ABSTRACT
SETTING: Although approximately 0.5 million cases of multidrug-resistant tuberculosis (MDR-TB) occur globally each year, surveillance data are limited. Botswana is one of the few high TB burden countries to have carried out multiple anti-tuberculosis drug resistance surveys (in 1995-1996, 1999 and 2002). OBJECTIVE: In 2007-2008, we conducted the fourth national survey of anti-tuberculosis drug resistance in Botswana to assess anti-tuberculosis drug resistance, including trends over time. In the previous survey, 0.8% (95%CI 0.4-1.5) of new patients and 10.4% (95%CI 5.6-17.3) of previously treated patients had MDR-TB. DESIGN: During the survey period, eligible specimens from all new sputum-smear positive TB patients and from all TB patients with history of previous anti-tuberculosis treatment underwent mycobacterial culture and anti-tuberculosis drug susceptibility testing (DST). RESULTS: Of 924 new TB patients and 137 with previous anti-tuberculosis treatment with DST results, respectively 23 (2.5%, 95%CI 1.6-3.7) and 9 (6.6%, 95%CI 3.3-11.7) had MDR-TB. The proportion of new TB patients with MDR-TB has tripled in Botswana since the previous survey. CONCLUSION: Combatting drug-resistant TB will require the scale-up of MDR-TB diagnosis and treatment to prevent the transmission of MDR-TB and strengthening of general TB control to prevent the emergence of resistance.
Subject(s)
Antitubercular Agents/therapeutic use , Drug Resistance, Multiple, Bacterial , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Pulmonary/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Botswana/epidemiology , Child , Child, Preschool , Female , Health Care Surveys , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Mycobacterium tuberculosis/isolation & purification , Sputum/microbiology , Time Factors , Treatment Outcome , Tuberculosis, Multidrug-Resistant/diagnosis , Tuberculosis, Multidrug-Resistant/epidemiology , Tuberculosis, Multidrug-Resistant/microbiology , Tuberculosis, Pulmonary/diagnosis , Tuberculosis, Pulmonary/epidemiology , Tuberculosis, Pulmonary/microbiology , Young AdultABSTRACT
Comprehensive understanding of the determinants of cross-subtype immune responses in HIV infection is critical to developing efficacious HIV vaccines against multiple viral subtypes. Because HIV-1 subtype A or recombinants comprising subtype A are prevalent in Africa and parts of Asia where HIV is spreading, we assessed the determinants of cross-subtype immune responses in HIV-infected blood donors from Cote d'Ivoire to peptides from a candidate CRF02_AG vaccine sequence, a subtype A sequence from western Kenya and a CRF01_AE sequence from Thailand. We present evidence that immune recognition of multiple viral subtypes is maintained by recognition of multiple epitopes. Our data suggest that complete escape of HIV from immune recognition is uncommon. Evaluation of these frequently generated cross-reactive responses should be included in immunogenicity trials of HIV vaccines.
