Under-diagnosis of smear-positive pulmonary tuberculosis in Nairobi, Kenya.

SETTING: Nairobi City Council Chest Clinic, Nairobi, Kenya. OBJECTIVE: To determine if under-reading of sputum smears is a contributing factor in the disproportionate increase in smear-negative tuberculosis in Nairobi, Kenya. METHODOLOGY: Between October 1997 and November 1998, patients fulfilling the local programme definition of smear-negative presumed pulmonary tuberculosis were enrolled in the study. Two further sputum specimens were collected for examination in a research laboratory by fluorescence microscopy. RESULTS: Of 163 adult subjects enrolled, 55% were seropositive for the human immunodeficiency virus type 1 (HIV-1). One hundred subjects had had two pre-study sputum smears assessed before recruitment and produced two further sputum specimens for re-examination in the research laboratory; of these 19 (19%) were sputum smear-positive on re-examination and a further seven (7%) became smear-positive on second re-examination. CONCLUSIONS: Of those patients with smear-negative presumed pulmonary tuberculosis by the local programme definition, 26% were smear-positive when reexamined carefully with two repeat sputum smears. This suggests that the high rates of smear-negative tuberculosis being seen may in part be due to under-reading. This is probably as a result of the overwhelming burden of tuberculosis leading to over rapid and inaccurate sputum examination. Retraining of existing technicians and training of more technicians is likely to reduce underreading and increase the yield of smear-positive tuberculosis. This finding also stresses the need for regular quality assurance

Opportunity for prevention of HIV and sexually transmitted infections in Kenyan youth: results of a population-based survey.

Background Data from sentinel serosurveillance are useful to estimate HIV infection in populations but may not be representative of the general population. General population-based surveys attempt to avoid selection bias and are the most appropriate for tracking changes in exposure to risk of HIV infection over time and assessing changes in behavior following prevention campaigns. Objectives To provide baseline data for targeted sexually transmitted infection (STI) and HIV infection prevention interventions by studying parameters of sexual behavior and knowledge of HIV infection and STIs, measuring health-seeking behavior related to STIs, and measuring gonorrhea, Chlamydia, syphilis, and HIV-1 prevalences. Design Population-based survey with stratified sampling by age group from randomly selected households in a suburb of Mombasa, Kenya. Methods A standard questionnaire was administered to 1497 consenting adults between the ages of 15 and 49 years who lived in randomly selected households. Urine and blood samples were obtained for the estimation of gonorrhea, chlamydial infection, syphilis, and HIV-1 infection prevalences. Results Sexual activity in the past 12 months was limited to one partner in all age groups for most sexually active men (68%) and women (88%). More men than women reported two or more partners in the past 12 months (23% vs. 5%, respectively). Almost one half of those persons in the 15- to 19-year-old age group (56% of boys and 48% of girls) were sexually active. Condom use was low with all sexual partners, more so for women than for men. Reported STI symptoms in the past 12 months were high for both men and women. Knowledge of STI symptoms and HIV infection was present but incomplete. Overall HIV seroprevalence was 10.8%, with significantly higher rates among women (13.7%) than among men (8.0%). HIV seroprevalence in the 15- to 19-year-old age group was 3.2%. Female gender, Protestant religion, Catholic religion, and being divorced, separated, and widowed were significantly associated with HIV seroprevalence. Prevalences of gonorrhea, chlamydial infection, and syphilis were 0.9%, 1.5%, and 1.3%, respectively. Conclusions This study emphasizes the vulnerability of young adults, in particular young women, to HIV infection and the need for intensive interventions in this group. The low use of condoms, incomplete knowledge of HIV infection and STIs, the high number of reported STIs, and the relatively low HIV-1 seroprevalence among the 15- to 19-year-old group indicate a large need for intensive STI and HIV infection prevention programs, especially for the 15- to 19-year-old age group

Factors responsible for differences between asymptomatic subjects and patients presenting an IgE sensitization to allergens. A GA(2)LEN project

The synthesis of allergen-specific IgE is required for the development of allergic diseases including allergic rhinitis and allergic asthma (patients), but many individuals with allergen-specific IgE do not develop symptoms (asymptomatic subjects). Differences may exist between asymptomatic subjects and patients. Whether the presence of allergen-specific IgE translates into clinical allergy most likely depends on a complex interplay of multiple factors. These include a family history of atopy, the levels of total serum IgE and, allergen-specific IgE or IgG, epitope-specificity of IgE and their degree of polyclonality (mono- vs polysensitized), as yet unidentified serum factors, the balance of T regulatory cells (Treg) and Th1/Th2 cells, the polymorphisms of the high affinity receptor for IgE (FcepsilonRI) and other factors regulating the activation of FcepsilonRI-bearing cells. Asymptomatic subjects may be more often monosensitized than patients who may be more often polysensitized. There are many unanswered important questions that need to be addressed in order to better understand how IgE sensitization translates into clinical allergy. The assessment of differences between the asymptomatic and symptomatic groups of subjects represent one of the scientific programs of Global Allergy and Asthma European Network funded by the European Union and the hypotheses underlying these differences are presented in this pape