Lessons learned during tuberculosis screening in public medical clinics in Francistown, Botswana.

In Botswana, where one quarter of the adult population is infected with the human immunodeficiency virus and the annual tuberculosis (TB) incidence is among the highest globally, intensified TB case finding is needed in health care facilities to detect and treat TB cases early and prevent transmission. During August-December 2009, TB screening was implemented among adults at patient intake in five clinics in Francistown. Among 11 779 TB screenings at intake, 926 were positive. Nineteen patients were diagnosed with TB. Routine TB screening at intake was operationally feasible, but had low yield. Innovative case-finding strategies are needed in Botswana.

Declining syphilis prevalence among pregnant women in northern Botswana: an encouraging sign for the HIV epidemic?

OBJECTIVES: To evaluate trends in syphilis prevalence among antenatal women in a high HIV prevalence setting in northern Botswana. METHODS: Laboratory logbooks of antenatal syphilis testing for 1992-2003 in Francistown, Botswana's second largest city, were reviewed, and a consecutive sample of 750 women per year from 1992-2003 were analysed. VDRL result and age were recorded. A positive result was considered a case. RESULTS: Overall syphilis prevalence (VDRL positive) among pregnant women in Francistown decreased from 12.4% in 1992 to 4.3% in 2003 (p< or =0.001). The downward trend in overall syphilis prevalence began in 1997. There was no change in syphilis prevalence from 1992-6. Beginning in 1997, there has been a significant decrease in syphilis prevalence in all age groups. CONCLUSIONS: Syphilis in pregnant women in Francistown has been decreasing for the last 6 years, despite extremely high HIV prevalence (stable at > or =40% since 1996) in the same population. Reasons contributing to the decline in syphilis rates may include nationwide implementation of syndromic management of sexually transmitted diseases (STDs) in 1992, improved access to health care, and less risky sexual behaviour. There is evidence from other sources indicating that risky sexual behaviour in Botswana has decreased during the HIV epidemic.

Etiology of pulmonary infections in predominantly HIV-infected adults with suspected tuberculosis, Botswana.

SETTING: In countries with high HIV rates, diagnosis of lower respiratory disease etiology is both challenging and clinically important. OBJECTIVE: To determine the etiology of lower respiratory tract disease among persons with suspected tuberculosis (TB) and abnormal chest X-rays in a setting with very high HIV seroprevalence. DESIGN: Cross-sectional prevalence data from a prospective cohort of predominantly hospitalized adults with suspected TB in Botswana, January-December 1997. RESULTS: Of 229 patients, 86% were HIV-positive and 71% had a pathogen identified. TB was confirmed in 52%, 17% had acute mycoplasma pneumonia, 3% had Pneumocystis carinii, 27% grew a bacterial pathogen from sputum and 8% from blood. Ninety-four per cent of TB diagnoses were made through expectorated sputum and only 5% of TB cases were diagnosed by sputum induction alone. Polymerase chain reaction (PCR) for Mycobacterium tuberculosis had positive and negative predictive values of 94% and 59%, respectively. Male sex, cough < 2 weeks, and tuberculin skin test > or = 5 mm were independently associated with culture-positive TB among persons with negative acid-fast bacilli smears. Co-infection with two or more pathogens occurred in 25%. CONCLUSIONS: Mycoplasma pneumoniae infection was quite common despite clinical suspicion of TB, and sputum induction and PCR did not significantly improve our ability to diagnose TB, although clinical presentation had some predictive value.

Risk factors for transmission of Mycobacterium tuberculosis from HIV-infected tuberculosis patients, Botswana.

OBJECTIVE: To identify risk factors for transmission of Mycobacterium tuberculosis from patients with tuberculosis and human immunodeficiency virus (HIV) infection in Botswana. DESIGN: Transmission was studied in 210 children aged <10 years (contacts) of unknown HIV status exposed to 51 adults with tuberculosis (index cases), including 41/49 (83.7%) with HIV infection. METHODS: Data collected on index cases included demographics, clinical and social characteristics, sputum, HIV, and CD4 lymphocyte results. Tuberculin skin testing was performed on contacts, and their parent or guardian was interviewed. A positive test was defined as > or = 10 mm induration. Skin test results were compared with results obtained from a population survey of children of similar age from the same community. RESULTS: A positive skin test was found in 12.1% of exposed children compared with 6.2% in the community (P = 0.005). Of the infected children, 22 (78.6%) were contacts of a close female relative. The risk of transmission increased with the degree of sputum smear positivity for acid-fast bacilli among female index cases (10.8% if smear 0+, 9.3% if smear 1+,29.4% if smear 2+, 44% if smear 3+, P < 0.001). In multivariate analysis, severe immunodeficiency (CD4 lymphocyte count <200 cells/mm3) among HIV-infected index cases was protective against transmission (OR 0.08, 95%CI 0.01-0.5, P = 0.006). CONCLUSION: The intensity of exposure to tuberculosis patients and the degree of sputum smear positivity for acid-fast bacilli remain important risk factors for transmission of M. tuberculosis during the era of HIV. However, tuberculosis patients with advanced AIDS may be less infectious than patients in earlier stages of AIDS.

Completeness and timeliness of treatment initiation after laboratory diagnosis of tuberculosis in Gaborone, Botswana.

SETTING: Gaborone, the capital of Botswana. OBJECTIVE: To determine the time from positive sputum smear microscopy for acid-fast bacilli (AFB) to initiation of therapy, and to identify risk factors for delays. DESIGN: Retrospective cohort study of medical records and surveillance data for patients with positive smear microscopy and newly diagnosed tuberculosis (TB) from January to May 1997. Treatment delay was defined as more than 2 weeks from the first positive sputum smear to the initiation of TB treatment. RESULTS: Of 127 patients identified, 15 (11.8%) had treatment delay, 13 (10.2%) had an incomplete workup (only one smear performed) and were not registered for TB treatment, and six (4.5%) had two or more positive smears but were not registered for TB treatment. Risk factors for treatment delay or non-registration included TB patients who had been diagnosed in a hospital outpatient setting vs. a clinic (RR 2.9, 95% CI 1.2-3.6, P = 0.02), or in a high volume vs. low volume clinic (RR 2.2, 95% CI 1.2-5.3, P = 0.01). CONCLUSION: More than a quarter of the smear-positive TB patients identified had treatment delay or no evidence of treatment initiation. Proper monitoring of laboratory sputum results and suspect TB patient registers could potentially reduce treatment delays and patient loss.