Human paragonimiasis in Viet Nam: epidemiological survey and identification of the responsible species by DNA sequencing of eggs in patients' sputum

Parasitological and sero-epidemiological surveys for human paragonimiasis were conducted in three provinces of Viet Nam. A total of 590 participants from two known endemic areas of human paragonimiasis (Sinho district of Laichau province and Lucyen district of Yenbai province) and from Dakrong district of Quangtri province where we recently found crab hosts heavily infected with Paragonimus westermani metacercariae. By multiple dot-ELISA screening, 28 (12.7%) out of 220 participants in Sinho district of Laichau province and 4 (3.3%) out of 120 participants in Lucyen district of Yenbai province were proven to be antibody-positive against the Paragonimus antigen. None of the 250 sera of the residents in Dakrong, Quangtri province, gave sero-positivity. Among a total of 32 sero-positive patients Paragonimus eggs were found in 6 cases. ITS2 sequences were successfully determined from a single Paragonimus egg from each patient. The results of homology search by BLAST and alignment clearly confirmed that Paragonimus eggs collected from 6 patients were all of Paragonimus heterotremus. The pathogenicity of P. westermani for human paragonimiasis in Viet Nam is still questionable and needs to be explored in the future.     

Characterization of M. tuberculosis strains from west African patients by spoligotyping

Analysis of Mycobacterium tuberculosis strains was carried out using isolates collected from 69 Senegalese and 20 Ivory Coast tuberculosis patients. These 89 isolates were typed by means of the spoligotyping technique, showing clusterized populations of bacterial strains. In the Senegalese patients, 35 genetic profiles were observed with 10 clusters of spoligotypes from 44 isolates. Among Ivory Coast patients, 11 spoligotypes were found for 20 isolates. A particular cluster of isolates was evident both in Senegalese (10) and Ivory Coast (11) patients. These results show the existence of polymorphism of the direct repeat region for African M. tuberculosis strains. However they suggest that additionnal markers are needed for accurate epidemiological studies in areas that are highly endemic for tuberculosis.     

Skin test for paragonimiasis among schoolchildren and villagers in Namback District, Luangprabang Province, Lao PDR

As a part of a broader effort to determine the status of Paragonimus species infection in Lao PDR, an epidemiological survey was conducted on villagers and schoolchildren in Namback District between 2003 and 2005. Among 308 villagers and 633 primary and secondary schoolchildren, 156 villagers and 92 children evidenced a positive reaction on a Paragonimus skin test. Only 4 schoolchildren out of 128 skin test-positive cases had Paragonimus sp. eggs in their sputum, all of which was collected on 1 day. Several types of crabs, which were identified as the second intermediate host of the Paragonimus species, were collected from markets and streams in a paragonimiasis endemic area for the inspection of metacercariae. Among the examined crabs, only "rock crabs" (Indochinamon ou) harbored Paragonimus sp. metacercariae, and it is speculated that the life cycle of Paragonimus sp. was maintained via rock crabs in Namback District, Lao PDR.     

Seroepidemiology of human immunodeficiency virus in Africa.

Serum samples from 6015 African subjects without symptoms of the acquired immune deficiency syndrome (AIDS) or contact with the disease were examined for antibodies to the human immunodeficiency virus by a combination of an enzyme linked immunosorbent assay and radioimmunoprecipitation (2567 samples) or by immunofluorescence (3448 samples). Serum samples had been collected between 1976 and 1984 in Senegal (n = 789), Liberia (935), Ivory Coast (1195), Burkina Faso (299), Nigeria (536), Gabon (1649), Zaire (15), Uganda (164), and Kenya (433). Only four samples contained antibodies. Three of these were from attenders at the Lambarene clinic in Gabon and one from a villager in Senegal. By contrast, two out of six AIDS suspects from Guinea-Bissau, all 13 patients with AIDS from Kinshasa (Zaire), and two out of three of their contacts were seropositive, all these specimens having been collected in 1985. These data show that fewer than one in a 1000 subjects were seropositive for AIDS at the time of sampling before 1985 and do not support the hypothesis of the disease originating in Africa.     

Wage rentals for reproducible human capital: evidence from Ghana and the Ivory Coast

Education, child nutrition, adult health/nutrition, and labor mobility are critical factors in achieving recent sustained growth in factor productivity. To compare the contribution of these four human capital inputs, an expanded specification of the wage function is estimated from household (LSMS) surveys of the Ivory Coast and Ghana. Specification tests assess whether the human capital inputs are exogenous, and instrumental variable techniques are used to estimate the wage function. Smaller panels from the Ivory Coast imply the magnitude of measurement error in the human capital inputs and provide more efficient instruments to estimate the wage equation. The conclusion emerges that weight-for-height and height are endogenous, particularly prone to measurement error, and heterogeneous in their effects on wages. Overall returns to these four forms of human capital are similar within each country for men and women, but education and migration returns are higher in the more rapidly growing Ivory Coast, and the wage effects of child nutrition proxied by height are greater in poorer, more malnourished Ghana.     

ELISA for detection of IgM and IgG antibodies to sandfly fever sicilian virus

• •An enzyme-linked immunosorbent assay (ELISA) was developed to detect specific human immunoglobulin G and M antibodies to sandfly fever Sicilian (SFS) virus. Acute and early convalescent serum pairs with ⩾ 7 days between the 2 specimens were available from 20 patients and all showed significant optical density (OD) increase and significant titre rise (⩾ 4-fold) by IgG ELISA. However, negative or borderline-positive sera were found as late as 11 days after onset of symptoms when tested by IgG ELISA.
• •Specific IgM antibodies were detected during the first week of symptoms, and maximum OD values were obtained during the first 4 weeks after onset of disease. The IgM OD values declined over the following 3–9 months. All sera collected later than 14 months post-onset were negative by IgM ELISA.
• •The combination of early antibody response and the need to test only one serum specimen gives IgM ELISA an advantage over IgG ELISA in patient diagnosis.
• •The IgG ELISA was also evaluated as a seroepidemiological tool and compared to a plaque reduction neutralization test (PRNT) using sera from a normal Cypriot population. Of 183 sera tested, 34 (19%) were positive in plaque reduction neutralization tests (PRNT) and 113 (62%) by IgG ELISA. A number of PRNT-negative sera were strongly positive by IgG ELISA and also by indirect immunofluorescence test, which may suggest the presence of a virus related to SFS in Cyprus which has not yet been isolated.

     

应用明胶颗粒凝集试验检测人免疫缺陷病病毒(HIV-1)抗体

明胶颗粒凝集试验是测定HIV-1抗体的新方法。本研究将明胶颗粒凝集试验与ELISA法、蛋白印迹法和间接免疫荧光试验做了比较,观察本方法的敏感性和特异性。共检测了195份来自法国和非洲象牙海岸的血清,凡是蛋白印迹法阳性的血清,明胶颗粒凝试验都是阳性。这表明本方法是特异和敏感的,方法简便,不需特殊仪器,省时,可用于HIV-1抗体的筛选,但多数蛋白印迹法可疑的血清,明胶颗粒试验均阴性。因此,对蛋白印迹法测出的可疑者应该用数种方法进行追踪检测。     

Histoire d’un itinéraire épidémiologique entre le Burkina Faso et la C?te d’Ivoire : le cas des foyers de maladie du sommeil de Koudougou

In the first half of the XXth century, while Upper-Volta (now Burkina Faso) was suffering a terrible epidemic of sleeping sickness, the French colonial administration encouraged the movement of people from Upper-Volta to Ivory Coast to meet their demands for labour. This led to the establishment of Mossi villages, such as those of Koudougou, in the Ivorian forest with populations originating from areas of Upper-Volta that were not only densely populated but also severely affected by sleeping sickness. Since 2000, most cases of sleeping sickness in the Koudougou district of Burkina Faso have been in people originally from Ivory Coast. Who are they? Where did they settle in Burkina Faso? Where do they come from in Ivory Coast? After having retraced the epidemiological history of Koudougou villages in Burkina Faso and Ivory Coast, the history of ten cases of sleeping sickness detected passively at Koudougou hospital since 2000 were analysed. All cases originated from the forest area of Ivory Coast. Understanding the spread of sleeping sickness between Burkina Faso and Ivory Coast will assist in the identification of areas of disease risk.     

Specific antibodies bound to secretory IgA in the sera of patients with intestinal infections]

Specific IgA and sIgA antibodies were studied in the sera of patients suffering from various intestinal diseases (dysentery, salmonellosis, typhoid fever, chronic typhoid carrier state) and in the sera of healthy persons immunized by parenteral route with typhoid alcohol vaccine. The nature of antibodies was identified in Coombs' test, using monospecific antisera to alpha-chain and to the secretory component. IgA and sIgA antibodies were revealed most frequently in the sera of dysentery patients and of chronic typhoid carriers. No sIgA antibodies were found in the sera of subcutaneously immunized persons. The presence of specific sIgA antibodies in the serum reflects the participation of local immune mechanisms in the formation of systemic immunity in the intestinal infections.     

Molecular variation in endothelial nitric oxide synthase gene (eNOS) in western Mediterranean populations

Endothelial nitric oxide synthase (eNOS or NOS3) is the main responsible for nitric oxide (NO) production in vascular system and different polymorphisms have been identified in epidemiological studies. Trying to test the eNOS genetic variation in general populations we studied the 27-bp VNTR in intron 4 and G894T substitution in exon 7 markers in 6 Western Mediterranean populations (3 from Iberian Peninsula, 1 from North Africa, and 2 from Sardinia) and a sample from Ivory Coast. The VNTR frequencies in Western Mediterranean and Ivory Coast fit well into the ranges previously described for Europeans and Sub-Saharans respectively, and a typical African allele has been detected in polymorphic frequencies in the Berber sample. The G894T substitution presents the highest frequencies described for the T allele in the North Mediterranean populations. Linkage disequilibrium is present between both markers in all populations except in the Ivory Coast sample. The variation found for these polymorphisms indicates that they may be a useful tool for population studies even at microgeographical level.     

ELISA of rat sera infected with Paragonimus iloktsuenensis

Enzyme-linked immunosorbent assay (ELISA) of paragonimiasis iloktsuenensis rat sera was performed using crude antigens of Paragonimus iloktsuenensis (PIA), P. westermani (PWA) and Clonorchis sinensis (CSA). Three crude antigens (PIA, PWA, CSA) were prepared to saline homogenated supernatants of whole adult worms. Infected rat sera were obtained biweekly from the albino rats fed 50-80 metacercariae of P. iloktsuenensis through gastric catheter. Experimental groups were divided into 4 groups: GI (controls), GII, GIII and GIV according to 1-7 worms as GII, 10-19 worms as GIII and 22-40 worms as GIV, respectively. In ELISA, the mean OD values of each group for the homologous antigen (PIA) were increased significantly compared to the control sera at the 4th week of infection. With the progress of duration of infection, the mean OD values of infected sera of GII & GIV continuously increased up to the 12th week (last week), but in GIII the mean OD value increased until the 10th week. No significance was noted among the infection dose groups (GII, GIII and GIV), after the 6th week of infection. Also, the OD values of all infected rats did not show any proportional relationships to the number of worms recovered. In brief, the antibody productivity of individual rats were strongly different. The rat sera infected with P. iloktsuenensis cross-reacted with those infected with P. westermani or C. sinensis, as identified by OD values.     

Fragmented forests, evolving flies: molecular variation in African populations of Drosophila teissieri

Microsatellite variation from eight loci was studied in five populations of Drosophila teissieri, a fruit-fly found only in the rain forests of sub-Saharan Africa. Five noncontiguous rain forest sites (from Tanzania, Gabon and Ivory Coast) were sampled to measure the effects of historical forest fragmentation on population structure in an obligatory forest-dwelling species. The Ivory Coast and Gabon populations showed a wider range of alleles, different modal alleles and had a higher genetic diversity than the three East African populations. As could be expected, genetic differentiation (FST) was significantly correlated with physical distance, but the westernmost population (Ivory Coast) showed values that were intermediate between the central (Gabon) and Eastern (Tanzania) populations. A migration-drift equilibrium in a stable continuum of populations did not appear adequate to describe the observed distribution. It seems probable that the species has undergone abrupt changes involving isolation, merging and migration of populations, as a consequence of repeated waves of forest fragmentation and coalescence.     

Sero-epidemiological survey of scrub typhus.

A total of 1017 human sera from ecologically different areas in the states of Rajasthan and Jammu & Kashmir were subjected to the CF test using the Gilliam strain antigen of R. tsutsugamushi. Results revealed that 2.4% and 3.5% of the populations examined in the two states respectively, were found to possess antibodies to the test antigen. The titres of positive sera varied from 1:8 to 1:32. Findings of this survey could be correlated with the local topography, presence or absence of vector and the exposure of susceptible population to the rickettsial agent. However, the presence of hidden foci in the neighbouring areas not covered by the current survey cannot be ruled out.     

Metacercarial infections of Paragonimus westermani in freshwater crabs sold in markets in Seoul

Status of metacercarial infections of Paragonimus westermani was observed in freshwater crabs, which were purchased at 3 markets in its peak season of 1990. All of 85 crabs were Eriocheir japonicus. No other species of Eriocheir were found. When crushed muscle and viscera was examined individually, the infection rate was 11.8%; and mean number of metacercariae was 2.1 per infected crab. Unless adequately cooked, freshwater crabs are still potential sources of human paragonimiasis.     

Population genetic analysis of the haemoglobins of the black-chinned tilapia

Three highly heterogeneous haemoglobin phenotypes, each composed of 22 different haemoglobin components, were identified among 17 West African populations of Sarotherodon melanotheron . Natural populations from (1) Senegal, (2) Ivory Coast/Ghana/Togo/Benin, and (3) Congo were distinguished. The heterogeneity and specificity of these respiratory pigments was based on genetic variations at the globin chain coding loci. In total, five different α-chains and four different β-chains were detected by acidic urea polyacrylamide gel electrophoresis (PAGE). Combinations of α-chains were characteristic for populations in (1) Senegal, (2) Ivory Coast, (3) Ghana/Togo/Benin, and (4) Congo. Pronounced variations at the β-globin chain cluster were found by acidic urea triton PAGE. Cladistic analyses of the globin chain characteristics confirmed the validity of the following taxonomic units previously ranked as sub-species: (1) populations from Ivory Coast, Ghana, Togo and Benin belong to the sub-species S. m. melanotheron ; (2) populations from Senegal form genetically a separate cluster representing the sub-species S. m. heudelotii ; (3) the Congo population, morphologically considered to represent the sub-species S. m. nigripinnis , forms another distinct unit; but there was no evidence of S. m. paludinosus within the samples from Senegal.     

Evaluation of IgG4 Subclass Antibody Detection by Peptide-Based ELISA for the Diagnosis of Human Paragonimiasis Heterotrema

A synthetic peptide was prepared based on the antigenic region of Paragonimus westermani pre-procathepsin L, and its applicability for immunodiagnosis for human paragonimiasis (due to Paragonimus heterotremus) was tested using an ELISA to detect IgG4 antibodies in the sera of patients. Sera from other helminthiases, tuberculosis, and healthy volunteers were used as the references. This peptide-based assay system gave sensitivity, specificity, accuracy, and positive and negative predictive values of 100%, 94.6%, 96.2%, 100%, and 88.9%, respectively. Cross reactivity was frequently seen against the sera of fascioliasis (75%) and hookworm infections (50%). Since differential diagnosis between paragonimiasis and fascioliasis can be easily done by clinical presentation and fascioliasis serology, this cross reaction is not a serious problem. Sera from patients with other parasitoses (0-25%) rarely responded to this synthetic antigen. This synthetic peptide antigen seems to be useful for development of a standardized diagnostic system for paragonimiasis.     

Quantitative study of alpha-1-antitrypsin in an ethnic group of Ivory Coast: the Abrons]

A logarithmic-normal distribution of the concentrations of alpha1AT in 578 Abrons in Ivory Coast was found. A significant, negative logarithmic regression of alpha1AT rates according to age is demonstrated. alpha1AT rate = 0,376 (log age) + 3,003 The quantitative analysis by immunoprecipitation of Technicon only does not permit a definitive conclusion as to the presence of allele Z.     

Presence of IgM Antibodies Which Sensitize HIV-1-Infected Cells to Cytolysis by Homologous Complement in Long-Term Survivors of HIV Infection

Although human cells are resistant to homologous human complement due to the presence of species-specific membrane inhibitors, a naturally occurring IgM antibody which recognizes an asialo-oligosaccharide can sensitize HIV-1-infected cells for complement-mediated cytolysis. Therefore, we investigated whether long-term survivors of HIV-1 infection harbor such antibodies in their sera. Thirty of 31 sera from HIV-1 seropositive hemophilia patients who have survived HIV-1 infection 10 years or more showed appreciable cytolytic activity, while only 2 sera of 10 seropositive patients presumed to have been infected with HIV-1 (due to sexual contact) more recently showed cytolytic activity. On the other hand, only 7 out of 43 sera from seronegative hemophilia patients showed cytolytic activity. Immunofluorescence staining for IgM on HIV-L -infected cells essentially correlated with the cytolytic capacity of the sera. Therefore, naturally occurring IgM antibodies and/or generated IgM antibodies reactive with the HIV-L -infected cells in patients might have been responsible for long-term survival due to complement-mediated immune cytolysis which may, in conjunction with cytotoxic T lymphocytes, synergistically suppress the infected cells in vivo. Therefore, the transfusion of such IgM antibodies could be effective for the treatment of HIV-L -infected individuals.     

A comparison of variation between a MHC pseudogene and microsatellite loci of the little greenbul (<Emphasis Type="Italic">Andropadus virens</Emphasis>)

Background  

We investigated genetic variation of a major histcompatibility complex (MHC) pseudogene (Anvi -DAB1) in the little greenbul (Andropadus virens) from four localities in Cameroon and one in Ivory Coast, West Africa. Previous microsatellite and mitochondrial DNA analyses had revealed little or no genetic differentiation among Cameroon localities but significant differentiation between localities in Cameroon and Ivory Coast.     

Two L1-peptides are excellent tools for serological detection of HPV-associated cervical carcinoma lesions

A persistent high risk human papillomavirus (HR-HPV) infection causes cervical intraepithelial lesions and cervical carcinoma. There is evidence that detecting anti-L1 antibodies could be successfully used for discriminating between cervical lesion patients and women having normal cytology. It was found that peptides 18283 (55PNNNKILVPKVSGLQYRVFR74) and 18294 (284LYIKGSGSTANLASSNYFPT300) from the L1-surface exposed regions were specifically recognised by antibodies from the cervical lesion patient sera. These peptides were tested against 165 womens' normal cytology sera and 148 cervical lesion or cervical cancer patients' sera. Less than 3.6% of women's normal cytology sera recognised peptides 18283 or 18294; on the contrary, 91% to 96% of the cervical lesion (CIN I to CIN III) or cervical cancer patient sera recognised peptides 18283 and 18294. These data show that anti-peptide 18283 and 18294 antibodies in the patients' sera are strongly associated with the presence of HR-HPV associated cervical lesions, showing 92-97% sensitivity and 89-95% specificity in recognising precancerous and cervical cancer patients. These two peptides could be excellent tools for use in large-scale serological screening of women populations at risk of developing cervical carcinoma.