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.

BACKGROUND: Drug 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. METHODS: A 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 Fisher's exact tests. RESULTS: The 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. CONCLUSIONS: Pharmacological 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.

Is infection by Dermatophilus congolensis underdiagnosed?

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.

Hospital-based surveillance for HTLV-1/2 infections in Spain.

In Western countries, HTLV-1 infection is recognized mainly among foreigners coming from endemic areas. In contrast, HTLV-2 is found predominantly in native intravenous drug users (IDUs). Spain has experienced a large wave of immigration, which could have influenced the current prevalence and distribution of HTLV-1 and HTLV-2 infection. A 1-day cross-sectional survey was carried out in May 2005 in 13 hospitals distributed across Spain. A total of 2873 outpatient subjects were screened for HTLV-1/2 antibodies. Although the majority of the study population consisted of native Spaniards, 206 (7.2%) were immigrants. Two cases of HTLV-1 and one of HTLV-2 infection were found (overall prevalence, 0.1%). The two individuals with HTLV-1 were immigrants from endemic areas and the single case of HTLV-2 infection was a former Spaniard IDU coinfected with HIV-1. In summary, the current prevalence of HTLV-1/2 infection in Spain is low, with no evidence of spread beyond the classical risk groups. However, a rapidly growing population of immigrants from HTLV-1-endemic areas in Spain could modify this pattern and periodic surveillance studies including both natives and immigrants are warranted.

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.

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.

Sustained virological response following HCV therapy is associated with non-progression of liver fibrosis in HCV/HIV-coinfected patients.

BACKGROUND: Chronic hepatitis C leads to progressive liver fibrosis, which is accelerated in HIV-coinfected patients. Unfortunately, hepatitis C virus (HCV) therapy provides sustained virological response (SVR) to only 40% of coinfected patients. Little is known about the regression of hepatic fibrosis in treated patients. METHODS: All coinfected patients who had completed a full course of HCV therapy at our institution were identified. Liver fibrosis staging was estimated using non-invasive procedures at the time of initiating HCV therapy and reassessed at the last patient's follow-up using elastometry (FibroScan). RESULTS: A total of 103 coinfected patients were identified. HCV genotype distribution was 1 (63%), 3 (29%) and 4 (8%). SVR had been attained by 34 individuals, while the remaining 69 were non-responders and/or relapsers. The mean lag time between the end of HCV therapy and the current assessment of liver fibrosis was 40 months, without differences between groups. Metavir score estimates were comparable before initiating HCV therapy in SVR and non-SVR patients. By contrast, current Metavir scores were lower in SVR than in non-SVR patients; for instance, F3-F4 estimates were 12% versus 54%, respectively (P < 0.001). Moreover, the longer the time elapsed after HCV therapy, the lower the liver fibrosis in SVR patients (rho = -0.39; P = 0.02). Conversely, liver fibrosis staging directly correlated with the lag following HCV therapy in non-SVR patients (rho = 0.25; P = 0.03). CONCLUSIONS: SVR after HCV therapy is associated with non-progression of liver fibrosis in HCV/HIV-coinfected patients, although this benefit may not be universal and improvement only been recognizable after several years of follow-up.

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

BACKGROUND: Soil-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. METHODS: We 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. RESULTS: There 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. CONCLUSIONS: Our 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.

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.

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 Ca(2+)-ATPase ortholog of the mammalian sarco-endoplasmic reticulum Ca(2+) 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.

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.

[Diagnosis of HIV-1 non-B subtypes and HIV-2]. / Diagnóstico de las infecciones por subtipos no B del VIH-1 y por VIH-2.

The high genetic diversity of human immunodeficiency virus (HIV) poses a significant challenge to the diagnosis and microbiological characterization of HIV infection. Because of the continual emergence of new variants and the global spread of HIV groups, subtypes and recombinant forms, accurate diagnostic tools are of prime importance. The present review analyzes the problems posed by HIV assays for antibody screening, nucleic acid testing and patient monitoring in HIV-1 non-B subtypes, as well as the utility of some recently introduced genetic algorithms, such as those proposed for the characterization of viral tropism. Overall, the reliability of serological and molecular tests for HIV-1 strains is high, except for the more genetically diverse HIV variants (HIV-1 group O, N, and HIV-2). In contrast, genetic algorithms show acceptable accuracy for HIV-1 subtype B, but are less accurate for non-B subtypes. In conclusion, the ongoing evolution of HIV requires constant monitoring of the performance of screening tests and provides a stimulus to the development of molecular assays to detect all spreading and emerging HIV variants. The availability of both in vitro and clinical data from studies of HIV-1 non-B subtypes will improve the performance of bioinformatics tools.