Human cystic echinococcosis in Morocco: Ultrasound screening in the Mid Atlas through an Italian-Moroccan partnership

Abstract

BackgroundCystic echinococcosis (CE) is a neglected parasitic zoonosis with considerable socioeconomic impact on affected pastoral communities. CE is endemic throughout the Mediterranean, including Morocco, where the Mid Atlas is the most prevalent area for both human and animal infection. The highest hospital annual incidence of human CE is recorded in the provinces of Ifrane and El Hajeb. However, hospital-based statistics likely underestimate the real prevalence of infection, as a proportion of cases never reach medical attention or official records.Methodology/Principal findingsIn 2012, a project on clinical management of CE in Morocco was launched with the aims of estimating the prevalence of human abdominal CE in selected rural communes of the above mentioned provinces using ultrasound (US) screening and training local physicians to implement US-based focused assessment and rational clinical management of CE according to the WHO-IWGE Expert Consensus. A total of 5367 people received abdominal US during four campaigns in April-May 2014. During the campaigns, 24 local general practitioners received >24 hours of hands-on training and 143 health education sessions were organized for local communities. We found an overall CE prevalence of 1.9%, with significantly higher values in the rural communes of Ifrane than El Hajeb (2.6% vs 1.3%; p<0.001). CE cysts were predominantly in inactive stage, especially in older age groups. However, active cysts were present also in adults, indicating acquisition of infection at all ages. Province of residence was the only risk factor consistently associated with CE infection.Conclusions/SignificanceOur results show a high prevalence and on-going, likely environmental transmission of CE in the investigated provinces of Morocco, supporting the implementation of control activities in the area by national health authorities and encouraging the acceptance and divulgation of diagnosis and treatment algorithms based on imaging for CE at both national and local level.

Potential risk factors associated with human cystic echinococcosis: a semi-structured questionnaire from a large population-based ultrasound cross-sectional study in Eastern Europe and Turkey

“…Our results are overall in line with those of the systematic review of Possenti and colleagues [14], and with the recent work carried out in Peru and Morocco [15, 16], individuating environmental contamination and likely “hand-to-mouth” transmission as the main factor responsible for CE transmission, while food/water source attribution likely not of primary importance.…”

“…Owned dog-related factors (owing dogs and length of dog ownership, reason for keeping dogs, allowing dogs to roam or enter the house, antiparasitic treatment of dogs) were not found associated with odds of human infection. This may result from the dog husbandry habits in the investigated areas, which may allow environmental contamination with parasite eggs even outside the premises of the interviewed person; also a variable meaning of “owing” a dog in different areas, as also noted in previous studies, may have influenced this result [15]. Food/drinking water-related factors such as consumption of unwashed vegetables and of potentially unsafe water were also not associated with increased odds of human infection.…”

“…This transmission cycle is perpetuated by the habit of giving raw viscera to dogs, individuated as a risk factor of borderline significance in our analysis, as it induces dog infection and in turn environmental contamination through shedding of infected feces. The fact that another habit potentially favouring the transmission of E. granulosus to dogs, that is home slaughtering of livestock, was not associated with increased odds of infection may be due to the common habit of obtaining viscera to feed dogs even if the household did not own and/or did not carry out informal slaughter, as also occurs in other geographical areas [15]. The risk deriving from environmental contamination appears reduced by socio-economic related factors: in our analysis, having a high education and drinking commercial water were associated with reduced odds of infection.…”

“…The same systematic review also found that factors related to habits involved in the perpetuation of the parasite life cycle (type of slaughtering, feeding dogs with raw viscera) were associated with increased risk of infection with variable statistical significance, while food- and water-borne pathways of transmission did not appear to impact significantly on human risk of acquiring CE [14]. Environmental contamination was identified as the main factor associated with CE infection also in more recent cross-sectional surveys carried out in endemic areas of Morocco [15] and Peru [16]. Factors associated with both parasite life cycle perpetuation and transmission through food or water were, on the contrary, reported as significantly associated with household risk of human CE in a recent Chinese study [17].…”

Watch and Wait Approach for Inactive Echinococcal Cyst of the Liver: An Update

“…9 Additional fieldwork confirmed these observations, and results of two studies focusing on the long-term follow-up of spontaneously inactivated cysts on a clinical rather than epidemiological basis, provided support to this line of conduct. [6][7][8][13][14][15][16] Hosch and others analyzed cyst material using light microscopy and ex-vivo magnetic resonance (MR) spectroscopy, and found that in CE4 and CE5 cysts no viable protoscoleces were seen on microscopy and a nonviable metabolic profile was seen on MR spectroscopy. 17 Although limited by the small sample size and the lack of information on the spontaneous or induced inactivation of CE4-CE5 cysts, and considering that light microcopy focusing on protoscolices could not provide accurate data on the viability of the germinal layer, this seminal work provides further support to field and clinical observations.…”