57 research outputs found

    Policy environment and male circumcision for HIV prevention: Findings from a situation analysis study in Tanzania

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    <p>Abstract</p> <p>Background</p> <p>Male circumcision (MC) has been shown to be effective against heterosexual acquisition of HIV infection and is being scaled up as an additional strategy against HIV in several countries of Africa. However, the policy environment (whether to formulate new specific policy on MC or adapts the existing ones); and the role of various stakeholders in the MC scale up process in Tanzania was unclear. We conducted this study as part of a situation analysis to understand the attitudes of policy makers and other key community and health authority decision makers towards MC, policy and regulatory environment, and the readiness of a health system to accommodate scaling up of MC services.</p> <p>Methods</p> <p>We conducted 36 key informants' interviews with a broad range of informants including civil servants, religious leaders, cultural and traditional gatekeepers and other potential informants. Study informants were selected at the national level, regional, district and community levels to represent both traditionally circumcising and non-circumcising communities.</p> <p>Results</p> <p>Study informants had positive attitudes and strong beliefs towards MC. Key informants in traditionally non-circumcising districts were willing to take their sons for medically performed MC. Religious leaders and traditional gatekeepers supported MC as it has been enshrined in their holy scripts and traditional customs respectively. Civil servants highlighted the need for existence of enabling policy and regulatory environment in the form of laws, regulations and guidelines that will ensure voluntary accessibility, acceptability, quality and safety for those in need of MC services. Majority of informants urged the government to make improvements in the health system at all levels to ensure availability of adequate trained personnel, infrastructure, equipment, and supplies for MC scale up, and insisted on the involvement of different MC stakeholders as key components in effective roll out of medically performed MC programme in the country.</p> <p>Conclusions</p> <p>Findings from the situation analysis in Tanzania have shown that despite the absence of a specific policy on MC, basic elements of enabling policy environment at national, regional, district and community levels are in place for the implementation of MC scale up programme.</p

    Duration of Protection Against Clinical Malaria Provided by Three Regimens of Intermittent Preventive Treatment in Tanzanian Infants

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    BACKGROUND: Intermittent preventive treatment in infants (IPTi) is a new malaria control tool. However, it is uncertain whether IPTi works mainly through chemoprophylaxis or treatment of existing infections. Understanding the mechanism is essential for development of replacements for sulfadoxine-pyrimethamine (SP) where it is no longer effective. This study investigated how protection against malaria given by SP, chlorproguanil-dapsone (CD) and mefloquine (MQ), varied with time since administration of IPTi. METHODS AND FINDINGS: A secondary analysis of data from a randomised, placebo-controlled trial in an area of high antifolate resistance in Tanzania was conducted. IPTi using SP, CD, MQ or placebo was given to 1280 infants at 2, 3 and 9 months of age. Poisson regression with random effects to adjust for potential clustering of malaria episodes within children was used to calculate incidence rate ratios for clinical malaria in defined time strata following IPTi. The short-acting antimalarial CD gave no protection against clinical malaria, whereas long-acting MQ gave two months of substantial protection (protective efficacy (PE) 73.1% (95% CI: 23.9, 90.5) and 73.3% (95% CI: 0, 92.9) in the first and second month respectively). SP gave some protection in the first month after treatment (PE 64.5% (95% CI: 10.6, 85.9)) although it did not reduce the incidence of malaria up to 12 months of age. There was no evidence of either long-term protection or increased risk of malaria for any of the regimens. CONCLUSION: Post-treatment chemoprophylaxis appears to be the main mechanism by which IPTi protects children against malaria. Long-acting antimalarials are therefore likely to be the most effective drugs for IPTi, but as monotherapies could be vulnerable to development of drug resistance. Due to concerns about tolerability, the mefloquine formulation used in this study is not suitable for IPTi. Further investigation of combinations of long-acting antimalarials for IPTi is needed. TRIAL REGISTRATION: Clinicaltrials.gov NCT00158574

    An experimental hut evaluation of Olysetยฎ nets against anopheline mosquitoes after seven years use in Tanzanian villages

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    BACKGROUND: Long-lasting insecticidal nets (LLINs) are advocated by WHO for protection against malaria. Of the three brands of LLINs currently approved by WHO, Olyset(R) is the only one currently granted full recommendation. With this type of LLIN, the insecticide (permethrin) is incorporated into the polyethylene fibre during manufacture and diffuses from the core to the surface, thereby maintaining surface concentrations. It has not been determined for how long Olyset nets remain protective against mosquitoes in household use. METHODS: Examples of Olyset nets, which had been in use in Tanzanian villages for seven years, were tested in experimental huts against naturally entering Anopheles gambiae and Anopheles funestus mosquitoes. Performance was compared with new Olyset nets, conventionally treated ITNs (either newly treated with alphacypermethrin or taken from local villages after 1.5 years of use) and untreated nets. All nets were artificially holed except for the seven-year Olyset nets, which had developed holes during prolonged domestic use. RESULTS: Anopheles funestus and An. gambiae in NE Tanzania are susceptible to pyrethroids. The new Olyset nets caused high mortality against An. funestus (73.9%) and An. gambiae (62.7%) in experimental huts. The seven-year Olyset nets caused 58.9% mortality against An. funestus and 40.0% mortality against An. gambiae. The freshly treated alphacypermethrin nets also caused high mortality against An. funestus (70.6%) and An. gambiae (72.0%); this decreased to 58.4% and 69.6% respectively after 1.5 years of use. The new Olyset nets inhibited blood-feeding by 40-50%. The 7 year Olyset nets showed no feeding inhibition over that shown by the untreated nets. The alphacypermethrin treated nets failed to inhibit blood-feeding after 1.5 years of use. However iHhhdn laboratory tunnel tests samples of all types of treated net including the 7 year Olyset inhibited blood-feeding by more than 95%. CONCLUSION: After seven years of use Olyset nets were still strongly insecticidal. Mosquito mortality decreased by only 20-35% over this period. However, Olyset would not provide personal protection after seven years unless it was in good condition and all holes fully repaired

    Overuse of artemisinin-combination therapy in Mto wa Mbu (river of mosquitoes), an area misinterpreted as high endemic for malaria

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    BACKGROUND: Adequate malaria diagnosis and treatment remain major difficulties in rural sub-Saharan Africa. These issues deserve renewed attention in the light of first-line treatment with expensive artemisinin-combination therapy (ACT) and changing patterns of transmission intensity. This study describes diagnostic and treatment practices in Mto wa Mbu, an area that used to be hyperendemic for malaria, but where no recent assessments of transmission intensity have been conducted. METHODS: Retrospective and prospective data were collected from the two major village health clinics. The diagnosis in prospectively collected data was confirmed by microscopy. The level of transmission intensity was determined by entomological assessment and by estimating sero-conversion rates using anti-malarial antibody responses. RESULTS: Malaria transmission intensity by serological assessment was equivalent to 40% of outpatients attending the clinics in 2006-2007 were diagnosed with malaria. Prospective data demonstrated a very high overdiagnosis of malaria. Microscopy was unreliable with < 1% of slides regarded as malaria parasite-positive by clinic microscopists being confirmed by trained research microscopists. In addition, many 'slide negatives' received anti-malarial treatment. As a result, 99.6% (248/249) of the individuals who were treated with ACT were in fact free of malaria parasites. CONCLUSION: Transmission intensity has dropped considerably in the area of Mto wa Mbu. Despite this, most fevers are still regarded and treated as malaria, thereby ignoring true causes of febrile illness and over-prescribing ACT. The discrepancy between the perceived and actual level of transmission intensity may be present in many areas in sub-Saharan Africa and calls for greater efforts in defining levels of transmission on a local scale to help rational drug-prescribing behaviour

    Evaluation of ICON Maxx, a long-lasting treatment kit for mosquito nets: experimental hut trials against anopheline mosquitoes in Tanzania.

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    BACKGROUND: Insecticide-treated nets are the primary method of preventing malaria. To remain effective, the pyrethroid insecticide must withstand multiple washes over the lifetime of the net. ICON(ยฎ) Maxx is a 'dip-it-yourself' kit for long-lasting treatment of polyester nets. The twin-sachet kit contains a slow-release capsule suspension of lambda-cyhalothrin plus binding agent. To determine whether ICON Maxx meets the standards required by the World Health Organization Pesticide Evaluation Scheme (WHOPES), the efficacy and wash fastness of ICON Maxx was evaluated against wild, free-flying anopheline mosquitoes. METHODS: ICON Maxx was subjected to bioassay evaluation and experimental hut trial against pyrethroid-susceptible Anopheles gambiae, Anopheles arabiensis and Anopheles funestus. Mosquito mortality, blood feeding inhibition and personal protection were compared between untreated nets, conventional lambda-cyhalothrin treated nets (CTN) washed either four times (cut-off threshold) or 20 times, and ICON Maxx-treated nets either unwashed or washed 20 times. RESULTS: In bioassay, ICON Maxx demonstrated superior wash resistance to the CTN. In the experimental hut trial, ICON Maxx killed 75 % of An. funestus, 71 % of An. gambiae and 47 % of An. arabiensis when unwashed and 58, 66 and 42 %, respectively, when 20 times washed. The CTN killed 52 % of An. funestus, 33 % of An. gambiae and 30 % of An. arabiensis when washed to the cut-off threshold of four washes and 40, 40 and 36 %, respectively, when 20 times washed. Percentage mortality with ICON Maxx 20 times washed was similar (An. funestus) or significantly higher (An. gambiae, An. arabiensis) than with CTN washed to the WHOPES cut-off threshold. Blood-feeding inhibition with ICON Maxx 20 times washed was similar to the CTN washed to cut-off for all three species. Personal protection was significantly higher with ICON Maxx 20 times washed (66-79 %) than with CTN washed to cut-off (48-60 %). CONCLUSIONS: Nets treated with ICON Maxx and washed 20 times met the approval criteria set by WHOPES for Phase II trials in terms of mortality and blood-feeding inhibition. This finding raises the prospect of conventional polyester nets and other materials being made long-lastingly insecticidal through simple dipping in community or home, and thus represents a major advance over conventional pyrethroid treatments

    Occurrence of the leucine-to-phenylalanine knockdown resistance (kdr) mutation in Anopheles arabiensis populations in Tanzania, detected by a simplified high-throughput SSOP-ELISA method

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    BACKGROUND: Molecular markers of insecticide resistance can provide sensitive indicators of resistance development in malaria vector populations. Monitoring of insecticide resistance in vector populations is an important component of current malaria control programmes. Knockdown resistance (kdr) confers resistance to the pyrethroid class of insecticides with cross-resistance to DDT through single nucleotide polymorphisms (SNPs) in the voltage-gated sodium channel gene. METHODS: To enable detection of kdr mutations at low frequency a method was developed that uses polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA)-based technology, allowing rapid, reliable and cost-effective testing of large numbers of individual mosquitoes. This was used to assay mosquitoes from sites in lower Moshi, Tanzania. RESULTS: Sequence-specific oligonucleotide probes (SSOP) were used for simultaneous detection of both East and West African kdr mutations with high specificity and sensitivity. Application of the SSOP-ELISA method to 1,620 field-collected Anopheles arabiensis from Tanzania identified the West African leucine-phenylalanine kdr mutation in two heterozygous individuals, indicating the potential for resistance development that requires close monitoring. CONCLUSION: The presence of the West African kdr mutation at low frequency in this East African population of An. arabiensis has implications for the spread of the kdr gene across the African continent

    Variability of respiratory rate measurements in children suspected with non-severe pneumonia in north-east Tanzania.

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    OBJECTIVE: Measurement of respiratory rate is an important clinical sign in the diagnosis of pneumonia but suffers from interobserver variation. Here, we assess the use of video recordings as a quality assurance tool that could be useful both in research and in training of staff. METHODS: Respiratory rates (RR) were recorded in children aged 2-59 months presenting with cough or difficulty breathing at two busy outpatient clinics in Tanzania. Measurements were repeated at 10-min intervals in a quiet environment with simultaneous video recordings that were independently reviewed by two paediatricians. RESULTS: Eight hundred and fifty-nine videos were sent to two paediatricians; 148 (17.2%) were considered unreadable by one or both. For the 711 (82.8%) videos that were readable by both paediatricians, there was perfect agreement for the presence of raised RR with a kappa value (ฮบ) of 0.85 (P < 0.001); and in 476 (66.9%) cases, both paediatricians agreed on the RR within 2 breaths per minute (ยฑ2 bpm). A reported illness of 5 days or more was associated with unreadable video recordings (OR = 3.44, CI: 1.5-6.08; P < 0.001). The multilevel model showed that differences between observers accounted for only 13% of the variability in RR. CONCLUSION: Video recordings are reliable tools for quality assurance of RR measurements in children with suspected pneumonia. Videos with a clear view of respiratory movements may also be useful in training primary healthcare staff

    The Dynamics of Naturally Acquired Immune Responses to Plasmodium falciparum Sexual Stage Antigens Pfs230 & Pfs48/45 in a Low Endemic Area in Tanzania

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    BACKGROUND: Naturally acquired immune responses against sexual stages of P. falciparum can reduce the transmission of malaria from humans to mosquitoes. These antigens are candidate transmission-blocking vaccines but little is known about the acquisition of sexual stage immunity after exposure to gametocytes, or their longevity and functionality. We conducted a longitudinal study on functional sexual stage immune responses. METHODOLOGY/PRINCIPAL FINDINGS: Parasitaemic individuals (nโ€Š=โ€Š116) were recruited at a health centre in Lower Moshi, Tanzania. Patients presented with gametocytes (nโ€Š=โ€Š16), developed circulating gametocytes by day 7 (nโ€Š=โ€Š69) or between day 7 and 14 (nโ€Š=โ€Š10) after treatment or did not develop gametocytes (nโ€Š=โ€Š21). Serum samples were collected on the first day of gametocytaemia and 28 and 84 days post-enrolment (or d7, 28, 84 after enrolment from gametocyte-negative individuals). Antibody responses to sexual stage antigens Pfs230 and Pfs48/45 were detected in 20.7% (72/348) and 15.2% (53/348) of the samples, respectively, and were less prevalent than antibodies against asexual stage antigens MSP-1(19) (48.1%; 137/285) and AMA-1 (52.4%; 129/246)(p<0.001). The prevalence of anti-Pfs230 (pโ€Š=โ€Š0.026) and anti-Pfs48/45 antibodies (pโ€Š=โ€Š0.017) increased with longer duration of gametocyte exposure and had an estimated half-life of approximately 3 months. Membrane feeding experiments demonstrated a strong association between the prevalence and concentration of Pfs230 and Pfs48/45 antibodies and transmission reducing activity (TRA, p<0.01). CONCLUSIONS/SIGNIFICANCE: In a longitudinal study, anti-Pfs230 and Pfs48/45 antibodies developed rapidly after exposure to gametocytes and were strongly associated with transmission-reducing activity. Our data indicate that the extent of antigen exposure is important in eliciting functional transmission-reducing immune responses
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