Prevalence of antibodies to Toxoplasma gondii among urban and rural residents in the Philippines.

A survey of antibodies to Toxoplasma gondii was carried out among residents in urban (Metro Manila) and rural (Mindoro and Leyte) areas in the Philippines. A total of 1,173 serum samples were examined for Toxoplasma antibody by an ELISA method. The overall seropositivity was 11.1% (n=904, 12.4% in males, 10.0% in females) in Metro Manila, 61.2% (n=152, 63.3% in males, 53.1% in females) in Mindoro, and 30.1% (n=113, 34.3% in males, 22.5% in females) in Leyte, indicating significantly higher (p<0.001) seropositivities in rural than urban settings. No significant differences in seropositivities were observed between males and females. In each group, seropositivity tended to increase with age of the subjects.     

Cytomegalovirus-induced flare of systemic lupus erythematosus.

Exacerbations of systemic lupus erythematosus (SLE) may be brought about by a number of factors, including stress, surgery, or infection. By interacting with immunologic mediators or by producing immune complexes, infections may exacerbate underlying autoimmune diseases such as SLE. This illustrative case report describes a woman who had SLE for 20 years who contracted cytomegalovirus mononucleosis that induced an exacerbation of her SLE.     

A review of Japanese encephalitis cases in the Philippines (1972-1985)

Few studies have shown that JE does occur in the Philippines with the majority of the cases affecting the 1-10 year age group in places where rice fields abound. The morbidity rate is 15-17%, with a mortality rate of about 7-30%.     

Demonstration of safety and enhanced seroprotection against hepatitis B with investigational HBsAg-1018 ISS vaccine compared to a licensed hepatitis B vaccine

Adults 40 years of age and older have been shown to be hypo-responsive immunologically to the currently available hepatitis B virus (HBV) vaccines. Three intramuscular doses of a Toll-like receptor 9 agonist, 1018 immunostimulatory sequence (1018 ISS) adjuvant, combined with recombinant hepatitis B surface antigen (HBsAg) demonstrated faster, superior, and more durable seroprotection than three doses of a licensed comparator HBV vaccine (Engerix-B^®). This investigational vaccine, HBsAg-1018 ISS, was well tolerated with a safety profile similar to the comparator vaccine. These results suggest that HBsAg-1018 may be more effective in this hypo-responsive population.     

Hepatitis A shifting epidemiology in South-East Asia and China

A review of the epidemiology of hepatitis A virus (HAV) infection over the last 20 years shows shifting patterns in the prevalence of antibodies to HAV (anti-HAV) throughout South-East Asia and China. A number of countries have shifted from high to moderate and from moderate to low endemicity, with a corresponding increase in the age of exposure from childhood to early adulthood. The changes have resulted from improvements in hygiene, sanitation and the quality of drinking water, reflecting improvements in living standards and socioeconomic progress. In general in the late 1970s and early 1980s, 85-95% of the population of developing countries like the Philippines, Korea, China and Thailand were anti-HAV-positive by age 10-15 years, compared with only about 50% in the more affluent countries like Malaysia and Singapore. In the early 1990s, 85-95% of the population were immune by age 30-40 years in the Philippines, Korea, China and Thailand, and by 50 years of age and above in Malaysia and Singapore. Similar trends were noted in Hong Kong, Taiwan and Japan. Exposure to HAV at a later age may be associated with an increase in hepatitis A morbidity and a greater propensity for outbreaks.     

A new isolate of hepatitis B virus from the Philippines possibly representing a new subgenotype C6

Hepatitis B virus (HBV) genotypes and subgenotypes show distinct geographical prevalence. A genotyping analysis of 28 samples from asymptomatic HBV carriers from the Philippines gave a distribution of HBV genotypes as expected from a previous study: 54% B (15/28), C5 18% (5/28), 14% D (4/28), 7% A1 (2/28). In addition, 7% (2/28) of the samples showed a double infection with genotypes B and D. One of the isolates sequenced completely, ph105, did not group into one of the known subgenotypes after phylogenetic analysis. Ph105 formed a separate clade in genotype C. With a genome length of 3,215 nt. and a serological subtype adr, ph105 exhibited the main features of most genotype C strains. However, ph105 differed by 4.1–7.2% from HBV subgenotypes C1 to C5 when comparing the nucleotide sequence of whole genomes. With only 4.1% difference ph105 was most closely related to subgenotype C2. SimPlot analysis gave no indication for recombination with known HBV genotypes. Ph105 fulfils all criteria for a new subgenotype C6. J. Med. Virol. 81:983–987, 2009. © 2009 Wiley‐Liss, Inc.     

Reactogenicity and immunogenicity of a varicella vaccine in healthy seronegative and seropositive subjects

The epidemiology of varicella appears to be changing: an unexplained upward age shift in varicella prevalence and a subsequent dramatic rise in morbidity and mortality among adolescents and adults have highlighted the importance of effective varicella mass vaccination programs. This age shift is being seen in temperate regions but is particularly marked in tropical and sub-tropical regions. To assess the need for serological pre-screening in mass vaccination programs, we performed an open study to compare the reactogenicity and immunogenicity of a varicella vaccine in initially seronegative and seropositive subjects to see whether there was an increase in reactogenicity among initially seropositive subjects. Two hundred and forty-six seronegative and seropositive male and female subjects, aged 9 months to 60 years, received a single dose of a live attenuated varicella virus (Oka-strain) vaccine, Varilrix (GlaxoSmithKline Biologicals, Rixensart, Belgium). Subjects were categorized according to antibody status and age group; serum antibodies were measured before and after vaccination (day 42). The study showed that there was no difference in reactogenicity in initially seropositive vaccinees compared with initially seronegative subjects. The varicella vaccine was found to be safe and well tolerated in all age groups. Ninety-eight percent of initially seropositive and 94.8% of initially seronegative subjects reported no clinical signs or symptoms during the 42-day follow-up period. The vaccine was immunogenic in both groups. The seroconversion rate after 6 weeks in initially seronegative subjects was 94.3%. In 53.0% of initially seropositive subjects of all age classes, a 4-fold rise in antibody titer was observed.