Use of TaqMan Array Cards to investigate the aetiological agents of diarrhoea among young infants with severe acute malnutrition

OBJECTIVE

Studies involving less sensitive conventional microscopy and culture-based approaches have identified distinct differences in diarrhoeal aetiology in childhood malnutrition. Our study involved the use of an advanced molecular biology technique, the TaqMan Array Cards (TAC), to elucidate the diarrhoeal aetiology among young infants with severe acute malnutrition (SAM).

METHOD

A total of 113 faecal samples was collected from SAM infants, aged 2-6 months, upon admission to the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) with complications of diarrhoea and related comorbidities. We used TAC for the detection of 29 different diarrhoeal enteropathogens from a single faecal sample. For comparison, we also analysed 25 diarrhoeal samples from well-nourished infants of similar age.

RESULTS

Higher odds of detection of all bacterial enteropathogens were associated with diarrhoea among SAM infants. In particular, the detection of Aeromonas sp (aOR: 25.7, p = 0.011), Campylobacter sp (aOR: 9.6, p < 0.01) and ETEC (aOR: 5.2, p = 0.022) was significantly associated with diarrhoea among SAM infants in comparison to well-nourished infants. 80% higher odds of detection of rotavirus and norovirus GII were associated with diarrhoea among well-nourished infants in comparison to SAM infants (aOR: 0.2, p < 0.05).

CONCLUSION

Our study findings demonstrate a difference in diarrhoeal aetiology among SAM and well-nourished young infants, which may be useful in providing an evidence-based logic for possible revision of treatment guidelines for treatment of young diarrhoeal infants with SAM in the early management of the menace of antimicrobial resistance.

Long-term impact of changing childhood malnutrition on rotavirus diarrhoea: Two decades of adjusted association with climate and socio-demographic factors from urban Bangladesh

Background

There is strong association between childhood rotavirus, diarrhoea, climate factors and malnutrition. Conversely, a significant nutritional transition (reduced under-nutrition) with a concurrent increasing trend of rotavirus infection in last decade was also observed among under 5 children, especially in developing countries including Bangladesh. Considering the pathophysiology of rotavirus, there might be an interaction of this nutrition transition which plays a pivotal role in increasing rotavirus infection in addition to climate and other man-made factors in urban areas such as Dhaka, Bangladesh.

Methods

Relevant monthly data from 1993–2012 were extracted from the archive of the Diarrhoeal Disease Surveillance System of icddr, b and linked with data collected from the Dhaka station of the Bangladesh Meteorological Department (mean temperature, rainfall, sea level pressure and humidity). Seasonal autoregressive integrated moving average time series models were deployed to determine the association between the monthly proportion of rotavirus infection and underweight, stunting and wasting adjusting for climate, socio-demographic and sanitation factors.

Finding

The proportion of rotavirus cases among all causes diarrhoea increased from 20% in 1993 to 43% in 2012 (Chi squared for trend p = 0.010). In contrast, underweight, stunting and wasting decreased from 59%-29% (p<0.001); 53%-21% (p<0.001) and 32%-22% (p<0.001) respectively over the same period. Mean ambient temperature increased from 25.76°C-26.62°C (p = 0.07); mean rainfall, sea level pressure and mean humidity decreased from 234.92–111.75 mm (p = 0.5), 1008.30–1006.61 mm of hg (p = 0.02) and 76.63%-70.26% (p<0.001), respectively. In the adjusted model, a decrease in monthly proportion of underweight [coef.: -0.189 (95% CI:-0.376, -0.003)] and wasting [-0.265 (-0.455, -0.075)] were significantly and inversely associated with rotavirus infection. However, an inverse but insignificant association was observed for stunting [-0.070 (-0.249, 0.109)].

Interpretation

The reduction of acute childhood malnutrition is significantly associated with increasing rotavirus diarrhoea among under-5 children. Thus mass vaccination in addition to interventions directed at man-made modifiable predictors for prevention and control is warranted.

Changing childhood malnutrition in Bangladesh: trends over the last two decades in urban–rural differentials (1993–2012)

Objective

The present study determined trends in malnutrition among under-5 children in urban and rural areas of Bangladesh.

Design

Surveillance.

Setting

The study was conducted in the urban Dhaka and the rural Matlab hospitals of the International Centre for Diarrhoeal Disease Research, Bangladesh, where every fiftieth patient and all patients coming from the Health and Demographic Surveillance System were enrolled.

Subjects

A total of 28 816 under-5 children were enrolled at Dhaka from 1993 to 2012 and 11 533 at Matlab between 2000 and 2012.

Results

In Dhaka, 46 % of the children were underweight, 39 % were stunted and 28 % were wasted. In Matlab, the corresponding figures were 39 %, 31 % and 26 %, respectively. At Dhaka, 0·5 % of the children were overweight and obese when assessed by weight-for-age Z-score >+2·00, 1·4 % by BMI-for-age Z-score >+2·00 and 1·4 % by weight-for-height Z-score >+2·00; in Matlab the corresponding figures were 0·5 %, 1·4 % and 1·4 %, respectively. In Dhaka, the proportion of underweight, stunting and wasting decreased from 59 % to 28 % (a 53 % reduction), from 54 % to 22 % (59 % reduction) and from 33 % to 21 % (36 % reduction), respectively, between 1993 and 2012. In Matlab, these indicators decreased from 51 % to 27 % (a 47 % reduction), from 36 % to 25 % (31 % reduction) and from 34 % to 14 % (59 % reduction), respectively, from 2000 to 2012. On the other hand, the proportion of overweight (as assessed by BMI-for-age Z-score) increased significantly over the study period in both Dhaka (from 0·6 % to 2·6 %) and Matlab (from 0·8 % to 2·2 %).

Conclusions

The proportion of malnourished under-5 children has decreased gradually in both urban and rural Bangladesh; however, the reduction rates are not in line with meeting Millennium Development Goal 1. Trends for increasing childhood obesity have been noted during the study period as well.

Gastroenteritis due to typhoidal Salmonella: a decade of observation at an urban and a rural diarrheal disease hospital in Bangladesh

Background

The study aimed to compare the socio-demographic, host and clinical characteristics, seasonality and antimicrobial susceptibility of Typhoidal Salmonella (Salmonella enterica serovar Typhi and Paratyphi) (TS) with diarrhea between urban and rural Bangladesh.

Methods

Relevant information of 77/25,767 (0.30%) and 290/17,622 (1.65%) patients positive with TS (in stool) were extracted from the data archive of Diarrheal Disease Surveillance System of icddr,b (urban Dhaka and rural Matlab Hospitals respectively) during 2000–2012. Comparison group (diarrhea patients negative for TS) was randomly selected from the database (1:3 ratio). Two poisson regression models were investigated for modelling seasonal effects on the number of cases.

Results

Salmonella Typhi was more frequently isolated in Dhaka than Matlab (57% vs. 5%, p < 0.001); while Salmonella Paratyphi was more frequent in Matlab than Dhaka (96% vs. 43%; p < 0.001). Fever [adj. OR-5.86 (95% CI: 2.16, 15.94)], antimicrobial use at home [5.08 (2.60, 9.90)], and fecal red blood cells [2.53 (1.38, 4.64)] were significantly associated with detection of TS in stool of patient from Dhaka. For Matlab, the correlates were, vomiting [1.88 (1.35, 2.64)], fecal macrophage [1.89 (1.29, 2.74)] in addition to fever and duration of diarrhea and antimicrobial use. At Dhaka, all Salmonella Typhi isolates were susceptible to ceftriaxone; while in Dhaka and Matlab however, for ciprofloxacin it was 45% and 91%, respectively. Susceptibility to chloramphenicol, ampicillin, trimethoprim-sulphamethoxazole and nalidixic acid ranged from 12%-58%. Salmonella Paratyphi were susceptible to ceftriaxone (99%). A significant seasonal trend and year difference (before and after 2007) for Matlab was observed (p < 0.001 for all effects). Dhaka does not show significant year or seasonal effects (p = 0.07 for years and p = 0.81 and p = 0.18 for the cos and sin components, respectively). While not significant, two seasonal peaks were observed in Dhaka (January-February and September-November); while a single peak (August-November) was observed in Matlab.

Conclusions

Proportion of serovar distribution of TS and their clinical characteristics, antimicrobial susceptibility and seasonal pattern were different among diarrhea patients in urban Dhaka and rural Matlab of Bangladesh.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2334-14-435) contains supplementary material, which is available to authorized users.