WHO surveillance case definitions for ILI and SARI

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The first phase of the SUN Movement focused on creating an enabling environment for nutrition and bringing multiple sectors and stakeholders together at country level. Being in a negative energy state can result in hunger, agitation, and even slight sleep problems. Jewish Schools, Institutions, and Sponsors. For the purpose of formulation of policies and strategies to control and prevent malnutrition, it is essential to assess continuously the nutritional problems in the country. This calls for a nation-wide monitoring system.

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On the other hand, four regions had low or very low rates of stunting. However, vast disparities within the low prevalence regions can exist.

Children in one country can have a very low stunting rate with less than 1 in 40 affected, while more than 1 in 10 of their peers in the country next door are at a disadvantage due to the irreversible physical and cognitive damage that can accompany stunted growth.

That said, overall trends are positive. Between and , stunting prevalence globally declined from In , nearly two out of five stunted children lived in South Asia while more than one in three lived in sub-Saharan Africa. The percentage change since is only shown where the change is significantly different. Worldwide in , 38 million, or 5. Eastern Europe and Central Asia had the highest overweight prevalence in with The lowest overweight prevalence in was seen in South Asia, at 3.

East Asia and the Pacific had the highest number of overweight children in with 8. Overall the two Asian regions East Asia and the Pacific and South Asia account for more than one out of every three overweight children in the world. Eastern Europe and Central Asia as well as North America are the only regions that have seen a statistically significant increase in number of overweight children between and In globally, 51 million children under five were wasted of which 16 million were severely wasted.

This translates into a prevalence of 7. In , more than half of all wasted children lived in South Asia and about one quarter in sub-Saharan Africa, with similar proportions for severely wasted children. Under-five wasting and severe wasting are highly sensitive to change.

Thus, estimates for these indicators are only reported for current levels In almost all countries with available data, stunting rates are higher among boys than girls. While analyses to determine underlying causes for this phenomenon are underway, an initial review of the literature suggests that the higher risk for preterm birth among boys which is inextricably linked with lower birth weight is a potential reason for this sex-based disparity in stunting.

Analysis is based on a subset of 92 countries with recent data by wealth quintile groupings covering 69 per cent of the global population. Children from the poorest 20 per cent of the population have stunting rates that are double the rate in comparison with the richest quintile. In South Asia, the absolute disparities between the richest and poorest children in regard to stunting are greater than in any other region. While the overall rates are lower, the relative disparities are greatest in Latin America and the Caribbean where the rate among the poorest is more than 4 times higher than among the richest.

An analysis of 54 countries with comparable trend data between around and around shows that gaps between the poorest 20 per cent and richest 20 per cent of children under five have closed by at least 20 per cent in the majority of upper-middle-income countries. However, in almost all low income countries, this gap has either remained the same or increased. Blencowe H et al. Preterm birth—associated neurodevelopmental impairment estimates at regional and global levels for Pediatric Research Volume No s1, December Please note that some children can suffer from more than one form of malnutrition — such as stunting and overweight or stunting and wasting.

There are currently no joint global or regional estimates for these combined conditions, but UNICEF has a country-level dataset with country level estimates, where re-analysis was possible.

Prevalence of stunting, wasting and overweight among children under 5 is estimated by comparing actual measurements to an international standard reference population. The new standards are the result of an intensive study project involving more than 8, children from Brazil, Ghana, India, Norway, Oman and the United States.

Overcoming the technical and biological drawbacks of the old reference population, the new standards confirm that children born anywhere in the world and given the optimum start in life have the potential to reach the same range of height and weight. The new standards should be used in future assessments of child nutritional status. It should be noted that because of the differences between the old reference population and the new standards, prevalence estimates of child anthropometry indicators based on these two references are not readily comparable.

It is essential that all estimates are based on the same reference population preferably the new standards when conducting trend analyses. Nutrition monitoring is the measurement of the changes in the nutritional status of a population or a specific group of individuals over time WHO, The paucity of reliable and comparable data from all parts of the country is a definite obstacle towards a realistic and disaggregated problem definition.

This calls for a nation-wide monitoring system. To achieve this, it is necessary to restructure and strengthen the existing National Nutrition Monitoring Bureau NNMB and to develop a mechanism for generating nationwide disaggregated data.

National Nutrition Policy, Govt. The National and State governments have been implementing a number of poverty alleviation programmes for the overall socioeconomic development of the community and several nutrition interventions to mitigate the problem of undernutrition. The Government of India's National Nutrition Policy, apart from setting nutrition goals to control and prevent malnutrition in the country, recommended that a National Nutrition Surveillance System should be developed.

For the purpose of formulation of policies and strategies to control and prevent malnutrition, it is essential to assess continuously the nutritional problems in the country. A with-without comparison can then be made between two areas, one benefiting from the programme and the other not external control group. This poses the problem of initial comparability of the two areas: Alternatively, two areas may be compared with an unequal level of implementation of the programme internal control group or, more simply still, groups of individuals or households may be compared which have not benefited of the programme at the same level, since the level to which target individuals are reached by programmes is generally variable.

Ideally, the impact evaluation should follow an experimental design, with randomization of the individuals or areas to receive or not the intervention. This is the most rigorous way to proceed in order to be able to conclude on the actual impact of the intervention.

In most cases, an impact evaluation of the crude effect will be quite acceptable, i. Elements suggesting a cause and effect relationship can be formulated, but without seeking absolute proof, if plausibility of the effectiveness of the programme appears sufficient to those in charge.

In , Vietnam implemented a national strategy of supplementation with vitamin A capsules through health centres to combat xerophthalmia. Three years later, an evaluation recorded a very high coverage of the populations at risk by the programme and, in addition, did not observe any clinical case of xerophthalmia based on a nationally representative sample of pre-school children.

In this case, there is little doubt that the result is directly linked to the programme, even if the evaluation cannot formally prove it: Plausibility of the link is very strong here. On the other hand, during the same period another country launched a programme to improve household food security, encompassing a certain number of measures such as the support to farm-gate prices for food crops and a reorganization of local markets on the basis of previously identified weaknesses.

The evaluation of the programme after several years of operation showed a slight improvement in the situation. Without a rigorous evaluation design, it is impossible to evaluate the relative share of improvement due to the programme or to other factors.

These elements will be useful each time it has to be decided whether the programme should be continued or not.

A group of convergent elements based on the available indicators will be established in order to reach a conclusion on its likely effectiveness. Often, for financial reasons, a programme cannot be implemented straight away in all the targeted areas; these will be incorporated into the programme gradually. However, the necessary indicators can usefully be collected in all the zones from the start, for this will provide elements for comparisons between zones with and without the programme and before and after the programme, which will in turn be useful to document the plausibility of effectiveness of the intervention.

This will make it easier to evaluate the sustainability of the programme by measuring the effect simultaneously in areas where the programme has been in operation for increasing durations. The purpose of an evaluation is not only to measure impact, but also to allow the programme to be adapted to changing conditions.

An early warning system will be evaluated primarily on its ability to foresee any worsening in the consequences of food crises among the groups most at risk; it will thus comprise a number of indicators on the strategies implemented according to the degree of vulnerability, on the levels of food consumption and on the nutritional status of these groups, for example.

However, it will also involve indicators to assess whether the situation is evolving towards greater stability improvement of climatic conditions or of food production, for example so that the primary objective of the programme can be refocused if the initial goal has become obsolete.

When evaluating programmes, a distinction is made in practice between impact which is the direct result of the programme, and longer term benefits, which encompass the indirect effects of the programme on the target population, or indeed the whole population, in terms of health, economic and social situation. In the case of an isolated programme, attention may be focused on its specific impact, but in the context of overall monitoring of a policy or group of programmes, the impact of the complete set of strategies will be the subject of regular evaluation - which will aim not so much at providing evidence of the effectiveness of one or another programme, but rather at verifying whether the situation is evolving in the desired direction, taking into account external circumstances and the programmes in operation.

Apart from regular measurement of progress, this will also provide an opportunity to check that the conceptual analysis on which the choice of different strategies was based is still relevant, or to see whether activities need refocusing. The aim is to examine changes in the situation in terms of the general objectives of the policy adopted, implying regular collection of a certain number of indicators of risk and of causes, as well as major basic indicators, to be used by country planners and by international agencies or donors, and assessment of trends.

This corresponds to one of the nine strategies proposed in by the ICN Plan of Action - which has been taken up since then by a number of countries for their national action plan - that of "assessing, analysing and monitoring nutrition situations". This implies setting up a proper nutrition surveillance system applied to planning. These national plans have explicit general goals with an order of magnitude for expected reductions in malnutrition levels or improvements in various sectors.

As a result of its plan, Ecuador, like other countries, anticipates fulfilling the following objectives in terms of improvements in the nutritional status of the population: Objectives will be all the more explicit and realistic if there is a recent "baseline" and an idea of trends in the past or in neighbouring countries or in countries with similar constraints. However, waiting for a complete baseline to be available would not be reasonable; one can start with existing data from the various services, or with rapid surveys carried out on a one-off basis when there are no data for a specific problem deemed to be important.

Yet implementing a policy must be an opportunity for also setting up a monitoring system - covering at least the main indicators of status and causes of malnutrition, which will be put in perspective with major agro-ecological and socio-economic indicators - in order to have an ongoing "log-book" of the situation and of time trends. After analysis, a country considers that the prevalence of low birthweight is too high and that the goal of reducing it implies i strengthening the performance of pre-natal health care services, ii promoting a better diet for mothers-to-be, either through better use of local food or the specific distribution of food supplements, and iii encouraging a reduction in the workload of pregnant women through various measures.

The precise actions to be undertaken and any precise quantification in terms of intermediate objectives depend of course on the specific country situation. Monitoring implementation of these actions will be based on a quantitative and qualitative assessment of the performance level of the units concerned number of rations distributed or number of persons who have used the services, percentage of services which have given advice and care of adequate quality to pregnant women, quality of rations distributed, level of use of the advice and care by the beneficiaries, etc.

At programme evaluation, outcomes and impact indicators can be based on changes in the frequency of consumption of certain foods by the women attending the units, or on changes in average birth weight and prevalence of low birth weight in the target population.

Indicators do not all have the same value. In theory this depends on their ability to best reflect a sometimes complex reality, but a trade-off will have to be found given the level of difficulty in collecting them.

Therefore, indicators are traditionally defined according to a certain number of properties that allow their value to be assessed, at least in a given context. Obviously they do not all present all the characteristics of a good indicator, so that it will have to be decided which characteristics are to be given priority when selecting indicators.

It entails that the indicator does indeed offer a true and as direct as possible measurement of the phenomenon considered. At conceptual level, it depends first of all on how clearly the phenomenon to be measured has been defined and also on the ability to measure it directly. This poses a problem where the phenomenon to be measured is linked to a multidimensional concept, and is thus difficult to measure in a global way.

There must, in particular, be a consensus on the level and significance of cut-off points for classification. A major standardization effort has for example been made in the field of measuring nutritional status and recommended dietary intakes, and this has helped give a more precise framework for use of the corresponding indicators. This is not always the case in other sectors, either because the indicators lend themselves less to quantification, or because such quantification depends very much on local circumstances.

Relevance in the context of planned use must, in this case, be based on a local analysis shared among the different stakeholders, as we will see below. Moreover, even if the indicator correctly describes a phenomenon, any systematic bias in collecting the corresponding information due to measurement methods or instruments will affect its validity. There is no overall indicator to provide a picture of "nutritional status", therefore a decision has to be made on which specific aspect of nutritional status is to be characterized: Even in the case of energy status, for example, no overall indicator is available; the indicator which is the most relevant for the aspect one wishes to prioritise - physical, biochemical, functional, etc.

For assessing the nutritional situation of a population, a set of individual anthropometric measurements have been adopted, that, when compared to reference values, make it possible to assess the status of individuals or populations; they constitute the corpus of relevant indicators to be used preferably over any other. However, when using these indicators, one should be aware of limitations to their validity: In the field of "food security", - again a very broad concept difficult to translate in simple terms - there is a considerable number of indicators, each reflecting a specific aspect and thus only relevant for a given aspect.

For example, in order to describe the level of food insecurity of a household, an indicator based on a quantitative criterion of food consumption or a qualitative criterion of the perception by the household of its own food insecurity situation will be more relevant than an indicator of prices of foodstuffs on the local market.

Imprecision due to measurement methods, variability from one day to another may limit the reproducibility of the indicator. This causes an increase in variance and implies that larger samples will be needed in order to assess correctly the level of the indicator and its variations over time.

Subjectivity bias is a frequent risk with indicators deriving from qualitative surveys, as they describe behaviours or opinions of households, for example, since the personality or technique of the person conducting the survey may influence the nature of responses.

Moreover, respondents to a questionnaire or subjects under observation can modify their responses or behaviour in a normative way. People who are overweight, for example, often minimise their actual food intake when interviewed for a food consumption survey. Reproducibility guarantees that an indicator can be measured at repeated intervals in a comparable manner - a quality which is crucial when using the indicator to assess and monitor the situation.

A complementary characteristic is specificity, which refers to the ability to identify those not affected by the risk or characteristic. Sensitivity is measured in practice by the ratio of the number of individuals identified by the indicator as being at risk or as having the characteristic to the number of individuals who are actually at risk or have the characteristic. Specificity is the ratio of the number of individuals not identified by the indicator to the number of individuals who are actually not at risk or do not possess the characteristic.

Sensitivity thus gives an idea of the degree of correct or misclassification linked to the use of an indicator. Not all indicators lend themselves to an assessment of sensitivity. Sensitivity applies essentially to indicators with cut-off values. Moreover, sensitivity is measured with respect to a given goal; sensitivity of an indicator such as weight-for-height at a given cut-off value will not be the same, depending on whether the goal is to identify children who are wasted or those who are at risk of dying in coming months.

Data for quick computation of these parameters sensitivity, specificity are not always available, so in practice, reference is made to existing data from the literature to find those closest to the chosen cut-off values and expected prevalences.

One particular aspect of sensitivity is the ability of an indicator to measure change, not in order to identify or target a particular category of individuals as previously but to detect the smallest possible change in the phenomenon described, in a significant way. While sensitivity, in general, is important when establishing a baseline, and for defining the target groups to which the activities will be directed, this ability for measuring change is crucial for assessing or monitoring trends, in particular to detect changes in the situation during implementation of the programme.

However, it is relatively inert when assessing small progressive changes in nutritional status over time, and the weight-for-height indicator will be preferred in this case, since it is more sensitive to change.

Also, urinary iodine will respond to introduction of salt iodization in a region quicker than prevalence of goitre, which will decline only slowly. In addition to these inherent characteristics of indicators, their operational value should be examined; it will be essential when the choice of indicators is made, especially in terms of speed and cost of collecting data for producing these indicators.

It represents the practical possibility of making available the indicator in question. It implies the feasibility of collecting the corresponding data by whatever means. There are indicators described as "ideal" which nobody is in practice able to collect. As a result of major international conferences and of programmes that have followed them during the last two decades, many of the required indicators are already systematically and regularly collected within the framework of such programmes and are thus very easily available.

It affects use of the indicator not only at the descriptive stage, but also when monitoring the situation. An indication of the quality of the measurements, of sampling and of the confidence interval of the result is essential here to assess dependability. Occasionally, it has been observed that the number of malnourished children estimated by nutritional surveys carried out by various organizations on identical populations and during the same periods, differed substantially; using the results for targeting purposes or for monitoring the situation is ruled out in this case.

The reason was usually the lack of precision of the anthropometric measurements or of the definition of age, and occasionally a sampling problem.

Data on food consumption obtained by weighing food are more precise than those obtained with the "recall" technique, although the former implies technical constraints and can therefore only apply to small samples, so that there is a broad confidence interval in the results.

Recall techniques, on the contrary, can easily be applied to a large sample, obviously with a smaller confidence interval. The various available data must therefore be carefully examined before using them for monitoring purposes, and a choice will sometimes be made between data collected with a higher level of accuracy but lower power at the level of the target population, or the opposite.

On this depends, in part, the speed and frequency with which the indicator can be regularly measured. When the data necessary for the construction of the indicator need to be collected specifically for evaluation or monitoring, cost should be considered; it depends on the difficulty and sophistication of the measurements, the accessibility of the objects or people to be measured, the frequency of collection and the complexity of the analysis subsequently.

The cost of non-collection may be measured, in the case of a food subsidy programme, for example, by the difference between the cost of the programme if it is carried out without particular targeting, in the absence of any indicator allowing targeting, and the cost of the programme for the target population, plus the cost of targeting, if the programme is to be directed at a high risk group only.

Nevertheless, information on the cost of collecting an indicator for each situation is seldom available. It is difficult to measure, and estimates are generally based on the cost of different types of survey within the country, taking account of the fact that several indicators are collected at the same time.

Indicators can be categorized schematically in the following way according to the level at which they are produced or made available:. They include both indicators regarding the implementation of services as well as indicators regarding the situation or the impact of actions under way. It is generally easy to obtain them from the departments concerned, which usually have time series that are very useful in distinguishing medium- and long-term trends.

Even so, it is not always possible to cross-tabulate these indicators, since they do not necessarily come from the same databases and are accessible only in a relatively aggregated form. It is also difficult to verify the quality of the original data. Lastly, even if the data are collected on a frequent basis monthly reports, for example , recovery and analysis may take too long. Such data tend not to be immediately accessible except in summary form, although it is easy to organize new analyses with the departments in charge of them.

These data allow statistical cross-tabulation to be made between the many variables collected simultaneously on the sample. Although carried out at best at very long intervals, they can be updated with reasonable projections, especially if information on trends in the fields of interest, based on routinely collected data, are also available.

These data are often kept together in national statistical offices. They consist of a regular collection of information based on a small number of selected indicators. The system varies by country, those that perform best are based on an explicit conceptual framework and are linked to a clear decision-making mechanism. They can represent a sound basis for central monitoring.

A particular category is derived from surveys conducted by international bodies for various purposes: These cross-sectional surveys are conducted directly at household level on samples which are representative at national level but of variable size; they include a wide variety of indicators in number, goals and qualities and are now frequently repeated.

Although conducted peripherally, they are generally available and used centrally. These sources, which are in principle fairly reliable, benefit from an advanced level of analysis allowing causal inference to be derived of relationships among various household indicators, and with individual indicators, such as nutritional status.

They represent a precious source when establishing a baseline and when analysing causes prior to launching an intervention. These are constructed primarily on the basis of routinely collected data from local government offices, community-based authorities. They are usually passed on as indicators or raw data to the central level, and then sent back to the decentralized levels, with varying degree of regularity, after analysis. They are often disaggregated by district or locality, but are not always representative, since they often refer only to users of the services under consideration.

They are generally grouped together at the central administrations of regions or administrative centres. The indicators relate primarily to activities that lend themselves to regular observation, either because they record activities indicators of operation or delivery of services or because they are necessary for decision-making crop forecasts, unemployment rates or for monitoring purposes market prices of staples, number of cases of diseases, etc.

They do not necessarily include indicators of the causes of the phenomena recorded and are not in principle qualitative indicators. Indicators collected at decentralized levels should meet both the needs of users on these levels and also those of users on the central level for the implementation and monitoring of programmes. If these regularly compiled indicators do not have any real use at the local level and are intended only for the national central level, there is a danger that their quality will drop over time, for lack of sufficient motivation of those responsible for collection and transmission - and gaps are therefore often found in available data sets.

Nevertheless, they are invaluable in giving a clear picture of the situation on the regional or district level, together with medium-term trends. Generally speaking, their limitation is the low level of integration of data from different sectors. A certain number of indicators, particularly those concerning the life of communities or households and not touching on the activities of the various government departments, are not routinely collected by such departments and are in any case not handed on to the regional or central offices.

They are sometimes collected at irregular intervals by local authorities, but most often by non-governmental organizations for specific purposes connected with their spheres of activity - health, hygiene, welfare, agricultural extension, etc.

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