Two Nigerian States (Plateau and Nasarawa) Have Eliminated Transmission of Human Onchocerciasis-A Report of Post-Ivermectin Mass Drug Administration Surveillance.

Transmission of Onchocerca volvulus (causing "river blindness") was interrupted in two states of Nigeria (Plateau and Nasarawa) in 2017 in accordance with 2016 WHO guidelines. Ivermectin mass drug administration was halted in January 2018, and posttreatment surveillance activities were conducted over a 3-year period. Vector Simulium damnosum s.l. flies were collected during the 2019 (39 sites) and 2020 (42 sites) transmission seasons. Head pools were tested by polymerase chain reaction for the presence of third-stage O. volvulus larvae; 15,585 flies were all negative, demonstrating an infective rate of < 1/2,000 with 95% confidence. In 2021, the Nigerian Federal Ministry of Health declared the two-state area as having eliminated transmission. Plateau and Nasarawa states are the first of 30 endemic states in Nigeria to have met the WHO criteria for onchocerciasis elimination. Post-elimination surveillance will need to continue given the risk of reintroduction of transmission from neighboring states.

Perceptions on the use of insecticide treated nets in parts of the Imo River Basin, Nigeria: implications for preventing malaria in pregnancy.

This study aimed at assessing perceptions on use of ITNs in parts of the Imo River Basin, Nigeria and its implications in preventing malaria in pregnancy. Data was collected using focus group discussions, key informant interviews and structured questionnaires. Results showed high awareness on the benefits of ITNs. Factors affecting use of ITNs included its high cost, perceptions of chemicals used to treat them as having dangerous effects on pregnancy, low utilization of antenatal care, husband's lack of interest in malaria prevention and perceptions that adolescent girls are at low risk of getting malaria. The implications of these findings include demystifying the negative perceptions on the chemicals used for net treatment and subsidizing the cost of ITNs to increase access. These findings provide important lessons for malaria programmes that aim at increasing access to ITNs by pregnant women in developing countries.

The Interruption of Transmission of Human Onchocerciasis by an Annual Mass Drug Administration Program in Plateau and Nasarawa States, Nigeria.

Plateau and Nasarawa states in central Nigeria were endemic for onchocerciasis. The rural populations of these two states received annual ivermectin mass drug administration (MDA) for a period of 8-26 years (1992-2017). Ivermectin combined with albendazole was given for 8-13 of these years for lymphatic filariasis (LF); the LF MDA program successfully concluded in 2012, but ivermectin MDA continued in areas known to have a baseline meso-/hyperendemic onchocerciasis. In 2017, serological and entomological assessments were undertaken to determine if MDA for onchocerciasis could be stopped in accordance with the current WHO guidelines. Surveys were conducted in 39 sites that included testing 5- to < 10-year-old resident children by using ELISA for OV16 IgG4 antibodies, and Onchocerca volvulus O150 pooled polymerase chain reaction (PCR) testing of Simulium damnosum s.l. vector heads. Only two of 6,262 children were OV16 positive, and none of 19,056 vector heads were positive for parasite DNA. Therefore, both states were able to meet WHO stop-MDA thresholds of an infection rate in children of < 0.1% and a rate of infective blackflies of <1/2,000, with 95% statistical confidence. Transmission of onchocerciasis was declared interrupted in Plateau and Nasarawa states by the Federal Ministry of Health, and 2.2 million ivermectin treatments/year were stopped in 2018. Post-treatment Surveillance was launched focusing on entomological monitoring on borders with neighboring onchocerciasis-endemic states. An apparent positive impact of the LF MDA program on eliminating hypo-endemic onchocerciasis was observed. This is the first stop-MDA decision for onchocerciasis in Nigeria and the largest single stop-MDA decision for onchocerciasis yet reported. This achievement, along with the process used in adapting and implementing the 2016 WHO stop-MDA guidelines, will be important as a potential model for decision makers and national onchocerciasis elimination committees in other African countries that are charged with advancing their programs.

The positive influence the Onchocerciasis Elimination Program for the Americas has had on Africa programs.

A recent article "Is onchocerciasis elimination in Africa feasible by 2025: a perspective based on lessons learnt from the African control programmes" in Infectious Diseases of Poverty claimed that undue influence on African programs by concepts developed by the Onchocerciasis Elimination Program of the Americas (OEPA) is detrimental to stopping mass drug administration (MDA) in Africa. This claim is made despite a record year for MDA stoppage in four African countries of > 3.5 million treatments in 2018, far exceeding any past OEPA or African Program for Onchocerciasis Control (APOC) stop MDA success.

Placental malaria in Owerri, Imo State, south-eastern Nigeria.

Malaria in pregnancy jeopardizes the outcome of pregnancy, affecting both the mother and the foetus. The prevalence of placental malaria in women, who routinely attended ante-natal clinics in Owerri, south-eastern Nigeria, was assessed using three hospitals between March 2004 and August 2005. Placental blood was collected in EDTA bottles from incisions made on cleaned basal plate of the placenta, within an hour of delivery. Blood collected was used to assess ABO blood group, haemoglobin level as well as malaria parasitaemia. Malaria parasitaemia was determined from thick and thin smears stained with Giemsa, while the haemoglobin level was measured using the cyanomethaemoglobin method. A total of 586 pregnant women were involved in this study with written consents. Malaria parasites were observed in 175 (29.9%) of the women on delivery. Of these women, 64 (36.6%) were anaemic. A significant relationship at P<0.05 variation, was observed between the prevalence of malaria parasites in the placenta and gravidity, age and blood group. The rate of occurrence of malaria parasitaemia, in the placenta of women who were on a weekly prophylaxis against malaria is alarming and calls for more serious efforts in the prevention of malaria especially in this vulnerable group.

The use of herbs in malaria treatment in parts of Imo State, Nigeria.

Persistence of malaria symptoms after treatment with over the counter available antimalarial drugs has resulted in a gradual loss of faith in orthodox drugs. There is thus an increased tendency towards the use of herbs in the treatment of malaria in Imo State, Nigeria. In this study we report activities of two herbalists in the treatment of malaria as well as the effectiveness of the herbal treatment. The study covered two areas namely, Umuneke Ugiri in Isiala Mbano Local Government Area (LGA) and Odummara Obi-Orodo in Mbaitoli LGA of Imo State, Nigeria. A participant-observation technique was used. Finger prick blood samples were collected from patients who visited the herbalists complaining of malaria, and blood smears were stained with Field's B stain. Blood smears were taken again one-week post-treatment. A total of 75 patients from Umuneke Ugiri and 265 patients from Odumara Obi-Orodo were involved in the study. All the 75 patients (100%) from Umuneke Ugiri and 163 (61.51%) patients from Odummara Obi-Orodo were positive for malaria parasites. Only 13 (17.3%) patients from Umuneke Ugiri and 149 (56.23%) from Odummara Obi-Orodo returned for the post-treatment blood parasite analysis. From Umuneke Ugiri 4 (31%) were still positive for malaria parasite while 9 (69%) were negative. All 149 patients from Odummara Obi-Orodo were negative. This indicates that the herbal treatment was effective. However, there is need for further studies into the efficacy of herbal concoctions, their effective life span, as well as possible toxic effects.

Concomitant bacteria in the blood of malaria patients in Owerri, southeastern Nigeria.

The presence of concomitant bacteria was assessed in the blood of 125 malaria positive patients and 60 malaria negative controls, resident in Owerri, southeastern Nigeria. Blood samples were cultured in MacConkey, Chocolate and Blood agar, respectively using oxoid signal system after the manufacturer's instructions. Blood cultures of 44 (35.2%) of the 125 malaria positive patients had bacterial growth while none was observed in the blood cultures of malaria negative patients. The bacteria species identified included: Staphylococcus aureus 4 (3.2%), Escherichia coli 3 (2.4%) Salmonella typhi 25 (20%), Klebsiella pneumoniae 10 (2.4%) and Pseudomonas aeruginosa 2 (1.6%). The presence of concomitant bacteria in malaria-positive cases usually results in persistence of malaria-like symptoms after treatment with antimalarials and subsequently taken as resistance of the parasites to the particular drugs in question. The significance of concomitant bacteria in the management of malaria should be given priority.

Specific serodiagnosis with adult Onchocerca volvulus antigen in an enzyme-linked immunosorbent assay.

The cross-reactivity of the blood from onchocerciasis, loiasis, and dipetalonemiasis was tested by a micro-ELISA technique, utilizing adult Onchocerca volvulus antigen and blood samples taken on filter paper. The average ELISA values (OD at 500 nm) were as follows: 0.58 in persons with O. volvulus microfilariae (n = 81), 0.49 in microfilariae-negatives from the same endemic area (n = 39), 0.15 in dipetalonemiasis (n = 27), and 0.25 in loiasis (n = 12), while those of 65 Dipetalonema perstans-negative people were markedly low (average 0.14) and that of 22 Loa loa-negatives, 0.22, respectively. This ELISA could successfully differentiate onchocerciasis from dipetalonemiasis and loiasis.

The occurrence of loiasis, mansonellosis and wuchereriasis in the Jarawa River Valley, central Nigeria.

In a study to assess the status of filariasis in the Jarawa River Valley of the savanna area of Nigeria, 940 self-selected residents from 10 villages were examined between March 1984 and April 1987. Overall results showed 105 (11.2%) had microfilaraemia and/or clinical signs of filariasis. Sixty-four (6.8%) and 20 (2.1%) persons, respectively, were infected with Mansonella perstans and Loa loa microfilariae (mff). Four of the 28 villagers examined had Wuchereria bancrofti mff in their night blood samples whereas 17 (1.8%) of all residents surveyed had clinical filariasis mainly due to lympho-obstructive manifestations: hydrocele (n = 11, 64.7%); enlargement of the inguinal nodes (n = 8, 47.1%) and elephantiasis (n = 2, 11.8%).

Validation of reports of nodules dissolution after repeated ivermectin treatment of onchocerciasis in southeastern Nigeria.

OBJECTIVE: To ascertain the validity of the claims by villagers in endemic communities in southeastern Nigeria that repeated ivermectin treatment cause disappearance or dissolution of onchocercal nodules. DESIGN: From baseline epidemiological data, four communities (Amuro, Aku, Nzerem Ikpem and Awuchinimo) were randomly chosen as the study sites. A total of 324 adults (hitherto had onchocercal nodules), aged > or = 20 years from these communities were enlisted in the study. After clinical examination, each of the villager was interviewed with structured, pre-tested questionnaire. Also personal and focus group discussion was held. RESULTS: Sixty nine (21.30%) respondents; 16.67% from Amuro, 32.26% from Aku, 19.05% from Nzerem Ikpem and 15% from Awuchnimo claimed that their nodules gradually dissolved or disappeared. A significant (p < 0.05) proportion (82.61%) attributed this phenomenon to repeated doses of ivermectin; 4.35% claimed it was not due to ivermectin therapy while 13.04% were not sure of the cause. CONCLUSION: The results have opened challenges in our understanding of the role of ivermectin therapy in endemic communities and calls for further studies of nodule dissolution in other onchocerciasis endemic communities.

The varied beneficial effects of ivermectin (Mectizan) treatment, as observed within onchocerciasis foci in south-eastern Nigeria.

In the treatment of humans, ivermectin (Mectizan((R))), a semi-synthetic macrocyclic lactone, is now primarily used as a rapid microfilaricide. The drug has several other benefits, however, and these have recently been investigated in five states in south-eastern Nigeria, where there have been mass treatments with ivermectin, for the control of Onchocerca volvulus, for more than 10 years. Between the January and December of 2005, 3125 adult onchocerciasis patients (each aged >/=20 years and known to have at least one clinical sign of onchocerciasis) were enlisted, clinically examined and interviewed. Relevant data were collected in the interviews, using a structured, pre-tested questionnaire, and in personal and focus-group discussions. Overall, 612 (19.6%) of the subjects reported that they had had nodules that had disappeared following repeated doses of ivermectin, although only 83.8% of the 612 attributed their nodule clearance to ivermectin (the other 16.2% being unsure of the cause). A larger percentage of the subjects (24.6%) reported that they had expelled intestinal helminths following the last round of ivermectin treatment (i.e. been dewormed). Other side-benefits reported in the study were improved vision (11.7% of subjects), reversal of secondary amenorrhea (4.5%), increased appetite (22.3%), reduction in arthritic or other musculo-skeletal pain (7.9%), reductions in the severity of body itching (18.5%) and skin rash (17.3%), darkening of leopard skin (6.6%), improved libido in men (6.6%), and clearance of head lice (4.5%). If, via health education, the local communities could be made more aware of the side-benefits of ivermectin treatment, the sustainability of the on-going programme of community-directed treatment with ivermectin (CDTI) in south-eastern Nigeria would probably be improved.

Musculo-skeletal pain (MSP) in onchocerciasis: a potential in the rapid low cost epidemiological survey and in the assessment of impact of ivermectin treatment on a community.

The diagnostic potential of musculo-skeletal pain (MSP) in the rapid assessment of onchocerciasis of morbidity and of the impact of ivermectin treatment in a community is brought to picture. The clinical impression is that MSP is a common, early, chronic important symptom of onchocerciasis. With a significant association with onchocerciasis, MSP has the potential of being an important operational diagnostic clue in the detection of onchocerciasis. It has the advantage of being easily recognizable, and therefore can be applied by primary health care workers. MPS is proved to cause the greatest morbidity, particularly among working farmers in areas where the forest strain of O. volvulus is predominant. Thus, onchocerciasis is contributing more than was perhaps realized to the reduced output of work from farmers. However, MPS, a parasitic rheumatism, is proved to be eminently susceptible to treatment by DEC.

Behavioural aspects and their possible uses in the control of dracontiasis (guinea-worm) in Igwun river basin area of Imo State, Nigeria.

Individuals suffering from dracontiasis from Igwun river basin area of Imo State Nigeria were randomly chosen, examined and interviewed between December 1988 and March 1989 with a view to ascertain some of the behavioural aspects that could be of help in the control/eradication of this disease as well as to ascertain whether local medication was of any chemotherapeutic significance. Of 100 guinea-worm patients males were significantly higher (P < 0.05) in number (63.0%). In the age-related distribution, children less than 10 years old and the members of the villages more than 60 years old accounted for only 5.0% of the patients whilst those in their productive years (10-60 year old) accounted for 95.0%. Only 10.5% of the respondents associated guinea-worm infection with the drinking of "polluted" water while most believed it was a familial trait (36.8%) or implicated their enemies (35.1%). As a result medications against the disease were mainly directed towards consulting the oracle and herbalists, and appeasing the gods. Most (98.0%) of them kept their dressing dry by refraining from immersing them in water. The concomitant behavioural aspects of these results are discussed in relation to their uses in the control/eradication of guinea-worm.

PIP: Between December 1988 and March 1989 in the Igwun river basin of Imo State, Nigeria, health workers randomly chose, examined, and interviewed 100 people with dracontiasis (Guinea-worm infection) living in the villages of Isi Ugwu, Ndi Okorie, Ndi Agwu, Ndi Oji, and Ndi Okereke in the Arochukwu/Ohafia local government area. Males were significantly more likely to be infected with guinea-worm than were females (63% vs. 37%; p .05). Guinea-worm infection was significantly associated with age (95% of cases were between 10-60 years old; p .05). 93% of the 228 villagers who completed a questionnaire about local disease perception, treatment/control, and sociocultural factors were familiar with Akwara (the local term for guinea-worm infection). 84.2% believed infants and the very old, who had low rate of guinea-worm infection, tended to not do farm work, which was indeed the case. 85.5% knew about the damaging effects of the infection. 36.8% believed Akwara was inherited. 35.1% thought enemies or gods caused Akwara. Just 10.5% made the connection between guinea-worm infection and drinking water from contaminated streams, ponds, and lakes. Most guinea-worm infected patients (42%) either just used the time-honored method of winding the emergent female worm around a small stick or the time-honored method in combination with other methods, such as herbalist treatment, consulting an oracle, and receiving Western medical treatment. 21% sought an oracle and received treatment from herbalists. 17% sought an oracle and appeased the gods to achieve relief from guinea-worm. 15% just received herbalist treatments. 5% only sought treatment at the hospital. Just 2 (3.8%) of the 53 patients with dressed guinea-worm blisters and ulcers immersed the dressing into a water source while retrieving water. This low number helped reduce the transmission of the larvae from the blisters/ulcers to the water. Guinea-worm was most devastating in Isi Ugwu, where people believed that drinking potable water separated them from their gods.

The socio-economic aspects of human onchocerciasis in Africa: present appraisal.

The pattern of socio-economic liability that has emerged due to human onchocerciasis in Africa has been particularly damaging. Due to debilitation and blindness, the sufferer is unable to maintain for long any type of productive activity. As a cause of permanent disability through blindness or serious visual impairment, it withdraws the affected individuals' potential supply of labour years of activity requiring vision. The desertation of many river valleys in the savannah zone that are agriculturally fertile have been attributed mainly to the effects of this disease. This has by definition, meant that emigrants impose demands upon other territories that are often agriculturally less fertile consequently resulting to constant population maladjustment. As a cause of death, infection removes individual's supply of labour years in the future. The social life obtainable in these areas is better imagined than seen. It is a common trend seeing chains of blind adults being led to markets or within cities by children with good vision-constituting destitutes. The distressing skin features give patients prematurely aged appearance and together with dreadful malformation due to sclerosing lymphadenitid, infected individuals show shyness towards free social interactions; even sexual life is greatly affected if not completely hindered. The present economic benefit analysis of control projects, limitations and needs for future studies are disoussed.

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.

Onchocerciasis in Plateau State; Nigeria: ecological background, local disease perception & treatment; and vector/parasite dynamics.

The physico-biological ecological complex in Plateau State has by definition increased the potential of most rivers to support the breeding and dispersal of vector species as well as human acquisition and dissemination of the disease for several months in a year. Though villagers in endemic areas are of the know of the nuisance of blackfly bites, but the majority of them lacked the aetiological knowledge of onchocercal lesion. Hence disease management is misdirected towards consulting the oracle and appeasing the gods. The vectors of onchocerciasis in Plateau State, S. damnosum, and S. sirbanum are wet season breeders with their peak biting density occurring at the height of rainy season. However, biting flies carry more infective parasites at the beginning and end of rain. These vectors exhibit bimodal biting activity: a small one in the morning hours and a pronounced evening peak. Biting activity is at least influenced by two major climatic factors; illumination and temperature. However, the fastest changing climatic factor relative to an increase in the biting activity of flies was illumination. Microfilarial load in the skin of patients does not significantly change throughout the year or when biopsies are taken under shade throughout the day. Extreme temperatures, however, have significant reducing effect on the skin microfilarial. The epidemiological relevance of these in the ongoing MECTIZAN delivery in the State are discussed.

The validity of haematuria in the community diagnosis of urinary schistosomiasis infections.

The validity and reliability of haematuria when used as screening criteria in community diagnosis of urinary schistosomiasis is presented. Between May and July, 1998, 1173 persons were screened for haematuria and examined for the presence of eggs of Schistosoma haematobium in their urine from all participating households in the Ozitem area of Bende Local Government Area, Abia State, Nigeria. Haematuria showed a sensitivity rate of 41.0% and specificity of 82.0% when used to identify cases of urinary schistosomiasis. Some factors that influenced the validity of haematuria as a diagnostic criterion are discussed. The use of haematuria amongst subjects in the first twenty years of their life is recommended.

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.

Chromosomes of Onchocerca volvulus (Spirurida: Onchocercidae): a comparative study between Nigeria and Guatemala.

Chromosomes of Nigerian Onchocerca volvulus were compared with those of Guatemalan O. volvulus. Both parasites had basically the same chromosomal construct (2n = 8, XY type). Autosomes consisted of a pair of large and two smaller pairs. Sex chromosomes were made up of medium sized X chromosome and very small Y chromosome. It was not possible to infer the position of the centromeres.

Onchocerciasis in Plateau State of Nigeria. II. The prevalence among residents around the Assob River area.

A study of the prevalence of human onchocerciasis in eight villages around the Assob River in Jos Plateau, Nigeria, was undertaken between October 1983 and March 1985 using the skin-snip method. A total of 1673 individuals were examined. One hundred and eighty five (11.06%) had microfilariae of Onchocerca volvulus in their skin biopsies, and of these infected people, five (2.7%) were blind. The highest prevalence rate recorded was in Ngwan Madaki, where 51 (26.3%) of the 194 people examined were infected. The lowest percentage prevalence was recorded in Dogon Fili with four (1.95%) of the 205 people examined being positive. The proportion of infected people increased with age; and onchocercal lesions were significantly more common in older than in younger persons (P less than 0.05). There was no significant difference between infection rates in males and females (P greater than 0.05), although the overall percentage infection and the numbers of onchocercal lesions were higher in males than in females.