Tobias Apinjoh

Dr. Tobias Apinjoh


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 February 2015 in PLOS ONE
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Journal Article
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TATobias Apinjoh
Tobias Apinjoh
JAJudith K. Anchang-Kimbi
Judith K. Anchang-Kimbi
RMRegina N. Mugri
Regina N. Mugri
DTDelphine A. Tangoh
Delphine A. Tangoh
RNRobert V. Nyingchu
Robert V. Nyingchu
EAEric A. Achidi
Eric A. Achidi
Insecticide Treated Nets (ITNs) have been shown to reduce morbidity and mortality, but coverage and proper utilization continues to be moderate in many parts of sub-Saharan Africa. The gains made through a nationwide free distribution were explored as well as the effect on malaria prevalence in semi-urban and rural communities in south western Cameroon. A cross sectional survey was conducted between August and December 2013. Information on net possession, status and use were collected using a structured questionnaire while malaria parasitaemia was determined on Giemsa-stained blood smears by light microscopy. ITN ownership increased from 41.9% to 68.1% following the free distribution campaign, with 58.3% (466/799) reportedly sleeping under the net. ITN ownership was lower in rural settings (adjusted OR = 1.93, 95%CI = 1.36–2.74, p<0.001) and at lower altitude (adjusted OR = 1.79, 95%CI = 1.22–2.62, p = 0.003) compared to semi-urban settings and intermediate altitude respectively. Conversely, ITN usage was higher in semi-urban settings (p = 0.002) and at intermediate altitude (p = 0.002) compared with rural localities and low altitude. Malaria parasitaemia prevalence was higher in rural (adjusted OR = 1.63, 95%CI = 1.07–2.49) compared to semi-urban settings and in those below 15 years compared to those 15 years and above. Overall, participants who did not sleep under ITN were more susceptible to malaria parasitaemia (adjusted OR = 1.70, 95%CI = 1.14–2.54, p = 0.009). Despite the free distribution campaign, ITN ownership and usage, though improved, is still low. As children who reside in rural settings have greater disease burden (parasitemia) than children in semi-urban settings, the potential gains on both reducing inequities in ITN possession as well as disease burden might be substantial if equitable distribution strategies are adopted.

30 April 2014 in Malaria Journal
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JAJudith K Anchang-Kimbi
Judith K Anchang-Kimbi
EAEric A Achidi
Eric A Achidi
TATobias Apinjoh
Tobias Apinjoh
RMRegina N Mugri
Regina N Mugri
HCHanesh Fru Chi
Hanesh Fru Chi
MTMarita Troye-Blomberg
Marita Troye-Blomberg
The determinants and barriers for delivery and uptake of IPTp vary with different regions in sub-Saharan Africa. This study evaluated the determinants of ANC clinic attendance and IPTp-SP uptake among parturient women from Mount Cameroon Area and hypothesized that time of first ANC clinic attendance could influence uptake of IPTp-SP/dosage and consequently malaria parasite infection status at delivery.

27 November 2013 in PLOS ONE
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TATobias Apinjoh
Tobias Apinjoh
JAJudith K. Anchang-Kimbi
Judith K. Anchang-Kimbi
CNClarisse Njua-Yafi
Clarisse Njua-Yafi
RMRegina N. Mugri
Regina N. Mugri
ANAndre N. Ngwai
Andre N. Ngwai
ICin collaboration with The MalariaGEN Consortium
in collaboration with The MalariaGEN Consortium
P. falciparum malaria is one of the most widespread and deadliest infectious diseases in children under five years in endemic areas. The disease has been a strong force for evolutionary selection in the human genome, and uncovering the critical human genetic factors that confer resistance to the disease would provide clues to the molecular basis of protective immunity that would be invaluable for vaccine development. We investigated the effect of single nucleotide polymorphisms (SNPs) on malaria pathology in a case- control study of 1862 individuals from two major ethnic groups in three regions with intense perennial P. falciparum transmission in Cameroon. Twenty nine polymorphisms in cytokine and toll-like receptor (TLR) genes as well as the sickle cell trait (HbS) were assayed on the Sequenom iPLEX platform. Our results confirm the known protective effect of HbS against severe malaria and also reveal a protective effect of SNPs in interleukin-10 (IL10) cerebral malaria and hyperpyrexia. Furthermore, IL17RE rs708567 GA and hHbS rs334 AT individuals were associated with protection from uncomplicated malaria and anaemia respectively in this study. Meanwhile, individuals with the hHbS rs334 TT, IL10 rs3024500 AA, and IL17RD rs6780995 GA genotypes were more susceptible to severe malarial anaemia, cerebral malaria, and hyperpyrexia respectively. Taken together, our results suggest that polymorphisms in some immune response genes may have important implications for the susceptibility to severe malaria in Cameroonians. Moreover using uncomplicated malaria may allow us to identify novel pathways in the early development of the disease.

6 February 2016 in Malaria Journal
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NCNJUA YAFI Clarisse
NJUA YAFI Clarisse
EAEric A. Achidi
Eric A. Achidi
JAJudith K. Anchang-Kimbi
Judith K. Anchang-Kimbi
TATobias Apinjoh
Tobias Apinjoh
RMRegina N. Mugri
Regina N. Mugri
TNTheresa Nkuo-Akenji
Theresa Nkuo-Akenji
Malaria and helminthiases frequently co-infect the same individuals in endemic zones. Plasmodium falciparum and helminth infections have long been recognized as major contributors to anaemia in endemic countries. Several studies have explored the influence of helminth infections on the course of malaria in humans but how these parasites interact within co-infected individuals remains controversial. In a community-based longitudinal study from March 2011 to February 2012, the clinical and malaria parasitaemia status of a cohort of 357 children aged 6 months to 10 years living in Mutengene, south-western region of Cameroon, was monitored. Following the determination of baseline malaria/helminths status and haemoglobin levels, the incidence of malaria and anaemia status was determined in a 12 months longitudinal study by both active and passive case detection. Among all the children who completed the study, 32.5 % (116/357) of them had at least one malaria episode. The mean (±SEM) number of malaria attacks per year was 1.44 ± 0.062 (range: 1–4 episodes) with the highest incidence of episodes occuring during the rainy season months of March–October. Children <5 years old were exposed to more malaria attacks [OR = 2.34, 95 % CI (1.15–4.75), p = 0.019] and were also more susceptible to anaemia [OR = 2.24, 95 % CI (1.85–4.23), p = 0.013] compared to older children (5–10 years old). Likewise children with malaria episodes [OR = 4.45, 95 % CI (1.66–11.94), p = 0.003] as well as those with asymptomatic parasitaemia [OR = 2.41, 95 % CI (1.58–3.69) p < 0.001] were susceptible to anaemia compared to their malaria parasitaemia negative counterparts. Considering children infected with Plasmodium alone as the reference, children infected with helminths alone were associated with protection from anaemia [OR = 0.357, 95 % CI (0.141–0.901), p = 0.029]. The mean haemoglobin level (g/dl) of participants co-infected with Plasmodium and helminths was higher (p = 0.006) compared to participants infected with Plasmodium or helminths alone. Children below 5 years of age were more susceptible to malaria and anaemia. The high prevalence of anaemia in this community was largely due to malaria parasitaemia. Malaria and helminths co-infection was protective against anaemia.

5 August 2015 in BMC Infectious Diseases
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TATobias Apinjoh
Tobias Apinjoh
RTRolland Bantar Tata
Rolland Bantar Tata
JAJudith K. Anchang-Kimbi
Judith K. Anchang-Kimbi
HCHanesh F. Chi
Hanesh F. Chi
EFEleanor M. Fon
Eleanor M. Fon
EAEric A. Achidi
Eric A. Achidi
Malaria remains a major global health burden despite the intensification of control efforts, due partly to the lack of an effective vaccine. Information on genetic diversity in natural parasite populations constitutes a major impediment to vaccine development efforts and is limited in some endemic settings. The present study characterized diversity by investigating msp1 block 2 polymorphisms and the relationship between the allele families with ethnodemographic indices and clinical phenotype. Individuals with asymptomatic parasitaemia (AP) or uncomplicated malaria (UM) were enrolled from rural, semi-rural and semi-urban localities at varying altitudes along the slope of mount Cameroon. P. falciparum malaria parasitaemic blood screened by light microscopy was depleted of leucocytes using CF11 cellulose columns and the parasite DNA genotyped by nested PCR. Length polymorphism was assessed in 151 field isolates revealing 64 (5) and 274 (22) distinct recombinant and major msp1 allelic fragments (genotypes) respectively. All family specific allelic types (K1, MAD20 and RO33) as well as MR were observed in the different locations, with K1 being most abundant. Eighty seven (60 %) of individuals harbored more than one parasite clone, with a significant proportion (p = 0.009) in rural compared to other settings. AP individuals had higher (p = 0.007) K1 allele frequencies but lower (p = 0.003) mean multiplicity of genotypes per infection (2.00 ± 0.98 vs. 2.56 ± 1.17) compared to UM patients. These results indicate enormous diversity of P. falciparum in the area and suggests that allele specificity and complexity may be relevant for the progression to symptomatic disease.

3 September 2019 in BMC Public Health
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CNCharles Njumkeng
Charles Njumkeng
TATobias Apinjoh
Tobias Apinjoh
JAJudith K. Anchang-Kimbi
Judith K. Anchang-Kimbi
EAElvis Tajoache Amin
Elvis Tajoache Amin
ETElvis A. Tanue
Elvis A. Tanue
EAEric A. Achidi
Eric A. Achidi
Insecticide-treated nets (ITNs) are a widely used tool that has been proven to be effective in the prevention and control of malaria in malaria endemic countries. However, usage varies among households and can greatly affect the benefits of ITNs as a control tool for malaria transmission. This study determined the coverage and usage of ITNS as well as associated factors and the effect of coverage and usage on the prevalence of malaria parasitemia within households in the Mount Cameroon area. A cross-sectional survey was conducted between August and September 2014 in six communities within the Mount Cameroon area. Households within the communities were enrolled through multistage sampling and household survey was done using a structured questionnaire. Capillary blood was collected for malaria parasite determination. Data was analysed using SPSS version 20 for windows. Differences in proportions were assessed using the Chi-square test while factors affecting ITNs usage were assessed in multivariate logistic regression at a statistical significance of P ≤ 0.05. A total of 504 households were surveyed, 1564 bed spaces reported while 915(58.5, 95% CI: 56.1–60.9) of the bed spaces had nets and 391(77.6, 95% CI, 74.0–80.2) of the households had at least one bed net. The odds of using ITNs was 2 folds higher (OR = 2.41; 95% CI 1.58–3.69 p = 0.001) and 3 folds higher (OR = 3.149, 95% CI 1.53–6.47 p = 0.002) among houses with 5 to 9 occupants and above 10 occupants respectively when compared to houses with less than 5 occupants. In addition, Individuals living in cement block houses were less likely to use ITNs. Compared to those living in wooden houses (OR = 0.488, 95% CI: 0.269–0.885; p = 0 .018). Rural communities had lower ITN coverage compared to semi-urban communities (p = 0.0001). Increase in ITNs coverage significantly reduces malaria prevalence (correlation − 0.899, p = 0.015). Despite the efforts made to scale up ITN distribution so that universal coverage can be attained, coverage remains low. Increasing coverage and putting in place a mechanism to replace torn nets will go a long way reduce the prevalence of malaria parasitemia.