Risk of adverse swallowing events and choking during deworming for preschool-aged children

Abstract

Author summary

To improve the health of young children with intestinal worm infections, the World Health Organization recommends that they periodically receive deworming medication. The medicines are safe and effective but young children occasionally choke on the chewable tablets. Rarely, this results in death. Consequently, the World Health Organization recommends that deworming tablets be crushed and given with water. To learn more about the risk of choking, we observed 1677 children 1–4 years of age being dewormed in 65 sites in India and Haiti. Of these, 18 children (1.1%) choked, none fatally. The most important factor associated with choking was giving a tablet to a child who was fussy, fearful or combative. Risk of choking could have been reduced by 79.5% if deworming was not forced on young children who were fussy, fearful, or combative or who resisted taking deworming medicine. Choking-related deaths in young children are preventable. Simple measures can reduce risk of choking and they should be more widely practiced by deworming programs for young children.

Introduction

Soil-transmitted helminthiasis (STH) is a group of parasitic diseases caused by the nematode worms Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm), Ancylostoma duodenale and Necator americanus (hookworm). The worms are transmitted to humans through fecal contamination of soil, either through skin penetration by larvae or through ingestion of embryonated eggs [1]. Although infection often results in subtle and non-specific symptoms such as malaise, nausea, and abdominal pain, STH is also associated with anemia, wasting, and impaired cognitive development [1–3]. More than one billion persons are affected by STH worldwide [4].

When the World Health Organization (WHO) launched its initiative to eliminate STH as a public health problem in 2001 [5], mass deworming, known as preventive chemotherapy, was focused largely on school-age children using schools as convenient, low-cost drug distribution posts [6]. In recognition of the inadequately addressed but significant public health burden of STH in younger children [7], WHO broadened its program to also emphasize at-risk preschool-age children (1–4 years, i.e., 12–59 months), with the aim of regularly reaching 75% with preventive chemotherapy by 2020 [8]. In 2015, 269 million children 1–4 years of age were considered at risk of STH and in need of preventive chemotherapy; an estimated 130 million (48%) were treated [9]. Many of these children were treated during “child health days,” in which deworming was provided with vitamin A supplements and other interventions [10].

The benefits of mass deworming are well-documented [1,2,7,11], although population-level effects may be hard to measure when STH prevalence is low [12–14]. Single doses of albendazole or mebendazole are safe and effective for preventive chemotherapy [15,16]. In STH-endemic countries, these drugs are most commonly available as chewable tablets. While more appropriate for young children than non-chewable tablets, chewable tablets for STH have been implicated in choking deaths of young children. The frequency with which this occurs in the context of preventive chemotherapy for STH is apparently low. However, the actual number is unknown because of the low sensitivity of serious adverse event (SAE) surveillance and the absence of a global reporting system for SAEs in young children being treated for STH. These factors hinder the collection of crucial information on the circumstances of the drug administration and subsequent events, making it difficult to draw accurate inferences regarding causality and, most importantly, to prevent further deaths.

Indirect sources provide a crude estimate of the magnitude of the problem. In 2007, WHO reported four fatal cases of choking in Ethiopian children who were given albendazole for STH [17]. Deaths related to preventive chemotherapy continue to be reported in the media [18], although it is difficult to be certain of causality in many of these cases. Between 2011 and 2016, the Children Without Worms program [19] was alerted, on average, to at least one suspected choking-related fatality every year (D. Addiss, personal communication). Anecdotally, these cases often occur when the child, struggling to resist taking a whole tablet, aspirates and the tablet lodges in the trachea. While one death per year represents a small number relative to the number of children dewormed [9], any such death is tragic and unacceptable.

Between 2004 and 2007, WHO issued three statements or recommendations for administering deworming medicine to young children in mass treatment settings. In 2004, WHO suggested that “the tablets can be crushed between two spoons and given with a glass of water for children that have difficulties in swallowing the tablets” (p. 13) [20]. In a 2007 document, Promoting Safety of Medicines for Children [17], WHO recommended that “scored tablets should be broken into smaller pieces or crushed for administration to young children; older children should be encouraged to chew tablets of albendazole” (p. 11). Age was not specified and the method of crushing the tablet was not indicated. Finally, in a 2007 edition of a Partnership for Parasite Control (PPC) newsletter, Action Against Worms [21], WHO recommended that, “For children under 3 years of age, tablets should be broken and crushed between two spoons, then water added to help administer the tablets (p. 7).” The document highlighted the need for training, supervision, and not forcing the child to take the medicine, and it recommended that drug distributors be trained in the Heimlich maneuver. Little is known about the extent to which the WHO recommendations are actually practiced.

Vitamin Angels, a non-governmental organization (NGO), provides vitamin A supplements and albendazole, as well as training in their administration, to hundreds of NGOs in countries that are co-endemic for STH and vitamin A deficiency [22]. Vitamin Angels recommends that its partner NGOs crush albendazole tablets for all children less than 59 months of age, using a heavy bottle or other object to crush the tablets inside a folded piece of clean paper. The crushed tablet is then poured from the paper into the mouth of the child [23].

Vitamin Angels also recommends specific infection control measures to reduce transmission of respiratory and other pathogens, since these organisms are readily spread in health care settings [24]. They stipulate that the service provider (the person administering the tablet) avoid physical contact with the child, wash his or her hands between children, use a clean piece of paper to administer the crushed tablet to each child, and dispose of the paper after each use [23].

We observed distributions of albendazole for STH to children 1–4 years of age in India and Haiti. The objectives were to: 1) evaluate the extent to which service providers are aware of and practice WHO recommendations for deworming preschool-age children; 2) document the incidence of, and identify risk factors for, adverse swallowing events, including choking; and 3) assess whether the approach recommended by Vitamin Angels is associated with a) greater likelihood of delivering the correct dose and the WHO-recommended form of albendazole (i.e., crushed, rather than whole, tablets for children 1–2 years of age); b) decreased risk of adverse swallowing events; and c) improved infection control practices. To address the third objective, observations were conducted both at sites affiliated with Vitamin Angels and those that were not.

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