Mobile Phones As Surveillance Tools: Implementing and Evaluating a Large-Scale Intersectoral Surveillance System for Rabies in Tanzania.

Katie Hampson and colleagues describe their experience of developing and deploying a large-scale rabies surveillance system based on mobile phones in southern Tanzania.

Verbal autopsy completion rate and factors associated with undetermined cause of death in a rural resource-poor setting of Tanzania.

BACKGROUND: Verbal autopsy (VA) is a widely used tool to assign probable cause of death in areas with inadequate vital registration systems. Its uses in priority setting and health planning are well documented in sub-Saharan Africa (SSA) and Asia. However, there is a lack of data related to VA processing and completion rates in assigning causes of death in a community. There is also a lack of data on factors associated with undetermined causes of death documented in SSA. There is a need for such information for understanding the gaps in VA processing and better estimating disease burden. OBJECTIVE: The study's intent was to determine the completion rate of VA and factors associated with assigning undetermined causes of death in rural Tanzania. METHODS: A database of deaths reported from the Ifakara Health and Demographic Surveillance System from 2002 to 2007 was used. Completion rates were determined at the following stages of processing: 1) death identified; 2) VA interviews conducted; 3) VA forms submitted to physicians; 4) coding and assigning of cause of death. Logistic regression was used to determine factors associated with deaths coded as "undetermined." RESULTS: The completion rate of VA after identification of death and the VA interview ranged from 83% in 2002 and 89% in 2007. Ninety-four percent of deaths submitted to physicians were assigned a specific cause, with 31% of the causes coded as undetermined. Neonates and child deaths that occurred outside health facilities were associated with a high rate of undetermined classification (33%, odds ratio [OR] = 1.33, 95% confidence interval [CI] (1.05, 1.67), p = 0.016). Respondents reporting high education levels were less likely to be associated with deaths that were classified as undetermined (24%, OR = 0.76, 95% CI (0.60, -0.96), p = 0.023). Being a child of the deceased compared to a partner (husband or wife) was more likely to be associated with undetermined cause of death classification (OR = 1.35, 95% CI (1.04, 1.75), p = 0.023). CONCLUSION: Every year, there is a high completion rate of VA in the initial stages of processing; however, a number of VAs are lost during the processing. Most of the losses occur at the final step, physicians' determination of cause of death. The type of respondent and place of death had a significant effect on final determination of the plausible cause of death. The finding provides some insight into the factors affecting full coverage of verbal autopsy diagnosis and the limitations of causes of death based on VA in SSA. Although physician review is the most commonly used method in ascertaining probable cause of death, we suggest further work needs to be done to address the challenges faced by physicians in interpreting VA forms. There is need for an alternative to or improvement of the methods of physician review.

Health status and quality of life among older adults in rural Tanzania.

BACKGROUND: Increasingly, human populations throughout the world are living longer and this trend is developing in sub-Saharan Africa. In developing African countries such as Tanzania, this demographic phenomenon is taking place against a background of poverty and poor health conditions. There has been limited research on how this process of ageing impacts upon the health of older people within such low-income settings. OBJECTIVE: The objective of this study is to describe the impacts of ageing on the health status, quality of life and well-being of older people in a rural population of Tanzania. DESIGN: A short version of the WHO Survey on Adult Health and Global Ageing questionnaire was used to collect information on the health status, quality of life and well-being of older adults living in Ifakara Health and Demographic Surveillance System, Tanzania, during early 2007. Questionnaires were administered through this framework to 8,206 people aged 50 and over. RESULTS: Among people aged 50 and over, having good quality of life and health status was significantly associated with being male, married and not being among the oldest old. Functional ability assessment was associated with age, with people reporting more difficulty in performing routine activities as age increased, particularly among women. Reports of good quality of life and well-being decreased with increasing age. Women were significantly more likely to report poor quality of life (odds ratio 1.31; p<0.001, 95% CI 1.15-1.50). CONCLUSIONS: Older people within this rural Tanzanian setting reported that the ageing process had significant impacts on their health status, quality of life and physical ability. Poor quality of life and well-being, and poor health status in older people were significantly associated with marital status, sex, age and level of education. The process of ageing in this setting is challenging and raises public health concerns.

Benefit of a single preoperative dose of antibiotics in a sub-saharan district hospital: minimal input, massive impact.

OBJECTIVE: To evaluate the impact of a single-shot preoperative antimicrobial prophylaxis (AMP) to reduce the rate of Surgical Site Infections (SSIs) in a rural sub-Saharan hospital. SUMMARY BACKGROUND DATA: We analyzed the incidence of SSIs in a rural Tanzanian hospital with very limited resources and found that AMP was administered after incision in 88% without covering the expected pathogens. Inadequacy and mistiming of AMP proved to be major risk factors for SSI in this study. Subsequently, 21.6% of patients developed an SSI after clean or clean-contaminated surgery, with 60% of detected pathogens being resistant to the administered antibiotics. In developed countries, preoperative single shot AMP is widely used and effective in the prevention of SSI. METHODS: Implementation and monitoring of guidelines for routine and adequate single shot AMP within 2 hours prior to incision in every clean and clean-contaminated intervention. RESULTS: In the preintervention group, 527 patients qualified for routine AMP that was administered in 88% of patients after incision and did not cover the expected pathogens to a large extent.114 patients (21.6%) developed an SSI, with 60% of detected pathogens being resistant to the administered antibiotics. After implementation of the guidelines, the incidence of SSIs significantly decreased from 21.6% to 4% (11/276). CONCLUSIONS: The implementation of a single shot AMP dramatically decreased the rate of SSI in a hospital with very limited resources. Such guidelines, developed by industrialized countries, are even more effective in non-industrialized countries.

Establishment of a large semi-field system for experimental study of African malaria vector ecology and control in Tanzania.

BACKGROUND: Medical entomologists increasingly recognize that the ability to make inferences between laboratory experiments of vector biology and epidemiological trends observed in the field is hindered by a conceptual and methodological gap occurring between these approaches which prevents hypothesis-driven empirical research from being conducted on relatively large and environmentally realistic scales. The development of Semi-Field Systems (SFS) has been proposed as the best mechanism for bridging this gap. Semi-field systems are defined as enclosed environments, ideally situated within the natural ecosystem of a target disease vector and exposed to ambient environmental conditions, in which all features necessary for its life cycle completion are present. Although the value of SFS as a research tool for malaria vector biology is gaining recognition, only a few such facilities exist worldwide and are relatively small in size (< 100 m2). METHODS: The establishment of a 625 m2 state-of-the-art SFS for large-scale experimentation on anopheline mosquito ecology and control within a rural area of southern Tanzania, where malaria transmission intensities are amongst the highest ever recorded, is described. RESULTS: A greenhouse frame with walls of mosquito netting and a polyethylene roof was mounted on a raised concrete platform at the Ifakara Health Institute. The interior of the SFS was divided into four separate work areas that have been set up for a variety of research activities including mass-rearing for African malaria vectors under natural conditions, high throughput evaluation of novel mosquito control and trapping techniques, short-term assays of host-seeking behaviour and olfaction, and longer-term experimental investigation of anopheline population dynamics and gene flow within a contained environment that simulates a local village domestic setting. CONCLUSION: The SFS at Ifakara was completed and ready for use in under two years. Preliminary observations indicate that realistic and repeatable observations of anopheline behaviour are obtainable within the SFS, and that habitat and climatic features representative of field conditions can be simulated within it. As work begins in the SFS in Ifakara and others around the world, the major opportunities and challenges to the successful application of this tool for malaria vector research and control are discussed.

Randomized controlled safety and efficacy trial of 2 vitamin A supplementation schedules in Tanzanian infants.

BACKGROUND: Vitamin A supplementation reduces morbidity and mortality in children living in areas endemic for vitamin A deficiency. Routine vitamin A supplementation usually starts only at age 9 mo, but high rates of illness and mortality are seen in the first months of life. OBJECTIVE: The objective of the study was to evaluate the safety and efficacy of vitamin A supplementation at the same time as routine vaccination in infants aged 1-3 mo. DESIGN: We recruited 780 newborn infants and their mothers to a randomized double-blind controlled trial in Ifakara in southern Tanzania. In one group, mothers received 60,000 microg vitamin A palmitate shortly after delivery, and their infants received 7500 microg at the same time as vaccinations given at approximately 1, 2, and 3 mo of age. In the other group, mothers received a second 60,000-microg dose when their infant was aged 1 mo, and their infants received 15,000 microg at the same time as the routine vaccinations. VAD was defined as a modified relative dose-response test result of >or=0.060. RESULTS: High-dose vitamin A supplementation was well tolerated. The relative risk of VAD at 6 mo in the high-dose group compared with the lower dose group was 0.91 (95% CI: 0.76, 1.09; P=0.32). Serum retinol and incidence of illness did not differ significantly between the 2 groups. Some vitamin A capsules degraded toward the end of the study. CONCLUSIONS: Doubling the doses of vitamin A to mothers and their young infants is safe but unlikely to reduce short-term morbidity or to substantially enhance the biochemical vitamin A status of infants at age 6 mo. The stability of vitamin A capsules merits further investigation.

Colorimetric phage-based assay for detection of rifampin-resistant Mycobacterium tuberculosis.

Tests based on bacteriophage replication enable rapid screening of Mycobacterium tuberculosis for drug resistance. We describe a novel broth-based colorimetric method for detecting phage replication. When clinical isolates were tested by this novel method, high concordance was observed with both the traditional phage assay and gene mutation analysis for detection of resistance to rifampin.

Risk factors for surgical site infection in a Tanzanian district hospital: a challenge for the traditional National Nosocomial Infections Surveillance system index.

The incidence of surgical site infections (SSIs) was 24% in a district hospital in Tanzania. Wound classification was not an independent risk factor for SSI, indicating that risk scores developed in industrialized countries may require adjustments for nonindustrialized countries. The National Nosocomial Infections Surveillance system score required adjustments to reliably predict SSI, probably to account for improper hygiene and the lack of adjustment for the duration of surgery (defined as the 75th percentile of the duration for each type of operative procedure) to reflect local circumstances. Multidrug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus and gram-negative pathogens expressing broad-spectrum beta-lactamases, have already emerged.

Relationship between haemoglobin and haematocrit in the definition of anaemia.

INTRODUCTION: Anaemia is the most frequent haematological disorder in childhood. The notion that defines naemia does not change throughout life, although parameters used for its evaluation show significant variations during childhood. Haematocrit (Hct) (%) is usually defined as three times the value of haemoglobin (Hgb) (g/dl), while the clinical definition of anaemia is related to either an abnormal Hct or Hgb value. OBJECTIVE: To evaluate the agreement between Hgb and Hct values in the definition of anaemia, the relationship between these two parameters and their age-dependence. METHODS: The Hct and Hgb paired values from children aged 2-18 months from Ifakara (Tanzania) and children aged 1-4 years from Manhiça (Mozambique) were analysed. Haematological determinations of the Manhiça samples were done using a KX-21N cell counter (Kobe, Japan) and Ifakara samples were analysed in a semiautomatic cell counter (Sysmex F800 microcell counter, TOA Medical Electronics, Kobe, Japan). The kappa-statistic was used to calculate the agreement between anaemia definitions in each group. Crude and multivariate relationship between Hct and Hgb levels were analysed by linear regression model estimation. The age-dependence of the crude ratio (Hct/Hgb) was analysed using linear regression models and fractional polynomials. RESULTS: The prevalences of mild and moderate anaemia as defined by Hgb levels in the Manhiça group were 61% and 6%, respectively, and 41% and 2% by Hct. In the Ifakara group these were 74% and 10%, respectively, by Hgb and 42% and 3% by Hct, respectively. Agreement between mild and moderate anaemia definitions made up from Hgb or from Hct levels were from fair to moderate. Hct levels decreased with age for high Hgb levels, whereas they increased for low Hgb levels. The classification of cases is improved when higher age-related cut-off values for Hct are used. The crude relationship between Hct and Hgb levels was significantly different from 3, and this was modified by age. The evaluation of the age-dependence ratio (Hct/Hgb) showed a non-linear relationship with an asymptotic trend to 3. CONCLUSIONS: Measurement of haematocrit count is easy and can be performed in most rural health care centres. However, the corresponding Hgb levels cannot be derived with an acceptable accuracy using the value 3 as a conversion factor. Furthermore, the commonly assumed 'equivalent' cut-off points for anaemia definitions need to be re-evaluated.