Group A streptococcal infection in an aboriginal community.

OBJECTIVE: To determine whether group A streptococcal infection and poststreptococcal sequelae are still a significant health issue for Aboriginal communities. DESIGN: A cross-sectional survey of streptococcal carriage, infection and antibody levels. SETTING: A north Queensland Aboriginal community. PARTICIPANTS: One hundred and twenty preschool and school-aged children (2 to 12 years of age) living in the Lockhart River Community on Cape York Peninsula. RESULTS: Pyoderma was present in 43% of the children and in 76% of these culture of skin lesions grew group A streptococci. Group A streptococci also grew from 13% of throat swabs, making a total of 36% of children culture positive. Anti-streptolysin O and anti-DNAase B levels were remarkably high and increased with age. CONCLUSIONS: The evidence presented confirms a high level of group A streptococcal carriage and infection in children of the Lockhart River Community. Further investigation of this problem is warranted in other Aboriginal communities with a view to instituting appropriate control programs.

Isolated hepatitis B core antibody--can response to hepatitis B vaccine help elucidate the cause?

The finding of a positive hepatitis B core antibody (anti-HBc) in the absence of hepatitis B surface antigen (HBsAg) or hepatitis B surface antibody (anti-HBs) is relatively uncommon. This finding is known to occur during the 'window period' of acute hepatitis B between loss of HBsAg and the appearance of anti-HBs. It may also occur with active infection or following resolution. The aim of this study was to determine if response to hepatitis B vaccination would allow the separation of these subgroups of patients with isolated anti-HBc. Seventeen patients with persistent isolated core antibody were vaccinated and serum obtained at 2, 4 and 8 weeks. Results were compared with a seronegative control group. Six subjects (35%) but no control patients (p = 0.016) responded with a titre of greater than 50mIU/mL at two weeks, suggesting an anamnestic response due to prior infection and immunity. A further seven subjects (41%) finally seroconverted (anti-HBs titre greater than 10mIU/mL) thus excluding chronic infection and suggesting initial false positive results. Only two subjects did not respond to a full course of vaccination, but neither they nor any other subjects were positive for HBV DNA. These results indicate that hepatitis B vaccination and subsequent measurement of anti-HBs will identify evidence of past infection in the form of an anamnestic response in up to one third of the patients and will also exclude chronic infection on the grounds of a normal vaccine response in a majority of the remainder.

The bacteriological prevalence of leptospiral infection in cattle and buffaloes in West Malaysia.

A cross-sectional bacteriological survey of cattle in West Malaysia revealed 14.4% (32/222) had leptospiral infection. Isolates were obtained from all except one herd with prevalence of infection in herds ranging from 0-44.8%. A small number of buffalo urine samples were examined and all of them were found to be negative. A leptospiral isolate obtained from a bovine kidney proved to be a new serovar of Leptospira interrogans and the name unipertama was assigned to it. Six other leptospiral serovars were isolated, namely canicola, australis, javanica, ballum, pomona and hardjo. All six serovars were isolated for the first time in cattle in Malaysia. Cattle in Malaysia appear to be the maintenance host for serovar hardjo. The presence of the other serovars in cattle was probably due to contact with the maintenance hosts, pigs for serovar pomona and rodents for the other three serovars. It appears that the epidemiology of leptospiral infection in cattle in Malaysia is similar to that reported overseas.