Matthew Lynch

Progression of active trachoma to scarring in a cohort of Tanzanian children

Risk factors for the incidence of scarring are needed to inform trachoma control programs in countries hyperendemic for this blinding disease. A cohort of pre-school children with constant, severe trachoma, and an age, sex, and neighborhood matched cohort of children without constant severe trachoma were followed for seven years to determine the incidence of scarring. The incidence of scarring in the children with constant severe trachoma was 29.2% versus 9.6% in the comparison group. In a model adjusting for multiple factors, significant predictors of scarring were increasing age, female, and constant severe trachoma (OR = 4.85, 95% CL = 2.05, 11.40). Infection with C. trachomatis at follow up was also associated with scarring in both groups of children. It is likely that these children have a different host response to infection, and represent a subgroup at high risk for the blinding complications of trachoma. Reducing exposure to infection in the community through antibiotics and changes in hygiene practices is still the most promising control strategy.

Caution is required when using health facility-based data to evaluate the health impact of malaria control efforts in Africa

The global health community is interested in the health impact of the billions of dollars invested to fight malaria in Africa. A recent publication used trends in malaria cases and deaths based on health facility records to evaluate the impact of malaria control efforts in Rwanda and Ethiopia. Although the authors demonstrate the use of facility-based data to estimate the impact of malaria control efforts, they also illustrate several pitfalls of such analyses that should be avoided, minimized, or actively acknowledged. A critique of this analysis is presented because many country programmes and donors are interested in evaluating programmatic impact with facility-based data. Key concerns related to: 1) clarifying the objective of the analysis; 2) data validity; 3) data representativeness; 4) the exploration of trends in factors that could influence malaria rates and thus confound the relationship between intervention scale-up and the observed changes in malaria outcomes; 5) the analytic approaches, including small numbers of patient outcomes, selective reporting of results, and choice of statistical and modeling methods; and 6) internal inconsistency on the strength and interpretation of the data. In conclusion, evaluations of malaria burden reduction using facility-based data could be very helpful, but those data should be collected, analysed, and interpreted with care, transparency, and a full recognition of their limitations.

Social and cultural factors affecting rates of regular retreatment of mosquito nets with insecticide in Bagamoyo District, Tanzania

Insecticide‐treated mosquito nets have an impact on mortality and morbidity in young children under controlled conditions. When integrated into larger control programs, there is the danger that rates of regular retreatment of the nets with insecticide will drop, greatly limiting their effectiveness as a public health intervention. In Bagamoyo District, Tanzania, rates of retreatment dropped significantly when payment for the insecticide was introduced. A series of neighbourhood (hamlet) meetings were held in all study villages to discuss peoples concerns about the insecticide and ways to increase rates of retreatment. Although changes were made in the procedure for retreatment, rates of retreatment remained lower than expected and showed marked variation within as well as between villages. We then conducted unstructured key informant interviews as well as informal discussions in a village with strong variation between different sectors of the village in rates of retreatment. While logistical problems were most frequently cited as reasons not to bring nets for retreatment, political and social divisions within the community provided a better explanation. This is borne out by the low response to rearrangements in logistics which made retreating the nets significantly easier for households, and the higher response when changes were made in the channels of communication as well as the logistic features. It is clearly more difficult for villagers to appreciate the benefits of the insecticide than those of the nets. Great emphasis needs to be placed on the insecticide and its beneficial effects from the outset for any large‐scale programme to be sustainable.

Strategic roles for behaviour change communication in a changing malaria landscape

Strong evidence suggests that quality strategic behaviour change communication (BCC) can improve malaria prevention and treatment behaviours. As progress is made towards malaria elimination, BCC becomes an even more important tool. BCC can be used 1) to reach populations who remain at risk as transmission dynamics change (e.g. mobile populations), 2) to facilitate identification of people with asymptomatic infections and their compliance with treatment, 3) to inform communities of the optimal timing of malaria control interventions, and 4) to explain changing diagnostic concerns (e.g. increasing false negatives as parasite density and multiplicity of infections fall) and treatment guidelines. The purpose of this commentary is to highlight the benefits and value for money that BCC brings to all aspects of malaria control, and to discuss areas of operations research needed as transmission dynamics change.

Evaluation of barriers to surgical compliance in the treatment of trichiasis

Purpose: Eyelid repair surgery can preventthe effects of trichiasis leading to visual loss.Cost, transportation difficulties, and familialresponsibilities have been identified as majorbarriers to surgical compliance. We evaluated whetheroffering trichiasis surgery in the village waseffective in increasing the rate of surgicalacceptance and in decreasing perceived barriers tosurgery. Methods: In 1989, 205 women withtrichiasis were identified in Central Tanzania andwere offered free surgery along with free transport. As of 1991, only 18% of these women had undergone thesurgery. We followed-up these women 7 years laterafter village level surgery was introduced.Results: Since 1991, an additional 12% ofthe women had undergone eyelid surgery. 44% wereconducted in the village. Surgical cases since 1991reported shorter travel times to the place of surgery,similar post-surgical problems, and fewer days in thehospital. While providing benefits to the patient,increased village eye services did not increase therate of surgical acceptance. The women who declinedsurgery did not know surgery in the village wasavailable and the perceived cost and transportationdifficulties continued to be barriers. 50% of thenon-acceptors stated that there was nothing that wouldenable them to accept surgical intervention despitethe fact that 3/4 of them reported eye symptoms thatinterfered with their daily activities.Conclusions: The cost efficacy of villagelevel eye services needs to be evaluated and theawareness of these services increased.

Viewpoint: evaluating the impact of malaria control efforts on mortality in sub-Saharan Africa.

Objective  To describe an approach for evaluating the impact of malaria control efforts on malaria‐associated mortality in sub‐Saharan Africa, where disease‐specific mortality trends usually cannot be measured directly and most malaria deaths occur among young children.

Universal coverage with insecticide-treated nets – applying the revised indicators for ownership and use to the Nigeria 2010 malaria indicator survey data

BackgroundUntil recently only two indicators were used to evaluate malaria prevention with insecticide-treated nets (ITN): “proportion of households with any ITN” and “proportion of the population using an ITN last night”. This study explores the potential of the expanded set of indicators recommended by the Roll Back Malaria Monitoring and Evaluation Reference Group (MERG) for comprehensive analysis of universal coverage with ITN by applying them to the Nigeria 2010 Malaria Indicator Survey data.MethodsThe two additional indicators of “proportion of households with at least one ITN for every two people” and “proportion of population with access to an ITN within the household” were calculated as recommended by MERG. Based on the estimates for each of the four ITN indicators three gaps were calculated: i) households with no ITN, ii) households with any but not enough ITN, iii) population with access to ITN not using it. In addition, coverage with at least one ITN at community level was explored by applying Lot Quality Assurance Sampling (LQAS) decision rules to the cluster level of the data. All outcomes were analysed by household background characteristics and whether an ITN campaign had recently been done.ResultsWhile the proportion of households with any ITN was only 42% overall, it was 75% in areas with a recent mass campaign and in these areas 66% of communities had coverage of 80% or better. However, the campaigns left a considerable intra-household ownership gap with 66% of households with any ITN not having enough for every family member. In contrast, the analysis comparing actual against potential use showed that ITN utilization was good overall with only 19% of people with access not using the ITN, but with a significant difference between the North, where use was excellent (use gap 11%), and the South (use gap 36%) indicating the need for enhanced behaviour change communication.ConclusionsThe expanded ITN indicators to assess universal coverage provide strong tools for a comprehensive system effectiveness analysis that produces clear, actionable evidence of progress as well as the need for specific additional interventions clearly differentiating between gaps in ownership and use.

Changing water-use patterns in a water-poor area: Lessons for a trachoma intervention project

An epidemiological survey carried out in the Dodoma region of Tanzania found that high rates of trachoma infection in pre-school children were associated with unwashed faces. Prior to a planned trachoma intervention project, a pilot study was done on household decisions about water use and perceptions about face washing and eye disease. The study found that mothers overestimated the amount of water necessary to wash a childs face. In addition, mothers would not change their water-use priorities without the consent of their husbands and the support of the community. Therefore a health education program was designed to address the perception that face washing required a great deal of water. The program also sought to involve and re-educate the whole community rather than focus only on the mothers who were most likely to wash the childrens faces.

The use of mediation analysis to assess the effects of a behaviour change communication strategy on bed net ideation and household universal coverage in Tanzania

BackgroundSBCC campaigns are designed to act on cognitive, social and emotional factors at the individual or community level. The combination of these factors, referred to as ‘ideation’, play a role in determining behaviour by reinforcing and confirming decisions about a particular health topic. This study introduces ideation theory and mediation analysis as a way to evaluate the impact of a malaria SBCC campaign in Tanzania, to determine whether exposure to a communication programme influenced universal coverage through mediating ideational variables.MethodsA household survey in three districts where community change agents (CCAs) were active was conducted to collect information on ITN use, number of ITNs in the household, and perceptions about ITN use and ownership. Variables relating to attitudes and beliefs were combined to make ‘net ideation’. Using an ideational framework, a mediation analysis was conducted to see the impact exposure to a CCA only, mass media and community (M & C) messaging only, or exposure to both, had on household universal coverage, through the mediating variable net ideation.ResultsAll three levels of exposure (CCA, M & C messaging, or exposure to both) were significantly associated with increased net ideation (CCA: 0.283, 95% CI: 0.136-0.429, p-value: <0.001; M & C: 0.128, 95% CI: 0.032-0.334, p-value: 0.018; both: 0.376, 95% CI: 0.170-0.580, p-value: <0.001). Net ideation also significantly increased the odds of having universal coverage (CCAOR: 1.265, 95% CI: 1.118-1.433, p-value: <0.001; M & COR: 1.264, 95% CI: 1.117-1.432, p-value: <0.001, bothOR: 1.260, 95% CI: 1.114-1.428, p-value: <0.001). There were no significant direct effects between any exposure and universal coverage when controlling for net ideation.ConclusionsThe results of this study indicate that mediation analysis is an applicable new tool to assess SBCC campaigns. Ideation as a mediator of the effects of communication exposure on household universal coverage has implications for designing SBCC to support both mass and continuous distribution efforts, since both heavily rely on consumer participation to obtain and maintain ITNs. Such systems can be strengthened by SBCC programming, generating demand through improving social norms about net ownership and use, perceived benefits of nets, and other behavioural constructs.

Household decisions among the Gogo people of Tanzania: Determining the roles of men, women and the community in implementing a trachoma prevention program

An epidemiological survey in rural Tanzania indicated that the rate of trachoma was elevated in children whose faces were unclean. To aid in designing a health education program to increase face washing, a descriptive village study was done to determine water use patterns, attitudes towards face washing, responsibility for child hygiene, and decision making processes in the household and community. The study found that mothers were responsible for both water use and the health and cleanliness of the children. However, health education could not be directed at the women alone because the decision to change behavior had to be sanctioned by the husband in the household, and the community as a whole. The final health campaign was designed to be compatible with the accepted patterns of decision making. This case study, as well as others which focus on womens groups as change agents, suggests several factors such as male migration and local authority structures which health planners may need to assess when designing health programs.