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Journal of Viral Hepatitis. 2003 Mar; 10(2):141-149.Hepatitis B (HB) is thought to be an expanding health problem in Russia. The incidence of infection was estimated from mandatorily reported HB cases in St Petersburg. The two-sided t-test for independent samples and the LOESS (locally-weighted regression) smoother were used to compare the age at infection for symptomatic, asymptomatic and chronic infections, by gender. The force of infection was estimated from seroprevalence data (907 sera taken in 1999) using a newly developed nonparametric method based on local polynomials, as well as an earlier method based on isotonic regression and kernel smoothers. With the local polynomial method, pointwise confidence intervals (95%) were constructed by bootstrapping. On average, men contracted HB infection at a significantly younger age than women (in 1999, 21.8 vs 22.7 years, respectively). The overall male to female ratio was 1.92. In 1999 the overall incidence almost doubled compared with the preceding years and tripled among the age groups with highest incidence (15–29-year olds: 85% of cases in 1999). The incidence increase was associated with a lower average age at infection (24.1 years in 1994 vs 22.1 years in 1999). The age and gender-specific force of infection estimates generally confirmed the incidence estimates and emphasized the usefulness of local polynomials to do this. Hence HB transmission in St Petersburg occurs mainly in young adults. The dramatic increase of infections in 1999 was probably due to injecting drug use. Without intervention, HB virus is expected to continue to spread rapidly with a greater proportion of female infections caused by sexual transmission. These trends may also provide an indication for HIV transmission. (author's)
BMJ. British Medical Journal. 1991 Nov 9; 303(6811):1189-90.The article proposes that the clinical case definition for Acquired Immunodeficiency Syndrome in Africa is an unworkable concept, with the wrong definition, incorrect validation, improper use, and consequently is a poor surveillance tool. The definition was proposed by the World Health Organization in 1986 to satisfy the use in countries with limited diagnostic resources, and resources for serological testing. Critical review until now of this procedure was lacking. Currently serological testing is available and of high quality. It does not seem justifiable to continue using a provisional surveillance definition. Abandoning this classification procedure may also lead to the focus on problems other than opportunistic infections and AIDs. Clinical surveillance is important, but as well morbidity and mortality need monitoring. It is argued that the definition is an unworkable concept because patients with underlying immunosuppression disorders such as AIDs can not be easily distinguished from chronic disease patients; i.e., pulmonary tuberculosis, renal failure, uncontrolled diabetes, or diarrhea with weight loss. Clinical accuracy is insufficient. It is the wrong definition because pulmonary tuberculosis with a persistent cough cannot be distinguished for those HIV positive and those not. There is inconsistency in the WHO clinical definition and the Centers for Disease Control definitions of AIDs. The incidence of tuberculosis in countries with unmodified clinical case definitions may contribute to an inflated number of AIDs cases. The wrong standards were used to validate the WHO definition in evaluative studies. The reference sensitivity ranges indicate that the definition is insensitive to identifying seropositive patients. Also, the HIV status of patients does not equate with AIDs. Although designed for surveillance, the clinical case definition is used by doctors for individual patient management. Labeling a patient as having AIDs, when he is HIV negative, leads to negative consequences. Researchers compare African AIDs data with North American data with imprecise and noncomparable definitions. As a surveillance tool in countries with a fragmentary or without a vital registration system, it is an inaccurate tool. Alternatives to obtaining data about the spread and impact of HIV are cluster sampling, hospital surveillance of selected populations, anonymous testing of pregnant women or patients in sexually transmitted disease clinics. In Nairobi, a necropsy survey found that 16% had AIDs but 38% were HIV positive.