South Asian Journal of Parasitology

Leucocytozoonosis in Desi Birds and a Review on the Etiology of Anemia in Desi Birds

2026-09-16T06:43:54+00:00

Leucocytozoonosis is a haemoprotozoan disease of domestic and wild birds caused by species of the genus Leucocytozoon and transmitted by blood-sucking vectors. Indigenous desi chickens reared under extensive or semi-intensive backyard systems may experience substantial vector exposure and can present with non-specific signs of disease. This article describes a clinical case in a two-year-old male Aseel chicken presented with a pale comb, depression, anorexia, ruffled feathers, and open-mouth breathing. Examination of a Giemsa-stained peripheral blood smear demonstrated Leucocytozoon spp. gametocytes, while haematological findings showed reduced haemoglobin (8 g/dL) and packed cell volume (25%). The bird showed clinical improvement following treatment with primaquine in combination with sulfamethoxazole and trimethoprim, together with supportive therapy. The review component outlines the pathogenesis, diagnosis, treatment, and prevention of leucocytozoonosis and considers the broader differential aetiology of anaemia in desi birds. Major mechanisms discussed include haemorrhagic and haemolytic anaemia associated with trauma, gastrointestinal parasites, ectoparasites, and haemoparasites, as well as non-regenerative anaemia related to nutritional deficiency, chronic disease, toxins, and disorders affecting haematopoiesis. The case and review together emphasise differentiation between regenerative and non-regenerative mechanisms when evaluating anaemia in backyard poultry. An integrated diagnostic approach combining history, clinical examination, haematology, blood-smear assessment, parasitological investigation, and targeted infectious-disease testing is emphasised for case interpretation and flock-level management.

Parasitic Contamination of Nigerian Naira Notes: A Critical Narrative Review of Public Health Risks, Evidence Gaps and Control Implications

2026-09-23T12:48:46+00:00

Nigerian currency is exchanged repeatedly across households, markets, transport systems, food outlets, health facilities and informal workplaces, creating frequent opportunities for deposition and transfer of faecal and environmental material. Studies conducted in several Nigerian cities have repeatedly recovered helminth eggs, protozoan cysts and other parasitic stages from Naira notes, but the public health meaning of these findings is often overstated because detection on a banknote is not equivalent to viability, infectivity or demonstrated transmission. This critical narrative review synthesises Nigerian evidence on parasitic contamination of Naira notes, evaluates the biological plausibility of currency-mediated transmission, examines methodological limitations, and considers implications for hygiene, food safety, currency management and research. Literature published from 2000 to 19 July 2026 was prioritised, with earlier foundational evidence included when needed. Across studies, reported contamination has varied widely, from approximately 14% to above 60%, with recurrent detection of Ascaris lumbricoides, Enterobius vermicularis, hookworm, Trichuris trichiura, Entamoeba histolytica and Giardia species. Dirty, mutilated and intensively circulated notes tend to show higher contamination, and several studies suggest lower contamination on polymer than paper substrates. Nevertheless, the evidence base is dominated by small, cross-sectional convenience samples, inconsistent note-condition classifications, microscopy without molecular confirmation, limited quality control, and near-absence of viability or transfer experiments. Misidentification is a material concern, particularly for morphologically similar cysts, ova and artefacts. The strongest conclusion is therefore that Naira notes are credible markers and potential vehicles of faecal-environmental contamination, not that they are established major causes of parasitic disease. Public health responses should prioritise hand hygiene, safe food handling, avoidance of saliva-assisted counting, improved withdrawal of heavily soiled notes, and targeted risk communication without promoting unnecessary fear of cash. Future studies should combine molecular identification, viability assays, controlled transfer experiments and epidemiological linkage to determine whether contamination translates into infection risk under real Nigerian conditions.

Evidence of Ivermectin Resistance in Sarcoptes scabiei var. canis Infesting Dogs: A Clinical and in vitro Study

2026-09-02T13:07:03+00:00

Sarcoptic mange caused by Sarcoptes scabiei var. canis is a contagious canine dermatosis, and apparent ivermectin treatment failure raises concern about reduced acaricide susceptibility. This study evaluated the clinical response to a three-dose ivermectin protocol and compared in vitro ivermectin susceptibility between mites recovered from clinically refractory dogs and a reference susceptible isolate. Thirty naturally infested dogs received subcutaneous ivermectin at 300 µg/kg on days 0, 14, and 28, with serial skin scrapings and pruritus assessment through day 42. Mites from refractory dogs were pooled as a field-resistant isolate and tested against a susceptible isolate using ivermectin contact bioassays. Twenty-four dogs (80%) became mite-negative with more than 75% pruritus resolution, whereas six dogs (20%) remained mite-positive with less than 25% pruritus reduction and were classified as clinically refractory. At 1% ivermectin, 24-hour mortality was 34% in the field-resistant isolate compared with 91% in the susceptible isolate. The 24-hour LC₅₀ was 0.71% for the field-resistant isolate and 0.09% for the susceptible isolate, corresponding to a resistance ratio of approximately 7.9. LT₅₀ at 1% increased from 2.1 to 9.4 hours. These findings are consistent with a marked phenotypic reduction in ivermectin susceptibility associated with clinical treatment failure and support confirmatory follow-up testing, careful acaricide selection, and continued surveillance.

Investigating the Potential Role of Invasive Golden Apple Snail Pomacea canaliculata in the Transmission of Schistosomiasis in Mwea, Kirinyaga County, Kenya

2026-09-07T09:19:32+00:00

Schistosomiasis is a major public health challenge in irrigation-based communities. The recent establishment of the invasive snail, Pomacea canaliculata, within the Mwea Irrigation Scheme has raised concerns regarding its interaction with native vector snails and its potential influence on schistosomiasis transmission. However, its ecological relationship with native vector snails and the temporal patterns of reported human schistosomiasis following its establishment remain unclear. This study aimed to evaluate ecological and epidemiological evidence for the potential indirect role of P. canaliculata in schistosomiasis transmission by assessing its spatiotemporal distribution and abundance relative to native vector snails and examining temporal trends in reported human schistosomiasis following its establishment. A cross-sectional survey was conducted at 32 sites in irrigation canals and rice paddies during the rainy and dry seasons to assess snail distribution and abundance, while hospital surveillance records for 2019–2025 were analysed for temporal trends. Seasonal and habitat-related differences in snail abundance were assessed using non-parametric tests, while temporal trends in reported human schistosomiasis were evaluated using linear regression and Kendall’s tau correlation. P. canaliculata occurred at all 32 sites, with significantly higher abundance during the rainy season and in irrigation canals (p ≤ 0.05). Native vector snails were absent from 18 (56.2%) sites occupied by P. canaliculata and co-occurred at 14 (43.8%) sites. Reported human schistosomiasis cases declined by 86.7% between 2019 and 2025, with a significant overall temporal decline. The widespread establishment of P. canaliculata, its occurrence where native vector snails were absent, and the concurrent decline in reported human schistosomiasis following its establishment suggest a potential indirect role in transmission through ecological effects on native vector snail populations. However, temporal ecological changes cannot be established from a cross-sectional study. Longitudinal studies are therefore required to determine whether the continued establishment of P. canaliculata results in measurable changes in native vector snail populations and schistosomiasis transmission over time.

Malaria Parasitaemia among Pregnant Women Attending Antenatal Care in Minna, Nigeria: A Historical Cross-Sectional Study from 2008

2026-09-17T12:32:58+00:00

Background: Malaria remains an important health concern among pregnant women in sub-Saharan Africa, with substantial variation in infection prevalence across populations, locations and diagnostic approaches. Historical data can provide useful epidemiological context for understanding past malaria burden and patterns. However, documented evidence from pregnant women attending antenatal care in Minna, Nigeria, during the earlier period remains limited, warranting analysis of the available 2008 dataset.

Aims: To describe the prevalence and distribution of microscopy-detected Plasmodium infection among pregnant women attending antenatal care at Minna General Hospital, Niger State, Nigeria, between May and July 2008, using the surviving historical aggregate data.

Study design: Historical cross-sectional design.

Place and Duration of Study: Department of Medical Laboratory Science and Antenatal Clinic, Minna General Hospital, Minna, Niger State, Nigeria, between May and July 2008.

Methodology: A total of 230 pregnant women were included. Information on malaria positivity, maternal age, gestational trimester, parity and Plasmodium species was retrieved from the subjects. Thick and thin blood films were prepared and stained with Giemsa and examined microscopically. Prevalence estimates were recalculated with 95% Wilson confidence intervals. Pearson chi-square tests were used for unadjusted associations with age group, trimester and parity.

Results: Plasmodium parasites were detected in 109/230 women (47.4%, 95% CI 41.0–53.8). Among positive samples, 106 (97.2%) were reported as Plasmodium falciparum and 3 (2.8%) as P. malariae. Positivity did not differ significantly by age group (χ²=6.65, df=4, p=0.155) or parity (χ²=0.21, df=1, p=0.645). Positivity varied across trimester categories (χ²=11.76, df=2, p=0.0028), with prevalence of 54.8% in the first trimester, 56.9% in the second and 33.3% in the third.

Conclusion: Microscopy-detected Plasmodium infection was common among the pregnant women represented in this historical Minna dataset in 2008. P. falciparum predominated. The trimester pattern should be interpreted as an unadjusted cross-sectional association rather than evidence of a causal effect of gestational age. These findings are best regarded as a historical reference point rather than a contemporary prevalence estimate.

Parasitological Profiles of Fish from Petroleum-Impacted Freshwater Ecosystems in Delta State, Nigeria

2026-09-18T06:20:39+00:00

This study assessed the parasitological profiles of fish from petroleum-impacted freshwater ecosystems in Delta State, Nigeria, and examined spatial associations between petroleum contamination and parasite burden. A total of 300 fish representing six freshwater species were collected from five sampling stations and examined for ectoparasites and endoparasites using standard parasitological procedures. Water samples were analysed for total petroleum hydrocarbons (TPH) and total polycyclic aromatic hydrocarbons (PAHs), while parasite prevalence, mean intensity and mean abundance were determined. Overall, 126 fish were infected, giving a prevalence of 42.0%. Clarias gariepinus had the highest prevalence (53.3%), whereas Chrysichthys nigrodigitatus had the lowest (30.0%). A total of 218 parasites were recovered; nematodes were most abundant (31.2%), followed by trematodes, cestodes, acanthocephalans and protozoans. The gastrointestinal tract accounted for 48.2% of recovered parasites. Parasite prevalence varied spatially from 26.7% at S1 to 58.3% at S4, and mean intensity ranged from 1.38 to 2.09. TPH concentrations ranged from 2.84 ± 0.31 to 14.72 ± 1.06 mg/L, with S4 recording the highest petroleum burden and parasitological indices. Petroleum contamination showed positive associations with parasite prevalence and mean intensity. These findings indicate substantial spatial variation in fish parasitism and support integrating parasitological indicators with petroleum monitoring in freshwater ecosystem assessment.

Transmission Potential of Lymphatic Filariasis Vectors in Selected Communities of Etim Ekpo Local Government Area, Akwa Ibom State, Nigeria: An Entomological Surveillance Study

2026-09-23T12:37:53+00:00

Background and Aims: Lymphatic filariasis (LF) remains a mosquito-borne parasitic disease for which entomological surveillance is important in assessing transmission potential. This study assessed the transmission potential of lymphatic filariasis (LF) vectors in selected communities of Etim Ekpo Local Government Area, Akwa Ibom State, Nigeria, based on mosquito species composition, physiological status and parity, and detection of Wuchereria bancrofti larval stages.

Study Design: Community-based entomological surveillance study.

Place and Duration of Study: Five selected communities in Etim Ekpo Local Government Area, Akwa Ibom State, Nigeria, from February to August 2024.

Methodology: Adult mosquitoes were collected monthly during three dry-season months (February–April) and three rainy-season months (June–August). Mosquitoes were morphologically identified using standard identification keys. Female mosquitoes were assessed according to abdominal physiological status and parity. A physiologically selected subset of 479 female mosquitoes was dissected and examined for L1, L2 and L3 filarial larval stages. Mosquitoes containing any larval stage were classified as infected, while those containing L3 were considered infectious.

Results: A total of 1,405 mosquitoes were collected, comprising Culex quinquefasciatus (393; 27.97%), Aedes aegypti (356; 25.34%), Anopheles gambiae (250; 17.79%), Culex pipiens (211; 15.02%) and Aedes albopictus (195; 13.88%). Female mosquitoes accounted for 756 (53.81%) of the total collection. Of these, 437 (57.80%) were parous and 319 (42.20%) were nulliparous. Of the 479 females dissected, none contained L1, L2 or L3 filarial larvae. The observed infection rate was therefore 0%, while the infectivity rate based on L3 detection was also 0%.

Conclusion: Mosquito taxa potentially capable of supporting LF transmission were present in the study area, including a substantial proportion of parous females. However, no filarial larval stages were detected among the 479 females examined by microscopy. This zero-detection result applies only to the dissected sample and sampling period and does not establish the absence or interruption of transmission in the wider population. Continued surveillance, preferably complemented by molecular xenomonitoring, is recommended.

The Prevalence of Schistosomiasis and Other Parasites among Farmers in Fiidi Council Ward of Makurdi Local Government Area, Benue State, Nigeria

2026-09-28T13:12:49+00:00

Schistosomiasis and intestinal parasitic infections remain important public health problems in tropical communities where unsafe water, inadequate sanitation and occupational exposure to contaminated soil and freshwater occur. Farmers may be particularly vulnerable because of their frequent environmental exposure. This study determined parasitic infection among 500 farmers from five communities in Fiidi Council Ward of Makurdi Local Government Area, Benue State, Nigeria. Early morning stool samples were examined macroscopically and microscopically using direct wet preparation and formol-ether concentration techniques, and a structured questionnaire was used to obtain demographic, knowledge and behavioural information. The overall participant-level positivity reported in the age- and sex-stratified analyses was 68/500 (13.6%). Stool microscopy records included 72 detections reported as S. haematobium (14.4% of 500 examined), 65 E. histolytica/dispar (13.0%), 58 hookworm (11.6%), 10 S. mansoni (2.0%), five P. hominis (1.0%), three A. lumbricoides (0.6%) and two unresolved Trichomonas spp. records originally labelled T. vaginalis (0.4%). Because the stated methodology describes stool examination only, the records labelled S. haematobium cannot be interpreted as confirmed urogenital S. haematobium infection. The microscopy-only Entamoeba findings are therefore reported conservatively as E. histolytica/dispar. Age was significantly associated with reported parasitic infection positivity (χ² = 44.53, df = 4, p < 0.001), whereas sex was not significantly associated (χ² = 0.83, df = 1, p = 0.361). The community tables contain distributions of recorded parasite detections rather than participant prevalence estimates because community-specific numbers examined are not provided. The findings document multiple stool-detected parasite records among farmers, but species-specific and community-specific inferences should be interpreted within these diagnostic and denominator limitations. Control efforts should emphasise health education, sanitation, safe water, protective footwear, periodic screening and confirmatory diagnosis where species-specific treatment or surveillance decisions are required.

A Survey of WASH (Water, Sanitation, and Hygiene) in Some Public Schools in Calabar South and Prevalence of Soil-Transmitted Helminths (STH) in the Schools

2026-10-02T12:44:19+00:00

Soil-transmitted helminth (STH) infections are an important public health issue affecting children in developing countries and are associated with significant morbidity and stunted growth and development. This study examined the current status of water, sanitation and hygiene (WASH) facilities and practices in selected public primary schools in Calabar South Local Government Area (LGA), Cross River State, Nigeria. A descriptive cross-sectional design was used, and 240 randomly selected preschool- and school-aged children were included. Standard parasitological and microscopic methods were used to isolate helminth ova from stool samples. Demographic and environmental data, such as age, sex, water and sanitation conditions, WASH-related communication of hygiene practices, and type of toilet facility, were also gathered using a structured questionnaire and statistically analysed. The overall prevalence of STH infections was 32.5%. Among all 240 children examined, species-specific prevalence was 19.17% for Ascaris lumbricoides (46/240), 7.92% for Trichuris trichiura (19/240), and 5.42% for hookworm (13/240). Among the 78 infected children, these species accounted for 58.97%, 24.35%, and 16.66% of infections, respectively. The distribution of helminth species was not significantly different (P > 0.05), based on chi-square analysis. However, differences were observed in infection rates across various environmental and behavioural factors. The prevalence observed in this study suggests that STH infection is endemic in the study area. The results indicate that intervention measures, such as periodic mass deworming, improved sanitation, and enhanced health education, are needed to help reduce transmission and reinfection among children.

Urinary Schistosomiasis Prevalence and Sociodemographic Risk Factors among Adults in Ekori, Yakurr Local Government Area, Cross River State, Nigeria

2026-10-08T04:25:19+00:00

Background and Aim: Urogenital schistosomiasis remains endemic in Nigeria, and adults with occupational, domestic and recreational freshwater contact may remain exposed. This study assessed the prevalence of Schistosoma haematobium infection and its sociodemographic distribution among adults at four freshwater-contact sites in Ekori, Yakurr Local Government Area, Cross River State.

Methods: A cross-sectional community survey was conducted from June 2025 to January 2026 among 637 adults aged 20–60 years. Urine samples collected between 10:00 and 14:00 h were centrifuged, and sediments were examined microscopically for terminal-spined eggs of S. haematobium. Questionnaire data covered age, sex, occupation, education, knowledge and water-contact behaviour. Associations were assessed using chi-square tests at the 0.05 level.

Results: Eighty-three participants were positive, giving an overall prevalence of 13.03%; 3.30% had haematuria. Prevalence was highest at Ekori beach (18.45%), followed by Ajere (14.79%), Afrekpe (9.77%) and Epenti (9.15%). Prevalence declined from 18.95% among participants aged 20–30 years to 7.92% among those aged 51–60 years and was higher among males (16.56%) than females (9.73%). Prevalence was 20.63% among civil servants, 14.58% among fishermen, 12.36% among traders and 10.58% among farmers, while participants with no formal education had the highest prevalence (31.53%).

Conclusion: Urinary schistosomiasis remains present among adults in Ekori, with variation across demographic groups and localities. Adult-focused surveillance, praziquantel treatment for at-risk groups, safe water, sanitation and targeted behaviour-change interventions should complement school-based control.

Water-Contact Behaviour, Community Knowledge and Freshwater Snail Ecology as Drivers of Urinary Schistosomiasis Transmission in Ekori, Cross River State, Nigeria

2026-10-08T05:20:18+00:00

Aims: Persistent urinary schistosomiasis transmission depends on human exposure to freshwater, contamination of water bodies, and the presence of suitable snail intermediate hosts. This article focuses on four freshwater sites in Ekori, examining behavioural exposure, community knowledge, and malacological findings.

Study Design: A cross-sectional and malacological community survey.

Place and Duration of Study: Four freshwater sites in Ekori, Yakurr Local Government Area, Cross River State, Nigeria, from June 2025 to January 2026.

Methodology: A cross-sectional survey was conducted among 637 adults, who provided urine samples and completed a predesigned questionnaire on water-contact activities and knowledge of schistosomiasis. Freshwater snails were collected with scoop nets from 23 sampling points at the Ekori, Afrekpe, Epenti, and Ajere beaches, identified morphologically, and exposed to light to induce cercarial shedding.

Results: Infection prevalence was highest among participants who reported swimming (23.41%), followed by fetching water (13.40%), bathing (7.41%), and washing (5.04%), with water-contact activity being significantly associated with infection (χ² = 24.184, p = 0.000023). Infection prevalence was 15.16% among participants without prior knowledge of schistosomiasis and 10.54% among those with prior knowledge. Fewer than one-third (27.9%) associated infection with contact with contaminated water, and none mentioned snails as part of transmission. Of 371 freshwater snails, 57.41% were Biomphalaria spp., 25.88% were Bulinus spp., and 16.71% were Lymnaea spp. Fifty-six snails (15.09%) shed cercariae.

Conclusion: The findings indicate that transmission in Ekori is maintained through an interconnected human–snail–water system. The observed pattern supports integrated chemotherapy, WASH, behaviour change, snail surveillance, and environmental management because of repeated water contact, gaps in transmission knowledge, and the presence of cercaria-shedding freshwater snails.