RESUMEN
OBJECTIVE: Prevalence, intensity and incidence of schistosomosis and soil-transmitted helminthosis among school children in an ignored area in Yemen were determined. The study aimed to investigate the impact of single doses of Praziquantel or Albenedazole or both, relating to sanitary, socioeconomic and behavioral practices on the prevalence and intensity of infections. METHODS: Out of a total number of 897 pupils, 453 were randomly selected from AlMahweet town and 444 from rural surrounding areas. Millipore filtration, modified Kato and precipitation techniques were applied for urine and stool analysis. RESULTS: Prevalence rates were 27% for schistosomosis, 61% for ascariosis, 21% for trichuriosis, 2% for fascilosis, 0.3% for entrobiosis, 0.7% for hook worm infection and 0.2% for strongloydiosis. Factors found confounding the relationship between schistosomosis and residence, under logistic regression analysis, were sex and frequency of water contact. Probability of infection by Bilharzia for boys who reside in rural AlMahweet and visit the water source is 0.52, compared to 0.30 for their mates who reside in AlMahweet town. Odds ratio estimates accounted for via residence was 2.5, via water contact 1.7 and via boys 3.2. With regards to other helminthic infections, availability of latrines remained the only significant factor under ANOVA. CONCLUSION: In conclusion, annual campaigns for treatment as a single control measure can reduce the infection rate of S. mansoni by 62.5%, T. trichura by 48% and A. lumbricoides by 24%. Whereas for S. hematobium the appropriate time interval for intervention should be shortened according to the findings of a properly designed intervention study before used as a single control measure. Since 77% of the children were infected by other helminthes, therefore mass treatment should be extended to cover all children. For those boys in rural AlMahweet who visited the water source during the week before the interview, mass treatment for schistosomosis is recommended since the prediction of infection rate reached 52%.
Asunto(s)
Albendazol/uso terapéutico , Antihelmínticos/uso terapéutico , Antiprotozoarios/uso terapéutico , Helmintiasis/tratamiento farmacológico , Helmintiasis/prevención & control , Praziquantel/uso terapéutico , Esquistosomiasis Urinaria/tratamiento farmacológico , Esquistosomiasis Urinaria/prevención & control , Esquistosomiasis mansoni/tratamiento farmacológico , Esquistosomiasis mansoni/prevención & control , Suelo/parasitología , Agua/parasitología , Adolescente , Análisis de Varianza , Niño , Preescolar , Helmintiasis/epidemiología , Helmintiasis/transmisión , Humanos , Incidencia , Modelos Logísticos , Prevalencia , Factores de Riesgo , Salud Rural/estadística & datos numéricos , Esquistosomiasis Urinaria/epidemiología , Esquistosomiasis Urinaria/transmisión , Esquistosomiasis mansoni/epidemiología , Esquistosomiasis mansoni/transmisión , Distribución por Sexo , Cuartos de Baño/estadística & datos numéricos , Salud Urbana/estadística & datos numéricos , Yemen/epidemiologíaRESUMEN
T helper lymphocytes are important regulatory cells for the immune response in chronic hepatitis C. They recognize peptides, which are generated from the viral proteins by antigen processing and are bound to MHC (major histocompatibility complex) class II molecules. However, antigen processing might also result in non-immunogenic peptide fragments that can modify T cell activation. - To identify such peptide fragments in hepatitis C, we studied binding of 15 synthetic HCV core derived peptides to MHC class II molecules of 9 human homozygous typing B cell lines (HT-BCLs) as well as T cell proliferation in 41 HLA-typed patients with chronic hepatitis C. - We identified a peptide (HCV core aa 59-83) which bound to 7 HT-BCLs, whereas PBMC of only 2 out of 36 patients with the corresponding HLA-DR alleles proliferated in response to this peptide. Competition experiments indicated that small amounts of peptide aa 59-83 specifically inhibited the proliferative response to the recombinant core protein but not to core derived immunogenic peptides. Our data show that a peptide fragment from the HCV core region aa 59-83 can interfere in vitro with immune recognition of the HCV core protein.
Asunto(s)
Hepacivirus/fisiología , Hepatitis C Crónica/inmunología , Activación de Linfocitos/efectos de los fármacos , Linfocitos/inmunología , Linfocitos/virología , Fragmentos de Péptidos/farmacología , Proteínas del Núcleo Viral/farmacología , Linfocitos B , Línea Celular , Antígenos HLA-DR/sangre , Hepatitis C Crónica/sangre , Humanos , Linfocitos/efectos de los fármacos , ARN Viral/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Proteínas del Núcleo Viral/químicaRESUMEN
In order to characterize intrahepatic cytokine production, the mRNA levels of interleukin (IL)-2, -4, and -10 and interferon (IFN)-gamma were semiquantitatively determined by reverse-transcription competitive polymerase chain reaction in liver specimens from patients with chronic hepatitis C (n = 23), chronic hepatitis B (n = 9), or primary biliary cirrhosis (n = 12) and normal liver (control) specimens (n = 12). IL-4 mRNA was undetectable. Similar IL-10 mRNA levels were detected in all samples studied, including the controls. Mean IFN-gamma and IL-2 mRNA levels were elevated in chronic inflammatory liver disease. IL-2 mRNA levels were similar in all 3 patient groups, but intrahepatic IFN-gamma mRNA levels were significantly higher in chronic hepatitis C than in chronic hepatitis B or primary biliary cirrhosis patients. This predominance of IFN-gamma may indicate a lower susceptibility of hepatitis C virus to the antiviral effects of this cytokine. The presence of IL-10 in normal liver may impair the induction of antiviral immune responses.