A 20-year population study of peripartum cardiomyopathy

BACKGROUND AND AIMS

The epidemiology of peripartum cardiomyopathy (PPCM) in Europe is poorly understood and data on long-term outcomes are lacking. A retrospective, observational, population-level study of validated cases of PPCM in Scotland from 1998 to 2017 was conducted.

METHODS

Women hospitalized with presumed de novo left ventricular systolic dysfunction around the time of pregnancy and no clear alternative cause were included. Each case was matched to 10 controls. Incidence and risk factors were identified. Morbidity and mortality were examined in mothers and children.

RESULTS

The incidence of PPCM was 1 in 4950 deliveries. Among 225 women with PPCM, obesity, gestational hypertensive disorders, and multi-gestation were found to be associated with having the condition. Over a median of 8.3 years (9.7 years for echocardiographic outcomes), 8% of women with PPCM died and 75% were rehospitalized for any cause at least once. Mortality and rehospitalization rates in women with PPCM were ∼12- and ∼3-times that of controls, respectively. The composite of all-cause death, mechanical circulatory support, or cardiac transplantation occurred in 14%. LV recovery occurred in 76% and, of those who recovered, 13% went on to have a decline in LV systolic function despite initial recovery. The mortality rate for children born to women with PPCM was ∼5-times that of children born to controls and they had an ∼3-times greater incidence of cardiovascular disease over a median of 8.8 years.

CONCLUSIONS

PPCM affected 1 in 4950 women around the time of pregnancy. The condition is associated with considerable morbidity and mortality for the mother and child. There should be a low threshold for investigating at-risk women. Long term follow-up, despite apparent recovery, should be considered.

Epidemiology of rotavirus diarrhea among children less than 5 years hospitalized with acute gastroenteritis prior to rotavirus vaccine introduction in India

Background

Rotavirus is an important cause of severe diarrhea requiring hospitalization, accounting for approximately 78,000 deaths annually in Indian children below 5 years of age. We present epidemiological data on severe rotavirus disease collected during hospital-based surveillance in India before the introduction of the oral rotavirus vaccine into the national immunization schedule.

Methods

The National Rotavirus Surveillance Network was created involving 28 hospital sites and 11 laboratories across the four geographical regions of India. From September 2012 to August 2016 children less than 5 years of age hospitalized for diarrhea for at least 6 h, were enrolled. After recording clinical details, a stool sample was collected from each enrolled child, which was tested for rotavirus antigen using enzyme immunoassay (EIA). Nearly 2/3rd of EIA positive samples were genotyped using reverse transcription polymerase chain reaction to identify the G and P types.

Results

Of the 21,421 children enrolled during the 4 years surveillance, 36.3% were positive for rotavirus. The eastern region had the highest proportion of rotavirus associated diarrhea (39.8%), while the southern region had the lowest (33.8%). Rotavirus detection rates were the highest in children aged 6–23 months (41.8%), and 24.7% in children aged < 6 months. Although rotavirus associated diarrhea was seen throughout the year, the highest positivity was documented between December and February across all the regions. The most common rotavirus genotype was G1P[8] (52.9%), followed by G9P4 (8.7%) and G2P4 (8.4%).

Conclusions

There is high burden of rotavirus gastroenteritis among Indian children below 5 years of age hospitalized for acute diarrhea thereby highlighting the need for introduction of rotavirus vaccine into the national immunization program and also for monitoring circulating genotypes.

Diversity of rotavirus genotypes circulating in children < 5 years of age hospitalized for acute gastroenteritis in India from 2005 to 2016: analysis of temporal and regional genotype variation

Background

From 2016, the Government of India introduced the oral rotavirus vaccine into the national immunization schedule. Currently, two indigenously developed vaccines (ROTAVAC, Bharat Biotech; ROTASIIL, Serum Institute of India) are included in the Indian immunization program. We report the rotavirus disease burden and the diversity of rotavirus genotypes from 2005 to 2016 in a multi-centric surveillance study before the introduction of vaccines.

Methods

A total of 29,561 stool samples collected from 2005 to 2016 (7 sites during 2005–2009, 3 sites from 2009 to 2012, and 28 sites during 2012–2016) were included in the analysis. Stools were tested for rotavirus antigen using enzyme immunoassay (EIA). Genotyping was performed on 65.8% of the EIA positive samples using reverse transcription- polymerase chain reaction (RT-PCR) to identify the G (VP7) and P (VP4) types. Multinomial logistic regression was used to quantify the odds of detecting genotypes across the surveillance period and in particular age groups.

Results

Of the 29,561 samples tested, 10,959 (37.1%) were positive for rotavirus. There was a peak in rotavirus positivity during December to February across all sites. Of the 7215 genotyped samples, G1P[8] (38.7%) was the most common, followed by G2P[4] (12.3%), G9P[4] (5.8%), G12P[6] (4.2%), G9P[8] (4%), and G12P[8] (2.4%). Globally, G9P[4] and G12P[6] are less common genotypes, although these genotypes have been reported from India and few other countries. There was a variation in the geographic and temporal distribution of genotypes, and the emergence or re-emergence of new genotypes such as G3P[8] was seen. Over the surveillance period, there was a decline in the proportion of G2P[4], and an increase in the proportion of G9P[4]. A higher proportion of mixed and partially typed/untyped samples was also seen more in the age group 0–11 months.

Conclusions

This 11 years surveillance highlights the high burden of severe rotavirus gastroenteritis in Indian children < 5 years of age before inclusion of rotavirus vaccines in the national programme. Regional variations in rotavirus epidemiology were seen, including the emergence of G3P[8] in the latter part of the surveillance. Having pre-introduction data is important to track changing epidemiology of rotaviruses, particularly following vaccine introduction.

Clinical relevance of cagA and vacA and association with mucosal findings in Helicobacter pylori-infected individuals from Chennai, South India

Helicobacter pylori is associated with a spectrum of severe gastrointestinal conditions. In this study, an attempt was made to correlate endoscopic mucosal patterns with H. pylori infection and examine the pathogenic potential of the strains. Among the 147 dyspeptic individuals studied, 42.2% were H. pylori infected. Association of H. pylori with type 3 and 4 mucosal patterns (P = 0.001) and intestinal metaplasia (P = 0.012) was seen. vacA was associated with histological (P = 0.014) and endoscopy findings (P = 0.009). Association of mucosal patterns with H. pylori infection could be useful for clinicians to decide on the need for eradication therapy.

Rotavirus gastroenteritis in Indian children < 5 years hospitalized for diarrhoea, 2012 to 2016

Background

In 2016, the Government of India introduced the oral rotavirus vaccine (ROTAVAC, Bharat Biotech, India) in 4 states of India as part of the Universal Immunization Programme, and expanded to 5 more states in 2017. We report four years of data on rotavirus gastroenteritis in hospitalized children < 5 years of age prior to vaccine introduction.

Methods

Children from 7 sites in southern and northern India hospitalized for diarrhoea were recruited between July 2012 and June 2016. Stool samples were screened for rotavirus using enzyme immunoassay (EIA). The EIA positive samples were genotyped by reverse-transcription polymerase chain reaction.

Results

Of the 5834 samples from the 7 sites, 2069 (35.5%) were positive for rotavirus by EIA. Genotyping was performed for 2010 (97.1%) samples. G1P[8](56.3%), G2P[4](9.1%), G9P[4](7.6%), G9P[8](4.2%), and G12P[6](3.7%) were the common genotypes in southern India and G1P[8](36%), G9P[4](11.4%), G2P[4](11.2%), G12P[6](8.4%), and G3P[8](5.9%) in northern India.

Conclusions

The study highlights the high prevalence of rotavirus gastroenteritis in India and the diversity of rotavirus genotypes across different geographical regions. Pre- vaccine surveillance data is necessary to evaluate the potential change in admission rates for gastroenteritis and circulating rotavirus genotypes after vaccine introduction, thus assessing impact.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6406-0) contains supplementary material, which is available to authorized users.

Cardiometabolic effects of a novel SIRT1 activator, SRT2104, in people with type 2 diabetes mellitus

Background

The cardiometabolic effects of SRT2104, a novel SIRT1 activator, were investigated in people with type 2 diabetes mellitus (T2DM).

Methods

Fifteen adults with T2DM underwent a randomised, double-blind, placebo-controlled cross-over trial and received 28 days of oral SRT2104 (2.0 g/day) or placebo. Forearm vasodilatation (measured during intrabrachial bradykinin, acetylcholine and sodium nitroprusside infusions) as well as markers of glycaemic control, lipid profile, plasma fibrinolytic factors, and markers of platelet-monocyte activation, were measured at baseline and at the end of each treatment period.

Results

Lipid profile and platelet-monocyte activation were similar in both treatment arms (p>0.05 for all). Forearm vasodilatation was similar on exposure to acetylcholine and sodium nitroprusside (p>0.05, respectively). Bradykinin-induced vasodilatation was less during treatment with SRT2104 versus placebo (7.753vs9.044, respectively, mean difference=−1.291,(95% CI −2.296 to −0.285, p=0.012)). Estimated net plasminogen activator inhibitor type 1 antigen release was reduced in the SRT2104 arm versus placebo (mean difference=−38.89 ng/100 mL tissue/min, (95% CI −75.47, to –2.305, p=0.038)). There were no differences in other plasma fibrinolytic factors (p>0.05 for all).

After 28 days, SRT2104 exposure was associated with weight reduction (−0.93 kg (95% CI −1.72 to −0.15), p=0.0236), and a rise in glycated haemoglobin (5 mmol/mol or 0.48% (0.26 to 0.70), p=0.004)

Conclusions

In people with T2DM, SRT2104 had inconsistent, predominantly neutral effects on endothelial and fibrinolytic function, and no discernible effect on lipids or platelet function. In contrast, weight loss was induced along with deterioration in glycaemic control, suggestive of potentially important metabolic effects.

Clinical trial registration

NCT01031108; Results.

Fire Simulation and Cardiovascular Health in Firefighters

BACKGROUND

Rates of myocardial infarction in firefighters are increased during fire suppression duties, and are likely to reflect a combination of factors including extreme physical exertion and heat exposure. We assessed the effects of simulated fire suppression on measures of cardiovascular health in healthy firefighters.

METHODS

In an open-label randomized crossover study, 19 healthy firefighters (age, 41±7 years; 16 males) performed a standardized training exercise in a fire simulation facility or light duties for 20 minutes. After each exposure, ex vivo thrombus formation, fibrinolysis, platelet activation, and forearm blood flow in response to intra-arterial infusions of endothelial-dependent and -independent vasodilators were measured.

RESULTS

After fire simulation training, core temperature increased (1.0±0.1°C) and weight reduced (0.46±0.14 kg, P<0.001 for both). In comparison with control, exposure to fire simulation increased thrombus formation under low-shear (73±14%) and high-shear (66±14%) conditions (P<0.001 for both) and increased platelet-monocyte binding (7±10%, P=0.03). There was a dose-dependent increase in forearm blood flow with all vasodilators (P<0.001), which was attenuated by fire simulation in response to acetylcholine (P=0.01) and sodium nitroprusside (P=0.004). This was associated with a rise in fibrinolytic capacity, asymptomatic myocardial ischemia, and an increase in plasma cardiac troponin I concentrations (1.4 [0.8-2.5] versus 3.0 [1.7-6.4] ng/L, P=0.010).

CONCLUSIONS

Exposure to extreme heat and physical exertion during fire suppression activates platelets, increases thrombus formation, impairs vascular function, and promotes myocardial ischemia and injury in healthy firefighters. Our findings provide pathogenic mechanisms to explain the association between fire suppression activity and acute myocardial infarction in firefighters.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01812317.

Expanded Indian National Rotavirus Surveillance Network in the Context of Rotavirus Vaccine Introduction

OBJECTIVE

To extend a nation-wide rotavirus surveillance network in India, and to generate geographically representative data on rotaviral disease burden and prevalent strains.

DESIGN

Hospital-based surveillance.

SETTING

A comprehensive multicenter, multi-state hospital based surveillance network was established in a phased manner involving 28 hospital sites across 17 states and two union territories in India.

PATIENTS

Cases of acute diarrhea among children below 5 years of age admitted in the participating hospitals.

RESULTS

During the 28 month study period between September 2012 and December 2014, 11898 children were enrolled and stool samples from 10207 children admitted with acute diarrhea were tested; 39.6% were positive for rotavirus. Highest positivity was seen in Tanda (60.4%) and Bhubaneswar (60.4%) followed by Midnapore (59.5%). Rotavirus infection was seen more among children aged below 2 years with highest (46.7%) positivity in the age group of 12-23 months. Cooler months of September to February accounted for most of the rotavirus associated gastroenteritis, with highest prevalence seen during December to February (56.4%). 64% of rotaviru -infected children had severe to very severe disease. G1 P[8] was the predominant rotavirus strain (62.7%) during the surveillance period.

CONCLUSION

The surveillance data highlights the high rotaviral disease burden in India. The network will continue to be a platform for monitoring the impact of the vaccine.

Intussusception in Children Aged Less than Five years

OBJECTIVE

To enumerate the cases of intussusception in Chennai during 2012-2013, describe the clinical profile, outcomes of case management and highlight the importance of systematically collecting this data in lieu of rotavirus vaccine introduction in India.

METHODS

Medical records of pediatric intussusception cases admitted in eight large hospitals in Chennai from July 2012 through June 2013 were retrospectively reviewed. Demographic and clinical data including diagnostic and treatment practices were obtained. Cases were categorized based on the diagnostic certainty criteria stipulated by the Brighton collaboration on intussusception.

RESULTS

During the one year of study period, 205 cases of intussusception were diagnosed in 8 hospitals in Chennai city of India. The median age at presentation was 9 mo (Inter Quartile Range, IQR 6-14) with a male to female ratio of 1.8:1. The commonest site of intussusception was ileocolic (80.4 %). Most of the cases (59.8 %) were managed non-surgically. Direct surgical intervention was carried out in 26.5 % cases whereas in 11.8% of cases, surgery was required after failure of non-surgical measures. Median duration of hospital stay was 3 d (IQR 1-5).

CONCLUSIONS

This study documents the case burden of intussusception among children in Chennai in a calendar year. Data on receipt of rotavirus vaccine was not available. The authors recommend collection of rotavirus vaccine data among all cases of intussusception in the country, and do retrospective analysis in other parts of the country and prospective surveillance in pediatric / immunization clinics to assess impact of rotavirus vaccine on intussusception rates in the post rotavirus vaccine introduction scenario.

Cardiovascular effects of urocortin 2 and urocortin 3 in patients with chronic heart failure

AIMS

Urocortin 2 and urocortin 3 may play a role in the pathophysiology of heart failure and are emerging therapeutic targets. We aimed to examine the local and systemic cardiovascular effects of urocortin 2 and urocortin 3 in healthy subjects and patients with heart failure.

METHODS

Patients with heart failure (n = 8) and age and gender-matched healthy subjects (n = 8) underwent bilateral forearm arterial blood flow measurement using forearm venous occlusion plethysmography during intra-arterial infusions of urocortin 2 (3.6-36 pmol min(-1) ), urocortin 3 (360-3600 pmol min(-1) ) and substance P (2-8 pmol min(-1) ). Heart failure patients (n = 9) and healthy subjects (n = 7) underwent non-invasive impedance cardiography during incremental intravenous infusions of sodium nitroprusside (573-5730 pmol kg(-1)  min(-1) ), urocortin 2 (36-360 pmol min(-1) ), urocortin 3 (1.2-12 nmol min(-1) ) and saline placebo.

RESULTS

Urocortin 2, urocortin 3 and substance P induced dose-dependent forearm arterial vasodilatation in both groups (P < 0.05 for both) with no difference in magnitude of vasodilatation between patients and healthy subjects. During systemic intravenous infusions, urocortin 3 increased heart rate and cardiac index and reduced mean arterial pressure and peripheral vascular resistance index in both groups (P < 0.01 for all). Urocortin 2 produced similar responses to urocortin 3, although increases in cardiac index and heart rate were only significant in heart failure (P < 0.05) and healthy subjects (P < 0.001), respectively.

CONCLUSION

Urocortins 2 and 3 cause vasodilatation, reduce peripheral vascular resistance and increase cardiac output in both health and disease. These data provide further evidence to suggest that urocortins 2 and 3 continue to hold promise for the treatment of heart failure.

Effects of the small molecule SIRT1 activator, SRT2104 on arterial stiffness in otherwise healthy cigarette smokers and subjects with type 2 diabetes mellitus

Objective

Arterial stiffness increases with age, and is associated with adverse cardiovascular outcome including increased mortality. The effect of the oral small molecule SIRT1 activator, SRT2104, on arterial stiffness was examined in otherwise healthy cigarette smokers and participants with type 2 diabetes mellitus.

Methods

24 otherwise healthy cigarette smokers and 15 people with stable type 2 diabetes were randomised in a double-blind placebo-controlled crossover trial and received 28 days of oral SRT2104 (2.0 g/day) or matched placebo. Blood pressure was measured using non-invasive oscillatory sphygmomanometry. Pulse wave analysis and velocity were measured using applanation tonometry at baseline and the end of each treatment period. Owing to the small sample size and similar trends for both groups, data for the two groups were pooled (post hoc analysis).

Results

Compared to placebo, treatment with SRT2104 was associated with a significant reduction in augmentation pressure (p=0.0273) and a trend towards improvement in the augmentation index and corrected augmentation index (p>0.05 for both). However, no changes were observed in pulse wave velocity and time to wave reflection (p>0.05). Systolic and diastolic blood pressures remained unchanged throughout the study. Treatment by cohort interaction was not significant for any of the pulse wave parameters, suggesting that the response to SRT2104 in otherwise healthy smokers and people with diabetes was consistent.

Conclusions

SRT2104 may improve measures of arterial stiffness in otherwise healthy cigarette smokers and in participants with type 2 diabetes. Definitive conclusions are not possible given the small sample size and exploratory nature of this analysis.

Trial registration number

NCT01031108.

Rotigaptide protects the myocardium and arterial vasculature from ischaemia reperfusion injury

AIM

Ischaemia-reperfusion injury (IRI) causes impaired endothelial function and is a major component of the adverse effects of reperfusion following myocardial infarction. Rotigaptide increases gap junction conductance via connexin-43. We tested the hypothesis that rotigaptide reduces experimental myocardial infarction size and ameliorates endothelial IRI in humans.

METHODS

Myocardial infarction study: porcine myocardial infarction was achieved by catheter-induced occlusion of the left anterior descending artery. In a randomized double-blind study, rotigaptide (n = 9) or placebo (n = 10) was administered intravenously as a 10 min bolus prior to reperfusion and continuously during 2 h of reperfusion. Myocardial infarction size (IS) was assessed as proportion of the area at risk (AAR). Human translational study: forearm IRI was induced in the presence or absence of intra-arterial rotigaptide. In a randomized double-blind study, forearm arterial blood flow was measured at rest and during intra-arterial infusion of acetylcholine (5-20 μg min(-1) ; n = 11) or sodium nitroprusside (2-8 mg min(-1) ; n = 10) before and after intra-arterial infusion of placebo or rotigaptide, and again following IRI.

RESULTS

Myocardial infarction study: Rotigaptide treatment was associated with a reduction of infarct size (IS/AAR[%]: 18.7 ± 4.1 [rotigaptide] vs. 43.6 ± 4.2 [placebo], P = 0.006). Human translational study: Endothelium-dependent vasodilatation to acetylcholine was attenuated after ischaemia-reperfusion in the presence of placebo (P = 0.007), but not in the presence of rotigaptide (P = NS). Endothelium-independent vasodilatation evoked by sodium nitroprusside was unaffected by IRI or rotigaptide (P = NS).

CONCLUSIONS

Rotigaptide reduces myocardial infarction size in a porcine model and protects from IRI-related endothelial dysfunction in man. Rotigaptide may have therapeutic potential in the treatment of myocardial infarction.

Cardiovascular effects of a novel SIRT1 activator, SRT2104, in otherwise healthy cigarette smokers

BACKGROUND

We examined the effect of the oral SIRT1 activator SRT2104 on cardiovascular function in otherwise healthy cigarette smokers.

METHODS AND RESULTS

Twenty-four otherwise healthy cigarette smokers participated in a randomized double-blind, placebo-controlled crossover trial and received 28 days of oral SRT2104 (2.0 g/day) or matched placebo. Plasma SRT2104 concentrations, serum lipid profile, plasma fibrinolytic factors, and markers of platelet and monocyte activation were measured at baseline and at the end of each treatment period together with an assessment of forearm blood flow during intra-arterial bradykinin, acetylcholine, and sodium nitroprusside infusions. Three hours postdose, mean plasma SRT2104 concentration was 1328 ± 748 ng/mL after 28 days of active treatment. Compared with placebo, serum lipid profile improved during SRT2104 administration, with reductions in serum total cholesterol (-11.6 ± 20 versus 6 ± 21 mg/dL), low-density lipoprotein cholesterol (-10 ± 17 versus 3 ± 21 mg/dL), and triglyceride (-39.8 ± 77 versus 13.3 ± 57 mg/dL) concentrations (P<0.05 for all). All vasodilators produced a dose-dependent increase in blood flow (P<0.0001) that was similar during each treatment period (P>0.05 for all). No significant differences in fibrinolytic or blood flow parameters were observed between placebo and SRT2014.

CONCLUSIONS

SRT2104 appears to be safe and well tolerated and associated with an improved lipid profile without demonstrable differences in vascular or platelet function in otherwise healthy cigarette smokers.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov. Unique identifier: NCT01031108.

Vascular effects of urocortins 2 and 3 in healthy volunteers

BACKGROUND

Urocortin 2 and urocortin 3 are endogenous peptides with an emerging role in cardiovascular pathophysiology. We assessed their pharmacodynamic profile and examined the role of the endothelium in mediating their vasomotor effects in vivo in man.

METHODS AND RESULTS

Eighteen healthy male volunteers (23±4 years) were recruited into a series of double-blind, randomized crossover studies using bilateral forearm venous occlusion plethysmography during intra-arterial urocortin 2 (3.6 to 120 pmol/min), urocortin 3 (1.2 to 36 nmol/min), and substance P (2 to 8 pmol/min) in the presence or absence of inhibitors of cyclooxygenase (aspirin), cytochrome P450 metabolites of arachidonic acid (fluconazole), and nitric oxide synthase (L-NMMA). Urocortins 2 and 3 evoked arterial vasodilatation (P<0.0001) without tachyphylaxis but with a slow onset and offset of action. Inhibition of nitric oxide synthase with L-NMMA reduced vasodilatation to substance P and urocortin 2 (P≤0.001 for both) but had little effect on urocortin 3 (P>0.05). Neither aspirin nor fluconazole affected vasodilatation induced by any of the infusions (P>0.05 for all). In the presence of all 3 inhibitors, urocortin 2- and urocortin 3-induced vasodilatation was attenuated (P<0.001 for all) to a greater extent than with L-NMMA alone (P≤0.005).

CONCLUSIONS

Urocortins 2 and 3 cause potent and prolonged arterial vasodilatation without tachyphylaxis. These vasomotor responses are at least partly mediated by endothelial nitric oxide and cytochrome P450 metabolites of arachidonic acid. The role of urocortins 2 and 3 remains to be explored in the setting of human heart failure, but they have the potential to have major therapeutic benefits.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov//. Unique identifier: NCT01096706 and NCT01296607.

Genotoxicity in agricultural farmers from Guntur district of South India—A case study

Background: Pesticides play an important role in controlling the pests on agricultural crops and thereby to increase the yield of agricultural produce. Farmers occupationally exposed to pesticides during spraying activities are more prone to genotoxicity than unexposed. Aim: To assess the genotoxicity in farmers, engaged in spraying complex mixture of pesticides in the cultivation of cotton crops. Material and methods: A total number of 152 male subjects were selected randomly from Guntur district of Andhra Pradesh (AP), South India. The demographic particulars viz., personal habits, duration of exposure to pesticides, types of pesticides used were collected from the study subjects using an interview schedule. Among them 76 subjects were farmers and the remaining individuals served as unexposed or controls. Blood samples from these subjects were collected for assessing the genetic damage by chromosomal aberrations (CAs) test and micronucleus test (MNT). Results: The results of the study indicated that CA was significantly higher with 2.8% in farmers who were exposed to pesticides when compared to unexposed (0.72%). However, there was a minor difference in MN with 0.13% and 0.12% between exposed and unexposed which was not statistically significant ( p < 0.05). Conclusion: A correlation between CA frequency and exposure to benzene hexachloride (BHC) pesticide residue was observed.

Lot quality assurance sampling for monitoring immunization coverage in Madras City

OBJECTIVE

To explore the usefulness of Lot Quality Assurance Sampling (LQAS) to identify divisions in a city that had immunization coverage levels of 80% for any of the four EPI vaccines.

METHODS

Only 43 divisions were considered for the study, the stratification factor being the death rate. The hypothesis that 80% coverage is 'unacceptable' was stipulated. Critical value (the number of unimmunized children) was chosen as 3. A simple random sample of 36 children in the age-group 12-23 months was taken from each selected division. Since sampling frames of children were not available, a simple random sample of 36 households was selected. Immunization status of each child was assessed by interviewing the child's mother/guardian. If the number of unimmunized children exceeded 3, then the division was regarded having coverage level 80% and rejected.

RESULTS

The coverage was classified as unacceptable(i. e., below 80%) in 19 divisions for Polio and DPT vaccines, in 26 divisions for Measles vaccine and in 4 divisions for BCG vaccine. The average time spent for undertaking the LQAS survey was 6 man-days per division.

CONCLUSION

This study demonstrated the utility of the LQAS technique in identifying 'unsatisfactory' pockets in Madras City, when the overall coverage was satisfactory. The technique will have greater application with an increase in the number of large units (cities/districts) having an overall coverage of 90% or more.

A concurrent comparison of a WHO-recommended 30-cluster survey and a modified version of it under Indian conditions in the estimation of immunization coverages

A concurrent comparison of the WHO 30-cluster sample survey method for estimating immunization coverages (DPT, Polio, BCG, Measles) and an Indian modification of (GOI) was undertaken in five districts in South India. The essential difference between the two methods is the manner in which the first household is selected in the chosen clusters. With the WHO method, it is chosen clusters. With the WHO method, it is chosen at random, whereas with the GOI method it is often close to the village centre. Estimates with the required degree of precision, i.e., 95% confidence limits of +/- 10 percentage points, were provided in 18 (90%) of 20 instances by the WHO method and in 19 (95%) by the GOI method, findings which are in accordance with expectation. The estimated coverages were, however, higher by the GOI method than by the WHO method in two districts, lower in one district, and in the remaining two districts there was no clear pattern. On the average, there was a suggestion that the GOI method yielded slightly higher coverages, but the differences were not statistically significant.

A comparison of a 30-cluster survey method used in India and a purposive method in the estimation of immunization coverages in Tamil Nadu

A 30-cluster survey method that is employed for estimating immunization coverages by the Government of India (GOI) was compared with a Purposive method, to investigate whether the likely omission of SC/ST and backward classes in the former would lead to the reporting of higher coverages. The essential difference between the two methods is in the manner in which the first household is selected in the chosen first stage sampling units (villages). With the GOI method, it is often close to the village centre, whereas with the Purposive method it is always in the periphery or in a pocket consisting of SC/ST or backward classes. A concurrent comparison of the two methods in three districts in Tamil Nadu showed no real differences in the coverage with DPT and BCG vaccines. However, the coverage was consistently higher by the GOI method in the case of the Polio vaccine (by 1.5%, 3.1% and 5.3% in the 3 districts), and the Measles vaccine (by 4.8%, 13.3% and 13.9%); the average difference was 3.3% for Polio vaccine (p = 0.08) and 7.3% for Measles vaccine (p = 0.01).

Estimation of immunisation coverages in children by WHO 30-cluster survey

A WHO 30-cluster survey for estimating immunisation coverages in infancy was undertaken in each of 5 districts in Tamil Nadu, strictly according to the specifications laid out in the WHO manual. The main aim was to examine whether the technique would provide estimates with the required degree of precision under Indian conditions. Of 60 sample survey estimates, 57 had the targeted degree of precision (i.e., 95% confidence limits of +/- 10 percentage points), which is in excellent agreement with expectation. The proportions of infants on whom immunisation was initiated, were very high for DPT vaccine (88-99%) and polio vaccine (85-99%); however, of those who had received the first dose, 23-39 per cent did not complete the 3-dose schedule. Estimated coverage with measles vaccine ranged from 15 to 54 per cent, while BCG coverage ranged from 53 to 97 per cent. Better health education regarding the need and correct age for immunisation, and more effective motivation at the time of administration of the first dose of DPT/polio vaccine, are recommended.