Antibiotic resistance of Streptococcus pneumoniae colonising the nasopharynx of HIV-exposed Tanzanian infants.

OBJECTIVES: To determine antibiotic susceptibility of colonising pneumococcal serotypes in HIV-exposed infants before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13), because HIV-exposed infants are at increased risk of invasive pneumococcal infections. METHODS: Antibiotic susceptibility of 104 pneumococcal isolates, cultured from the nasopharynx from Tanzanian HIV-exposed infants, was determined using the disc diffusion method and the E-test according to EUCAST version 4.0 (2014) criteria. RESULTS: A total of 69.2% of isolates were intermediately susceptible for benzyl penicillin (MIC 0.06-2 mg/l ); no high-level resistance was found. All isolates but one were susceptible to ampicillin. Regarding non-beta-lactam antibiotics, 19.2% of isolates were resistant to doxycycline, 3.8% to erythromycin and 97.1% to trimethoprim/sulfamethoxazole. A total of 15.4% of isolates were resistant to three antibiotic classes or more. There were no differences in antibiotic susceptibility between vaccine and non-vaccine serotypes. Reduced susceptibility of colonising pneumococcal isolates for commonly used antibiotics is common in HIV-exposed Tanzanian infants. CONCLUSIONS: High-dose penicillin and ampicillin remain appropriate first choices for non-meningeal pneumococcal infections in this group.

Chest radiography for predicting the cause of febrile illness among inpatients in Moshi, Tanzania.

AIM: To describe chest radiographic abnormalities and assess their usefulness for predicting causes of fever in a resource-limited setting. MATERIALS AND METHODS: Febrile patients were enrolled in Moshi, Tanzania, and chest radiographs were evaluated by radiologists in Tanzania and the United States. Radiologists were blinded to the results of extensive laboratory evaluations to determine the cause of fever. RESULTS: Of 870 febrile patients, 515 (59.2%) had a chest radiograph available; including 268 (66.5%) of the adolescents and adults, the remainder were infants and children. One hundred and nineteen (44.4%) adults and 51 (20.6%) children were human immunodeficiency virus (HIV)-infected. Among adults, radiographic abnormalities were present in 139 (51.9%), including 77 (28.7%) with homogeneous and heterogeneous lung opacities, 26 (9.7%) with lung nodules, 25 (9.3%) with pleural effusion, 23 (8.6%) with cardiomegaly, and 13 (4.9%) with lymphadenopathy. Among children, radiographic abnormalities were present in 87 (35.2%), including 76 (30.8%) with homogeneous and heterogeneous lung opacities and six (2.4%) with lymphadenopathy. Among adolescents and adults, the presence of opacities was predictive of Streptococcus pneumoniae and Coxiella burnetii, whereas the presence of pulmonary nodules was predictive of Histoplasma capsulatum and Cryptococcus neoformans. CONCLUSIONS: Chest radiograph abnormalities among febrile inpatients are common in northern Tanzania. Chest radiography is a useful adjunct for establishing an aetiologic diagnosis of febrile illness and may provide useful information for patient management, in particular for pneumococcal disease, Q fever, and fungal infections.

Dynamics of nasopharyngeal bacterial colonisation in HIV-exposed young infants in Tanzania.

OBJECTIVES: To estimate the prevalence of nasopharyngeal bacterial colonisation (NPBC) patterns in young Tanzanian HIV-exposed infants and to analyse the influence of maternal NPBC and of the infant's HIV status on the NPBC pattern. METHODS: Longitudinal cohort study of neonates born to HIV-infected mothers visiting Kilimanjaro Christian Medical Centre, Tanzania, between 2005 and 2009. Demographic and clinical data and nasopharyngeal bacterial cultures were obtained at the age of 6 weeks, 3 and 6 months, and at one time point, a paired mother-infant nasopharyngeal swab was taken. RESULTS: Four hundred and twenty-two swabs were taken from 338 eligible infants. At 6 weeks of age, colonisation rates were 66% for Staphylococcus aureus, 56% for Streptococcus pneumoniae, 50% for Moraxella catarrhalis and 14% for Haemophilus influenzae. Colonisation with S. aureus diminished over time and was more common in HIV-infected infants. S. pneumoniae and H. influenzae colonisation rose over time and was more prevalent in HIV-uninfected children. Co-colonisation of S. pneumoniae with H. influenzae or M. catarrhalis was mostly noticed in HIV-infected infants. S. pneumoniae and M.catarrhalis colonisation of the mother was a risk factor for colonisation in HIV-uninfected infants, while maternal S. aureus colonisation was a risk factor for colonisation in HIV-infected infants. Among the 104 S. pneumoniae isolates, 19F was most prevalent, and 57 (55%) displayed capsular serotypes represented in the 13-valent pneumococcal conjugate vaccine. CONCLUSIONS: NPBC was common in Tanzanian HIV-exposed infants. The significant prevalence of pneumococcal vaccine serotypes colonising this paediatric population justifies the use of the 13-valent pneumococcal vaccine to reduce the burden of pneumococcal invasive disease.