Spatial Distribution of PCR-Identified Species of Anopheles gambiae senu lato (Diptera: Culicidae) Across Three Eco-Vegetational Zones in Cross River State, Nigeria.

Anopheles gambiae sensu lato complex (An. gambiae s.l.) describes a group of nine morphologically indistinguishable members that vary in their distribution, ability to transmit malaria, and susceptibility to pyrethroids. Here, we recorded the spatial patterns of PCR-identified An. gambiae s.l. complex species collected from four sites in Cross River State, Nigeria that represented three different ecological zones. Trapping was conducted between October 2015 and June 2016. Anopheles gambiae s.l. complex species identification was performed using species-specific primers followed by An. gambiae and An. coluzzii differentiation using the restriction fragment length polymorphism (RFLP) method. Bivariate and multivariate logistic regression models were used to identify ecological and seasonal variables closely associated with An. coluzzii and An. gambiae distribution. Out of 1,388 An. gambiae s.l. successfully amplified, 1,074 (77.4%) were An. coluzzii, 278 (20%) were An. gambiae, and 25 (1.8%) were hybrids (An. coluzzii/An. gambiae). A very small number of An. arabiensis (0.8%, n = 11) were also collected. Statistical analysis indicated that An. coluzzii is predominant in Guinea-savannah and tropical rainforest, and is highly associated with rainy seasons, while, An. gambiae is prevalent in mangrove swamp forest during dry seasons. Only 13 An. gambiae s.l. females were infected with Plasmodium falciparum (P. falciparum). The sporozoite infection rate was higher in mangrove swamp forest (53.8%, n = 7) than in rain forest (38.5%, n = 5) followed by Guinea-savannah (7.7%, n = 1) ecological zones. These results provide important insights for strategic planning of malaria control programs in Nigeria.

Ecological niche modeling for predicting the potential geographical distribution of Aedes species (Diptera: Culicidae): A case study of Enugu State, Nigeria.

Arbovirus transmission by Aedes mosquitoes has long been a significant problem in Africa. In West Africa, Aedes vector management faces significant challenges; lack of recent Aedes distributional data and potential distributional modeling hinder effective vector control and pose serious public health issues. In this study, larval and adult mosquitoes were collected from four study sites in Enugu State, Nigeria every other month between November 2017 and September 2018. A total number of 2997 Aedes mosquitoes were collected and identified, and 59 positive field occurrence points for both Aedes adult and larvae were recorded. A total of 18 positive occurrence points were used for modeling. Ecological Niche Models (ENMs) were used to estimate the current geographic distribution of Aedes species (spp.) in Enugu State, south-east Nigeria, and mosquito presence was used as a proxy for predicting risk of disease transmission. Maximum Entropy distribution modeling or "MaxEnt" was used for predicting the potential suitable habitats, using a portion of the occurrence records. A total of 23 environmental variables (19 bioclimatic and four topographic) were used to model the potential geographical distribution area under current climatic conditions. The most suitable habitat for Aedes spp. was predicted in the northern, central, and southeastern parts of Enugu State with some extensions in Anambra, Delta, and Edo States in the west, and Ebonyi State in the east. Seasonal temperature, precipitation of the wettest month, mean monthly temperature range, elevation, and precipitation of the driest months were the highest estimated main variable contributions associated with the distribution of Aedes spp. We found that Aedes spp. prefer to be situated in environmental conditions where precipitation of wettest month ranged from 265 to 330 mm, precipitation of driest quarter ranged from 25 to 75 mm while precipitation of wettest quarter ranged from 650 to 950 mm. Aedes mosquitoes, such as Ae. aegypti and Ae. albopictus, pose a significant threat to human health, hence, the results of this study will help decision makers to monitor the distribution of these species and establish a management plan for future national mosquito surveillance and control programs in Nigeria.

The impact of cinnarizine and griseofulvin on juvenile and adult stages of Schistosoma mansoni.

Schistosomiasis affects millions globally. There is no vaccine, and treatment depends entirely on praziquantel (PZQ). Field isolates exhibit reduced susceptibility to PZQ, and resistance has been experimentally induced, suggesting that reliance on a single treatment is particularly dangerous. The present study investigated the value of cinnarizine and griseofulvin against Schistosoma mansoni through their in vitro effects on adult worms and oviposition as well as in vivo evaluation in early and late infection, compared to PZQ, in a preliminary experimental model. In vitro, both cinnarizine and griseofulvin showed uncoupling, sluggish worm movement and complete absence of ova at 100 µg/ml. In early infection, cinnarizine showed a significant reduction in the number of porto-mesenteric couples compared to the griseofulvin and control groups, a finding similar to PZQ. Remarkably, cinnarizine significantly exceeded PZQ and griseofulvin in reducing the total worm burden. In late infection, cinnarizine and griseofulvin showed results similar to PZQ by significantly reducing the numbers of hepatic and porto-mesenteric couples and total worm burden compared to controls. Cinnarizine performed better than griseofulvin by reducing hepatic and intestinal ovum counts, and it led to complete disappearance of the first two immature stages. The current work suggests the possibility of using cinnarizine and griseofulvin, mainly in late S. mansoni infection, especially cinnarizine, which showed similar results to PZQ and surpassed it in early infection. Further studies are required to elucidate their exact mechanisms of action and particularly their synergistic effect with PZQ.

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.

Characterization of tachyzoite and bradyzoite antigens of Toxoplasma gondii recognized by immunoglobulins G, M and A in an experimental model of reactivated toxoplasmosis.

Toxoplasma gondii tachyzoite and bradyzoite antigens that are recognized during reactivated toxoplasmosis were studied in comparison with those recognized during acute and chronic infections, in murine models of toxoplasmosis. Both tachyzoite and bradyzoite antigens of the RH and KSU T. gondii strains, respectively, were resolved by sodium- dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) then probed by immunoblot (IB) (Western blot) with mice antisera elicited by different states of toxoplasmosis to allow parallel analysis of antigen recognition by immunoglobulin G, M, and A antibodies. T. gondii tachyzoite and bradyzoite antigens were well studied by IB recording some specific and commonly shared antigens. A complex array of T. gondii tachyzoite and bradyzoite antigens was revealed in the three states of toxoplasmosis. During reactivated toxoplasmosis the commonly shared tachyzoite and bradyzoite antigens were the dominantly recorded antigens. Also, antigens of tachyzoite at 48 KDa and bradyzoite at 40 KDa were recognized in reactivated toxoplasmosis by IgM and IgG, respectively, and not in other states by the same immunoglobulin. The virulent RH and avirulent KSU strains of T. gondii showed some similarities.