the past c. 0.8 cal. ka and features remarkably high accumulation rates (1—4 cm/yr) in comparison with those of previous delta fronts. We also examined the temporal distribution of grain size and magnetic susceptibility in all 16 cores. Results show soil-derived superparamagnetic (SP) minerals generally occur, and even dominate, in the recent ( c. 1.7 cal. ka) Yangtze delta fine-grained sediment, as shown by high values of frequency-dependent magnetic susceptibility (both χFD and χFD%). Rock-derived magnetite dominates generally in the river channel and delta front sand bodies as a result of hydrodynamic sorting, but is also enriched in both fine and coarse-grained sediment formed more recently ( c. 0.8 cal. ka), as evidenced by rising values of mass specific magnetic susceptibility (χLF). SP grains were deposited as early as the late Neolithic, possibly indicating local deforestation associated with the use of fire at that time. We suggest major deforestation in the drainage basin started c. 1.7 cal. ka BP, and intensified after c. 0.8 cal. ka BP when both χLF and χFD show the highest values. We therefore conclude that upland deforestation and cultivation as a result of the migration of human populations from northern China since c. 1.7 cal. ka BP resulted in increased sediment discharge of the Yangtze and played an important role in recent delta construction.

Gastric tubes as vectors of Helicobacter pylori transmission

Peptic ulcer was a rare disease before 1850. The prevalence of peptic ulcer increased gradually in persons born between 1870 and 1900. A similar decay in opposite direction of the prevalence occurred after the 1960–1970s. Although the pathogenesis of peptic ulcer is readily explained by the Helicobacter pylori infection, the bacterium occurred many thousands years ago and followed the migrations of human populations; consequently, its presence does not explain the increase in peptic ulcer prevalence. Gastric tubes for secretory testing were introduced from 1871 and their use was extended gradually in the then growing departments of gastroenterology, becoming a very popular, though unpleasant method. There is circumstantial evidence from the pre- H. pylori era that gastric/enteral infections could be transmitted though contaminated gastric tubes/electrodes. The author’s hypothesis is based on the temporary overlap of the increased peptic ulcer prevalence and the extensive use of gastric secretory testing. The use of contaminated gastric tubes in sick persons harbouring pathogenic strains of the bacterium could have led to the transmission of the infection by gastro-oral route to the patients’ ward-mates and on, to their family members: years later, new ulcer or dyspeptic patients may have come from such groups. The current decay in peptic ulcer prevalence could be due to the decreased use of secretory testing and implementation of rigorous disinfection rules.

Local stabilization and network synchronization: The case of stationary regimes

Relationships between local stability and synchronization in networks of identical dynamical systems are established through the Master Stability Function approach. First, it is shown that stable equilibria of the local dynamics correspond to stable stationary synchronous regimes of the entire network if the coupling among the systems is sufficiently weak or balanced (in other words, stationary synchronous regimes can be unstable only if the coupling is sufficiently large and unbalanced). Then, it is shown that [de]stabilizing factors at local scale are [de]synchronizing at global scale again if the coupling is sufficiently weak or balanced. These results allow one to transfer, with almost no effort, what is known for simple prototypical models in biology and engineering to complex networks composed of these models. This is shown through a series of applications ranging from networks of electrical circuits to various problems in ecology and sociology involving migrations of plants, animal and human populations.

Cutting carbon, improving health

Events such as the financial crisis and climate change are not quirks of the marketplace or quirks of nature. Instead they are markers of massive failure in international systems that govern the way nations and their populations interact. The contagion of our mistakes shows no mercy and makes no exceptions on the basis of fair play. For example, countries that have contributed least to greenhouse-gas emissions will be the first and hardest hit by climate change. 1 McMichael A Campbell-Lendrum D Kovats R et al. Climate change. in: Ezzati M Lopez A Rodgers A Murray C Comparative quantification of health risks: global and regional burden of disease due to selected major risk factors. World Health Organization, Geneva2004 Google Scholar The climate dividend“Climate change is the biggest global health threat of the 21st century.” So concluded a Lancet—UCL Commission earlier this year.1 A systematic appraisal of available evidence showed that the risks from changing patterns of disease, food insecurity, unsafe water and sanitation, damage to human settlements, extreme events, and population growth and migration were far more severe for human health than most observers had understood. The message added an important new dimension to the political debate about how to respond to climate change. Full-Text PDF Public health benefits of strategies to reduce greenhouse-gas emissions: household energyEnergy used in dwellings is an important target for actions to avert climate change. Properly designed and implemented, such actions could have major co-benefits for public health. To investigate, we examined the effect of hypothetical strategies to improve energy efficiency in UK housing stock and to introduce 150 million low-emission household cookstoves in India. Methods similar to those of WHO's Comparative Risk Assessment exercise were applied to assess the effect on health that changes in the indoor environment could have. Full-Text PDF Public health benefits of strategies to reduce greenhouse-gas emissions: urban land transportWe used Comparative Risk Assessment methods to estimate the health effects of alternative urban land transport scenarios for two settings—London, UK, and Delhi, India. For each setting, we compared a business-as-usual 2030 projection (without policies for reduction of greenhouse gases) with alternative scenarios—lower-carbon-emission motor vehicles, increased active travel, and a combination of the two. We developed separate models that linked transport scenarios with physical activity, air pollution, and risk of road traffic injury. Full-Text PDF

Geographic distribution of methyltransferases of Helicobacter pylori: evidence of human host population isolation and migration

BackgroundHelicobacter pylori colonizes the human stomach and is associated with gastritis, peptic ulcer, and gastric cancer. This ubiquitous association between H. pylori and humans is thought to be present since the origin of modern humans. The H. pylori genome encodes for an exceptional number of restriction and modifications (R-M) systems. To evaluate if R-M systems are an adequate tool to determine the geographic distribution of H. pylori strains, we typed 221 strains from Africa, America, Asia, and Europe, and evaluated the expression of different 29 methyltransferases.ResultsIndependence tests and logistic regression models revealed that ten R-M systems correlate with geographical localization. The distribution pattern of these methyltransferases may have been originated by co-divergence of regional H. pylori after its human host migrated out of Africa. The expression of specific methyltransferases in the H. pylori population may also reflect the genetic and cultural background of its human host. Methyltransferases common to all strains, M. HhaI and M. NaeI, are likely conserved in H. pylori, and may have been present in the bacteria genome since the human diaspora out of Africa.ConclusionThis study indicates that some methyltransferases are useful geomarkers, which allow discrimination of bacterial populations, and that can be added to our tools to investigate human migrations.

Helicobacter pylori typing as a tool for tracking human migration

Helicobacter pylori strains from different geographic areas exhibit clear phylogeographical differentiation; therefore, the genotypes of H. pylori strains can serve as markers for the migration of human populations. Currently, the genotypes of two virulence factors of H. pylori, cagA and vacA, and multilocus sequence typing (MLST) are widely used markers for genomic diversity within H. pylori populations. There are two types of cagA: the East Asian type and the Western type. In addition, the right end of the cag pathogenicity island is divided into five subtypes and there are distinct mosaic structures at the signal region and the middle region of vacA. Using combinations of the cagA, cag right end junction, and vacA genotypes, five major groups (East Asia type, South/Central Asia type, Iberian/Africa type and Europe type) have been defined according to geographical associations. MLST has revealed seven modern population types and six ancestral population types of H. pylori, and is a useful tool for mapping human migration patterns. Serial studies of large numbers of H. pylori strains, including strains isolated from aboriginal populations, show that MLST analysis provides more detailed information on human migration than does the analysis of human genetics. H. pylori infection is rapidly declining as a result of improvements in personal hygiene and quality of life. The molecular epidemiology of H. pylori infection has much to tell us and should be studied before it disappears entirely.