Impact Survey Results after SAFE Strategy Implementation in 15 Local Government Areas of Kebbi, Sokoto and Zamfara States, Nigeria

Purpose: To determine prevalence of trachoma after interventions in 15 local government areas (LGAs) of Kebbi, Sokoto and Zamfara States, Nigeria.

Methods: A population-based impact survey was conducted in each LGA using Global Trachoma Mapping Project (GTMP) protocols. In each LGA, 25 villages were selected, except in Arewa LGA, where we selected 25 villages from each of four subunits to obtain finer-resolution prevalence information. Villages were selected with probability proportional to size. In each village, 25 households were enrolled and all consenting residents aged ≥1 year were examined by GTMP-certified graders for trachomatous inflammation—follicular (TF) and trachomatous trichiasis (TT). Information on sources of household water and types of sanitation facilities used was collected through questioning and direct observation.

Results: The number of households enrolled per LGA ranged from 623 (Kware and Tangaza) to 2488 (Arewa). There have been marked reductions in the prevalence of TF and TT since baseline surveys were conducted in all 15 LGAs. Eight of the 15 LGAs have attained TF prevalences <5% in children, while 10 LGAs have attained TT prevalences <0.2% in persons aged ≥15 years. Between 49% and 96% of households had access to water for hygiene purposes within 1 km of the household, while only 10–59% had access to improved sanitation facilities.

Conclusion: Progress towards elimination of trachoma has been made in these 15 LGAs. Collaboration with water and sanitation agencies and community-based trichiasis surgery are still needed in order to eliminate trachoma by the year 2020.

Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease

The distribution of trachoma in Nigeria is spatially heterogeneous, with large-scale trends observed across the country and more local variation within areas. Relative contributions of individual and cluster-level risk factors to the geographic distribution of disease remain largely unknown. The primary aim of this analysis is to assess the relationship between climatic factors and trachomatous trichiasis (TT) and/or corneal opacity (CO) due to trachoma in Nigeria, while accounting for the effects of individual risk factors and spatial correlation. In addition, we explore the relative importance of variation in the risk of trichiasis and/or corneal opacity (TT/CO) at different levels. Data from the 2007 National Blindness and Visual Impairment Survey were used for this analysis, which included a nationally representative sample of adults aged 40 years and above. Complete data were available from 304 clusters selected using a multi-stage stratified cluster-random sampling strategy. All participants (13,543 individuals) were interviewed and examined by an ophthalmologist for the presence or absence of TT and CO. In addition to field-collected data, remotely sensed climatic data were extracted for each cluster and used to fit Bayesian hierarchical logistic models to disease outcome. The risk of TT/CO was associated with factors at both the individual and cluster levels, with approximately 14% of the total variation attributed to the cluster level. Beyond established individual risk factors (age, gender and occupation), there was strong evidence that environmental/climatic factors at the cluster-level (lower precipitation, higher land surface temperature, higher mean annual temperature and rural classification) were also associated with a greater risk of TT/CO. This study establishes the importance of large-scale risk factors in the geographical distribution of TT/CO in Nigeria, supporting anecdotal evidence that environmental conditions are associated with increased risk in this context and highlighting their potential use in improving estimates of disease burden at large scales.

Trichiasis (TT) and corneal opacity (CO) are chronic stages of trachoma, which remains an important cause of blindness. This study used multilevel spatial models to investigate risk factors for TT/CO in Nigeria, including data for more than 13,500 adults aged 40 years and above collected in the 2007 National Blindness and Visual Impairment survey. Individual-level risk factors were consistent with those identified in other studies, including a higher risk in females, older individuals and those with lower socioeconomic status. After controlling for these factors, there was evidence that a number of environmental and climatic factors are associated with the distribution of TT/CO in Nigeria. These findings establish for the Nigerian context the importance of risk factors at different scales for the later stages of trachoma, supporting anecdotal evidence that hotter, drier environmental conditions are associated with increased risk.

Mapping trachoma in 25 local government areas of Sokoto and Kebbi states, northwestern Nigeria

INTRODUCTION

The WHO global initiative on elimination of trachoma by 2020 (GET 2020) recommends mapping of trachoma at district (Local Government Area (LGA)) levels to enable planning and control activities in affected communities worldwide. The aim of the present study was to provide baseline data on trachoma for the LGAs of Sokoto and Kebbi states, Nigeria.

METHODS

A population-based cross-sectional survey was conducted in 25 LGAs between November 2011 and May 2012. The WHO guidelines for trachoma control and risk factor assessment were used in the planning and conduct of the survey.

RESULTS

The prevalence of trachomatous inflammation-follicular in children aged 1-9 years ranged from 0.3% in Sokoto South to 15.6% in Kalgo LGA. The prevalence of trachomatous trichiasis (TT) in adults (>14 years) ranged from 0.03% in three LGAs to 0.6% in Gudu LGA. Logistic regression analysis for the trachoma risk factors after χ(2) analysis showed only distance from water source as a significant risk factor (OR>1, p<0.5). Clean face, access to latrines and knowledge of trachoma prevention were significantly protective (OR<1, p<0.5) against active disease. The average number of persons in need of TT lid surgery ranged from 0 in 3 LGAs to 397 in Danko-Wasagu LGA. Mass antibiotic distribution is needed in 4 LGAs. The estimated number of households in need of latrines and improved water sources are high, with 1 LGA requiring 34 500 latrines and 20 000 improved water sources.

CONCLUSIONS

There is a burden of active trachoma of different endemicity levels in all the surveyed LGAs. The burden of trachoma risk factors remains a challenge despite the global effort to decrease the risk factors through the Millennium Development Goals.

Tracing children with blindness and visual impairment using the key informant survey in a district of north-Western Nigeria

Purpose:

To identify children with irreversible blindness in a district of northern Nigeria for enrolment into an inclusive education pilot project.

Materials and Methods:

Using key informants (KIs) working and residing within the communities, children with blindness and visual impairment in Gwadabawa local government area (LGA) were identified and then examined by a team of ophthalmologists/optometrists. Data analysis was performed manually using simple percentages and proportions.

Results:

Sixty children were reported with visual problems by parents/guardians of whom 58 (97%) were examined. Twenty children (35%) were blind, 17 (29%) were irreversibly blind, and 9 (16%) had low vision (<6/18 to 3/60) with presenting vision. The major causes of childhood blindness were corneal opacity/phthisis bulbi (75%), and cataract (15%). The cause of irreversible blindness in these children was largely preventable (80%) as it was due to childhood-related illnesses, such as vitamin A deficiency and measles.

Conclusions:

The major causes of childhood blindness in the study area were avoidable and the use of KI survey in this study provided an opportunity for service delivery.

Challenges of trachoma control: an assessment of the situation in northern Nigeria

Over the last three decades, a lot has been achieved in the control of trachoma worldwide. New assessment techniques, effective evidence-based control strategy with new methods and drugs, and an aggressive global partnership for the control of the disease have evolved. As such the number of people with the disease and blindness due to the disease had drastically reduced. Trachoma is now only responsible for about 4% of blindness worldwide down from 12% some few decades ago. Some countries are on the verge of eliminating the disease as a public health problem. Despite these achievements numerous challenges remain for achieving trachoma control in endemic communities. This article highlights the challenges faced in one of the known trachoma endemic areas – northern Nigeria. Aspects on the dearth of complete situational data on trachoma, fragmented implementation of the SAFE strategy, community apathy, difficulties faced in ensuring safe, and quality lid surgery in the most difficult terrain where the disease thrives are discussed here. Other unique challenges like managing children with severe trichiasis, curbing the high rate of early-onset recurrence of trichiasis after lid rotation surgery and challenges to maintain supply of antibiotics and implementation of facial cleanliness and environmental improvement components of the control strategy are presented along with the learnt experiences and recommendations. These challenges and their remedies are likely to be shared by other trachoma endemic areas in Africa.

Couching in Nigeria: prevalence, risk factors and visual acuity outcomes

PURPOSE

Couching is an ancient treatment for cataract which is still practiced in some of the poorer developing countries, particularly in sub-Saharan Africa. The purpose of this study is to describe risk factors for couching and visual acuity outcomes in a nationally representative sample of adults aged 40 years and above in Nigeria.

METHODS

Probability in proportion size methods were used to identify a representative sample. Of the 15,375 adults enumerated, 13,582 were interviewed and examined. Examination included logMar acuities, slit lamp examination and dilated fundoscopy with digital fundus imaging.

RESULTS

Almost half of the 583 eyes undergoing a procedure for cataract had been couched (249 eyes, 42.7%). Individuals living in rural areas (P = 0.033) and in the two underserved northern administrative zones (P = 0.33; P = 0.002) were more likely to have been couched. Visual outcomes were poor according to World Health Organization categories, with 55.8% of people and 73.1% of eyes having a presenting visual acuity of less than 3/60 and only 9.7% and 2.4% of people and eyes respectively having a good outcome (6/18 or better). None were wearing an aphakic correction, and with correction acuities improved but 42.6% of eyes were still blind (< 3/60).

CONCLUSIONS

Couching is still widely practiced in Nigeria and visual outcomes are very poor. The population needs to be made aware of the risks associated with the procedure, and services for high quality, affordable cataract surgery need to be expanded, particularly in rural areas and in the north of the country.

Outcome of cataract surgery in Nigeria: visual acuity, autorefraction, and optimal intraocular lens powers--results from the Nigeria national survey

OBJECTIVE

To describe presenting and corrected visual acuities after cataract surgery in a nationally representative sample of adults. Another objective was to describe refractive errors in operated eyes and to determine the optimal range of intraocular lens (IOL) powers for this population.

DESIGN

Cross-sectional, population-based survey.

PARTICIPANTS

Adults aged 40 years and more were selected using multistage stratified sampling and proportional to size procedures. A sample size of 15027 was calculated, and clusters were selected from all states.

METHODS

Individuals who had undergone cataract surgery were identified from interview and examination. All had their presenting visual acuity (VA) measured using a reduced logarithm of the minimum angle of resolution chart and underwent autorefraction. Corrected VAs were assessed using the autorefraction results in a trial set. An ophthalmologist conducted all examinations, including slit-lamp and dilated fundus examination. Causes of visual loss were determined for all eyes with a presenting VA <6/12 using the World Health Organization recommendations. Biometry data were derived from 20449 phakic eyes using the SRK-T formula after excluding those with poor VA or corneal opacities.

MAIN OUTCOME MEASURES

Presenting and corrected visual acuities in pseudo/aphakic individuals and autorefraction findings; biometry profile of Nigerian adults.

RESULTS

Data from 288 eyes of 217 participants were analyzed. Only 39.5% of eyes had undergone IOL implantation at surgery. Only 29.9% of eyes had a good outcome (i.e., ≥6/18) at presentation, increasing to 55.9% with correction. Use of an IOL was the only factor associated with a good outcome at presentation (odds ratio 9.0; 95% confidence interval, 4.3-18.9; P=0.001). Eyes undergoing cataract surgery had a higher prevalence and degree of astigmatism than phakic eyes. Biometry data reveal that posterior chamber IOL powers of 20, 21, and 22 diopters (D) (A constant 118.0) will give a postoperative refraction range of -2.0 D to emmetropia in 71.4% of eyes, which increases to 82.6% if 19 D is also included.

CONCLUSIONS

Postoperative astigmatism needs to be reduced through better surgical techniques and training, and use of biometry should be standard of care.

Causes of blindness and visual impairment in Nigeria: the Nigeria national blindness and visual impairment survey

PURPOSE

Determine causes of blindness and visual impairment among adults aged >or=40 years.

METHODS

Multistage, stratified, cluster random sampling with probability proportional to size procedures were used to identify a nationally representative sample of 15,027 persons >or=40 years of age. Distance vision was measured with a reduced logMAR tumbling E-chart. Clinical examination included a basic eye examination of all subjects and a more detailed examination of those who had presenting vision <6/12 in either eye. Cause for vision loss was assigned to all subjects with presenting vision <6/12 in any eye.

RESULTS

Of the 15,122 persons aged >or=40 years who were enumerated, 13,599 (89.9%) were examined. In 84%, blindness was avoidable. Uncorrected refractive errors were responsible for 57.1% of moderate (<6/18-6/60) visual impairment. Cataract (43%) was the commonest cause of blindness (<3/60). Prevalence of cataract-related blindness was 1.8% (95% CI: 1.57-2.05) and glaucoma-related blindness was 0.7% (95% CI: 0.55-0.88). Increasing age was associated with increasing prevalence of all major blinding conditions. Females, illiterate persons, and residents in the North East geopolitical zone had significantly higher odds of cataract-induced blindness and severe visual impairment.

CONCLUSIONS

The high proportion of avoidable blindness, with half being attributable to cataract alone and uncorrected refractive errors being responsible for 57% of moderate visual impairment, means that appropriate and accessible refraction and surgical services need to be provided. If priority attention is not given, the number of blind and severely visually impaired adults in Nigeria will increase by >40% over the next decade.

Long-term complications of extracapsular cataract extraction with posterior chamber intraocular lens implantation, in Nigeria

AIM

To identify the long-term complications of extracapsular cataract extraction with posterior chamber intraocular lens implantation surgery, in the National Eye Centre, Kaduna, Nigeria.

METHODS

The study is a retrospective review of patients that have had extracapsular cataract extraction with posterior chamber intraocular lens implantation, in the National Eye Centre, Kaduna, Nigeria from January 1996 to December 1999. The medical records of all patients that satisfy these criteria were retrieved. Information collected included age, sex, eye operated upon, intra-operative complications, pre-operative visual acuity and last follow-up, and long-term post-operative complications.

RESULT

Medical records of only 66 patients (71 eyes) that maintained a minimum follow-up of at least one year were retrievable. No major intra-operative complications were recorded. Only one eye had posterior capsule rent. Ninety percent of the operated eyes had vision of 6/60 or better one year post-operative. The overall visual outcome (WHO criteria) was borderline. Of the corrected eyes, the consultants have a statistically significantly better outcome than residents. The following post-operative complications were recorded in 25 (35.2%) eyes: pseudophakic bullous keratopathy (11.3%); posterior capsular opacification (7.0%); persistent inflammation (7.0%); secondary glaucoma (2.8%); pupil distortion (5.6%); and ocular hypotony (1.4%).

CONCLUSION

ECCE + PC-IOL microsurgery is associated with long-term complications like PBK (Pseudophakic bullous keratopathy) and PCO (Posterior capsular opacification). Their management creates new demands in our country. This study is limited by the small number of eyes eligible for review at least one year after surgery.

Vitamin A deficiency in Nigeria

Childhood blindness is second only to cataract in magnitude of world blindness when the "blind years" is considered. The "blind years" is the number of years a person lives with blindness. Studies have shown that over 34%-69% of childhood blindness in Nigeria is caused by corneal opacity, which results mainly from an interplay of vitamin A deficiency, measles and harmful traditional eye practices. However, vitamin A deficiency which manifests in the eye as xerophthalmia is the dominant problem in these children. The purpose of this review is to stress the importance of xerophthalmia, which is of public health significance, as an important cause of childhood blindness in Nigeria. Studies involving surveys of xerophthalmia, childhood and nutritional blindness are reviewed with data extracted from a nationwide survey on prevalence of xerophthalmia. The likely explanation for vitamin A deficiency in Nigerian children is discussed with possible solutions and recommendations made to control this avoidable and devastating cause of blindness.

Trial of Trachoma Rapid Assessment in a subdistrict of northern Nigeria

PURPOSE

To assess the usefulness of Trachoma Rapid Assessment (RA) in priority ranking of trachoma areas.

METHODS

RA was conducted concurrently with a cross-sectional trachoma prevalence survey in some villages selected from the communities at risk for trachoma in the Kaita Local Government Area of northern Nigeria. The RA team consisted of two ophthalmic nurses. Pen torches and loupes were used for the examination. Data were collected on the seven components of the RA 'information pyramid' for all the selected villages. The data were analyzed using the RA methodology guidelines to determine the priority villages for trachoma intervention. This was compared with the ranking from the cross-sectional trachoma prevalence survey.

RESULTS

The results of RA were found to be in agreement with the cross-sectional survey in 53.3% of the villages in the priority ranking of trichiasis, while in the priority ranking of active trachoma the agreement between the two methods was found to be 60%. The risk factors for trachoma were shown to be of high magnitude in all the villages using both the RA method and the prevalence survey.

CONCLUSION

RA may be a more useful tool when applied to a vast area where the risk of trachoma is likely to differ greatly between different parts of the area. In the determination of the trichiasis pattern of a community by RA, it may be more useful to use the actual number of trichiasis cases in the area rather than the prevalence of trichiasis. The operational definition of some risk factor indicators seems very subjective and vague. The RA method needs more validation to sharpen the indicators used.

Cataract blindness and barriers to uptake of cataract surgery in a rural community of northern Nigeria

AIMS

A population based cross sectional survey was conducted to determine the magnitude of cataract blindness and the barriers to uptake of cataract services in a rural community of northern Nigeria.

METHODS

1461 people out of 1924 registered eligible people were examined. The study population was chosen by two stage cluster random sampling. In the first sampling stage 15 villages were randomly chosen while in the final stage 170 people who were 40 years and over were selected in each village. Each selected person had visual acuity recorded for both eyes. Those with vision of less than 3/60 in the better eye were assessed for cataract. People with cataract were asked why they had not sought medical attention.

RESULTS

A blindness prevalence of 8.2% (95% CI 5.8%-10.5%) was found among the sampled population. Cataract was responsible for 44.2% of the blindness. Thus, a cataract blindness prevalence of 3.6% was found. The cataract surgical coverage (people) was 4.0% and the couching coverage (people) was 18%. The main barrier to seeking cataract surgery was cost of the service (61%).

CONCLUSION

Some regions of the world still have high burden of cataract blindness that needs attention. Such areas need an effective free cataract outreach programme.

Magnitude of trachoma and barriers to uptake of lid surgery in a rural community of northern Nigeria

AIMS

A population-based cross-sectional survey for trachoma prevalence was conducted in a subdistrict of northern Nigeria. The objectives of the survey were to determine the magnitude and pattern of trachoma and the barriers to uptake of lid surgery in the area.

METHODS

A total of 2903 people of all ages were examined out of 3715 registered eligible persons. The study population was chosen by a two-stage cluster random sampling technique. Each person was examined for signs of trachoma. The World Health Organization (WHO) simplified trachoma grading was used. Persons with trichiasis that had not attended hospital were asked why they had not sought hospital treatment.

RESULTS

A blindness prevalence of 1.5% (95% CI 0.4%-2.7%) was found in the study population. About 20% of the blindness were due to trachoma. The prevalence of trichiasis among women 15 years and above was found to be 8.6% (95% CI 6.8%-10.7%). The prevalence of active trachoma among children was 11.8% (95% CI 10.1%-13.3%). Over 90% of people with trichiasis have not sought medical attention. The major identified factor that prevents people from accessing hospital treatment for trichiasis was cost (57%).

CONCLUSION

This study suggests that trachoma is of public health significance in this area; as such, an effective trachoma control program with emphasis on lid surgery should be established.