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PubMed2000

Is malnutrition declining? An analysis of changes in levels of child malnutrition since 1980.

Nutritional status is the best global indicator of well-being in children. Although many surveys of children have been conducted since the 1970s, lack of comparability between them has made it difficult to monitor trends in child malnutrition. Cross-sectional data from 241 nationally representative surveys were analysed in a standard way to produce comparable results of low height-for-age (stunting). Multilevel modelling was applied to estimate regional and global trends from 1980 to 2005. The prevalence of stunting has fallen in developing countries from 47% in 1980 to 33% in 2000 (i.e. by 40 million), although progress has been uneven according to regions. Stunting has increased in Eastern Africa, but decreased in South-eastern Asia, South-central Asia and South America; Northern Africa and the Caribbean show modest improvement; and Western Africa and Central America present very little progress. Despite an overall decrease of stunting in developing countries, child malnutrition still remains a major public health problem in these countries. In some countries rates of stunting are rising, while in many others they remain disturbingly high. The data we have presented provide a baseline for assessing progress and help identify countries and regions in need of populationwide interventions. Approaches to lower child malnutrition should be based on successful nutrition programmes and policies.

Child↗
PubMed2005

Trichinella britovi etiological agent of sylvatic trichinellosis in the Republic of Guinea (West Africa) and a re-evaluation of geographical distribution for encapsulated species in Africa.

In West Africa, Trichinella infection was documented in humans and animals from Senegal in the 1960s, and the biological characters of one isolate showed a lower infectivity to domestic pigs and rodents when compared with that of a Trichinella spiralis pig isolate from Europe. To identify the Trichinella species present in West Africa, a survey was conducted in a total of 160 wild animals in the Republic of Guinea. Three Viverridae, one true civet (Viverra civetta) and two African palm civets (Nandinia binotata) from the Fouta Djallon Massif, Pilimini Subprefecture, were found positive by artificial digestion of muscle samples. Trichinella larvae from these three viverrids were identified as Trichinella britovi and no difference was detected in three examined sequences from these African isolates and the reference strain of T. britovi from Europe, indicating common ancestry, an historically continuous geographic distribution, and recent isolation for African and European populations. The detection of T. britovi in West Africa modifies our knowledge about the distribution of encapsulated species of Trichinella in Africa. Thus, Trichinella nelsoni is now considered to have a distribution limited to the Eastern part of the Afrotropical region from Kenya to South Africa. This provides a plausible explanation for the presence of Trichinella T8 in Namibia and South Africa, and further suggests that T. britovi could be the Trichinella species circulating among wild animals of Northern Africa.

Animals↗
PubMedDate not supplied

Epidemiology of liver cancer in Europe.

Liver cancer (LC) ranks fifth in frequency in the world, with an estimated 437,000 new cases in 1990. The estimates are different when LC frequency is analyzed by sex and geographical areas. In developed areas, the estimates are 53,879 among men and 26,939 among women. In developing areas, the estimates are 262,043 in men and 93, 961 in women. Areas of highest rates include Eastern and South Eastern Asia, Japan, Africa and the Pacific Islands (LC age-adjusted incidence rates [AAIRs] ranging from 17.6 to 34.8). Intermediate rates (LC AAIRs from 4.7 to 8.9 among men) are found in Southern, Eastern and Western Europe, Central America, Western Asia and Northern Africa. Low rates are found among men in Northern Europe, America, Canada, South Central Asia, Australia and New Zealand (LC AAIRs range from 2.7 to 3.2). In Europe, an excess of LC incidence among men compared with women is observed, and the age peak of the male excess is around 60 to 70 years of age. Significant variations in LC incidence among different countries have been described and suggest differences in exposure to risk factors. Chronic infection with the hepatitis B virus (HBV) and hepatitis C virus (HCV) in the etiology of LC is well established. In Europe, 28% of LC cases have been attributed to chronic HBV infection and 21% to HCV infection. Other risk factors such as alcohol consumption, cigarette smoking and oral contraceptives may explain the residual variation within countries. Interactions among these risk factors have been postulated. New laboratory techniques and biological markers such as polymerase chain reaction detection of HBV DNA and HCV RNA, as well as specific mutations related to LC, may help to provide quantitative estimates of the risk related to each these factors.

Adolescent↗
PubMed1993

On the intrinsic force of convergence to stability.

"Observed populations differ greatly in the speed with which they approach the stable form, but what determines rates of convergence is not fully understood.... Here we examine the trajectory to stability, derive a mathematical expression for the force of convergence, and provide an approximate relationship in terms of the mean and variance of the stable net maternity function." Trajectories for Japan, Togo, and the United States are used as illustrations. (SUMMARY IN FRE)

Africa↗
PubMed1996

[Tuberculosis in recent immigrants in Barcelona].

BACKGROUND: The aim of the present was to study the prevalence of infection and tuberculous disease as well as the fulfillment of secondary antituberculin chemoprophylaxis in immigrants according to their geographic origin. PATIENTS AND METHODS: A descriptive study was carried out of 1,489 immigrants under the age of 35 years attended in the Tropical and Imported Disease Unit Drassanes in Barcelona, Spain from 1989 to 1994. RESULTS: The patients were from 79 countries, with 81.7% being males and 18.3% females (p < 0.001) of a mean age 26.1 +/- 5.7 and 23.4 +/- 7.5 years, respectively. Forty-three percent of the cases presented Mantoux test response > or = 10 mm of induration. The highest percent of positivity was observed in patients from Subsaharian Africa (52%) followed by Eastern Europeans and Asians (44%), South and Central Americans (38%) and Middle East and Northern Africa (34%) (p < 0.001). Thirty-nine percent of the 359 patients who initiated secondary antituberculin chemoprophylaxis completed the 6 months of treatment with the highest fulfillment being found in Africans (49%) followed by Americans (42%) and Asians (39%). The lowest rate was observed in the Eastern Europeans (20%) (p < 0.001). Fifty-six percent of the patients abandoned secondary antituberculin prophylaxis within the first three months. Eighteen cases of active tuberculosis were diagnosed. CONCLUSIONS: The prevalence of tuberculous infection and disease is high immigrants in Barcelona, Spain. The fulfillment of chemoprophylaxis is low and abandoned early. These facts should be evaluated when designing prevention and control programs.

Adult↗
PubMed1997

Tick-borne diseases of sheep and goats caused by Babesia, Theileria or Anaplasma spp.

A review is given on the Babesia, Theileria, and Anaplasma species infecting sheep and goats. B. ovis is the most important disease agent. It is transmitted by Rhipicephalus bursa, R. turanicus, Hyalomma anatolicum excavatum, and probably by R. evertsi evertsi B. ovis is widely spread in southern Europe, the Middle East, and central Asia. Its geographical distribution in South and East Asia and in Africa is widely unknown. B. motasi obviously represents several nosodemes in separate regions. It is not pathogenic for intact sheep in northern Europe, whereas it is probably more pathogenic than B. ovis in India and northern Africa. The known vectors of B. motasi are Haemaphysalis punctata and R. bursa. Theileria hirci is transmitted by H. a. anatolicum but occurs outside the distribution area of this tick. Malignant theileriosis of sheep and goats is an important disease in Iraq, Iran, and India. An attenuated macroschizont vaccine is successfully being used in Iran. Anaplasma ovis is transmitted by R. bursa and probably other ticks in the Old World and by Dermacentor andersoni in the New World. A. ovis is widely spread in the Old World. Outbreaks occur only under extreme conditions. The identity of the tick-borne disease agents of sheep and goats and of their vector ticks is uncertain in many regions of the Old and the New World.

Anaplasmosis↗
PubMed1993

Crossovers that link populations with the same vital rates.

"In this paper, we consider crossovers of demographic density distributions from...populations that have the same fertility and mortality rates. We focus on observed populations and their associated stationary and stable models, and on proportional distributions of persons, births, deaths and reproductive values.... Three different populations were selected to represent a range of demographic behavior. Those populations are Japan 1963, a low mortality, low fertility population; Togo 1961, a high mortality, high fertility population; and the United States 1919-1921, a population whose fertility and mortality are intermediate."

Africa↗
PubMed1999

Internal transcribed spacer sequence phylogeny of Crambe L. (Brassicaceae): molecular data reveal two Old World disjunctions.

Crambe L. (Brassicaceae) is an Old World genus with a disjunct distribution among four major centers of species diversity. A phylogenetic analysis of nucleotide sequences of the internal transcribed spacers (ITS) of the nuclear ribosomal repeat was conducted with 27 species of Crambe and 18 related genera. Cladistic analyses using weighted and unweighted parsimony support Crambe as a monophyletic genus with three major lineages. The first comprises those taxa endemic to the Macaronesian archipelagos. Taxa with a predominant Mediterranean distribution form the second assemblage, and a disjunction between east Africa (C. abyssinica) and the Mediterranean (C. hispanica) occurs in this clade. The third lineage includes all Eurosiberian-Asian taxa and C. kilimandscharica, a species from the highlands of east Africa. A basal biogeographic split between east Africa and Eurasia is present in the third clade. The patterns of relationships in the ITS tree are concordant with known climatic events in northern Africa and southwestern Asia since the middle Miocene. The ITS trees are congruent with the current sectional classification except for a few members of sections Crambe, Leptocrambe, and Orientecrambe (C. cordifolia, C. endentula, C. kilimandscharica, and C. kotschyana). Low levels of support in the basal branches do not allow resolution of which genera of the subtribes Raphaniae or Brassicinae are sister to Crambe. Both subtribes appear to be highly polyphyletic in the ITS trees.

Base Composition↗
PubMed2002

A comparison of HLA-DR and -DQ allele and haplotype frequencies in Trinidadian populations of African, South Asian, and mixed ancestry.

Using polymerase chain reaction-sequence-specific primer (PCR-SSP) typing, this study determined the frequency of human leukocyte antigen (HLA) DR- and -DQ alleles and haplotypes in individuals of African (n = 75), South Asian (n = 98), and mixed (n = 102) ancestry from the Caribbean island of Trinidad. We detected 19 different haplotypes containing DRB3, 8 containing DRB4, 6 containing DRB5, and 6 different haplotypes without DRB3/4/5 genes. Twenty-nine haplotypes were identified in Africans, 24 in the South Asians, and 32 in the mixed group. We detected significant differences between the populations, principally at the DQA1 and DQB1 loci, although the allele frequency for DRB1*0901 was highest in the Africans (p(c) < 0.05). Trinidad African and mixed groups were generally more diverse than the South Asians and displayed a wider range of DRB1-DQB1 associations; DQB1*02 and DQB1*0301 each associated with five to six different DRB1 alleles in the Africans and mixed group but only two in South Asians. In the Africans and the mixed group, DQB1*04 was found with DRB1*0302 and DRB1*04, but only with DRB1*08 in the South Asians. Trinidad Africans revealed consistencies with populations in Western, Central, and Northern Africa, but differed considerably from individual populations on the African continent. Trinidad South Asians displayed similar allele frequencies and associations to other populations from Northern India.

Alleles↗
PubMed2003

The origin and dispersion of human parasitic diseases in the old world (Africa, Europe and Madagascar).

The ancestors of present-day man (Homo sapiens sapiens) appeared in East Africa some three and a half million years ago (Australopithecs), and then migrated to Europe, Asia, and later to the Americas, thus beginning the differentiation process. The passage from nomadic to sedentary life took place in the Middle East in around 8000 BC. Wars, spontaneous migrations and forced migrations (slave trade) led to enormous mixtures of populations in Europe and Africa and favoured the spread of numerous parasitic diseases with specific strains according to geographic area. The three human plasmodia (Plasmodium falciparum, P. vivax, and P. malariae) were imported from Africa into the Mediterranean region with the first human migrations, but it was the Neolithic revolution (sedentarisation, irrigation, population increase) which brought about actual foci for malaria. The reservoir for Leishmania infantum and L. donovani--the dog--has been domesticated for thousands of years. Wild rodents as reservoirs of L. major have also long been in contact with man and probably were imported from tropical Africa across the Sahara. L. tropica, by contrast, followed the migrations of man, its only reservoir. L. infantum and L. donovani spread with man and his dogs from West Africa. Likewise, for thousands of years, the dog has played an important role in the spread and the endemic character of hydatidosis through sheep (in Europe and North Africa) and dromadary (in the Sahara and North Africa). Schistosoma haematobium and S. mansoni have existed since prehistoric times in populations living in or passing through the Sahara. These populations then transported them to countries of Northern Africa where the specific, intermediary hosts were already present. Madagascar was inhabited by populations of Indonesian origin who imported lymphatic filariosis across the Indian Ocean (possibly of African origin since the Indonesian sailors had spent time on the African coast before reaching Madagascar). Migrants coming from Africa and Arabia brought with them the two African forms of bilharziosis: S. haematobium and S. mansoni.

Africa↗
PubMed1988

Senegal.

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Africa↗
PubMed1993

Current status of the diagnosis and control of African horse sickness.

African horse sickness (AHS) is an infectious, non-contagious, highly fatal viral disease of Equidae, transmitted by arthropod vectors of the genus Culicoides, and endemic in Africa south and east of the Sahara. The disease is caused by a virus of the Reoviridae family, genus Orbivirus, and 9 serotypes have been recognized. Recent outbreaks of AHS in the Iberian peninsula and Northern Africa emphasize the need for accurate diagnosis and rapid implementation of control measures. In this paper, the epizootiological factors, clinical signs and necropsy findings of AHS are discussed, and an updated review of diagnostic laboratory methods together with a description of the main control measures is given.

Africa↗
PubMed1985

Guinea.

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Africa↗
PubMed1998

[Genomic subtypes of hepatitis C virus: epidemiology, diagnosis and clinical consequences].

Hepatitis C virus demonstrates a high degree of variability HCV isolates have been classified into at least six genotypes, according to the percentage of nucleotide sequence homology. Geographical differences in the distribution of virus genotypes are well documented. Types 1, 2 and 3 are the major types observed in Japan, Western Europe and North America; type 4 has been found in Central and Northern Africa and in the Middle East; type 5 has been described in South Africa, type 6 in South-East Asia. The relative prevalence of these genotypes varies between different regions. In the Indian subcontinent, subtype 1b seems to be the most prevalent type, but many isolates have been described, related to genotype 3, in Northern and Southern India, Pakistan and Nepal. HCV genotypes may have potential clinical implications: a) the association with the severity of liver disease is still controversial; b) the association between some genotypes, particularly 1b, and a poor response to interferon alpha therapy has been well established; c) genotyping may be useful for identifying some unusual modes of transmission of the virus. Finally, the variability of HCV virus has major implications for the design of new vaccines strategies since there is no cross-protection between different HCV types.

Genotype↗