Prevalence of Molecular Markers of Plasmodium Falciparum Resistance to Proguanil and Pyrimethamine in Children with Haemoglobin Phenotypes SS and AA in Benin City, Nigeria.

BACKGROUND: Chemoprophylaxis against Plasmodium falciparum (Pf) is advocated in children with sickle cell anaemia (SCA). Among them, antifolates: proguanil and pyrimethamine had replaced initial chemoprophylactic drugs because of widespread resistance. In recent past, efficacy of these antifolates has also come under scrutiny due to increasing level of drug resistance. Specific point mutations on Plasmodium falciparum dihydrofolate reductase gene (pfdhfr) have been linked with resistance to proguanil and pyrimethamine and they can be used as markers in monitoring prevalence and level of resistance to the drugs. OBJECTIVES: To determine the prevalence of molecular markers of Plasmodium falciparum resistance to proguanil and pyrimethamine in children with SCA. METHODS: A total of 146 Plasmodium falciparum isolates (71 from children with SCA and 75 from those with Haemoglobin AA: HbAA) were evaluated for point mutations and mutant haplotypes on the pfdhfr gene using nested polymerase chain reaction amplification followed by direct sequencing. RESULTS: The triple (S108N+N51I+C59N) mutant haplotype was present in 100.0% and 96.0% of samples from children with SCA and HbAA respectively. S108T, A16V and 1164L mutationswere not present in both groups. CONCLUSION: High prevalence of triple mutant haplotype mediates significant resistance to pyrimethamine and implies that pyrimethamine resistance is fixed in the study locale. However, the absence of pfdhfr S108T and A16V mutations, which indicate specific resistance to proguanil but not to pyrimethamine, suggests that proguanil is still useful even in the face of pyrimethamine resistance. The threat of proguanil resistance is however real due to high prevalence of the triple mutant pfdhfr haplotype.

CONTEXTE: La chimioprophylaxie contre Plasmodium falciparum (Pf) est préconisée chez les enfants atteints de drépanocytose. (DCA). Parmi eux, les antifoliques : proguanil et pyriméthamine ont remplacé les médicaments chimioprophylactiques initiaux en raison d'une résistance généralisée. Ces derniers temps, l'efficacité de ces antifoliques a également été remise en question en raison de l'augmentation de la résistance aux médicaments. Des mutations ponctuelles spécifiques sur le dihydrofolate de Plasmodium falciparum dihydrofolate réductase (pfdhfr) ont été associées à la résistance au proguanil et à l'antifongiqueet elles peuvent être comme marqueurs pour surveiller la prévalence et le niveau de la résistance à ces médicaments. OBJECTIFS: Déterminer la prévalence des marqueurs moléculaires de la résistance de Plasmodium falciparum au proguanil et à la pyriméthamine chez les enfants atteints d'ACS. MÉTHODES: Un total de 146 isolats de Plasmodium falciparum (71 falciparum (71 provenant d'enfants atteints d'ACS et 75 d'enfants présentant une hémoglobine AA : HbAA) ont été évalués pour détecter des mutations ponctuelles et des haplotypes mutants sur le gène pfdhfr en utilisant une amplification en chaîne par réaction en chaîne par polymérase nichée suivie d'un séquençage direct. RÉSULTATS: L'haplotype mutant triple (S108N+N51I+C59N) était présent chez 100,0 % et 96 % des patients.était présent dans 100,0 % et 96,0 % des échantillons provenant d'enfants atteints de SCA et HbAA respectivement. Les mutations S108T, A16V et 1164L n'étaient pas présentes dans les deux groupes. CONCLUSION: La prévalence élevée de l'haplotype triple mutant est à l'origine d'une résistance significative à la pyriméthamine et à l'HbA une résistance significative à la pyriméthamine et implique que la résistance à la pyriméthamine est fixe dans le groupe pyriméthamine et implique que la résistance à la pyriméthamine est fixe dans la région étudiée. Cependant, l'absence des mutations S108T et A16V de pfdhfr, qui indiquent une résistance une résistance spécifique au proguanil mais pas à la pyriméthamine, suggère que le proguanil reste utile même en cas de résistance à la pyriméthamine résistance à la pyriméthamine. La menace de la résistance au proguanil est cependant réelle en raison de la prévalence élevée de l'haplotype triple mutant pfdhfr haplotype.

Usefulness of Mantoux Test in BCG-Vaccinated Children without a BCG Scar.

INTRODUCTION: Bacille Calmette Guerin (BCG) vaccination is an important tool for the prevention of tuberculosis especially in highly endemic countries like Nigeria. The BCG scar which develops following BCG immunization is regarded as evidence of successful vaccination. Thus, when a child fails to develop a scar there are concerns that the immunization may not have been successful. BCG scars have recently become important because of their association with improved child survival. Tuberculin sensitivity has been used as a surrogate for successful response to BCG vaccination. The aim of this study was to find out what proportion of children with scar failure is tuberculin positive. METHODS: A prospective audit of children who presented between January and December 2016 for Tuberculin skin testing (TST) because of failure to develop BCG scar was carried out. TST was carried out by intradermal injection of 0.1ml of Purified Protein Derivative into the volar aspect of the left forearm. The size of reactions was measured 72 hours later. RESULTS: Of 279 requests for TST among children aged less than 15 years, 32(11.5%) were because of BCG scar failure. There were 14 (43.8%) males and majority of the children, 22 (68.8%) were aged between 6 and 12 months. Majority, 19 (61.3%) had negative test reading (£4mm). Indeterminate values of 5-9mm were seen in 10 (32.3%) while 2 (6.5%) had positive results (³10mm) Conclusion: TSTof children without BCG scars may be useful in identifying presumptive cases of tuberculosis and children who may require prophylaxis.

Comparison of obesity, overweight and elevated blood pressure in children attending public and private primary schools in Benin City, Nigeria.

BACKGROUND: Overweight and obesity in children, and adolescents is on the rise globally. Affected children are prone to cardio-metabolic problems later in life, especially hypertension. The prevalence of obesity/overweight may differ depending on school type. Private schools are attended mostly by children of the affluent, while public schools are attended predominantly by those in the low and middle socio-economic classes. OBJECTIVE: To compare the prevalence of overweight, obesity and elevated blood pressure (BP) in pupils attending public and private primary schools in an urban community in Nigeria. MATERIALS AND METHODS: In this cross sectional study, the BMI and BP of pupils in public and private primary schools, recruited by multistage sampling method, were measured. Their nutritional status was categorized using their BMI percentiles. Analysis was by SPSS. RESULTS: A total of 1466 pupils were recruited, 814(55.5%) were in public schools and 722(49.2%) were males. The prevalence of overweight and obesity was higher in private schools 11.8% and 11.7% compared to public schools 3.3% and 0.9%. The mean systolic BP of pupils in public schools 96.8 ± 12.5 mmHg was higher than that in private schools 95.5 ± 10.2 mmHg, p = 0.032. Distribution of pupils with prehypertension and hypertension between private and public schools was not significantly different. CONCLUSION: The prevalence of overweight and obesity is higher in pupils attending private schools compared to those in public school. Urgent measures are needed to stem this tide through education, weight reduction and physical activity programs, especially in pupils attending private schools.

Caregivers' vector control methods and their impact on malaria outcome in under-five presenting in tertiary health institution in Nigeria.

BACKGROUND AND AIMS: Integrated vector control especially use of insecticide-treated bed nets have been reported as effective malaria preventive strategies. This study aimed at documenting factors that influence regular use of insecticide-treated nets in under-fives and impact of vector control methods on malaria outcome (severe malaria prevalence and mortality) in under-fives presenting in a tertiary health institution in Nigeria. METHODS: Cross-sectional study carried out from June 2012 and July 2013. Data was obtained by researcher-administered questionnaire and malaria was confirmed in each child by microscopy. RESULTS: 329 caregiver (31.2 ± 6.0 years) /child (20.7 ± 14.0 months) pair were recruited. Netting of doors/windows (80.0%) was the most practiced vector control method. 177 (53.8%) caregivers possessed insecticide-treated bed nets, and only a quarter of their under-5s regularly sleep in these nets. Children from lower social class statistically significantly sleep in the nets (p = 0.03), however, presence of 2 or more nets in a household independently predicted its regular use for the under-5s (ß = 1.09, OR = 3, p = 0.02). Prevalence of severe malaria was 36.2% and mortality was 52 per 1000. Combination of regular use of insecticide treated nets, environmental sanitation, indoor insecticide spray and netting of household doors/windows significantly predicted low prevalence of severe malaria compared to each of the malaria vector control methods used singly by the caregivers (ß = 1.66, OR =5.0, p = 0.04). CONCLUSIONS: Integrated vector control remains the most effective method of malaria vector control at the community.

Risk Factors and Clinical Correlates of Hepatitits B Seroprevalence in Nigerian Children

Introduction: Establishing risk factors for a disease enables early identification of those with the disease (through screening) as well as targeted prevention and control measures. The significance and relative importance of such risk factors may differ based on geographic location and they may change over time with the institution of control measures. In this study we examined the association between HBsAg seropositivity; some risk factors and clinical features.Methodology: Consecutive children aged 2 months to 16 years who were admitted to a Children's Emergency Room were recruited. Data on the presence / absence of risk factors such as previous blood transfusion; scarifications; receipt of unsafe injections and previous surgery were obtained. History to ascertain previous or present history of jaundice and pale coloured stool was obtained. Examination to detect hepatomegaly and spenomegaly was carried out. Blood samples were assayed for HBsAg.Results: Of the 150 children recruited 84(56%) were male. The mean (SD) age of the children was 33.0(39.1) months. HBsAg seropositivity was 13.9%. Circumcision; scarification; ear piercing; history of blood transfusion; receipt of unsafe injections; present/ past history of jaundice and malnutrition were not significantly associated with being seropositive (p0.05).Conclusion: This study did not identify any pathognomonic clinical feature of hepatitis b seroprevalence. The lack of association between HBsAg seropositivity and the studied risk factors may represent a real improvement in infection control measures. Further research is required to ascertain if there are still some unidentified risk factors for hepatitis B transmission in Nigerian children

Serum zinc values in children with congenital heart disease.

BACKGROUND: Some children with congenital heart diseases (CHD) may have increased pulmonary blood flow that causes recurrent bronchopneumonia and congestive heart failure. Serum zinc is reduced in children with pneumonia and patients on diuretics. OBJECTIVE: To evaluate the serum zinc level of children with CHD and their controls without CHD. METHOD: The subjects were 41 children with CHD confirmed on echocardiography recruited from a paediatric cardiology clinic in a tertiary centre in Nigeria. The controls were 41 children without CHD. Biodata and anthropometric measurements were taken. The serum zinc was determined using atomic absorption spectrophotometer method. RESULT: The mean difference in the serum zinc of the subjects 101.3 ± 21.6 µg/dl and controls 106.5 ± 18.3 µg/dl, was not significant, p = 0.351. The subjects with pneumonia had a lower mean serum zinc value 89.5 ± 15.0 µg/dl compared to those without pneumonia 103.9 ± 22.2 µg/dl, p = 0.006. The mean serum zinc values of the subjects on diuretic was not statistically different from those not on diuretic, p = 0.599. CONCLUSION: The serum zinc levels of the subjects and controls were not significantly different. Children with CHD and pneumonia had significantly lower zinc level compared to those without pneumonia.

Cardiovascular responses to blood transfusion in children with anemic heart failure.

INTRODUCTION: This study evaluated the cardiovascular responses to blood transfusion in children with anemic heart failure using mostly clinical parameters. MATERIALS AND METHODS: Consecutive patients with anemic heart failure presenting to a children's emergency room and requiring blood transfusion were assessed for heart rate (HR), respiratory rate (RR), systolic blood pressure (SBP), liver size, and oxygen saturation (O 2 sat) pre-transfusion, 1-2 h into transfusion (intra-transfusion), immediate post-transfusion, and at late post-transfusion (24 h later). RESULTS: A total of 75 patients were recruited of which 46 (61.3%) were males. Their mean age was 43.8 ± 40.3 months while their mean PCV at presentation was 15.0 ± 4.5%. There was a significant mean net reduction of 10 beat per minute (bpm) between the pre (139.7 ± 25.2 bpm) and intra-transfusion (129.6 ± 22.0 bpm) HR, P = 0.0004. The mean net reduction of 4 cycles/ min between the pre and intra-transfusion RR was also significant, P = 0.0033. The two parameters declined in values subsequently. CONCLUSION: The HR and RR are two easily measurable indices with reduction in HR and RR by 10 bpm and 4 cycles/min, respectively, from pre-transfusion to intra-transfusion observations.

Re-emergence of diphtheria and pertussis: implications for Nigeria.

In the prevaccine era pertussis and diphtheria were responsible for significant morbidity and mortality in children. In the United States of America more than 125,000 cases of diphtheria with 10,000 deaths were reported annually in the 1920s. In the same period about 1.7 million cases of pertussis with 73,000 deaths were also reported. Vaccination against these two diseases has caused remarkable reduction in the morbidity and mortality from these diseases both in developed and developing countries. The initial vaccines were the combined diphtheria toxoid and whole cell pertussis vaccine. The recent reported increases in the incidence of these two diseases in countries, which maintain high childhood vaccination coverage is a source of concern not only to these countries but also for developing countries with weak immunization programmes. Nigeria for example reported 11,281 cases of pertussis, the second highest number of cases worldwide in 2009. Waning immunity in adult and adolescent populations has been reported and epidemiologically, more cases are being reported in adults and adolescents. Also a high proportion of pertussis cases are being reported in infants and most of these infant cases are linked to adult/adolescent sources. Recent approaches to control of these diseases include booster doses of combined diphtheria, tetanus and acellular pertussis vaccine while the cocooning strategy (which is immunizing every person who is likely to have contact with a given infant such as mother, father, grandparents and health care workers) is being used in a number of countries. For developing countries including Nigeria where the capacity for making the diagnosis of both diseases is limited, strengthening of routine immunization as well as diagnostic capacity is imperative. Research to determine current levels of immunity in children, adolescents and adults is required. This will enable the determination of the need for booster doses and the age at which such boosters should be administered. Improved surveillance will be needed to delineate current epidemiological profiles of both diseases.

Normal oscillometric heart rate of term African infants in the early days of life.

BACKGROUND: Heart rate (HR) measurement is an important means of evaluating clinical status of newborns. Differences in HR between caucasian and negroid infants have been reported. Clinical estimation of HR is less accurate than estimates using devices. AIM: To establish the normal HR of term negroid newborns in the early days of life using an oscillometric device. METHODS: The mean of three HR readings of consecutively recruited term newborns was obtained with Dinamp 8100 monitor (Critikon, Tampa, FL). On recruitment, the infants were aged between 1 and 4 days. Gestational age was determined by menstrual dates and the Dubowitz method. RESULTS: A total of 473 term newborns were recruited, 229 (48.4%) of whom were males. Median HR was 132 (range 90-189) beats per minute (bpm). The lowest median HR (130 bpm) was obtained on the 3rd day of life and this was significantly different from the highest value of 138 bpm recorded on the 4th day of life (P = 0.025). The 5th and 95th percentiles were 111 and 158 bpm, respectively. CONCLUSION: The lower limit of the range of oscillometrically generated normal HR in term African newborns in the early days of life is lower than that which is commonly used in clinical practice.

Breast Feeding Practice among Medical Women in Nigeria.

BACKGROUND: Health care workers are important in the promotion, protection and support of breast feeding. Their ability to do this may be influenced by their knowledge, personal experiences and work. PATIENTS AND METHOD: The breast feeding experience of 36 female medical doctors who had babies within the preceding two years and had resumed work was evaluated using a semi-structured self administered questionnaire. RESULT: All respondents knew that babies should be exclusively breast fed for the first six months of life but only 60% knew that breast feeding should continue until two years. The exclusive breast feeding rate for the studied doctors was 11.1%. Before their babies were six months old, about 75% of respondents had resumed work whilst over 50% had started taking calls. Most could not breast feed during working or call hours. Alternative feeds during working or call hours included expressed breast milk in 34.4% and infant formula in 21.9%. Feeding bottle was the major method (77.4%) for feeding these alternatives. Work schedule was rearranged to allow breast feeding in only 27.3% of respondents. CONCLUSION: Failure to carry out exclusive breast feeding, the use of infant formula and feeding bottles (rather than cup feeding) are practices that may be inimical to the practice of breast feeding in society in general. The suboptimal breast feeding experience in these doctors and the identified knowledge deficits may limit their effectiveness in promoting and supporting breast feeding among their patients and communities. Female medical personnel should be empowered to carry out optimal feeding of their own infants.

Attitude of health care workers to patients and colleagues infected with human immunodeficiency virus.

Discrimination against persons living with HIV/AIDS in hospital settings has been documented. This study examined the attitude of health care workers (HCWs) to nurses, doctors and patients infected with HIV. A total of 345 respondents selected by multistage sampling techniques were surveyed, using a semi-structured questionnaire, which explored respondents' attitude to HIV-infected patients and colleagues with HIV/AIDS. HCWs were unwilling to accept that medical procedures be carried out on them by HIV-infected doctors and nurses, with almost 80% refusing surgery or assistance at surgery on them by an HIV-infected doctor or nurse. They were also significantly more unwilling to accept that medical procedures be carried out on them by an infected colleague, compared with their carrying out the same procedure on an HIV-infected patient. Thus, HCWs seemed to believe that the risk of contracting HIV was higher if an infected HCW were to perform medical procedures on them, and fear of contracting HIV seemed to be the driving force for their negative attitudes. Education on occupational risks of HIV, provision of a safe working environment with enforcement of universal precautions, as well as provision of post-exposure prophylaxis are suggested as ways to enable HCWs to change their attitudes.

Attitude of Health Care Workers to Patients and Colleagues Infected with Human Immunodeficiency Virus

Discrimination against persons living with HIV/AIDS in hospital settings has been documented. This study examined the attitude of health care workers (HCWs) to nurses; doctors and patients infected with HIV. A total of 345 respondents selected by multistage sampling techniques were surveyed; using a semi-structured questionnaire; which explored respondents' attitude to HIV-infected patients and colleagues with HIV/AIDS. HCWs were unwilling to accept that medical procedures be carried out on them by HIV-infected doctors and nurses; with almost 80refusing surgery or assistance at surgery on them by an HIV-infected doctor or nurse. They were also significantly more unwilling to accept that medical procedures be carried out on them by an infected colleague; compared with their carrying out the same procedure on an HIV-infected patient. Thus; HCWs seemed to believe that the risk of contracting HIV was higher if an infected HCW were to perform medical procedures on them; and fear of contracting HIV seemed to be the driving force for their negative attitudes. Education on occupational risks of HIV; provision of a safe working environment with enforcement of universal precautions; as well as provision of post-exposure prophylaxis are suggested as ways to enable HCWs to change their attitudes