Spatiotemporal and seasonal transmission dynamics of Schistosoma haematobium and snail infectivity in Ase River catchment, Delta State, Nigeria.

Bulinus are intermediate snail hosts of Schistosoma haematobium. Despite their vectorial role, the transmission dynamics and infectivity of these intermediate snail hosts remain understudied in the Ase River. This longitudinal study evaluated the geospatial and seasonal transmission patterns and infectivity of three S. haematobium vectors between November 2020 and October 2022 in the Ase River catchment, Delta State, Nigeria. Eleven (11) geospatial water contact coordinates were mapped for monthly spatiotemporal collection of Bulinus species along the Ase River and its catchment, for two years. Snail sampling was performed for 45 min at each study site using scooping/hand-picking techniques and subsequently counted, identified and recorded. Snails of the Bulinus genus were individually placed in a beaker containing distilled water and exposed to light to shed cercariae which were identified to be human schistosome type. The number of infected snails for each month and season was also documented to analyze the spatiotemporal and seasonal transmission dynamics of infectivity. Out of the 2345 Bulinus snails collected, a total of 41.45% were found to be infected with S. haematobium. The monthly infectivity of Bulinus snails varied significantly (P < 0.05) throughout the study period (P = < 0.0001; F = 23.11; df = 11). Further analysis showed a strong significant association (χ2 = 23.57; df = 11; p = 0.015) between the study years. The Principal Component Analysis (PCA) results suggest that Bulinus infectivity within the Ase River catchment area was primarily associated with the months of February and January. B. truncatus consistently had the highest transmission potential, followed by B. globosus and B. senegalensis. ANOVA confirms that the monthly/study site infectivity and transmission potential in B. truncates, B. globosus and S. senegalensis were statistically, significant (P < 0.05). These results demonstrated a clear distinction in the patterns and relationships between the different months in terms of snail infectivity and seasonal transmission potential. This understanding will help in the continuous monitoring and targeted interventions to control schistosomiasis transmission in Ase River.

Evaluating Malaria Prevalence Using Clinical Diagnosis Compared with Microscopy and Rapid Diagnostic Tests in a Tertiary Healthcare Facility in Rivers State, Nigeria.

The World Health Organization's policy on laboratory test of all suspected malaria cases before treatment has not yielded significant effects in several rural areas of Sub-Saharan Africa due to inadequate diagnostic infrastructure, leading to high morbidity and mortality rates. A cross-sectional randomized study was conducted to evaluate the validity of clinical malaria diagnosis through comparison with microscopy and rapid diagnostic test kits (RDTs) using 1000 consenting outpatients of a tertiary hospital in Nigeria. Physicians conducted clinical diagnosis, and blood samples were collected through venous procedure and analyzed for malaria parasites using Giemsa microscopy and RDT kits. Microscopy was considered the diagnostic "gold standard" and all data obtained were statistically analyzed using Chi-square test with a P value <0.05 considered significant. Malaria prevalence values of 20.1%, 43.1%, and 29.7% were obtained for clinical diagnosis, microscopy, and RDTs, respectively (P < 0.05). Values of 47.2%, 95.9%, and 77.8% were obtained for sensitivity, specificity, and diagnostic accuracy, respectively, in clinical diagnosis, while RDTs had sensitivity, specificity, and diagnostic accuracy values of 73.7%, 97.3%, and 88.3%, respectively, when compared to microscopy (P < 0.05). Clinical diagnosed malaria cases should be confirmed with a parasite-based laboratory diagnosis and more qualitative research is needed to explore why clinicians still use clinical diagnosis despite reported cases of its ineffectiveness.

Evaluation of the effectiveness and compliance of intermittent preventive treatment (IPT) in the control of malaria in pregnant women in south eastern Nigeria.

Controlling malaria in pregnancy has been an important component of the millennium development goal and intermittent preventive treatment (IPT) is considered an important tool in controlling malaria among pregnant women. In this study, we evaluated the level of compliance to IPT use as well as its effect on malaria infection among pregnant women attending antenatal clinic in south eastern Nigeria. Peripheral blood smears and placental histology were used as diagnostic tools to determine infection rate. Our data show that compliance to IPT use was poor (33%) when compared with non-compliance (67%). Infection rate was significantly lower among IPT users (39%) than in non-users (71%) (X(2) = 39·95; P<0·05). Maternal anaemia was also lower in IPT users (4%) than in non-users (18%). Taken together, IPT use appears to be important in reducing infection rate and maternal anaemia. Therefore, its adoption is highly recommended and this could be improved through public enlightenment campaign and adequate funding.

The effects of quarry mining on the epidemiology of Schistosoma haematobium in schoolchildren, in Ishiagu, south-eastern Nigeria.

Over the last two decades there has been a noticeable increase in the activities of quarry-mining companies in the Ishiagu area of south-eastern Nigeria. These activities have produced an ever-growing number of abandoned quarry pits that usually quickly fill with water and appear to become suitable habitats for the freshwater snails that may act as intermediate hosts of Schistosoma haematobium. To examine the potential role of quarry mining on the prevalence of urinary schistosomiasis caused by S. haematobium, urine samples were collected from 1819 schoolchildren in northern Ishiagu (an area with intense mining activities and many quarry pits) and from 252 schoolchildren in southern Ishiagu (an area with no mining activity or quarry pits). When these 2071 samples were checked for schistosome eggs, 1005 (48.5%) were found positive and 252 (25.1%) of the infected children showed visible haematuria. The children from northern Ishiagu were much more likely to be infected than the children from the south (53.3% v. 13.9%; P<0.001). Curiously, only the children from northern Ishiagu showed a gender-related difference in prevalence that was statistically significant, with boys more likely to be infected than girls (60.9% v. 38.5%; P<0.001). Although the 'children' investigated varied in age from 5 to 20 years, no statistically significant increase or decrease in prevalence with age was apparent. Four species of snails (Bulinus globosus, B. rohlfsi, B. forskalii and B. senegalensis) were found in the overall study area but B. globosus was only found in the quarry pits in northern Ishiagu and never in the water bodies of southern Ishiagu. It does appear that quarry-mining activity in the Ishiagu area is a factor in the local epidemiology of urinary schistosomiasis, with the water bodies that form in the abandoned quarry pits serving as the principal foci of transmission.

Urinary schistosomiasis among school children in an endemic community in south-eastern Nigeria.

Studies were carried out on urinary schistosomiasis among school children aged 6 to 21 in Abia State, Nigeria. Of the total 1,165 children examined for eggs of S. haematobium in their urine, 245 (21.03%) were infected. Male children had significantly (P < 0.05) higher infection (64.08%) than their female counterparts (35.92%). Age-related infection rate showed significant difference (P < 0.05) with the highest infection rate (46.94%) recorded among children between the ages of 12 and 14 years. As with infection rate, the intensity of infection was significantly higher (P < 0.05) in males (35.50 eggs/10 ml urine) then in females (28.73 eggs/10 ml urine). 4 (1.63%) of the infected individuals had heavy infection (400 eggs/10 ml urine). There was a gradual increase of mean egg count with age up to 12-14 years after which there was a decrease. Viability test showed that of the 245 children infected 151 (61.63%) had viable eggs in their urine sample. The number of males with viable eggs (62.25%) was significantly higher (P < 0.05) than the females (37.74%). Also in the number of infected individuals with viable eggs a significant difference among age groups was observed. It was significantly higher (P < 0.05) among the age group 12-14 years than in any other group. Among the infected children 38 (15.51%) had haematuria (which represents 95% of the 41 individuals with trace of blood in their urine). There was a significant association (P < 0.05) between haematuria and infection rate/intensity.

Sustainable urban development and human health: septic tank as a major breeding habitat of mosquito vectors of human diseases in south-eastern Nigeria.

Septic tank mosquitoes in Abia State University Okigwe, south-eastern Nigeria were studied using exit traps between November 1988 and April 1989. The results were revealing and striking. Apart from the common septic tank mosquitoes, Culex p. quinquefasciatus, Cu. cinereus and Aedes aegypti, which have been previously commonly found breeding in ammonia and nitrate-rich waters of latrines and septic tanks, the other species, Cu. horridus, Cu. tigripes and Aedes vittatus, have not been commonly reported as colonizing septic tanks in Nigeria. Three out of these six mosquito species observed are vectors of human diseases: Aedes aegypti and Aedes vittatus are vectors of Yellow fever and Cu. p. quinquefasciatus is a potential vector of Bancroftian filariasis and a world-wide vector of various arboviruses. The fact that these mosquito vectors are able to breed in highly polluted waters of septic tanks during the harsh dry months when most surface water bodies are dry is epidemiologically important. The breeding of these mosquito vectors of human diseases around human dwellings indicates an intense man-vector contact creating a high level risk to the crowded urban population. The public health implications of this urbanization/modernization problem and solutions are discussed.

Aflatoxin and human diseases

Fungi invasion of our agricultural products and food lead to mouldiness and production of mycotoxin . These mycotoxin are toxic secondary metabolites elaborated by the fungi. They can cause diseases generally referred to as mycotoxicoses; the fungi per se are not involved in the disease process. One of such secondary metabolites of mouldiness is aflatoxin (which are exotoxin). The aflatoxin - producing species of fungi belong to the genus aspergillus Micheli 1729; which forms a large proportion of all the moulds encountered in our agricultural and industrial works. Their contamination of the foods and feeds (maize; sorghum; millet; rice; wheat soyabean etc) constitute an important toxicological hazard