African Journal of Parasitology Research

African Journal of Parasitology Research Vol. 2 (1), pp. 046-054, January, 2015. © International Scholars Journals

Full Length Research Paper

An investigation on the dynamics of insecticide resistance in Anopheles gambiae from southern Benin and the metabolic resistance mechanisms involved

*Gildas Armel, Modeste Fabrice and Hervé Carlos

Department of Parasitology/Microbiology, National University of Benin, Abomey Calavi, Benin.

*Corresponding author. E-mail: [email protected]

Accepted 17 December, 2014

Abstract

Permanet 2.0 distribution was made free in October, 2008 and May, 2009 in Oueme Department. OlysetNet distribution was also made free in July, 2011 throughout the entire country by Beninese National Malaria Control Programme to increase coverage of long-lasting insecticidal nets (LLINs). We investigated the dynamics of insecticide resistance in Anopheles gambiae from southern Benin and the metabolic resistance mechanisms involved. Larvae and pupae of A. gambiae s. l. were collected from the breeding sites in Littoral and Oueme Departments. Centers for Disease Control and Prevention (CDC) susceptibility tests were conducted on unfed female mosquitoes aged 2 to 5 days old with stock solutions of permethrin, deltamethrin and dichlorodiphenyltrichloroethane (DDT). CDC biochemical assays using synergists were also carried out. A. gambiae Ladji populations were resistant to permethrin and DDT in 2008 and in 2013. A. gambiae Sekandji populations were susceptible to deltamethrin in 2008 and in 2013 whereas these populations were resistant to this product in 2010. A. gambiae Sekandji populations were resistant to DDT in 2008 and in 2013. The DDT resistance level in A. gambiae Ladji and Sekandji populations recorded in 2013 was higher than the one observed in 2008. The metabolic resistance conferred by detoxifying enzymes is an indication of phenotypic resistance to both DDT and pyrethroids.

Key words: Dynamics, piperonyl butoxide, S.S.S-tributylphosphorotrithioate, ethacrynic acid, insecticide, vectors, resistance.

African Journal of Parasitology Research Vol. 2 (6), pp. 108-112, June, 2015. © International Scholars Journals

Full Length Research Paper

A cross-sectional study on the prevalence and risk factors associated with Toxocara canis infections in dogs

*Emmanuel Charles Kalu, Rotimi H. Emeka and Olaka K. Pascal

Department of Microbiology, Faculty of Medicine, Imo State University, Owerri, Nigeria.

*Corresponding author. E-mail: [email protected]

Accepted 17 February, 2015

Abstract

The objective of this cross-sectional study was to determine the prevalence and risk factors associated with Toxocara canis infections in dogs. The study was conducted in three communities in Southwest Nigeria between January, 2011 and February, 2012. Faecal samples (n=474) were processed by modified Kato-Katz procedure. Multiple logistic regression analysis was used to assess risk factors for T. canis. An overall prevalence of 34.6% was recorded for T. canis . Intensity of infection, determined by the mean number of eggs per gram of faeces (±standard error of mean [SEM]) was 4301.2 ± 348.4. Age of dogs and the mode of life were identified as the significant risk factors for T. canis. The odds of being infected with T. canis decreased with age. Dogs aged 0 to 6 months were 7.9 times more likely to harbour T. canis than dogs aged 31 months and above. The odds of harbouring T. canis by stray dogs were 2.7 times more than the kennel dogs. This study shows that T. canis infection is high in puppies and stray dogs. There is the need for establishment of deworming program to improve the health status of the dogs and to reduce the risk of zoonotic infection in humans.

Key words: Parasitism, epidemiology, pets, toxocariasis, larva migrans.

African Journal of Parasitology Research Vol. 2 (8), pp. 135-142, August, 2015. © International Scholars Journals

Short Communication

A cross sectional study of two seasons in villages of the Sanaga to identify main Simuliids and mosquitoes genus and species

*¹Baleguel Therese, ¹Kuete Fabien and Tassen Thomas²

¹Faculty of Medicine and Pharmaceutical Sciences, Fonab Polytechnic, Cameroon

²Faculty of Medicine and Biomedical Sciences, University of Ngaoundere, Bangante, Cameroon.

*Corresponding author. E-mail: [email protected]

Accepted 13 March, 2015

Abstract

Most riverine villages of the Sanaga river are known endemic for vector-borne diseases. Two cross sectional surveys were set during two seasons in villages of the Sanaga mid valley to identify main Simuliids and mosquitoes genus and species, their specific biotopes and fluctuations of their abundance with respect to distance from the river banks and seasons. The study villages are located close to 5 and 35 km from the Sanaga river edges. Both larva and adult stages were assessed using known methods. All adults Simuliids, larvae and nymphs were identified as Simulium damnosum. Larvae and nymphs were collected only in the river stream and adults near the banks, farms and near households. Adults and larvae abundance was greater in the rainy season whereas nymphs were more abundant in the dry season. Endophilic mosquitoes harvested were Anopheles and Culex. Their abundance was greater in villages close to the river. Species and resting densities varied with distance from the river edges. Culicidae larvae collected belonged to Aedes, Anopheles and Culex. Fourteen species were identified, 3 of Anopheles, 5 of Aedes and 6 of Culex. Some species showed broad specificity to biotopes. This study indicates that mosquito fauna is more diversified at larval stage in the Sanaga mid valley; some having broad specificity to breading sites. The Sanaga river harbours most of the species found in the water bodies. Indoor adult mosquitoes are less diversified indicating that most of the mosquito found at larval stage may breed mostly outdoor. Simulium larvae and pupae breed specifically in the falls and rapids of the Sanaga stream. Both sexes of adult Simulium are found near the river, whereas only females are found near households and in farms. Adults Simulium density decreases with the distance from the river with two picks of abundance in the day.

Key words: Biodiversity, Culicidae, Simuliidae, Sanaga River.

African Journal of Parasitology Research Vol. 2 (3), pp. 072-081, March, 2015. © International Scholars Journals

Full Length Research Paper

An evaluation of the dynamics of insecticide resistance and the rate of kdr metamorphosis of the primary malaria vector Anopheles arabiensis in rural villages of Lower Moshi, North Eastern Tanzania

*Mizengo H. Kikwete, Bernard O. Pinda and John Membe

Department of Medical Parasitology, Faculty of Medicine, University of Dar es Salaam, Dar es Salaam, Tanzania.

Corresponding Authors. Email: [email protected]

Accepted 13 January, 2015

Abstract

The major foci of pyrethroid resistance in 1990 to 2010 were in West and Central African populations of Anopheles gambiae s.s. Pyrethroid resistance in Anopheles arabiensis has been reported in several countries of East and Central Africa. Four cross-sectional surveys of A. arabiensis in Lower Moshi were conducted in 2009, 2011, 2012 and 2013 to determine levels of resistance to pyrethroids, organochlorines, organophosphates and carbamates using World Health Organization (WHO) standard diagnostic dosages. Mosquitoes were identified to species level and genotyped for both L1014F and L1014S mutations by hydrolysis probe assays. A. arabiensis remains the dominant malaria vector in the area. Full susceptibility to dichlorodiphenyltrichloroethane (DDT), organophosphates and carbamates was recorded in all eight villages. Following the current WHO guidelines, resistance to permethrin and lambdacyhalothrin was observed in 2009 with mortality rates ranging from 80 to 90% and from 66 to 97% for lambdacyhalothrin. Reduced susceptibility to deltamethrin was observed (87 to 97% mortality). The percentage mortality to permethrin, deltamethrin, lambdacyhalothrin was less than 90% in 2013 in all villages except in one village where mortality rate for deltamethrin was found to be 99%. These results clearly demonstrate the presence of pyrethroid resistance in A. arabiensis in Lower Moshi. The L1014F resistant allele was detected in one mosquito out of 642 that were screened for kdr mutation (allele frequency of 0.08%). The lack of DDT resistance coupled with previous studies showing very low frequency kdr suggests that enzyme-based mechanisms are responsible for resistance in A. arabiensis. Further studies are needed to investigate operational impact of observed resistance on malaria vector control interventions in the area.

Key words: Anopheles, resistance, mortality, dynamics, mutation, insecticide.

African Journal of Parasitology Research Vol. 2 (7), pp. 119-124, July, 2015. © International Scholars Journals

Full Length Research Paper

An assessment of the level of co-infection of malaria parasite and HIV in pregnant women in Akure, Ondo State, Nigeria

*Tekena F. Omolewa, Chinua U. I and Micheal Soyinka

Department of Biology, Faculty of Medicine, University of Ibadan, Ibadan, Nigeria.

*Corresponding author. E-mail: [email protected]

Accepted 9 March, 2015

Abstract

Malaria and human immunodeficiency virus (HIV) in pregnancy are the major factors contributing to adverse maternal and perinatal outcome. HIV increases pregnant women’s chances of contracting malaria, increases the risk of developing anaemia, delivering a low birth weight infant and premature delivery. This study was designed to investigate the level of co-infection of malaria parasite and HIV in pregnant women in State Specialist Hospital, Akure. 616 pregnant women aged 15 to 46 years who attended major referral health facilities for ante-natal purposes between February and April, 2012 were included for the study. ‘Determine’ and Uni-Gold rapid diagnostic tests kits were used to determine HIV status, giemsa stained thick blood smear of patients were examined for presence of the asexual stages of Plasmodium parasite. Out of 616 pregnant women, 28 (4.55%) were HIV positive and 597 (96.92%) had malaria parasite. Among HIV negative women, 569 (96.8%) had malaria parasite infection while 28 (100%) of the HIV positive women had the infection. This study revealed that 92.37% had malaria alone, none of the women had HIV only and 28 (4.55%) were co-infected with both pathogens, indicating that all HIV positive women also harbor malaria parasite. There was moderate correlation between HIV and malaria parasite p < 0.05 which is suggestive that women infected with HIV are most likely to be infected with malaria due to their compromised immune system which makes them more susceptible to malaria infection. The rate of malaria infection was generally high in the sampled population though majority was infected at low parasiteamia. This is therefore attributed to the endemic nature of the disease in Ondo state of Nigeria

Key words: Human immunodeficiency virus (HIV), malaria, co-infection HIV-MALARIA, antenatal care, pregnant women.