Congenital rubella in south India: diagnosis using saliva from infants with cataract

ToRCH-screening in pediatric cataract revisited: A North Indian tertiary care centre study

Purpose:

To analyze and report ToRCH-serology screening profile (Toxoplasma gondii [TOX], rubella [RV], cytomegalovirus [CMV], and herpes simplex virus [HSV-I/II]) in pediatric cataract.

Methods:

In this prospective analytical study, 1,026 consecutive children were screened, of which 46 children with clinically diagnosed congenital (n = 26) and developmental cataract (n = 20) were included. Post-traumatic and familial cataracts were excluded. Sera of all children were tested both qualitatively and quantitatively for IgG/IgM-antibodies against ToRCH agents in a sequential manner.

Results:

Overall, IgM/IgG-seropositivity against ≥1 ToRCH agent was reported in 91.3% (42/46) children. IgM (±IgG) positivity against ≥1 ToRCH agent was reported in 26.08% (12/46) children (nine congenital and three developmental cataract; P = 0.18), which included 8.7% (4/46) children reported positive against ≥2 agents. Finally, 13% (6/46) children were reported to be sero-clinical-positive (three were infants and three were >1 year age, P = 0.55; five congenital and one developmental cataract, P = 0.21). Either alone or combined, RV attributed to the majority (50%; 6/12) of the IgM (±IgG) and sero-clinical-positive (50%; 3/6) children. None of the children were HSV-II IgM-positive. Laboratory-confirmed congenital rubella syndrome was reported in 4.3% (2/46) children. One sero-clinical-positive infant with rare coexisting bilateral persistent fetal vasculature was also reported. IgG-alone positivity was reported highest with CMV in 67.4% (31/46) children, whereas 43.4% (20/46) children were found nonimmune to RV.

Conclusion:

The current study emphasizes the need to interpret ToRCH-screening in pediatric cataract with caution. Interpretation should include both serial qualitative and quantitative assays in tandem with clinical correlation to minimize the diagnostic errors. Clinicians should remain vigilant regarding sero-clinical-positivity in older children too who might pose a threat to the spread of infection.

Congenital Infection and Congenital Cataract in Tanzania: A Case Control Study

Background: Cataract is the commonest cause of childhood blindness in sub Saharan Africa (SSA). The significance of congenital rubella and human cytomegalovirus (HCMV) infection in the etiology is not known. Objectives: We aimed to investigate prevalence of both viruses in cases of congenital cataract and controls. Methods: Lens tissue was collected (from cases), blood and saliva from cases and controls. Using ELISA, we tested blood samples for rubella and cytomegalovirus IgM. Quantitative polymerase chain reaction (qPCR) was also used for detection of the viruses. Results: Cytomegalovirus was detected using qPCR in 72.9% saliva specimens of cases compared to 38.5% of controls (P = 0.0001). Cytomegalovirus IgM was also detected in 10.8% blood specimens of cases and only 1.5% control (P = 0.01). Rubella IgM was detected in 13.8% blood specimens of cases and only 3.1% controls (P = 0.01). In lens aspirates of cases, 12.7% were HCMV positive and 11.1% were rubella positive by qPCR. Cases had lower birth weights (mean = 2.8 kg) than controls (mean = 3.2 kg), independent of viral status (P = 0.004). Conclusions: Although most of the children in the study presented too late to be sure that infection was congenital, our study strongly suggests that HCMV and rubella infection appear important causes of congenital cataract in Tanzania hence virology testing of infantile cataract cases may be useful in assessing effectiveness of immunization programs as they are established throughout SSA.

Prevalence and causes of childhood blindness in India: A systematic review

Childhood blindness is one of the priority targets of Vision 2020-Right To Sight due to its impact on the psychological and social growth of the child. An extensive search was performed to locate research papers on childhood blindness prevalence and its causes in the community based and blind schools, respectively, conducted from 1990 onward up to the present. Cross references were also manually searched along with expert consultation to enlarge the reference data. A total of five community-based studies on the prevalence including two refractive error studies conducted all over India in children less than 16 years were found. The causes of childhood blindness from the available blind school studies revealed that causes of childhood blindness have mainly shifted from corneal causes to whole globe abnormalities. This article highlights that though with the availability of proper healthcare facilities, the trend is changing for the causes but still a lot of effort in the form of timely neonatal eye care facilities, pediatric surgical services and proper refraction strategies is required.

Construction and implications of structural equation modeling network for pediatric cataract: a data mining research of rare diseases

BACKGROUND

The majority of rare diseases are complex diseases caused by a combination of multiple morbigenous factors. However, uncovering the complex etiology and pathogenesis of rare diseases is difficult due to limited clinical resources and conventional statistical methods. This study aims to investigate the interrelationship and the effectiveness of potential factors of pediatric cataract, for the exploration of data mining strategy in the scenarios of rare diseases.

METHODS

We established a pilot rare disease specialized care center to systematically record all information and the entire treatment process of pediatric cataract patients. These clinical records contain the medical history, multiple structural indices, and comprehensive functional metrics. A two-layer structural equation model network was applied, and eight potential factors were filtered and included in the final modeling.

RESULTS

Four risk factors (area, density, location, and abnormal pregnancy experience) and four beneficial factors (axis length, uncorrected visual acuity, intraocular pressure, and age at diagnosis) were identified. Quantifiable results suggested that abnormal pregnancy history may be the principle risk factor among medical history for pediatric cataracts. Moreover, axis length, density, uncorrected visual acuity and age at diagnosis served as the dominant factors and should be emphasized in regular clinical practice.

CONCLUSIONS

This study proposes a generalized evidence-based pattern for rare and complex disease data mining, provides new insights and clinical implications on pediatric cataract, and promotes rare-disease research and prevention to benefit patients.

Salivary Diagnostics in Pediatrics: Applicability, Translatability, and Limitations

In the last decade, technological advances, combined with an improved appreciation of the ability of saliva to inform caregivers about both oral health and systemic disease, have led to the emergence of salivary diagnostic platforms. However, the majority of these assays have targeted diseases that more commonly affect the adult population, largely neglecting infants and children who arguably could benefit the most from non-invasive assessment tools for health monitoring. Gaining access into development, infection, and disease through comprehensive "omic" analyses of saliva could significantly improve care and enhance health access. In this review, we will highlight novel applications of salivary diagnostics in pediatrics across the "omic" spectrum, including at the genomic, transcriptomic, proteomic, microbiomic, and metabolomic level. The challenges to implementing salivary platforms into care, including the effects of age, diet, and developmental stage on salivary components, will be reviewed. Ultimately, large-scale, multicenter trials must be performed to establish normative biomarker values across the age spectrum to accurately discriminate between health and disease. Only then can salivary diagnostics truly translate into pediatric care.

Detecting infection in neonates: promises and challenges of a salivary approach

Premature newborns present unique challenges for the caregiver. Their clinical fragility and immature immune system places them at increased risk for bacterial and viral infections. Current clinical standard of care mandates invasive phlebotomy to assess an infant for an infection. However, serial blood draws can lead to blood transfusions and the infliction of noxious stimuli to this vulnerable population. Salivary screening for common neonatal morbidities, such as infections, could vastly improve the care for these infants and positively affect their long-term clinical outcomes. Recent technological advancements have improved our ability to detect thousands of proteins and/or microbes from a single salivary sample, making noninvasive assessment in neonates a possibility. This article reviews the clinical applications and challenges associated with integrating salivary analysis for infectious surveillance into the neonatal population.

Burden of Congenital Rubella Syndrome (CRS) in India: a systematic review

BACKGROUND

Rubella, though a mild, vaccine-preventable disease, can manifest with severe teratogenic effects in the fetus labeled as congenital rubella syndrome (CRS) due to primary maternal rubella infection. Despite a reduction in disease burden of several vaccine-preventable diseases through childhood immunization, CRS continues to account for preventable severe morbidity including childhood blindness, deafness, heart disease, and mental retardation.

OBJECTIVE

To conduct a systematic review to describe the prevalence of CRS and its contribution to major long-term handicaps in Indian population. Another objective was to estimate the susceptibility to rubella infection in Indian adolescent girls and women of reproductive age-group. We also explored strategies to decrease CRS in India by identifying the immunogenicity of rubella containing vaccines (RCV) in Indian children and women, as well as their coverage in India.

METHODS

Publications reporting CRS prevalence in general population as well as selected subgroups i.e., suspected intra-uterine infection, congenital ocular abnormalities, deafness, congenital heart disease, mental retardation, and congenital malformations, seroprevalence to rubella (IgG) amongst women and adolescents, and immunogenicity and coverage of RCVs in Indian population were retrieved through a systematic search. Primary databases employed were Medline through PubMed and IndMed, websites of the WHO, and UNICEF. No restrictions were applied in terms of study designs. The primary outcome measure was congenital rubella syndrome (CRS) which was further categorized as suspected CRS and confirmed CRS as defined by World Health Organization (WHO).

RESULTS

Comprehensive evidence about the true burden of CRS in India is not available. Almost all studies have been done in nstitutional/hospital set-ups and community-based studies are grossly lacking. There are no studies assessing the prevalence of CRS in general population. All studies have evaluated the CRS burden in symptomatic cohorts of children. 1-15% of all infants suspected to have intra-uterine infection were found to have laboratory evidence of CRS. About 3-10% of suspected CRS cases are ultimately proven to have confirmed CRS with the aid of laboratory tests. CRS accounts for 10-15% of pediatric cataract. 10-50% of children with congenital anomalies have laboratory evidence of CRS. 10-30% of adolescent females and 12-30% of women in the reproductive age-group are susceptible to rubella infection in India. RCVs are highly immunogenic in Indian adolescents and women. The coverage data of RCVs in India is not available. However, the coverage of MMR vaccine has been reported as 42%, 30% and 5% from Delhi, Chandigarh and Goa, respectively.

CONCLUSION

This systematic review identifies and explores factors associated with the prevalence of CRS in India. There is a need for urgent action in terms of revamping the national immunization policy and introduction of RCVs in the national immunization program. Active surveillance of rubella and CRS is needed to redress the burden of CRS in India.

Oral fluid testing during 10 years of rubella elimination, England and Wales

Surveillance of rubella in England and Wales has included immunoglobulin M testing of oral (crevicular) fluid from reported case-patients since 1994. The need for laboratory confirmation to monitor rubella elimination is emphasized by poor sensitivity (51%, 95% confidence interval 48.9%–54.0%) and specificity (55%, 95% confidence interval 53.7%–55.6%) of the clinical case definition. During 1999–2008, oral fluid from 11,709 (84%) of 13,952 reported case-patients was tested; 143 (1.0%) cases were confirmed and 11,566 (99%) were discarded (annual investigation and discard rate of clinically suspected rubella cases was 2,208/100,000 population). Incidence of confirmed rubella increased from 0.50 to 0.77/1 million population when oral fluid testing was included. Oral fluid tests confirmed that cases were more likely to be in older, unvaccinated men. Testing of oral fluid has improved ascertainment of confirmed rubella in children and men and provided additional information for assessing UK progress toward the World Health Organization elimination goal.

Congenital rubella syndrome and rubella in Vellore, South India

Rubella, a mild, vaccine-preventable disease, can manifest as congenital rubella syndrome (CRS), a devastating disease of the fetus. To emphasize the inadequacy of the existing rubella vaccination programme in India, we evaluated epidemiological evidence of rubella virus activity with data available from a tertiary-care centre. The proportion of suspected CRS cases that were laboratory confirmed increased from 4% in 2000 to 11% in 2008. During the same period, 329 clinically suspected postnatal rubella cases were tested of which 65 (20%) were laboratory confirmed. Of women (n=770) of childbearing age, 12·5% were susceptible to rubella.

Rubella outbreak in the Netherlands, 2004-2005: high burden of congenital infection and spread to Canada

BACKGROUND

In The Netherlands and Canada the measles, mumps, rubella vaccine coverage is high. In 2004 a rubella outbreak started in the Netherlands in a population subgroup with low coverage, with subsequent spread to Canada.

METHODS

We examined data on rubella cases in the Netherlands and Canada reported between September 2004 and July 2005. In The Netherlands we established enhanced surveillance for congenital rubella while in Canada we carried out a cohort study to estimate vaccine effectiveness.

RESULTS

In The Netherlands and Canada, 387 and 309 rubella cases were reported, respectively. Of these, 97% were in unvaccinated individuals of orthodox protestant denomination. Reported consequences of rubella in pregnancy were 2 fetal deaths and 14 infants with congenital infection. Of the latter, 11 had clinical defects including deafness in all but eye defects in none. The estimated vaccine effectiveness was 99.3% (95% CI: 95.3%-99.9%). Closely related strains of rubella virus genotype 1G were found in Dutch and Canadian cases.

CONCLUSIONS

A large rubella outbreak occurred in The Netherlands with spread to Canada in a population subgroup with religious objections to vaccination. Its major public health importance was due to the high burden of congenital disease, international spread and implications for measles and rubella surveillance and elimination. Congenital deafness occurred more frequently and eye defects less frequently than expected. The estimated rubella vaccine effectiveness was very high. Our results demonstrate the risks associated with heterogeneity in rubella vaccine coverage. High rubella vaccine coverage in all population subgroups and sensitive surveillance are crucial for elimination of rubella and CRS.

Rubella

Rubella is associated with an 80% risk of congenital abnormalities if acquired in the first 12 weeks of pregnancy. Reinfection in early pregnancy presents a much smaller risk. Prenatal diagnosis may be useful to assess the risk to the fetus. Congenital rubella is a progressive disease and some abnormalities will not be present at birth. Rubella and congenital rubella are usually diagnosed by detection of rubella-specific IgM; it may be difficult to confirm a diagnosis of congenital rubella in children over 3 months of age. Rubella vaccines are usually combined with measles and mumps vaccines. Their use has enabled some industrialised countries to eliminate rubella and congenital rubella. Countries should ensure that susceptible women of child-bearing age and health care workers are offered a rubella-containing vaccine. Rubella vaccine is contraindicated during pregnancy, but if a pregnant woman is inadvertently vaccinated it is not an indication for termination or prenatal diagnosis.

Reducing global disease burden of measles and rubella: Report of the WHO Steering Committee on research related to measles and rubella vaccines and vaccination, 2005

The WHO Steering Committee reviewed and evaluated the progress towards global control of measles and rubella and provided guidelines for future research activities concerning both diseases during its meeting in New Delhi, in April 2005. Global measles vaccination coverage increased from 71% in 1999 to 76% in 2004 and indigenous transmission was interrupted or kept at very low levels in many countries. However, Africa and Southeast Asia continue to experience endemic transmission and high mortality rates, despite a global mortality reduction of 39% between 1999 and 2003. On the basis of reports from countries with continued indigenous measles virus transmission, future control strategies as well as advantages and potential drawbacks of global measles eradication were discussed. Similarly the burden of rubella and congenital rubella syndrome (CRS) as well as the cost-effectiveness of rubella vaccination was assessed using different methods in several countries without vaccination programs. As measles and rubella viruses continue to circulate surveillance and control strategies need further optimization. RT-PCR was considered as an alternative method for laboratory diagnosis of CRS. The value of dried blood spots and oral fluid as alternative samples for measles and rubella IgG and IgM detection and genotype determination was evaluated. However further validation of these methods in different settings is required before their routine use can be recommended.

Evaluation of a commercial rubella IgM assay for use on oral fluid samples for diagnosis and surveillance of congenital rubella syndrome and postnatal rubella

BACKGROUND

Clinical diagnosis (surveillance) of rubella is unreliable and laboratory confirmation is essential. Detection of virus specific IgM in serum is the most commonly used method. However, the use of serum necessitates the drawing of blood, either through venipuncture or finger/heel prick, which can be difficult in young babies. Oral fluid samples have proved useful as an alternative, less invasive sample for virus specific IgM detection however until recently no commercial rubella IgM tests were available, restricting the usefulness of this approach.

OBJECTIVES

To evaluate the performance of the Microimmune Rubella IgM capture EIA using oral fluid samples from outbreaks as well as in cases of suspected congenital rubella syndrome (CRS).

STUDY DESIGN

Paired serum and oral fluids were collected from cases during a rubella outbreak in three provinces in Turkey. Matched serum and oral fluid samples were collected from children with suspected CRS in an active surveillance programme at the Aravind Eye Hospital in South India. Serum samples were collected as part of the measles surveillance programme in Ethiopia.

RESULTS

On serum samples the sensitivity and specificity of the Microimmune Rubella IgM capture EIA compared to Behring Enzygnost rubella IgM test was 96.9% (62/64; 95% CI 94.2-100%) and 100% (53/53; 95% CI 93.2-100%). On oral fluids compared to matched Behring results on serum the sensitivity was 95.5% (42/44; 95% CI 84.5-99.4%). The sensitivity and specificity of Microimmune Rubella IgM capture EIA on oral fluids from suspected CRS cases compared to serum results using Behring Enzygnost IgM assay was 100% (95% CI 84.5-100%) and 100% (95% CI 95.8-100.0%) respectively.

CONCLUSION

Microimmune Rubella IgM capture EIA has adequate performance for diagnosis and surveillance of rubella in outbreak using either serum or oral fluid specimens.

Measurement of tetanus antitoxin in oral fluid: a tool to conduct serosurveys

BACKGROUND

Serosurveys that measure tetanus antitoxin can complement immunization coverage surveys to allow evaluation of immunization services in developing countries. Measurement of IgG tetanus antitoxin in oral fluid was investigated as a practical and noninvasive alternative to and correlate of serum antibodies.

METHODS

Serum and oral fluid were collected from Malian infants, toddlers and adults (males without a history of tetanus vaccination). Specific IgG tetanus antitoxin was measured by enzyme-linked immunosorbent assay in serum (S-ELISA) and oral fluid (OF-ELISA).

RESULTS

One hundred forty-two pairs of serum and oral fluid samples were collected from infants, 35 pairs from toddlers and 35 pairs from adults. IgG tetanus antitoxin titers measured by OF-ELISA were 100-fold lower than those measured by S-ELISA but they correlated strongly (r = 0.90, P < 0.001). All 35 toddlers who had received 2 or 3 doses of diphtheria-tetanus-pertussis (DTP) vaccine (100%) had serum tetanus antitoxin levels >or=0.15 IU/mL and 28 of 35 (80%) had oral fluid values >or=0.0015 IU/mL. Among adults lacking a history of tetanus immunization, only 6 of 35 (17.1%) had serum titers >or=0.15 IU/mL and 4 of 35 (11%) had oral fluid titers >or=0.0015 IU/mL in oral fluid.

CONCLUSIONS

IgG tetanus antitoxin in oral fluid correlates well with levels in serum. OF-ELISA values >or=0.0015 IU/mL constitute protection against tetanus and in subjects >12 months of age imply multiple prior contacts with immunization services. IgG tetanus antitoxin measured by OF-ELISA provides a logistically practical alternative for performing seroprevalence surveys.

Rubella

Maternal rubella is now rare in many developed countries that have rubella vaccination programmes. However, in many developing countries congenital rubella syndrome (CRS) remains a major cause of developmental anomalies, particularly blindness and deafness. WHO have provided recommendations for prevention of CRS, and, encouragingly, the number of countries introducing rubella vaccination programmes has risen. However, declining uptake rates due to concerns about the measles-mumps-rubella vaccine in the UK, and increasing numbers of cases in some European countries coupled with poor uptake rates might jeopardise this progress. Surveillance of postnatally and congenitally acquired infection is an essential component of CRS prevention since rubella is difficult to diagnose on clinical grounds alone. Laboratory differentiation of rubella from other rash-causing infections, such as measles, parvovirus B19, human herpesvirus 6, and enteroviruses in developed countries, and various endemic arboviruses is essential. Reverse transcriptase PCR and sequencing for diagnosis and molecular epidemiological investigation and detection of rubella-specific IgG and IgM salivary antibody responses in oral fluid are now available.

Environmental risk factors in congenital malformations of the eye

Developmental eye defects such as coloboma are a significant cause of visual morbidity in children, and are more common in India than elsewhere. The possible role of environmental factors in the aetiology of these conditions was investigated by studying birth order, symptoms of vitamin A deficiency (night blindness), drug use and maternal illness in pregnancy, rubella antibodies and exposure to agricultural chemicals. Through hospital records and community-based rehabilitation programmes in Andhra Pradesh, children with colobomata were recruited from schools for the blind. Eighty-three mothers of affected children were interviewed. The results showed that 43% of parents were consanguineous, that 19% had a positive family history and that the frequency of coloboma was highest in second-born children. Eleven (16%) mothers had a history of night blindness while pregnant with the affected child; seven (8%) took medication during the 1st trimester, abortifacients in two cases; three reported fever in the 1st trimester; and 11 (13%) reported exposure to agricultural chemicals.

Unseen blindness, unheard deafness, and unrecorded death and disability: congenital rubella in Kumasi, Ghana

OBJECTIVES

Although rubella serosusceptibility among women of reproductive age in West Africa ranges from 10% to 30%, congenital rubella syndrome has not been reported. In Ghana, rubella immunization and serologic testing are unavailable. Our objectives were to identify congenital rubella syndrome cases, ascertain rubella antibody seroprevalence during pregnancy, and recommend strategies for congenital rubella syndrome surveillance.

METHODS

Congenital rubella syndrome cases were identified through prospective surveillance and retrospective surveys of hospital records. A rubella serosurvey of pregnant urban and rural women was performed.

RESULTS

Eighteen infants born within a 5-month period met the congenital rubella syndrome case definitions, coinciding with a 9-fold increase in presentation of infantile congenital cataract. The congenital rubella syndrome rate for this otherwise unrecorded rubella epidemic was conservatively estimated to be 0.8 per 1000 live births. A postepidemic rubella immunity rate of 92.6% was documented among 405 pregnant women; susceptibility was significantly associated with younger age (P = .000) and ethnicity (northern tribes, P = .024).

CONCLUSIONS

Congenital rubella syndrome occurs in Ghana but is not reported. Information about congenital rubella syndrome and rubella in sub-Saharan Africa is needed to evaluate inclusion of rubella vaccine in proposed measles control campaigns.

Diagnosis of rubella infection by detecting specific immunoglobulin M antibodies in saliva samples: a clinic-based study in Niterói, RJ, Brazil

This study was designed to investigate whether saliva could be a feasible alternative to serum for the diagnosis of recent rubella infection in a clinic setting. Forty-five paired blood and saliva samples collected 1 to 29 days after onset of illness were tested for specific immunoglobulin (Ig) M by antibody-capture radioimmunoassay (MACRIA). Rubella IgM was detected in all serum samples and in 38 (84.4%) saliva specimens. Forty-six serum and saliva samples from other patients with rash diseases were tested by MACRIA for control purposes and two saliva specimens were reactive. The saliva test had specificity of 96%. These results indicate that salivary IgM detection may be a convenient non-invasive alternative to serum for investigation of recent rubella cases, especially for disease surveillance and control programmes.

Detection of rubella virus-specific immunoglobulin G in saliva by an amplification-based enzyme-linked immunosorbent assay using monoclonal antibody to fluorescein isothiocyanate

An immunoglobulin G (IgG)-capture enzyme-linked immunosorbent assay (ELISA) for rubella virus is described. The assay uses a fluorescein isothiocyanate (FITC)-anti-FITC amplification system. The detection limit of the ELISA was approximately 7 IU of rubella virus-specific IgG per ml of serum sample. For saliva samples the performances of the capture ELISA and previously described radioimmunoassay were assessed, and the results of those two assays were compared to the rubella virus-specific IgG result obtained by a commercial ELISA (Behring Enzygnost) with a panel of paired serum and saliva samples. This comparison showed that the capture ELISA with saliva was more sensitive than the radioimmunoassay and that the results correlated better with the serum IgG result than the results of the radioimmunoassay did, with an overall sensitivity of 82% and a rank correlation of 0.68, whereas the sensitivity and rank correlation for the radioimmunoassay were 74% and 0.45, respectively. For subjects of 10 years of age or younger, the ELISA with saliva had a sensitivity of 94% and a specificity of 100% compared to the results of the ELISA (Behring Enzygnost) for rubella virus-specific IgG with corresponding serum samples. The sensitivity was much lower for subjects ages 17 years or older. The assay may have wider epidemiological use with saliva specimens, particularly those from children.

An evaluation of oral-fluid collection devices for the determination of rubella antibody status in a rural Ethiopian community

We compared 3 different oral-fluid collection devices to assess their suitability for use in community studies of rubella antibody. Of 58 individuals enrolled from 13 households from a southern Ethiopian village, 38 provided a blood sample and oral fluids by the 3 devices: 2 proprietary, Omni-SAL and OraSure, and a third a polystyrene sponge swab (Sponge). The Sponge swab, used like a toothbrush, was most acceptable to survey staff and to participants of all ages, although it proved ill-adapted for fluid extraction. The other devices more often caused participant discomfort or anxiety, particularly in the young. Statistical comparison of rubella-specific immunoglobulin (Ig) G in oral fluid, measured by antibody-capture radioimmunoassay, and in serum, by indirect enzyme-linked immunosorbent assay, showed no clear differences between the devices in oral-fluid performance. Specificity range was 75-100% and sensitivity 73-85%, relative to serum. Specific-antibody levels declined with increasing age, with concomitant decreases in sensitivity, as previously documented. The relationship between specific IgG and total IgG in oral fluid differed by device. Specific IgG levels were highly correlated between paired samples using the Sponge device. We consider the Sponge device to be the most suitable for community survey work, although the extraction method requires improvement. Further work is needed to improve the sensitivity of antibody status determination in adults.

Childhood blindness and low vision in Uganda

PURPOSE

To examine the causes and outcome of subnormal vision starting in childhood in Uganda, to aid in planning for its avoidance and for rehabilitation.

METHODS

All those seen having subnormal vision with onset from birth to 15 years (total 1135) (schools 1983-97; community 1988-97) were included in the study. Clinical examination was performed and a World Health Organisation (WHO) form completed, with analysis by its computer program. Main outcome measures were visual acuity, signs of eye pathology, outcome of treatment and refraction and low vision assessment.

RESULTS

By WHO category 14.8% had visual impairment, 6.5% severe visual impairment, 63.2% were blind and 15.2% were too young to test. The acuities and causes were similar in school and community groups, excepting cortical visual impairment and multiple impairment, which are much commoner in the community. Cataract was the largest cause of visual impairment (30.7%) and surgical outcome was unsatisfactory. Visual loss following corneal ulceration was the second commonest cause of subnormal vision (22.0%).

CONCLUSIONS

Cataract and corneal damage cause half of all subnormal vision, which is avoidable for both. Cataract surgery needs to be upgraded. To prevent corneal visual loss, primary health care should continue to be expanded, especially measles immunisation and nutrition care; rubella immunisation should be added. Special education needs to be greatly expanded. Public perceptions need changing if results are to be improved and help offered to more than the present minority.

The importance of prenatal factors in childhood blindness in India

The causes of visual loss in 1411 children attending schools for the blind in different geographical areas in India are described. Ninety-three percent (1318) of the children were severely visually impaired (SVI) or blind (i.e. corrected acuity in the better eye of <20/200 [<6/60]). In 60% of SVI/blind children vision loss was attributable to factors operating in the prenatal period, in 47% the prenatal factors were known and definite, and in 13% prenatal factors were the most probable causes. Hereditary retinal dystrophies and albinism were seen in 19% of SVI/blind children and 23% had congenital ocular anomalies. There were variations in the relative importance of different causes by state. The observed pattern of causes of visual loss is intermediate between those seen in industrialised countries and in the poorest developing countries. This suggests that strategies to combat childhood blindness in India need to address concurrently both preventable and treatable causes. The need for aetiological studies, particularly on anophthalmos and microphthalmos, is highlighted.

Control of rubella and congenital rubella syndrome (CRS) in developing countries, Part 1: Burden of disease from CRS

Congenital rubella syndrome (CRS) can lead to deafness, heart disease, and cataracts, and a variety of other permanent manifestations. In developing countries, the burden of CRS has been assessed as follows: by surveillance of CRS; by surveillance of acquired rubella; by age-stratified serosurveys; and by serosurveys documenting the rubella susceptibility of women of childbearing age. During rubella outbreaks, rates of CRS per 1000 live births were at least 1.7 in Israel, 1.7 in Jamaica, 0.7 in Oman, 2.2 in Panama, 1.5 in Singapore, 0.9 in Sri Lanka, and 0.6 in Trinidad and Tobago. These rates are similar to those reported from industrialized countries during the pre-vaccine era. Special studies of CRS have been reported from all WHO regions. Rubella surveillance data show that epidemics occur every 4-7 years, similar to the situation in Europe during the pre-vaccination era. In developing countries, the estimated average age at infection varies from 2-3 years to 8 years. For 45 developing countries we identified serosurveys of women of childbearing age that had enrolled > or = 100 individuals. The proportion of women who remained susceptible to rubella (e.g. seronegative) was < 10% in 13 countries. 10-24% in 20 countries, and > or = 25% in 12 countries. Discussed are methods to improve the surveillance of rubella and CRS in developing countries.

Epidemiology of cataract in childhood: a global perspective

Cataract is the most important cause of treatable childhood blindness. There are an estimated 200,000 children blind from cataract worldwide; 20,000 to 40,000 children with developmental bilateral cataract are born each year. Rubella is still an important cause of preventable disease in many countries. In the developing world, there is a need to improve early case detection and referral services and to establish centers with expertise in the assessment, surgical treatment, and long-term management of the child with cataract.