Prevalence of Soil-Transmitted Helminths at Baseline and after Albendazole Treatment in the School-Age Children of Forcibly Displaced Myanmar Nationals in Bangladesh

Abstract

The forcibly displaced Myanmar nationals (FDMNs) known as Rohingya refugees are the largest group of stateless individuals globally. According to the emergencies humanitarian actors at the United Nations Office for the Coordination of Humanitarian Affairs, the worldwide refugee crisis involving FDMNs is intensifying at the fastest rate in history. Growing public health demands are being exacerbated by current difficulties in addressing poor access to health services, severe food shortages, and a lack of adequate housing. Infectious diseases constitute a major public health emergency in this vulnerable population. A study was carried out in FDMN children to investigate common soil-transmitted helminth (STH) infection at the time of enrollment and prospectively followed-up to 12 months after 2 doses albendazole treatment. At baseline, the prevalence of STH infection with at least one species was found to be 91.7% and 87.3% for Kato-Katz (KK) and quantitative polymerase chain reaction (qPCR) methods, respectively. Similarly, for follow-up children, the overall infection rate was 95.3% and 91.5%, respectively. Trichuris trichiura was the most predominant STH infection by both KK (baseline 87%, follow-up 89.1%) and qPCR (baseline 77.5%, follow-up 82.9%). The overall prevalence of stunting in the children was 37.8% at baseline and rose to 51.3% at 12 months. Alpha-1 antitrypsin (r = 0.13, P = 0.01) and myeloperoxidase (r = 0.12, P = 0.01) levels showed a positive correlation with Aascaris lumbricoides egg count per gram at baseline. An in-depth investigation is urgently needed to identify the underlying protective measures and the root cause of STH infections to improve the health of FDMN children.

Figure 1.

Study design flow diagram. MUAC = mid-upper arm circumference; qPCR = quantitative polymerase chain reaction; STH = soil-transmitted helminth.

Figure 2.

Euler diagram of co-infections detected by Kato–Katz (KK) and quantitative polymerase chain reaction (qPCR) methods. Soil-transmitted helminth egg or DNA were detected in stool samples collected from forcibly displaced Myanmar national children in Bangladesh using KK or multiplex qPCR for both baseline and follow-up (N = 386).

Figure 3.

Observed soil-transmitted helminth (STH) infection intensity prevalence by Kato–Katz as per WHO STHs eggs count guidelines. Prevalence was estimated from stool samples collected from forcibly displaced Myanmar national children for both baseline and follow-up.

Figure 4.

Overview of diagnostic performance of soil-transmitted helminth (STH) species determined by KK and multiplex real-time qPCR methods. The bar graph illustrates the % prevalence of STH infestation in individuals as determined by two methods. KK = Kato–Katz; qPCR = quantitative polymerase chain reaction.

Figure 5.

Relationship between cycle threshold (Ct) values measured by multiplex quantitative polymerase chain reaction (qPCR) and eggs per gram detected using Kato–Katz (KK). Soil-transmitted helminth egg or DNA was detected by KK and multiplex qPCR in stool samples collected from forcibly displaced Myanmar national children aged 6–16 years in Bangladesh. The Spearman correlation between eggs per gram and Ct values was –0.35 in baseline and –0.31 in follow-up for Ascaris lumbricoides (P < 0.001), and for Trichuris trichiura, it was –0.15 (P = 0.01) at baseline and –0.17 (P = 0.003) at follow-up.

Figure 6.

Correlation analyses between levels of fecal biomarkers (A1AT and MPO) with soil-transmitted helminth species egg count per gram for both baseline (A–F) and follow-up (G–L) samples. Spearman’s correlation coefficient was calculated for P values. A1AT = alpha-1 antitrypsin; MPO = myeloperoxidase.