Scabies and impetigo in Samoa: A school-based clinical and molecular epidemiological study

Abstract

Background Common infections of the skin such as impetigo and scabies represent a large burden of disease globally, being particularly prevalent in tropical and resource-limited settings. Efforts to address these infections through mass drug administrations have recently been shown as efficacious and safe. In Samoa, a Pacific Island nation, there is a marked lack of epidemiological data for these neglected tropical diseases, or appreciation of their drivers in this setting. Methods An observational, cross-sectional survey of children aged between 4 and 15 years attending primary schools in rural areas of Upolu Island, Samoa was carried out to assess the prevalence of impetigo and scabies in schoolchildren residing in rural Samoa, integrated with descriptive epidemiological and microbial genomic data. A phylogenetic assessment of local Staphylococcus aureus isolated from Samoan schoolchildren was performed to estimate putative community transmission. Findings In this survey, the prevalence of impetigo observed in Samoan schoolchildren was one of the highest described globally (57•1%, 95% CI [53•8–60•5%], 476/833). Associations between active impetigo and age and gender were noted, with younger children and males more commonly affected (aOR2•8 [1•8-4•7]and aOR1•8 [1•3-2•5], respectively). The prevalence of scabies was similar to that seen in other South Pacific island countries (14•4%, 95% CI [12•2–17•0%], 120/833). Transmission of S. aureus was predicted, primarily between those children attending the same school. Carriage of S. pyogenes was notably low, with pharyngeal carriage observed in less than 2% of schoolchildren, consistent with earlier studies from Samoa. Interpretation This study describes a considerable burden of disease attributed to impetigo and scabies in Samoa. These findings will be valuable in addressing the public health challenge posed by these conditions, providing baseline prevalence data and highlighting practical strategies to reduce transmission of relevant microbes and parasites in this setting. Tala Tomua O a’afiaga o le pa’u i fa’ama’i o le po’u (impetigo) ma le utu o le pa’u (scabies), ua tele naua le fanau ua maua ai i le pasefika, ma le lalolagi atoa. O fuafuaga vaai mamao ma polokalame e fofoina ai nei faafitauli, e aofia ai le inumaga o fualaau e tapeina ai nei fa’ama’i, ua aliali mai ai e mafai ona faatamaia nei fa’ama’i. E le o tele ni tusitusiga ma faamaumauga i totonu o Samoa, pe ta’atele nei fa’amai o le pa’u pe leai. Ona o le le faatauaina o nei fa’ama’i, e le o iloa fo’i ni mafuaga ma nisi tulaga e faateleina ai nei fa’ama’i o le pa’u i Samoa. Faatinoina o le suesuega O le suesuega faasaenisi i le fanau aoga i le va o le 4 ma le 15 tausaga o loo ao’oga i le tulaga lua i nisi o nu’u i tua i Upolu, na faatinoina ai suesuega lea, ia suesuei...

Addressing normalization using culturally relevant approaches: An important adjunct to reducing the burden of impetigo and scabies

“…Impetigo, a bacterial infection caused by Streptococcus pyogenes (6•0% in this study) and S. aureus (24•2%) of the superficial dermis affects up to 162 million children at any one time [3] . Three out of every five school-children in Samoa have active or recently healed impetigo, far higher than the global median impetigo prevalence at 12•3% (IQR 4•2–19•4%), surpassing previous estimates for the Oceania region (excluding Australia and New Zealand: 29•7%, IQR 17•2–48•1%) [3] which correlate more closely to active impetigo (purulent or crusted) reported [1] . Although not part of the initial survey design, the researchers sought treatment for children with severe impetigo and scabies – an important consideration to incorporate in the design of all skin infection surveillance studies.…”

“…Skin infections are confirmed as a public health priority not a benign, nuisance condition normalised by families and healthcare professionals [2] . The impetigo prevalence is amongst the highest in the world at 57 • 1% (95% CI 53 • 8-60 • 5%) with active (or highly transmissible) impetigo affecting almost one in three school children ( [3] which correlate more closely to active impetigo (purulent or crusted) reported [1] . Although not part of the initial survey design, the researchers sought treatment for children with severe impetigo and scabies -an important consideration to incorporate in the design of all skin infection surveillance studies.…”

“…Taiaroa and colleagues report high impetigo and scabies prevalence from a cross sectional, observational study among school children in rural Samoa [1] . Skin infections are confirmed as a public health priority not a benign, nuisance condition normalised by families and healthcare professionals [2] .…”

“…Scabies treatment may reduce the burden of both scabies and impetigo. Mass Drug Administration (MDA) provides a rapid and effective response to scabies, albeit with implementation challenges [1] . MDA of ivermectin for scabies was effective and also reduced impetigo prevalence at 12 and sustained at 24 months without additional antibacterial treatment [6] .…”

Microbial Contamination Survey of Environmental Fresh and Saltwater Resources of Upolu Island, Samoa

“…The pathogenic species S. aureus was detected in one in six FW samples; this bacterium can lead to wound and blood infections, and has the ability to acquire antibiotic resistance (e.g., MRSA), presenting a major threat in areas with lower health system standards [41,42]. A recent study of impetigo infections in school children of the Faleaili district in south Samoa reported a 57.1% infection rate in children that coincided with Staphylococci contaminated sites (Figure 3B), namely Lotofaga and Taofatila [43]. These high incidence rates of infections suggest an endemic issue that is partially supported by our findings.…”