Spatial distribution and ecological niche modeling of geographical spread of Anopheles gambiae complex in Nigeria using real time data.

The need for evidence-based data, to inform policy decisions on malaria vector control interventions in Nigeria, necessitated the establishment of mosquito surveillance sites in a few States in Nigeria. In order to make evidence-based-decisions, predictive studies using available data becomes imperative. We therefore predict the distribution of the major members of the Anopheles gambiae s.l. in Nigeria. Immature stages of Anopheles were collected from 72 study locations which span throughout the year 2020 resulted in the identification of over 60,000 Anopheline mosquitoes. Of these, 716 breeding sites were identified with the presence of one or more vector species from the An. gambiae complex and were subsequently used for modelling the potential geographical distribution of these important malaria vectors. Maximum Entropy (MaxEnt) distribution modeling was used to predict their potentially suitable vector habitats across Nigeria. A total of 23 environmental variables (19 bioclimatic and four topographic) were used in the model resulting in maps of the potential geographical distribution of three dominant vector species under current climatic conditions. Members of the An. gambiae complex dominated the collections (98%) with Anopheles stephensi, Anopheles coustani, Anopheles funestus, Anopheles moucheti, Anopheles nilli also present. An almost equal distribution of the two efficient vectors of malaria, An. gambiae and Anopheles coluzzii, were observed across the 12 states included in the survey. Anopheles gambiae and Anopheles coluzzii had almost equal, well distributed habitat suitability patterns with the latter having a slight range expansion. However, the central part of Nigeria (Abuja) and some highly elevated areas (Jos) in the savannah appear not suitable for the proliferation of these species. The most suitable habitat for Anopheles arabiensis was mainly in the South-west and North-east. The results of this study provide a baseline allowing decision makers to monitor the distribution of these species and establish a management plan for future national mosquito surveillance and control programs in Nigeria.

Intensity and clinical morbidities of tungiasis in an impoverished south-west Nigerian community.

Sand fleas infestation, Tunga penetrans, remains a neglected tropical disease of public-health concern in many countries. Tungiasis can lead to destruction of the feet causing serious discomfort and deformities. This study aim was to determine the intensity rate and clinical morbidities of tungiasis among the people living in Igbokoda, Ondo State, Nigeria. A community-based cross-sectional survey was conducted among households in three villages in Igbokoda. Hands and feet of selected household members were examined, while fleas on different floor types of houses were sampled by soil collection and extraction by tullgren funnel method. Sand fleas were equally sampled from legs of infested individuals by hand picking. Intensity was determined in terms of number of lesions and fleas in different floor-types. Tungiasis-associated morbidities was assessed using acute and chronic lesions severity scores. The study revealed that moderate infestation was observed in 173 infested individuals and severe infestation in 16 infested individuals. A total of 5293 lesions was observed out of which 3098 were viable. The flea burdens on sampled floors and legs were 127 and 146 fleas respectively occurring mostly in unpaved veranda and rooms (65 and 62 fleas respectively). Tungiasis lesions observed in males were more intense compared to females. Flea lesions and burdens with respect to age stratification and location were significant P < 0.0001. Difficulty in walking, pain upon pressure and deformation of the feet were the most common tungiasis-associated morbidity recorded. Also, tungiasis-associated morbidities, and flea number sampled on legs and on floor of environment were reportedly intense. Therefore, scaling up an appropriate and affordable intervention approach targeted at the fleas would serve as a relief to the scourge of tungiasis in Igbokoda community.

Evaluating the potentials of randomised integrated control trial on tungiasis in a South-western Nigerian community.

Considering the fact that new, safe and incorporable treatment alternatives to therapeutic prophylaxis for tungiasis are lacking and sometimes proving difficult, this present study evaluated the potentials of integrating control approach involving focal premise treatment using 5% emulsifiable concentrate of cypermethrin, and topical application of Piper guineense oil with personal protection. Of the 90 houses selected, their floors were classified into paved rooms & unpaved verandas, paved verandas & unpaved rooms, paved rooms & verandas, and unpaved rooms & verandas, and tested for the presence of sand fleas using the sweeping and beating as well as soil collection and extraction by tullgren funnel method before fumigation. A total of 100 individuals partitioned into four groups of 25 individuals each were assigned 3%, 5%, 10% and 15% of P. guineense oil irrespective of stages of embedded fleas. The mean of sand fleas decreased from 1.14, 0.07, 0.21, and 1.66 to 0.37, 0.02, 0.09 and 1.08 after two weeks of single spray compared to the untreated location (p <  0.001). Furthermore, the mean lesions of stage I reduced to 0 after 2 to 6 days of 3%, 5%, 10% and 15% ointment application, and stage II and III after 10 to 12 days of 10% and 15% application respectively. The difference between tungiasis stages and exposure time for P. guineense ointment was highly significant p = 0.007 and p = 0.0002. Notable reduction in severity score of acute and chronic tungiasis was observed thus indicating effectiveness of the topical ointment. Hexanolic oil extracts of P. guineense in 10% and 15% concentration would kill embedded sand flea and ameliorate the sufferings in endemic settings.

Assessing the potentials of two local topical ointments as affordable treatment against tungiasis infestation: A self-experimentation in Igbokoda, Nigeria.

Infestations caused by penetration of Tunga penetrans (Siphonaptera: Hectopsyllidae) in cutaneous sub-layers present morbidities and resulting mortalities if surgical treatment remains the obtainable. Considering the neglected nature of this infestation and the absence of marketable product, we report an observation on the use of grounded naphthalene in kerosene ointment, and powder of Piper guineense in coconut oil ointment as affordable treatment of embedded tungiasis flea in Igbokoda. A total of 80 individuals partitioned into two groups of 40 individuals each were assigned the locally made topical ointment irrespective of stages of tungiasis lesions. The mean of stage I, II and III tungiasis lesions treated with grounded naphthalene in kerosene ointment respectively decreased from 1.83, 3.42 and 3.89 to 0 after 5-6 days (p < .05). Also, the mean of stage I, II and III tungiasis lesions treated with grounded P. guineense ointment respectively decreased from 1.52, 3.10 and 5.00 to 0 after 6 to 7 days of treatment exposure (p < .05). Very high significant difference between stages and exposure days of participants assigned the two topical ointment was recorded p < .0001 and p = .0005 respectively. Naphthalene ointment and to a lesser extent P. guineense ointment is best to control and hinder development cycle of embedded fleas irrespective of infested part and stage of infection.