Aranzazu Amor

Seroprevalence of HIV-1, HBV, HTLV-1 and Treponema pallidum among pregnant women in a rural hospital in Southern Ethiopia

BACKGROUND Human immunodeficiency virus type 1 (HIV-1), hepatitis B virus (HBV), human T-cell lymphotropic virus type 1 (HTLV-1) and Treponema pallidum represent major public health problems in sub-Saharan countries. These infections can be transmitted from mother to children and may cause severe morbidities in their offspring. Ethiopia is among the countries where HIV-1, HBV and T. pallidum infections are highly prevalent. However, information on seroprevalence of these infections among antenatal care attendees is very scarce and the majority of studies have been conducted in pregnant women from urban areas. OBJECTIVES To determine the seroprevalence of HIV-1, HBV, HTLV-1 and T. pallidum infections among pregnant women in a rural hospital in Southern Ethiopia. STUDY DESIGN A cross-sectional study was conducted among consecutive pregnant women attending a mother and child clinic in August 2008. RESULTS A total of 165 pregnant women were included. The seroprevalence of HIV-1 was 1.8% (95% confidence intervals [CI]: 0.6-5.2%), and for HBV (HBsAg seropositivity) was 6.1% (95% CI: 3.3-10.8%). Co-infection with HIV-1 and HBV was detected in one patient (prevalence: 0.6%; 95% CI: 0.1-3.4%). No cases of HTLV-1 infection and syphilis were found (95% CI: 0-2.3%). CONCLUSIONS A far from negligible percentage of pregnant women from rural areas harbour HBV, and to a lesser extent, HIV-1 infections. Continuing efforts to strengthen the existing health education program and comprehensive screening for all pregnant women are necessary to prevent mother-to-child transmission of HBV and HIV-1.

Is Infection by Dermatophilus congolensis Underdiagnosed

ABSTRACT Dermatophilus congolensis, which affects animal species, is an uncommon human infection. Few cases, mainly in tropical areas, have been reported. We describe the first human infection in Spain in a traveler returning from Central America. Diagnosis of human infection may be underestimated in people in contact with animals.

Seroreversion of HIV antibodies in patients with prolonged suppression of viraemia under HAART.

Prolonged virus suppression in chronically HIV-infected patients could hypothetically lead to antibody seroreversion. Eighty-four HIV-positive individuals with undetectable viraemia for longer than 5 years under HAART were examined. Only one individual, who had initiated HAART shortly after primary HIV infection, showed seroreversion. In contrast, the cure of hepatitis C virus (HCV) with interferon in 25 controls led to the loss of HCV antibodies in most cases. This information indirectly reflects that whereas HCV may be eradicable HIV is not.

Multidrug-resistant and heteroresistant Mycobacterium tuberculosis and associated gene mutations in Ethiopia

BACKGROUND The prevalence of multidrug-resistant tuberculosis (TB) among new and retreatment cases in 2011 in Ethiopia was 2.7% and 17.9%, respectively. However, data on heteroresistance and gene mutation profiles of Mycobacterium tuberculosis were not documented. METHODS A cross-sectional study was conducted on 413 TB-positive clinical specimens submitted between 2012 and 2014 to Bahir Dar Regional Laboratory Center for confirmation of multidrug resistance. Resistance determining genes were analyzed using a line probe assay. RESULTS Of 413M. tuberculosis isolates, 150 (36.3%) were multidrug-resistant, 19 (4.6%) were resistant only to rifampicin, and 26 (6.3%) were resistant to isoniazid. Of 169 rifampicin-resistant and 176 isoniazid-resistant isolates, only eight (4.7%) showed rifampicin heteroresistance and only two (1.13%) showed isoniazid heteroresistance. Failing of the rpoB WT8 gene with corresponding hybridization of rpoB MUT3 (S531L substitution) accounted for 85 (50.3%) rifampicin-resistant mutations. Among 176 isoniazid-resistant isolates, 155 (88.1%) strains had the Ser315Thr1 substitution. CONCLUSIONS The prevalence of multidrug-resistant M. tuberculosis was high in the study area. Ser531Leu and Ser315Thr1 substitutions were the highest gene mutations for rifampicin and isoniazid, respectively.

Molecular markers in plasmodium falciparum linked to resistance to anti-malarial drugs in samples imported from Africa over an eight-year period (2002-2010): impact of the introduction of artemisinin combination therapy

BackgroundDrug resistance is a major problem to control Plasmodium falciparum infection in endemic countries. During last decade, African countries have changed first-line treatment to artemisinin-based combinations therapy (ACT); sulphadoxine-pyrimethamine (SP) is recommended for Intermittent Preventive Therapy (IPT). Molecular markers related to P falciparum resistance were analysed for the period of transition from SP to ACT, in isolates imported from Africa.MethodsA first group of samples was taken in the period between June 2002 and June 2006 (n = 113); a second group in the period between November 2008 and August 2010 (n = 46). Several alleles were analysed by nested PCR-RFLP: 51, 59, 108, 164, in the pfdhfr gene; 436, 437, 540, 581, in the pfdhps gene; 86, 1246, in the pfmdr1 gene and 76, in the pfcrt gene. The prevalence of alleles in the groups was compared with the chi-squared or Fishers exact tests.ResultsThe pfdhfr N51I, C59R and S108N were over to 90% in the two groups; all samples had the I164. In the pfdhps, 437 G and 581 G, increased up to 80% and 10.9% (p = 0.024), respectively in the second group. The 540 G decreases (24% to 16.%) and the 436A disappears at the end of the follow-up (p = 0.004) in the second group. The 76I-pfcrt stayed over 95% in the two groups. Prevalence of 86Y-pfmdr1 decreased over eight years.ConclusionsPharmacological pressure affects the resistance strains prevalence. As for SP, the disappearance of 436A and the decrease in 540 G suggest that these mutations are not fixed. On the other hand, studies carried out after ACT introduction show there was a selection of strains carrying the SNPs N86Y, D1246Y in pfmdr1. In this work, the prevalence of pfmdr1- D1246Y is increasing, perhaps as a result of selective pressure by ACT. Continued surveillance is essential to monitor the effectiveness of treatments.

High prevalence of Strongyloides stercoralis in school-aged children in a rural highland of north-western Ethiopia: the role of intensive diagnostic work-up

BackgroundSoil-transmitted helminthiases (hookworms, Ascaris lumbricoides and Trichuris trichiura) are extremely prevalent in school-aged children living in poor sanitary conditions. Recent epidemiological data suggest that Strongyloides stercoralis is highly unreported. However, accurate data are essential for conducting interventions aimed at introducing control and elimination programmes.MethodsWe conducted a cross-sectional survey of 396 randomly selected school-aged children in Amhara region in rural area in north-western Ethiopia, to assess the prevalence of S. stercoralis and other intestinal helminths. We examined stools using three techniques: conventional stool concentration; and two S. stercoralis-specific methods, i.e. the Baermann technique and polymerase chain reaction. The diagnostic accuracy of these three methods was then compared.ResultsThere was an overall prevalence of helminths of 77.5%, with distribution differing according to school setting. Soil-transmitted helminths were recorded in 69.2%. Prevalence of S. stercoralis and hookworm infection was 20.7 and 54.5%, respectively, and co-infection was detected in 16.3% of cases. Schistosoma mansoni had a prevalence of 15.7%. Prevalence of S. stercoralis was shown 3.5% by the conventional method, 12.1% by the Baermann method, and 13.4% by PCR, which thus proved to be the most sensitive.ConclusionsOur results suggest that S. stercoralis could be overlooked and neglected in Ethiopia, if studies of soil-transmitted helminths rely on conventional diagnostic techniques alone. A combination of molecular and stool microscopy techniques yields a significantly higher prevalence. In view of the fact that current control policies for triggering drug administration are based on parasite prevalence levels, a comprehensive diagnostic approach should instead be applied to ensure comprehensive control of helminth infections.

Characterization of the Plasmodium falciparum Sarcoplasmic/Endoplasmic Reticulum Ca2+-ATPase Gene in Samples from Equatorial Guinea before Implementation of Artemisinin-Based Combination Therapy

Plasmodium falciparum resistance to the primary drugs used for treatment of malaria has become the main obstacle to malaria control. Artemisinin combination therapies are the current treatment strategy, and it has been suggested that resistance to artemisinin derivatives may be related to mutations in the Plasmodium falciparum sarcoplasmic-endoplasmic reticulum Ca2+-ATPase ortholog of the mammalian sarco-endoplasmic reticulum Ca2+ ATPase gene, known as the pfatp6 gene. Thus, the purpose of this study was to determine the prevalence of single-nucleotide polymorphisms (SNPs) in pfatp6. The presence of different SNPs was detected by polymerase chain reaction amplification of the pfatp6 gene, and then sequencing to identify all possible alleles of the gene. A total of 20 SNPs were detected, including eight SNPs that have not been previously described: K481R in Malabo; R801H on Annobon Island; and the synonymous SNPs a141t, c1788t, a2211g, t2739g, a2760c, and g2836a. The genotypic profile of pfatp6 in samples from Equatorial Guinea, may be a useful epidemiologic tool for monitoring local efficacy of artemisinin combination therapies.

Diagnóstico de las infecciones por subtipos no B del VIH-1 y por VIH-2

Resumen La diversidad genetica del virus de la inmunodeficiencia humana (VIH) constituye un reto para su identificacion y caracterizacion microbiologica. A la continua aparicion de nuevas variantes se une la diseminacion global de tipos, subtipos y formas recombinantes, lo que obliga a conocer la fiabilidad de las pruebas diagnosticas empleadas para reconocer dichas cepas. En esta revision se analizan los problemas que actualmente plantean los metodos de cribado, diagnostico y monitorizacion de las variantes geneticas distintas del VIH-1 subtipo B. Tambien se examina el rendimiento de algunos algoritmos diagnosticos de introduccion mas reciente, como los propuestos para caracterizar el tropismo viral. Mientras que el comportamiento de las pruebas serologicas y de acidos nucleicos es excelente para la mayoria de las cepas del VIH, exceptuando las geneticamente mas separadas (VIH-1 grupos O, N y VIH-2), el de las herramientas bioinformaticas es mas pobre, y principalmente es fiable para el subtipo B del VIH-1. En conclusion, la continua diversidad genetica del VIH obliga a estar atento al rendimiento de las pruebas de cribado y es un estimulo constante para el desarrollo de tecnicas moleculares que aseguren la deteccion de todas las infecciones por VIH. La incorporacion de los resultados de estudios in vitro y clinicos sobre las variantes distintas del VIH-1 subtipo B permitira una mejora de las plataformas bioinformaticas.

Imported Dengue Infection in a Spanish Hospital with a High Proportion of Travelers from Africa: A 9-Year Retrospective Study

Epidemiological data on dengue in Africa are still scarce. We investigated imported dengue infection among travelers with a high proportion of subjects from Africa over a 9-year period. From January 2005 to December 2013, blood samples from travelers with clinical suspicion of dengue were analyzed. Dengue was diagnosed using serological, antigen detection, and molecular methods. Subjects were classified according to birthplace (Europeans versus non-Europeans) and last country visited. Overall, 10,307 serum samples corresponding to 8,295 patients were studied; 62% were European travelers, most of them from Spain, and 35.9% were non-Europeans, the majority of whom were born in Africa (mainly Equatorial Guinea) and Latin America (mainly Bolivia, Ecuador, and Colombia). A total of 492 cases of dengue were identified, the highest number of cases corresponding to subjects who had traveled from Africa (N = 189), followed by Latin America (N = 174) and Asia (N = 113). The rate of cases for Africa (4.5%) was inferior to Asia (9%) and Latin America (6.1%). Three peaks of dengue were found (2007, 2010, and 2013) which correlated with African cases. A total of 2,157 of past dengue infections were diagnosed. Non-Europeans who had traveled from Africa had the highest rate of past infection (67.8%), compared with non-Europeans traveling from Latin America (38.7%) or Asia (35%). Dengue infection in certain regions of Africa is underreported and the burden of the disease may have a magnitude similar to endemic countries in Latin America. It is necessary to consider dengue in the differential diagnosis of other febrile diseases in Africa.

Diarrhoeagenic Escherichia coli pathotypes in travellers attending a tropical medicine unit in a Spanish hospital.

Travellers’ diarrhoea is the most common travel-related illness. More than 60 % of cases are caused by a variety of bacterial enteropathogens, of which diarrhoeagenic Escherichia coli (DEC) is a significant contributor (Riddle et al., 2006; Shah et al., 2009). The major distinguishing factors between pathogenic and non-pathogenic E. coli strains is the presence of virulence genes, which encode various known mechanisms of pathogenicity. Based on these virulence factors and the patient clinical picture, at least five pathotypes of DEC have been described: verocytotoxin (VT)-producing E. coli (VTEC), enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC) and enteroaggregative E. coli (EAEC). VTEC strains produce VT1 and/or VT2. ETEC is defined by the presence of heat-labile and heat-stable E. coli enterotoxins, encoded by eltA and estA genes, respectively. EPEC is associated with the virulence factor intimin, encoded by the eae gene. The eae gene may also be present in VTEC strains. EPEC is divided into two types according to the presence of bundle-forming pili, a fimbrial adhesin that is a virulence determinant of typical EPEC but is absent from atypical EPEC (aEPEC). EIEC strains are related closely to Shigella spp. in terms of phylogeny and pathogenesis, and are characterized by the presence of the ipaH gene (Kaper et al., 2004). EAEC strains are characterized by a DNA fragment sequence known as CVD432 that usually also contains the virulence gene aggR. Serotyping and biochemical analysis have been widely applied in the diagnosis of gastrointestinal pathogens, but cannot be used for identifying DEC pathotypes. For this reason, DEC infections are often undiagnosed. Identification of the characteristic virulence genes, by hybridization or PCR, is an obvious choice for DEC diagnosis (Persson et al., 2007).