The linear antigenic epitopes of the Epstein-Barr virus replication activator protein (ZEBRA), recognised by specific serum IgG in nasopharyngeal carcinoma (NPC), were determined. This was achieved by synthesizing the entire amino acid sequence of ZEBRA as a set of 29, 22-residue peptides with an overlap of 14 amino acids. The ZEBRA peptides were tested in enzyme-linked immunosorbent assay (ELISA) for IgG binding in sera from 37 selected NPC patients who had IgG antibodies to the native ZEBRA protein. The most immunogenic epitope was peptide 1 at the amino-terminal end with 36 of the sera reactive against it. Further analysis of peptide 1, using the multipin peptide-scanning technique, defined a 10-amino-acid sequence FTPDPYQVPF, which was strongly bound by IgG. Two other regions of ZEBRA were also identified as immunodominant IgG epitopes, namely peptide 11 (amino acids 82-103) and peptide 19/20 (amino acids 146-175) with 8-13 of the NPC sera reactive against the peptides. The number of peptides reactive with individual NPC serum varies from 1 to 6 or more and there is some correlation between a greater number of peptide (at least 4) bound and a higher (at least 1:40) titre of serum IgA to viral capsid antigen. The immunodominant ZEBRA peptide 1 could be utilised in IgG ELISA for the detection of NPC.
This paper presents the socio-economic profile of households in the Family Dynamics Study (FDS) (1997-2001) and makes comparisons with the earlier Functional Groups Study (FGS) (1992-1996). For the current study, FGS villages with a high prevalence of child malnutrition were purposively selected. In each village selected, all households were included, and interviews with a structured questionnaire were conducted in April-May 1998. Incomes were generally low and incidence of poverty was high; 49.6% of the households were under the poverty line income, of which 37.2% were poor and 12.4% were hard core poor. Overall, only 23.2% of heads of households were in agricultural occupations, others being primarily waged workers and petty traders. Livestock rearing was widespread (57.8%), and most households (90.4%) owned at least one motorised vehicle, the most common being the motorcycle. The majority of households had refrigerators (73.6%), washing machines (58.8%), and televisions (91.1%); but telephones (42.2%), mobile phones (6.1%) and computers (2.3%) were less common. Although 99.7% of households had electricity supply and 95.1% had either a flush or pour flush latrine, only 57.4% had piped water supply. In comparison to the FGS, poverty in the current study is lower (49.6% of FDS households are poor compared to 55.2% of FGS households), the proportion of household heads in agricultural occupations is also lower (26.9% compared to 55.3%), while all other socioeconomic indicators were better, except for piped water supply, which remains inadequate for households in the current study.