Evidence for a 'healthy pregnant woman effect' in Niakhar, Senegal?

BACKGROUND: Although it is generally believed that pregnancy exposes women to a wide variety of excess health risks that go beyond the direct obstetric complications of pregnancy, the epidemiological evidence in support of such excess indirect risks is inconclusive. In this article we attempt to document the contribution of indirect causes of death to maternal mortality in rural Senegal by using an epidemiological approach whereby the time spent during pregnancy and postpartum is considered a transient period of exposure to the health hazards of childbearing. METHODS: We use data from an ongoing demographic surveillance system in Niakhar, Senegal and calculate rate ratios comparing death rates in pregnant or recently pregnant women (exposed) with death rates in other women (unexposed), including and excluding direct obstetric deaths. RESULTS: Between ages 20 and 44, pregnancy does not confer additional risks to women. After excluding direct obstetric deaths, exposed women aged 20--39 have surprisingly lower risks of death than unexposed women of the same age. For the very young (15-19) and the very old (45-49), on the other hand, the excess risks associated with pregnancy are considerable and, among women age 45 or older, persist even after excluding direct obstetric deaths. CONCLUSION: The apparent protective effect of pregnancy on women's health that is observed in this study illustrates the paradoxical nature of the concept of indirect causes of maternal mortality, and the difficulties in measuring the risks of death attributable to the pregnancy. Further studies aimed at separating risks attributable to the pregnancy from those that are incidental to the pregnancy are required.

Seasonal variation in direct obstetric mortality in rural Senegal: role of malaria?

We explore a possible link between malaria and maternal death in a rural area of Senegal by assessing the seasonal pattern of maternal mortality by cause and examining whether this pattern coincides with the malaria season. Overall mortality in women 15-49 years of age did not differ by season, while maternal and direct obstetric deaths were significantly more frequent during the rainy/malaria season than during the rest of the year, even after adjusting for place of delivery.

Social and epidemiological aspects of guinea worm control.

Dracunculiasis prevention should be simple: in a population at risk, everyone may be protected by the filtration of drinking water. The research described in this paper allowed the authors to follow the acceptance of new information by villagers in nine localities in Mali. Two strategies were studied: safe water supply (bore-hole or cement lined wells) plus health education on the one hand, and health education alone (based on filtration) on the other. Safe water supply is undoubtedly an effective strategy whereas the success of the health education intervention is uncertain. This experience showed that health education as the only means of control failed due to a lack of social cohesion or of coordinated group-action. Also, when dracunculiasis control is not a population's priority goal, the constraints on systematic filtration are too great and a tendency to discontinue the filtration process occurs. On the other hand, when dracunculiasis is considered to be a serious problem by the population, new information about systematic filtration is better assimilated and leads to behavioural changes. In order that the goal of eradicating dracunculiasis by 1995 should not be an utopic dream, it is necessary to prioritize the allocation of clean rural water supply projects only to those endemic villages where the conditions that allow for health education to be successful are met.

[Ivermectin and pregnancy in mass treatment in Mali]. / Ivermectine et grossesses en traitement de masse au Mali.

During july 1989, we have done a retrospective study, in Koba's valley in a savanna onchocerciasis area of Mali, after a mass treatment in rural community with ivermectin. 435 women aged from 15 to 45 years, among 461 with can be submitted to ivermectin risk during their pregnancy period, was seen and overhauled. In 1987, the frequency of women who received ivermectin during their pregnancy period (treated by error), was 17.7%, and 17.3% in 1988. We have seen any difference, between exposed and not exposed women to this error ivermectin treatment, comparing their in utero-mortality, new born mortality an the level of malformations. In spite of careful clinical monitoring in the field, the risk to give ivermectin to pregnancy women in rural community, is very high during mass treatment. Because traditionally (taboos), pregnancy is a forbidden subject. Sociological and anthropological studies, pregnancy field laboratory test and health education, are needed in african rural community before mass treatment with ivermectin.

[Water contacts in dracunculiasis-infected patients in Mali: transmission risk activities]. / Contacts homme-eau chez des malades atteints de dracunculose au Mali: activités à risque de transmission.

The aim of this study lies in the identification of human activities responsible for the transmission of the Guinea worm in an endemic village in Diema Region in Mali. Human water contacts observations started after a census followed by the implementation of a bi-monthly notification system, carried out from May to November 1993. Water contacts were noticed and observed from the mid-July to the end of November of the same year. The first case of dracunculiasis observed was randomly drawn out of a list of the families with obvious cases. The patent case activities involving either surface water, traditional wells or bore-hole water were recorded for 10 consecutive days. During this observation period, contacts made by other patients with the same water sources were also recorded. After 14 days, the case list was updated and a new case selected out of families previously selected. This cycle was repeated until the end of the study period. A "contact at risk for transmission" was defined by a close correspondence between the location of the worm's emergence and the surface of the skin exposed to water, within two weeks following emergence. Contacts were described according to water sources, activities in relation to water, date, gender and age. Observations were made on 103 patients who had 2506 activities in relation with a water body: 1132 of these activities implied a skin contact with the water. Only 133 (9%) of these water contacts were at risk for transmission, 75% took place during the months of August and September, 80% were related to surface waters and 20% to traditional wells. Woman household activities and boys games were the major activities at risk, in contrast to economic activities (watering cattle). The low proportion of "at risk activities" evaluated in this study suggests that a small number of water contacts is sufficient to maintain the transmission. The case implications of the current eradication strategy might not be sufficient alone to break the transmission and should therefore be associated with a reinforcement of the use of filters for drinking water together with an health education.

[A new combined vaccine against yellow fever and measles in infants aged 6 to 24 months in Mali]. / Etude d'un noveau vaccin combiné contre la fièvre jaune et la rougeole chez des enfants agés de 6 a 24 mois au Mali.

In a rural area in Mali, 453 children were randomly enrolled in a study comparing the safety and the immunogenicity of a combined yellow-fever-measles freeze dried vaccine with each yellow-fever and measles separate administration. Children were divided in 2 populations 4-8 and 12-24 month old. 249 were controlled for measles (inhibition of hemagglutination) and yellow-fever (seroneutralization) antibodies. Seroconversion rates for measles were 82% when administrated before 9 months and 100% when given in 12-24 months period. Measles GMT is similar whatever the schedule or the age group; so, early vaccination does not impair the immunogenetic response. Moreover, 96% of the children vaccinated before 9 months still have detectable measles protective antibodies 8 months after. Among the initially seronegative children, the yellow-fever response is satisfactory with 92 to 96% seroconversion rate and post-immunization GMT ranging 16.5 to 29.5 without any statistical difference between the vaccine and age groups. The safety of the combined yellow-fever-measles vaccine is assessed by the rare number of reactions which are equivalent with the normally expected reactions with each vaccine administered separately. The results demonstrate the satisfactory immunogenicity and safety of the combined yellow-fever-measles vaccine. Combine yellow-fever-measles vaccination could help to improve the feasibility of EPI.

[Prevalence of pulmonary tuberculosis and HIV infection in the district of Diré in Mali]. / Prévalences de la tuberculose pulmonaire et de l'infection par le VIH dans le cercle de Diré au Mali.

In 1990, a study was made in the district of Diré, North Mali in West Africa, to determine the prevalence of pulmonary tuberculosis and HIV infections in general population. From 1,814 subjects tested, 1.1% (n = 20) have active pulmonary tuberculosis and 0.2% (n = 4) were seropositive with HIV1 or HIV1 + 2. No relation was made between the two diseases.

[Tolerance of ivermectin treatment of rural communities infected by savannah onchocerciasis in Mali]. / Tolérance d'un traitement de collectivités rurales atteintes d'onchocercose de savane par l'ivermectine au Mali.

In an open clinical trial in phase IV, 856 onchocerciasis infected subjects received 150 micrograms/kg of ivermectin in May 1987. While 607 were included as witness. This cohort was revisited 7 and 12 months after. In June 1988, the same treatment was administrated to the previously treated subjects, and the witnesses received their first ivermectin' dose. The clinical tolerance of the treatment appears good and, even improved during the second dose one year after. Among the subjects treated in May 1987, 15.2% of them showed secondary reactions mostly discrete or moderate, precocious and quickly reversible after a second dose. Only 8 of them were incommodated in their daily occupations. A second treatment of these same subjects one year later, caused reactions of feeble intensity 3.7% only. The research of intolerance risk factors, incriminated the high density of microfilaremia. This incite to be careful in mass treatment of hyperendemic area.

[Verbal autopsy to measure maternal mortality in rural Senegal]. / Application de l'autopsie verbale dans la mesure de la mortalité maternelle en milieu rural au Sénégal.

OBJECTIVES: The aim of this paper is to study the use of verbal autopsy in order to assess maternal mortality indicators in rural settings and to determine the limits and difficulties related to that practice. MATERIAL AND METHODS: This study was carried out in 3 rural sites (Niakhar in the region of Fatick, Bandafassi in Tambacounda region and Mlomp in the region of Ziguinchor). These sites had been under demographic and epidemiological surveillance for several years. Data were collected through two sources: a questionnaire filled out by data collectors during the demographic surveillance and a complementary survey done by an epidemiologist among families completed by information from the registers of health structures. For all female deaths (15-49 years), the detailed sequence of the events leading to the death were stated in a clinical file of verbal autopsy. All the files had been submitted to two independent obstetricians for analysis. The character of maternal death and the cause of the death (direct, indirect ou undetermined) were processed. The discordant cases were submitted to another expert epidemiologist for analysis. The 10th international classification of diseases of WHO was used as a reference to identify maternal deaths and their causes. RESULTS: This demographic surveillance has led to a complete registration of female deaths and the analysis of female deaths has helped to measure maternal indicators during the observed time period. Among the 471 female deaths, 97 maternal deaths were identified in Niakhar, 36 in Bandafassi and 10 in Mlomp. The proportion of maternal deaths was 30.6% in Niakhar, 32.7% in Bandafassi and 22.7% in Mlomp. The ratio of maternal mortality was 575 per 100,000 live births (LB) in Niakhar, 930/100,000 live births in Bandafassi and 436/100,000 LB in Mliomp. The risk of maternal death was 1 women in 21 in Niakhar, 1 in 16 in Bandafassi and 1 in 41 in Mlomp. Maternal mortality rate was 13.3/10,000 reproductive age women in Niakhar, 17/10,000 in Bandafassi and 6.9/10,000 in Mlomp. Sociocultural limits related to interdiction in the society, and language barriers are seen as limits for applying verbal autopsy practices. Also, a lack of precision in data collection because of lack of information delivered by the interviewee or because of lack of experience of the interviewer could be limitations. This study carried out in a rural setting could not show national maternal mortality level. It takes time to complete verbal autopsy leading to excessive cost. CONCLUSION: Verbal autopsy remains an interesting method for measuring maternal mortality. It has advantages in rural areas where many deliveries still occur at home. Further accuracy in data collection is needed for a precise analysis of each case.

[Cholera epidemic in Senegal in 1995-1996: an example of geographic approach to health]. / L'épidémie de choléra de 1995-1996 au Sénégal: un exemple de démarche de géographie de la santé.

There have been many cholera outbreaks in Senegal since 1971. The last outbreak began in the Dakar region in August 1995. It spread to the Diourbel, Fatick, Saint-Louis and Thies regions. In January 1996, the outbreak hit the Niakhar study area in the Fatick region. A team from ORSTOM (the French Institute of Scientific Research for Development in Cooperation) has been recording demographic events in this area for almost 15 years. The geographic approach is based on the automated mapping of cholera in hamlets and villages. Such studies investigate the factors determining the spread of diseases, within the context of land use. Three sets of data were used: demographic data that had been routinely collected and were available from a database, digitized maps and epidemiological data from a surveillance system set up to monitor the outbreak. A series of incidence maps, over time and on various scales, were generated using specialized software. The maps were analyzed and the outbreak was found to be heterogeneous over time. There were two waves of the outbreak and differences according to age and gender. The degree of heterogeneity depended on the place of residence. Heterogeneity was probably determined by village size, roads and the concentration of inhabitants within hamlets, which is roughly equivalent to the number of people per bore hole. These preliminary results suggest that further research is necessary, looking at different geographical scales (e.g. households, districts and regions). Qualitative studies of water use and the organization of the water supply are also required.

The senegalese cholera epidemic of 1995 to 1996, an example of the geographic approach to health studies

There have been many cholera outbreaks in Senegal since 1971. The last outbreak began in the Dakar region in August 1995. It spread to the Diourbel, Fatick, Saint-Louis and Thies regions. In January 1996, the outbreak hit the Niakhar study area in the Fatick region. A team from ORSTOM (the French Institute of Scientific Research for Development in Cooperation) has been recording demographic events in this area for almost 15 years. The geographic approach is based on the automated mapping of cholera in hamlets and villages. Such studies investigate the factors determining the spread of diseases, within the context of land use. Three sets of data were used: demographic data that had been routinely collected and were available from a database, digitized maps and epidemiological data from a surveillance system set up to monitor the outbreak. A series of incidence maps, over time and on various scales, were generated using specialized software. The maps were analyzed and the outbreak was found to be heterogeneous over time. There were two waves of the outbreak and differences according to age and gender. The degree of heterogeneity depended on the place of residence. Heterogeneity was probably determined by village size, roads and the concentration of inhabitants within hamlets, which is roughly equivalent to the number of people per bore hole. These preliminary results suggest that further research is necessary, looking at different geographical scales (e.g. households, districts and regions). Qualitative studies of water use and the organization of the water supply are also required.

[Frequency of skin consultations in the activities of internal medicine service at national hospital of Point G in bamako]. / Fréquence des consultations dermatologiques dans les activités du service de médecine interne de l'hôpital national du point g a bamako.

AIM: To investigate epidemiologic clinical, paraclinical and therapeutic appearances of skin diseases identified in the Internal Medicine Department. PATIENTS AND METHODS: This was a retrospective descriptive study on records collected from January 1st, 1997 to September 30th, 2000. Have been selected records of patients who consulted and / or hospitalized for a dermatological reason. RESULTS: The average age was 36.42 ± 16.52 years. Female sex predominated with 55.06% for a ratio of 0.81. Dermatological consultation represented 30.41% of the activities of Internal Medicine. The pruritic dermatoses predominated (60.12%) among those infectious etiologies (45.46%), inflammatory dermatoses reaction (26.49%), dermatitis tumor (10.39%), autoimmune dermatoses (6.56%) and vasculitis (1.19%). Prurigo, herpes zoster and Kaposi's sarcoma with frequencies of 22.41%, 16.38% and 12.93% were most often associated with HIV / AIDS. The therapy consisted of prescription antiseptic, topical corticosteroids of compounding, antibiotic and antifungal orally. CONCLUSION: Skin conditions are often common in internal medicine, infectious causes and especially reaction. Kaposi's sarcoma because of its association with HIV is common skin tumor identified. The usual drugs remain effective.

BUT: Étudier les aspects épidémioclinique, paraclinique et thérapeutique des affections cutanées recensées dans le service de Médecine Interne. PATIENTS ET MÉTHODE: Il s'agissait d'une étude rétrospective descriptive portant sur les dossiers colligés du 1er Janvier 1997 au 30 Septembre 2000. Ont été retenus les dossiers des patients ayant consulté et/ou hospitalisé pour un motif dermatologique. RÉSULTATS: La moyenne d'âge était de 36,42±16,52 ans. Le sexe féminin prédominait avec 55,06% pour un ratio de 0,81. La consultation dermatologique représentait 30,41% des activités du service de Médecine Interne. Les dermatoses prurigineuses ont prédominé (60,12%) parmi celles de cause infectieuse (45,46%), les dermatoses réactionnelles inflammatoires (26,49%); les dermatoses tumorales (10,39%); les dermatoses auto-immunes (6,56%) et les vascularites (1,19%). Le prurigo, le zona et la maladie de Kaposi avec des fréquences respectives de 22,41%; 16,38% et 12,93% étaient le plus souvent associés au VIH/SIDA. La thérapeutique a consisté à la prescription d'antiseptique, de dermocorticoïdes, de préparation magistrale, d'antibiotique et d'antimycosique per os. CONCLUSION: Les affections dermatologiques sont souvent fréquentes en Médecine Interne, de causes surtout infectieuse et réactionnelle. La maladie de Kaposi en raison de son association avec le VIH, est la fréquente tumeur cutanée recensée. Les médicaments usuels demeurent efficaces.

[Ocular manifestations in rheumatoid arthritis: 24 cases in Abidjan]. / Manifestations oculaires au cours de la polyarthrite rhumatoide: a propos de 24 cas vues a Abidjan.

OBJECTIVE: Determine the prevalence and the main ocular manifestations in rheumatoid arthritis in Abidjan. PATIENTS AND METHODS: Prospective and descriptive study of 24 patients with rheumatoid arthritis fulfilling the criteria of the American College of Rheumatology, views from September 2003 to August 2004 in department of rheumatology at the University Hospital of Cocody. The patients performed an eye examination including: visual acuity examination at the slit lamp, ocular fundus, color vision and visual field. RESULTS: Ocular manifestations were observed in 9 of 24 patients representing a prevalence of 37.5%. There were 03 cases of decreased visual acuity, 03 cataract, 02 keratitis cases and 01 cases of anterior uveitis. No fundus abnormality in color vision and visual field was highlighted. These manifestations were found between 5 and 10 years (04 cases) and after 10 years (05 cases) of evolution of the disease. The term rheumatoid arthritis influenced the occurrence of ocular manifestations (P = 0.00). CONCLUSION: Ocular manifestations in rheumatoid arthritis are rare in our practice and were mainly affected by visual acuity, annexes and anterior segment of the eye.

OBJECTIF: Déterminer la prévalence et les principales manifestations oculaires au cours de la polyarthrite rhumatoïde à Abidjan. PATIENTS ET MÉTHODE: Etude prospective descriptive de 24 polyarthrites rhumatoïdes répondant aux critères de l'American College of Rheumatology, vues de Septembre 2003 à Août 2004 au service de rhumatologie du CHU de Cocody. Les patients ont effectué un examen ophtalmologique comprenant: acuité visuelle, examen à la lampe à fente, fond d'œil, vision des couleurs et champ visuel. RÉSULTATS: Les manifestations oculaires étaient observées chez 9 des 24 patients soit une prévalence de 37,5 %. Il s'agissait de 03 cas de baisse de l'acuité visuelle, 03 cas de cataracte, 02 cas de kératite et 01 cas d'uvéite antérieure. Aucune anomalie au fond d'œil, à la vision des couleurs et du champ n'a été mise en évidence. Ces manifestations ont été découvertes entre 5 et 10 ans (04 cas) et après 10 ans (05 cas) d'évolution de la maladie. La durée de la polyarthrite rhumatoïde influençait la survenue des manifestations oculaires (P=0,00). CONCLUSION: Les manifestations oculaires au cours de la polyarthrite rhumatoïde sont peu fréquentes dans notre pratique et étaient principalement des atteintes de l'acuité visuelle, des annexes et segment antérieur de l'œil.

Assessment of maternal mortality and late maternal mortality among a cohort of pregnant women in Bamako, Mali.

OBJECTIVE: Few prospective studies have been undertaken of maternal mortality in sub-Saharan Africa. National statistics are inadequate, and data from hospitals are often the only source of information available. Reported maternal mortality ratios may therefore show large variations within the same country, as in Mali. This study was designed to produce an estimate of the maternal mortality ratio for the population of Bamako. DESIGN: Prospective cohort study. SETTING: Bankoni (population 59,000), a district of Bamako (population 700,000). POPULATION: 5782 pregnant women identified during quarterly household visits. METHODS: After enrolment, two follow up visits, at six weeks and one year after delivery, were performed to collect information on the pregnancy, its outcome, the method of delivery, the puerperium and the first year after birth. Detailed inquiries on deaths were undertaken in the community, the maternity units and the reference hospital. MAIN OUTCOME MEASURES: Maternal mortality ratio, late maternal mortality, likely cause of death. RESULTS: Complete data at follow up were available on 4717 women (82%) (4653 single and 64 twin pregnancies). Most of the women had antenatal care were and delivered in a district maternity hospital. There were 4580 live births (96%). Fifteen maternal deaths were recorded, yielding an overall maternal mortality ratio of 327 per 100,000 live births. Hypertensive disorders and haemorrhage were the main causes of death. Five more deaths occurred within 42 days or one year after delivery. CONCLUSIONS: This study gave an estimate of the maternal mortality ratio for the population of Bamako, and stressed the need of better emergency obstetric care and the importance of late maternal mortality.

PIP: This study assessed the nature and extent of maternal mortality (MM) among a cohort of pregnant women in urban Bamako, Mali. Data were obtained from a sample of 5782 pregnant women identified during March 1989 and September 1992. Interviews were conducted at 6 weeks and 1 year after delivery. Other clinical information was collected from households and medical records in 1993. By 1994, 4717 women had been traced. Over 95% of the sample were married and Muslim. About 16% were primiparous. Over 25% had 4 or more children. Most women had some contact with local health centers during pregnancy. Only 10% delivered at home. 24-55% delivered in maternity units that were different from their source of prenatal care. 4580 had live births; 198 had late abortions or stillbirths. The MM ratio was 327/100,000 (15 deaths). The lifetime risk of maternal death was 2.7%. Inclusion of the 5 late maternal deaths raised the MM ratio to 436/100,000. 13 deaths were due to direct causes. 7 deaths were due to hemorrhage, including 1 abortion and 2 cases of ruptured uterus. 4 were due to hypertensive disorders during pregnancy. 3 died from sepsis after cesarean section, including 2 cases of obstructed labor. 6 women delivered and died at a national teaching hospital. 5 were delivered at a district maternity hospital and died at the referred national teaching hospital. 3 died at home.

[Role of iron deficiency in anemia in pregnant women in Mali]. / Place de la carence martiale dans l'anémie de la femme enceinte au Mali.

The epidemiological characteristics of iron deficiency anemia after radioimmunoassay of serum and erythrocyte ferritin were evaluated in 209 Malian women at the time of delivery in a maternity unit in Bamako, Mali. The incidence of iron deficiency anemia was high (36.8%). This incidence did not reflect socio-economic status, nor even any particular obstetric history, but was significantly higher in younger mothers (aged under 26). The severity of anemia was such that 2.4% of women would require a blood transfusion post-partum. It looks therefore desirable, in Mali, to screen routinely and to ensure the prevention of iron deficiency in adolescent girls and to include, in the prevention of anemia of pregnant women, routine iron supplements from the beginning of pregnancy.

Maternal mortality and access to obstetric services in West Africa.

OBJECTIVES: Process evaluation has become the mainstay of safe motherhood evaluation in developing countries, yet the extent to which indicators measuring access to obstetric services at the population level reflect levels of maternal mortality is uncertain. In this study we examine the association between population indicators of access to obstetric care and levels of maternal mortality in urban and rural West Africa. METHODS: In this ecological study we used data on maternal mortality and access to obstetric services from two population-based studies conducted in 16 sites in eight West African countries: the Maternal Mortality and Obstetric Care in West Africa (MAMOCWA) study in rural Sénégal, Guinea-Bissau and The Gambia and the Morbidité Maternelle en Afrique de l'Ouest (MOMA) study in urban Burkina Faso, Côte d'Ivoire, Mali, Mauritanie, Niger and Sénégal. RESULTS: In rural areas, maternal mortality, excluding early pregnancy deaths, was 601 per 100,000 live births, compared with 241 per 100,000 for urban areas [RR = 2.49 (CI 1.77-3.59)]. In urban areas, the vast majority of births took place in a health facility (83%) or with a skilled provider (69%), while 80% of the rural women gave birth at home without any skilled care. There was a relatively close link between levels of maternal mortality and the percentage of births with a skilled attendant (r = -0.65), in hospital (r = -0.54) or with a Caesarean section (r = -0.59), with marked clustering in urban and rural areas. Within urban or rural areas, none of the process indicators were associated with maternal mortality. CONCLUSION: Despite the limitations of this ecological study, there can be little doubt that the huge rural-urban differences in maternal mortality are due, at least in part, to differential access to high quality maternity care. Whether any of the indicators examined here will by themselves be good enough as a proxy for maternal mortality is doubtful however, as more than half of the variation in mortality remained unexplained by any one of them.

Hypohaptoglobinaemia as an epidemiological and clinical indicator for malaria. Results of two studies in a hyperendemic region in West Africa.

Hypohaptoglobinaemia is a common phenomenon in tropical countries, where it is probably due to malaria-induced haemolysis. Two studies were carried out in a hyperendemic zone of West Africa to test its specificity and usefulness as an epidemiological indicator for measuring malaria endemicity. The first study evaluated the prevalence of hypohaptoglobinaemia before and after courses of antimalarial chemotherapy of varying duration. The second monitored haptoglobin levels in an untreated population during a whole year to compare its seasonal variations with those of several classic indicators of malaria. These studies suggest that in regions where malaria is endemic the prevalence of hypohaptoglobinaemia could be as useful an indicator as the parasitic index but would be much easier to establish and to monitor.