Molecular xenomonitoring (MX) and transmission assessment survey (TAS) of lymphatic filariasis elimination in two villages, Menoufyia Governorate, Egypt.

Lymphatic filariasis (LF) is focally endemic in Egypt where the female mosquito, Culex pipiens, is responsible for its transmission. The aim of the study was to investigate the impact of implementation of the 13th round of MDA in two Egyptian villages in the Menoufyia Governorate area after failing the transmission assessment survey (TAS) in 2005 using two methods, and to decide whether it is safe to stop MDA in these, as well as in similar implementation units (IUs). To achieve this aim, both the immunochromatographic card test (ICT) and molecular xenomonitoring (MX) techniques were employed. A cross-sectional study was carried out in the villages in 2014 with two sections: Section (1): a school-based survey where all the primary school entrants (6-7) years of age were tested by ICT. Section (2): a mosquito-based survey where a total of 152 mosquito pools collected from Samalay and 167 from Kafr El-Tarainah were tested for the presence of the gDNA of Wuchereria bancrofti microfilaria by real-time PCR assays. The results revealed that all primary school children in both villages were 100% negative for antigenemia. Also, all mosquito pools were 100% negative for the microfilarial gDNA.

Surveillance of lymphatic filariasis 5 years after stopping mass drug administration in Menoufiya Governorate, Egypt.

The World Health Organization recommends that before lymphatic filariasis elimination in an area can be confirmed, an additional survey should be performed at least 5 years after stopping mass drug administration. The current study aimed to determine the status of lymphatic filariasis 5 years after cessation ofthe mass drug administration in 3 sentinel Egyptian villages in Menoufiya Governorate. The rapid immunochromatographic card test (ICT) and a new commercial antibody detection kit (CELISA®) were used. All 1321 primary-school children aged 6-7 years old were ICT negative but 27 children were antibody positive. All households surveyed in one village with the highest antibody prevalence were ICT negative, indicating an absence of lymphatic filariasis. The CELISA antibody kit needs more standardization and development to be useful under field conditions. We conclude that lymphatic filariasis is no longer a public health problem in these villages and other villages with similar epidemiological conditions.

Surveillance of lymphatic filariasis 5 years after stopping mass drug administration in Menoufiya governorate, Egypt

توصي منظمة الصحة العالمية بإجراء مسوحات إضافية بعد مرور 5 سنوات على الأقل على إيقاف الإعطاء الجموعي للأدوية قبل تأكيد التخلص من داء الخيطيات اللمفاوي. وتهدف الدراسة الحالية إلى التعرف على الوضع الذي آل إليه داء الخيطيات اللمفاوي بعد مرور 5 سنوات على إيقاف إعطاء الأدوية الجموعي في 3 قرى خافرة في محافظة المنوفية في مصر. واستخدم الباحثون اختبار البطاقة السريعة للاستشراب المناعي ICT، وحقيبة تجارية لكشف الأضداد هي سيليسا [CELISA[R]. واتضح للباحثين أن جميع الأطفال في المرحلة الابتدائية والذين تتراوح أعمارهم بين 6 - 7 سنوات وعددهم 1321 طفا كانوا سلبيين، وأن هناك 27 طفلا لديهم إيجابية في الأضداد. كما أن جميع الأسر التي أجري المسح عليها في إحدى القرى التي كانت الأعلى من حيث معدل انتشار الأضداد كانوا سلبيين باختبار البطاقة السريعة الاستشراب المناعي، مما يشير إلى غياب داء الخيطيات اللمفاوي. أما حقيبة سيليسا التجارية فتحتاج إلى المزيد من المعايرة والتطور حتى تصبح مفيدة في العمل الميداني. واستنتج الباحثون أن داء الخيطيات اللمفاوي لم يعد من مشكلات الصحة العامة في هذه القرى وفي القرى الأخرى التي تشابهها في الظروف الوبائية

ABSTRACT The World Health Organization recommends that before lymphatic filariasis elimination in an area can be confirmed, an additional survey should be performed at least 5 years after stopping mass drug administration. The current study aimed to determine the status of lymphatic filariasis 5 years after cessation of the mass drug administration in 3 sentinel Egyptian villages in Menoufiya Governorate. The rapid immunochromatographic card test (ICT) and a new commercial antibody detection kit (CELISA®) were used. All 1321 primary-school children aged 6–7 years old were ICT negative but 27 children were antibody positive. All households surveyed in one village with the highest antibody prevalence were ICT negative, indicating an absence of lymphatic filariasis. The CELISA antibody kit needs more standardization and development to be useful under field conditions. We conclude that lymphatic filariasis is no longer a public health problem in these villages and other villages with similar epidemiological conditions.

RÉSUMÉ L'Organisation mondiale de la Santé recommande de mener une enquête supplémentaire au moins cinq ans après l'arrêt de l'administration massive de médicaments avant de confirmer l'élimination de la filariose lymphatique dans une zone donnée. La présente étude visait à déterminer le statut de la filariose lymphatique cinq ans après l'arrêt de l'administration massive de médicaments dans trois villages sentinelles égyptiens du Gouvernorat de Menoufiya. Le test immunochromatographique sur carte (ICT) rapide et un nouveau kit de détection d'anticorps commercial (CELISA®) ont été utilisés. L'ensemble des 1321 écoliers du primaire âgés de 6 à 7 ans avaient des résultats négatifs à l'ICT mais 27 enfants avaient des résultats positifs aux anticorps. Tous les ménages qui ont fait l'objet d'une enquête dans un village où la prévalence des anticorps était la plus élevée ont eu des résultats négatifs à l'ICT, ce qui indique une absence de filariose lymphatique. Le kit de détection d'anticorps CELISA doit faire l'objet d'un développement et d'une normalisation plus poussés pour être utile dans des conditions de terrain. Nous en concluons que la filariose lymphatique ne représente plus un problème de santé publique dans ces villages ainsi que dans d'autres villages ayant des conditions épidémiologiques similaires.