α-Thalassaemia trait is associated with antibody prevalence against malaria antigens AMA-1 and MSP-1.

A longitudinal study was conducted in a low endemic area in northern Tanzania to examine the influence of the α-thalassaemia trait on malaria incidence and antibody responses to malaria apical membrane antigen-1 (AMA-1) and merozoite surface protein1-19 (MSP-119). Out of 394 children genotyped for α-thalassaemia trait, 4.1% (16 of 394) and 30.7% (121 of 394) were homozygous and heterozygous, respectively. During the 1 year follow-up, four incidents of malaria cases were detected without an evident association with α-thalassaemia. Being heterozygous or homozygous for α-thalassaemia was associated with an increased prevalence of antibodies to AMA-1 [odds ratio (OR): 1.83, 95% confidence interval (CI): 1.07-3.12, p = 0.027] and MSP-1 (OR: 2.04, 95% CI: 1.16-3.60, p = 0.013) after adjustment for age and reported bednet use. The observed association between α-thalassaemia and malaria antibody responses may reflect longer-term differences in antigen exposure or differences in antibody acquisition upon exposure in this low endemic setting.

Quality of paediatric blood transfusions in two district hospitals in Tanzania: a cross-sectional hospital based study.

BACKGROUND: Blood transfusion (BT) can be lifesaving for children; however, monitoring the quality of BT is important. The current study describes the quality of paediatric BT delivered in two district hospitals in north-east Tanzania in order to identify areas for quality assurance and improvement in the administration of BT. METHODS: All 166 children admitted in the paediatric wards and receiving BT through April to June 2007 were prospectively observed. Medical records, request forms and registers in the laboratories were reviewed to identify blood source, blood screening and indications for BT. BT was observation before, during and after transfusion process. RESULTS: Malaria related anaemia accounted for 98% of the BTs. Ninety-two percent of the children were assessed for paleness. Clinical signs such as difficult breathing and symptoms of cardiac failure were only assessed in 67% and 15% of the children respectively, prior to the BT decision. Pre-transfusion haemoglobin and body temperature were recorded in 2/3 of the patients, but respiratory rate and pulse rate were not routinely recorded. In 40% of BTs, the transfusion time exceeded the recommended 4 hours. The zonal blood bank (ZBB) and local donors accounted for 10% and 90% of the blood, respectively. ABO and RhD typing and screening for HIV and syphilis were undertaken in all transfused blood. Evidence for hepatitis B or C infection was not checked except in the ZBB. CONCLUSION: Criteria for BT are not always fulfilled; time to initiate and complete the transfusion is often unacceptable long and monitoring of vital signs during BT is poor. Blood from the ZBB was often not available and BT often depended on local donors which implied lack of screening for hepatitis B and C. It is recommended that an external supervision system be established to monitor and evaluate the quality of BT performance in the laboratories as well as in wards.

HIV-1 pol diversity among female bar and hotel workers in Northern Tanzania.

A national ART program was launched in Tanzania in October 2004. Due to the existence of multiple HIV-1 subtypes and recombinant viruses co-circulating in Tanzania, it is important to monitor rates of drug resistance. The present study determined the prevalence of HIV-1 drug resistance mutations among ART-naive female bar and hotel workers, a high-risk population for HIV-1 infection in Moshi, Tanzania. A partial HIV-1 pol gene was analyzed by single-genome amplification and sequencing in 45 subjects (622 pol sequences total; median number of sequences per subject, 13; IQR 5-20) in samples collected in 2005. The prevalence of HIV-1 subtypes A1, C, and D, and inter-subtype recombinant viruses, was 36%, 29%, 9% and 27%, respectively. Thirteen different recombination patterns included D/A1/D, C/A1, A1/C/A1, A1/U/A1, C/U/A1, C/A1, U/D/U, D/A1/D, A1/C, A1/C, A2/C/A2, CRF10_CD/C/CRF10_CD and CRF35_AD/A1/CRF35_AD. CRF35_AD was identified in Tanzania for the first time. All recombinant viruses in this study were unique, suggesting ongoing recombination processes among circulating HIV-1 variants. The prevalence of multiple infections in this population was 16% (n = 7). Primary HIV-1 drug resistance mutations to RT inhibitors were identified in three (7%) subjects (K65R plus Y181C; N60D; and V106M). In some subjects, polymorphisms were observed at the RT positions 41, 69, 75, 98, 101, 179, 190, and 215. Secondary mutations associated with NNRTIs were observed at the RT positions 90 (7%) and 138 (6%). In the protease gene, three subjects (7%) had M46I/L mutations. All subjects in this study had HIV-1 subtype-specific natural polymorphisms at positions 36, 69, 89 and 93 that are associated with drug resistance in HIV-1 subtype B. These results suggested that HIV-1 drug resistance mutations and natural polymorphisms existed in this population before the initiation of the national ART program. With increasing use of ARV, these results highlight the importance of drug resistance monitoring in Tanzania.

Prevalence of drug resistance mutations and HIV type 1 subtypes in an HIV type 1-infected cohort in rural Tanzania.

The development of resistance mutations in drug-targeted HIV-1 genes compromises the success of antiretroviral therapy (ART) programs. Genotyping of these mutations enables adjusted therapeutic decisions both at the individual and population level. We investigated over time the prevalence of HIV-1 primary drug resistance mutations in treatment-naive patients and described the HIV-1 subtype distribution in a cohort in rural Tanzania at the beginning of the ART rollout in 2005-2007 and later in 2009. Viral RNA was analyzed in 387 baseline plasma samples from treatment-naive patients over a period of 5 years. The reverse transcriptase (RT) and protease genes were reversely transcribed, polymerase chain reaction (PCR) amplified, and directly sequenced to identify HIV-1 subtypes and single nucleotide polymorphisms associated with drug resistance (DR-SNPs). The prevalence of major DR-SNPs in 2005-2007 in the RT gene was determined: K103N (5.0%), Y181C (2.5%), M184V (2.5%), and G190A (1.7%), and M41L, K65KR, K70KR, and L74LV (0.8%). In samples from 2009 only K103N (3.3%), M184V, and T215FY (0.8%) were detected. Initial frequencies of subtypes C, A, D, and recombinants were 43%, 32%, 18%, and 7%, respectively. Later similar frequencies were found except for the recombinants, which were found twice as often (15%), highlighting the subtype diversity and a relatively stable subtype frequency in the area. DR-SNPs were found at initiation of the cohort despite very low previous ART use in the area. Statistically, frequencies of major mutations did not change significantly over the studied 5-year interval. These mutations could reflect primary resistances and may indicate a possible risk for treatment failure.