Amikacin Concentrations Predictive of Ototoxicity in Multidrug-Resistant Tuberculosis Patients

Aminoglycosides, such as amikacin, are used to treat multidrug-resistant tuberculosis. However, ototoxicity is a common problem and is monitored using peak and trough amikacin concentrations based on World Health Organization recommendations. Our objective was to identify clinical factors predictive of ototoxicity using an agnostic machine learning method. We used classification and regression tree (CART) analyses to identify clinical factors, including amikacin concentration t hresholds that pre- dicted audiometry-confirmed ototoxicity among 28 multidrug-resistant pulmonary tuberculosis patients in Botswana. Amika- cin concentrations were measured for all patients. The quantitative relationship between predictive factors and the probability of ototoxicity were then identified using probit analyses. The primary predictors of ototoxicity on CART analyses were cumula- tive days of therapy, followed by cumulative area under the concentration-time curve (AUC), which improved on the primary predictor by 87%. The area under the receiver operating curve was 0.97 on the test set. Peak and trough were not predictors in any tree. When algorithms were forced to pick peak and trough as primary predictors, the area under the receiver operating curve fell to 0.46. Probit analysis revealed that the probability of ototoxicity increased sharply starting after 6 months of therapy to near maximum at 9 months. A 10% probability of ototoxicity occurred with a threshold cumulative AUC of 87,232 days · mg · h/liter, while that of 20% occurred at 120,000 days · mg · h/liter. Thus, cumulative amikacin AUC and duration of therapy, and not peak and trough concentrations, should be used as the primary decision-making parameters to minimize the likelihood of ototoxicity in multidrug-resistant tuberculosis

Co-infection with HPV Types from the Same Species Provides Natural Cross-Protection from Progression to Cervical Cancer

The worldwide administration of bivalent and quadrivalent HPV vaccines has resulted in cross-protection against non-vaccine HPV types. Infection with multiple HPV types may offer similar cross-protection in the natural setting. We hypothesized that infections with two or more HPV types from the same species, and independently, infections with two or more HPV types from different species, associate with protection from high-grade lesions

Subtype Distribution of Human Papillomavirus in HIV-Infected Women With Cervical Intraepithelial Neoplasia Stages 2 and 3 in Botswana

Human papillomavirus (HPV) vaccines containing types 16 and 18 are likely to be effective in preventing cervical cancer associated with these HPV types. No information currently exists in Botswana concerning the HPV types causing precancerous or cancerous lesions. Our goal was to determine the prevalence of HPV types associated with precancerous cervical intraepithelial neoplasia (CIN) stages 2 and 3 in HIV-infected women in Gaborone, Botswana. HIV-infected women referred to our clinic with high-grade intraepithelial lesion on the Pap smear were enrolled in the study. HPV typing was only performed if the histopathology results showed CIN stage 2 or 3 disease using linear array genotyping (CE-IVD, Roche Diagnostics).One hundred HIV-infected women were identified with CIN stages 2 or 3 between August 11, 2009 and September 29, 2010. Eighty-two of 100 women enrolled had coinfection by multiple HPV subtypes (range, 2 to 12). Of the remaining 18 women, 14 were infected with a single high-risk subtype and 4 had no HPV detected. Overall, 92 (92%) women were infected with at least 1 high-risk HPV subtype, and 56 were coinfected with more than 1 high-risk HPV type (range, 2 to 5). Fifty-one (51%) women had HPV subtypes 16, 18, or both. HPV 16 and 18 are the most common types in HIV-infected women with CIN 2 or 3 in Gaborone, Botswana, suggesting that the implementation of HPV vaccination programs could have a significant impact on the reduction of cervical cancer incidence. However, given the relative lack of knowledge on the natural history of cervical cancer in HIV-infected women and the significant prevalence of infection and coinfection with other high-risk HPV types in our sample, the true impact and cost-effectiveness of such vaccination programs need to be evaluated

Survey of Childhood Blindness and Visual Impairment in Botswana

Background/aims In terms of blind-person years, the worldwide burden of childhood blindness is second only to cataracts. In many developing countries, 30–72% of childhood blindness is avoidable. The authors conducted this study to determine the causes of childhood blindness and visual impairment (VI) in Botswana, a middle-income country with limited access to ophthalmic care. Methods This study was conducted over 4 weeks in eight cities and villages in Botswana. Children were recruited through a radio advertisement and local outreach programmes. Those ≤15 years of age with visual acuity \u3c6/18 in either eye were enrolled. The WHO/Prevention of Blindness Eye Examination Record for Children with Blindness and Low Vision was used to record data. Results The authors enrolled 241 children, 79 with unilateral and 162 with bilateral VI. Of unilateral cases, 89% were avoidable: 23% preventable (83% trauma-related) and 66% treatable (40% refractive error and 31% amblyopia). Of bilateral cases, 63% were avoidable: 5% preventable and 58% treatable (33% refractive error and 31% congenital cataracts). Conclusion Refractive error, which is easily correctable with glasses, is the most common cause of bilateral VI, with cataracts a close second. A nationwide intervention is currently being planned to reduce the burden of avoidable childhood VI in Botswana

Artificial Intelligence and Amikacin Exposures Predictive of Outcomes in Multidrug-Resistant Tuberculosis Patients

Aminoglycosides such as amikacin continue to be part of the backbone of treatment of multidrug-resistant tuberculosis (MDR- TB). We measured amikacin concentrations in 28 MDR-TB patients in Botswana receiving amikacin therapy together with oral levofloxacin, ethionamide, cycloserine, and pyrazinamide and calculated areas under the concentration-time curves from 0 to 24 h (AUC0 –24). The patients were followed monthly for sputum culture conversion based on liquid cultures. The median duration of amikacin therapy was 184 (range, 28 to 866) days, at a median dose of 17.30 (range 11.11 to 19.23) mg/kg. Only 11 (39%) pa- tients had sputum culture conversion during treatment; the rest failed. We utilized classification and regression tree analyses (CART) to examine all potential predictors of failure, including clinical and demographic features, comorbidities, and amikacin peak concentrations (Cmax), AUC0 –24, and trough concentrations. The primary node for failure had two competing variables, Cmax of \u3c67 mg/liter and AUC0 –24 of \u3c568.30 mg · h/L; weight of \u3e41 kg was a secondary node with a score of 35% relative to the primary node. The area under the receiver operating characteristic curve for the CART model was an R2 �� 0.90 on posttest. In patients weighing \u3e41 kg, sputum conversion was 3/3 (100%) in those with an amikacin Cmax of \u3e67 mg/liter versus 3/15 (20%) in those with a Cmax of \u3c67 mg/liter (relative risk [RR] �� 5.00; 95% confidence interval [CI], 1.82 to 13.76). In all patients who had both amikacin Cmax and AUC0 –24 below the threshold, 7/7 (100%) failed, compared to 7/15 (47%) of those who had these parameters above threshold (RR �� 2.14; 95% CI, 1.25 to 43.68). These amikacin dose-schedule patterns and exposures are virtually the same as those identified in the hollow-fiber system model

An Epidemiologic Review of Enteropathogens in Gaborone, Botswana: Shifting Patterns of Resistance in an HIV Endemic Region

Background The epidemiology of diarrheal disease in Botswana, an HIV endemic region, is largely unknown. Our primary objective was to characterize the prevalent bacterial and parasitic enteropathogens in Gaborone, Botswana. Secondary objectives included determining corresponding antimicrobial resistance patterns and the value of stool white and red blood cells for predicting bacterial and parasitic enteropathogens. Methodology/Principal Findings A retrospective cross-sectional study examined laboratory records of stool specimens analyzed by the Botswana National Health Laboratory in Gaborone, Botswana from February 2003 through July 2008. In 4485 specimens the median subject age was 23 [interquartile range 1.6–34] years. Overall, 14.4% (644 of 4485) of samples yielded a pathogen. Bacteria alone were isolated in 8.2% (367 of 4485), parasites alone in 5.6% (253 of 4485) and both in 0.5% (24 of 4485) of samples. The most common bacterial pathogens were Shigella spp. and Salmonella spp., isolated from 4.0% (180 of 4485) and 3.9% (175 of 4485) of specimens, respectively. Escherichia coli (22 of 4485) and Campylobacter spp. (22 of 4485) each accounted for 0.5% of pathogens. Comparing antimicrobial resistance among Shigella spp. and Salmonella spp. between two periods, February 2003 to February 2004 and July 2006 to July 2008, revealed an increase in ampicillin resistance among Shigella spp. from 43% to 83% (p\u3c0.001). Among Salmonella spp., resistance to chloramphenicol decreased from 56% to 6% (p\u3c0.001). The absence of stool white and red blood cells correlated with a high specificity and negative predictive value. Conclusions/Significance Most gastroenteritis stools were culture and microscopy negative suggesting that viral pathogens were the majority etiologic agents in this Botswana cohort. Shigella spp. and Salmonella spp. were the most common bacteria; Isospora spp. and Cryptosporidium spp. were the most common parasites. Resistance to commonly used antimicrobials is high and should be closely monitored

Leveraging a Rapid, Round-the-Clock HIV Testing System to Screen for Acute HIV Infection in a Large Urban Public Medical Center

Methods The hospital laboratory performed round-the-clock rapid HIV antibody testing on venipuncture specimens from patients undergoing HIV testing in hospital and community clinics, inpatient settings, and the emergency department. For patients with negative results, a public health laboratory conducted pooled HIV RNA testing for acute HIV infection. The laboratories communicated positive results from the hospital campus to a linkage team. Linkage was defined as one outpatient HIV-related visit. Results Among 7,927 patients, 8,550 rapid tests resulted in 137 cases of HIV infection (1.7%, 95% CI 1.5%–2.0%), of whom 46 were new HIV diagnoses (0.58%, 95% CI 0.43%–0.77%). Pooled HIV RNA testing of 6,704 specimens (78.4%) resulted in 3 cases of acute HIV infection (0.05%, 95% CI 0.01%–0.14) and increased HIV case detection by 3.5%. Half of new HIV diagnoses and 2/3 of acute infections were detected in the emergency department and urgent care clinic. Rapid test sensitivity was 98.9% (95% CI 93.8%– 99.8%); specificity was 99.9% (95% CI 99.7%–99.9%). Over 95% of newly diagnosed and out-of-care HIV-infected patients were linked to care. Conclusions Patients undergoing HIV testing in emergency departments and urgent care clinics may benefit from being simultaneously screened for acute HIV infection

Outcomes in HIV-Infected Adults With Tuberculosis at Clinics With and Without Co-Located HIV Clinics in Botswana

SETTING Gaborone, Botswana. OBJECTIVE To determine if starting anti-tuberculosis treatment at clinics in Gaborone without co-located human immunodeficiency virus (HIV) clinics would delay time to highly active antiretroviral therapy (HAART) initiation and be associated with lower survival compared to starting anti-tuberculosis treatment at clinics with on-site HIV clinics. DESIGN Retrospective cohort study. Subjects were HAART-naïve, aged ≥21 years with pulmonary tuberculosis (TB), HIV and CD4 counts ≤250 cells/mm3 initiating anti-tuberculosis treatment between 2005 and 2010. Survival at completion of anti-tuberculosis treatment or at 6 months post-treatment initiation and time to HAART after anti-tuberculosis treatment initiation were compared by clinic type. RESULTS Respectively 259 and 80 patients from clinics without and with on-site HIV facilities qualified for the study. Age, sex, CD4, baseline sputum smears and loss to follow-up rate were similar by clinic type. Mortality did not differ between clinics without or with on-site HIV clinics (20/250, 8.0% vs. 8/79, 10.1%, relative risk 0.79, 95%CI 0.36–1.72), nor did median time to HAART initiation (respectively 63 and 66 days, P = 0.53). CONCLUSION In urban areas where TB and HIV programs are separate, geographic co-location alone without further integration may not reduce mortality or time to HAART initiation among co-infected patients