Prevalence and risk factors of coliform-associated mastitis and antibiotic resistance of coliforms from lactating dairy cows in North West Cameroon.

BACKGROUND: Coliform bacteria are major causative agents of bovine mastitis, a disease that has devastating effect on dairy animal health and milk production. This cross-sectional study, carried out in the North West region of Cameroon, sought to determine the prevalence of bovine mastitis, coliforms associated with bovine mastitis, risk factors for infection and the antibiotic resistance pattern of coliform bacterial isolates. MATERIALS AND METHODS: A total of 1608 udder quarters were sampled from 411 cows using a questionnaire, clinical examination, California Mastitis Test and milk culture. Primary isolation of coliform bacteria was done on MacConkey agar while identification of coliforms employed Gram-staining and biochemical testing. Each coliform bacterial isolate was challenged with 11 antibiotics using the Kirby-Bauer disc diffusion method. RESULTS: The prevalence of mastitis was 53.0% (218/411) and 33.1% (532/1608) at the cow- and quarter-levels respectively. Overall, 21.9% (90/411) cows and 8.2% (132/1608) udder quarters showed coliform mastitis. Escherichia coli was isolated in 7.0% of mastitis milk, and other coliforms isolated were Enterobacter cloacae (12.6%), Klebsiella pneumoniae (2.4%), Enterobacter sakazakii (1.1%), Klebsiella oxytoca (0.8%), Citrobacter freudii (0.4%), Serratia ficaria (0.4%) and Serratia liquefaciens (0.2%). Lactation stage, breed, history of mastitis and moist/muddy faeces contaminated environment were significantly associated (P-value < 0.05) with coliform mastitis. Coliform isolates (99.0%; 203/205) were resistant to at least one antibiotic tested. Amoxicillin had the highest resistance (88.8%) while norfloxacin had the least resistance (3.4%). Multidrug resistance was exhibited by 52.7% (108/205) of the isolates in a proportion of 27.8% Enterobacter cloacae, 10.7% E. coli, 6.3% Klebsiella pneumoniae, 2.9% Enterobacter sakazakii, 2.0% Klebsiella oxytoca, 1.0% Citrobacter freundii, 1.0% Serratia ficaria, 0.5% Serratia liquefaciens and 0.5% Serratia odorifera. CONCLUSION: Results indicate a need to educate these dairy farmers about mastitis (particularly subclinical), proper hygiene methods in milking and the public health implications of consuming contaminated raw milk.

The effect of climatic factors on the number of malaria cases in an inland and a coastal setting from 2011 to 2017 in the equatorial rain forest of Cameroon.

BACKGROUND: Weather fluctuation affects the incidence of malaria through a network of causuative pathays. Globally, human activities have ultered weather conditions over time, and consequently the number of malaria cases. This study aimed at determining the influence of humidity, temperature and rainfall on malaria incidence in an inland (Muyuka) and a coastal (Tiko) settings for a period of seven years (2011-2017) as well as predict the number of malaria cases two years after (2018 and 2019). METHODS: Malaria data for Muyuka Health District (MHD) and Tiko Health District (THD) were obtained from the Regional Delegation of Public Health and Tiko District Health service respectively. Climate data for MHD was obtained from the Regional Delegation of Transport while that of THD was gotten from Cameroon Development Coorporation. Spearman rank correlation was used to investigate the relationship between number of malaria cases and the weather variables and the simple seasonal model was used to forecast the number of malaria cases for 2018 and 2019. RESULTS: The mean monthly rainfall, temperature and relative humidity for MHD were 200.38 mm, 27.050C, 82.35% and THD were 207.36 mm, 27.57 °C and 84.32% respectively, with a total number of malaria cases of 56,745 and 40,160. In MHD, mean yearly humidity strongly correlated negatively with number of malaria cases (r = - 0.811, p = 0.027) but in THD, a moderate negative yearly correlation was observed (r = - 0.595, p = 0.159). In THD, the mean seasonal temperature moderately correlated (r = 0.599, p = 0.024) positively with the number of malaria cases, whereas MHD had a very weak negative correlation (r = - 0.174, p = 0.551). Likewise mean seasonal rainfall in THD moderately correlated (r = - 0.559, p = 0.038) negatively with malaria cases, contrary to MHD which showed a very weak positive correlation (r = 0.425, p = 0.130). The simple seasonal model predicted 6,842 malaria cases in Muyuka, for 2018 and same number for 2019, while 3167 cases were observed in 2018 and 2848 in 2019. Also 6,738 cases of malaria were predicted for MHD in 2018 likewise 2019, but 7327 cases were observed in 2018 and 21,735 cases in 2019. CONCLUSION: Humidity is the principal climatic variable that negatively influences malaria cases in MHD, while higher seasonal temperatures and lower seasonal rain fall significantly increase malaria cases in THD.

Detection of Antimicrobial Resistance, Pathogenicity, and Virulence Potentials of Non-Typhoidal Salmonella Isolates at the Yaounde Abattoir Using Whole-Genome Sequencing Technique.

One of the crucial public health problems today is the emerging and re-emerging of multidrug-resistant (MDR) bacteria coupled with a decline in the development of new antimicrobials. Non-typhoidal Salmonella (NTS) is classified among the MDR pathogens of international concern. To predict their MDR potentials, 23 assembled genomes of NTS from live cattle (n = 1), beef carcass (n = 19), butchers' hands (n = 1) and beef processing environments (n = 2) isolated from 830 wet swabs at the Yaounde abattoir between December 2014 and November 2015 were explored using whole-genome sequencing. Phenotypically, while 22% (n = 5) of Salmonella isolates were streptomycin-resistant, 13% (n = 3) were MDR. Genotypically, all the Salmonella isolates possessed high MDR potentials against several classes of antibiotics including critically important drugs (carbapenems, third-generation cephalosporin and fluoroquinolone). Moreover, >31% of NTS exhibited resistance potentials to polymyxin, considered as the last resort drug. Additionally, ≤80% of isolates harbored "silent resistant genes" as a potential reservoir of drug resistance. Our isolates showed a high degree of pathogenicity and possessed key virulence factors to establish infection even in humans. Whole-genome sequencing unveiled both broader antimicrobial resistance (AMR) profiles and inference of pathogen characteristics. This study calls for the prudent use of antibiotics and constant monitoring of AMR of NTS.

Prevalence and virulence gene profiles of Escherichia coli O157 from cattle slaughtered in Buea, Cameroon.

BACKGROUND: Escherichia coli O157 is an emerging foodborne pathogen of great public health concern. It has been associated with bloody diarrhoea, haemorrhagic colitis and haemolytic uremic syndrome in humans. Most human infections have been traced to cattle and the consumption of contaminated cattle products. In order to understand the risk associated with the consumption of cattle products, this study sought to investigate the prevalence and identify virulence genes in E. coli O157 from cattle in Cameroon. METHOD: A total of 512 rectal samples were obtained and analysed using conventional bacteriological methods (enrichment on modified Tryptone Soy Broth and selective plating on Cefixime-Tellurite Sorbitol Mac-Conkey Agar) for the isolation of E. coli O157. Presumptive E. coli O157 isolates were confirmed serologically using E. COLIPROTM O157 latex agglutination test and molecularly using PCR targeting the rfb gene in the isolates. Characterisation of the confirmed E. coli O157 strains was done by amplification of stx1, stx2, eaeA and hlyA virulence genes using both singleplex and multiplex PCR. RESULTS: E. coli O157 was detected in 56 (10.9%) of the 512 samples examined. The presence of the virulence genes stx2, eaeA and hylA was demonstrated in 96.4% (54/56) of the isolates and stx1 in 40 (71.4%) of the 54. The isolates exhibited three genetic profiles (I-III) with I (stx1, stx2, eaeA and hlyA) being the most prevalent (40/56; 71.4%) while two isolates had none of the virulence genes tested. CONCLUSION: A proportion of cattle slaughtered in abattoirs in Buea are infected with pathogenic E. coli O157 and could be a potential source of human infections. We recommend proper animal food processing measures and proper hygiene be prescribed and implemented to reduce the risk of beef contamination.

Molecular epidemiology of noroviruses in children under 5 years of age with acute gastroenteritis in Yaoundé, Cameroon.

Norovirus is a common cause of acute gastroenteritis (AGE) among children in developing countries. Limited data on the prevalence and genetic variability of norovirus are available in Cameroon, where early childhood mortality due to AGE is common. We tested 902 fecal specimens from children younger than 5 years of age hospitalized with AGE between January 2010 and December 2013. Overall, 76 (8.4%) samples tested positive for norovirus, of which 83% (63/76) were among children below 12 months old. Most of the noroviruses detected were in children infected between July and December of each year. All norovirus-positive specimens were genotyped, with 80% (61/76) being GII.4 (three variants detected). Genotypes GI.2, GI.6, GII.1, GII.2, GII.3, GII.6, GII.16, GII.17, and GII.21 were also detected. Interestingly, GII.4 Sydney and GII.17 Kawasaki viruses were found as early as 2010, years before their emergence globally. This study suggests norovirus is a significant cause of moderate to severe gastroenteritis among young children in Cameroon. The results are important to highlight appropriate prevention and control strategies for reducing the burden of norovirus disease.

Helicobacter pylori in patients with gastritis in West Cameroon: prevalence and risk factors for infection.

OBJECTIVES: Helicobacter pylori is a pathogenic bacterium that parasitizes the gastric mucous layer and the epithelial lining of the stomach causing duodenal ulcers, gastric ulcers and cardiovascular disease amongst others. This study aimed at establishing the epidemiologic profile of H. pylori infection in gastritis patients presenting at the Melong District Hospital. RESULTS: Blood, stool and epidemiological data collected from 500 patients were analyzed for the presence of H. pylori antibody in serum, antigen in stool and elucidation of risk factors captured in questionnaires. Of 500 blood samples, 217 (43.4%) were seropositive with male and female seroprevalences of 45.5% (61/134) and 42.6% (156/366) respectively. Similarly, 47.4% (237/500) samples tested positive for stool antigen with prevalences of 47.0% (63/134) for males and 47.5% (174/366) for females. The antigen prevalence was higher (53.2%; 118/222) in older patients (> 50 years) than in younger patients (42.8%; 119/278; P = 0.021). The antigen test had a higher (47.4%) prevalence than the antibody test (43.4%). Educational level, source of income, source of drinking water, age of patients, and alcohol consumption had positive associations with H. pylori infection. These results have clinical and epidemiological significance and call for intervention to mitigate the situation.

Detection of Ehrlichia ruminantium infection in cattle in Cameroon.

OBJECTIVES: Ehrlichia ruminantium infection (heartwater) is a major constraint that impacts negatively on the cattle industry development in sub-Saharan Africa and so far, little is known of the presence of heartwater in cattle in Cameroon. This study sought to investigate the prevalence of E. ruminantium infection in cattle in Cameroon and to determine the predictors of infection. RESULTS: A species-specific semi-nested pCS20 polymerase chain reaction was used to screen the buffy coats from 182 cattle (comprising 82 cattle that received intensive tick control regimen and 100 cattle on strategic tick control) from two study sites in Cameroon for E. ruminantium DNA in a cross-sectional study. E. ruminantium infection was confirmed in 12 (6.6%) of the 182 cattle comprising 11 that received intensive tick control and one on strategic tick control. Of the 12 cattle detected, 11 were apparently healthy and one was clinically diagnosed of heartwater. All DNA sequences of pCS20 amplicons were identical to each other (a representative sequence deposited in GenBank under accession number JQ039939). These findings which have veterinary and epidemiological significance, suggest the need for further investigation to determine the extent and role of heartwater in cattle in Cameroon.

Genetic Studies of Vibrio cholerae in South West Cameroon-A Phylogenetic Analysis of Isolates from the 2010-2011 Epidemic.

INTRODUCTION: During the cholera outbreak from 2010 to 2011 in Cameroon, 33,192 cases with 1,440 deaths (case fatality ratio 4.34%) were reported to the World Health Organization. Of these, the South West Region reported 3,120 clinical cases. This region is in the Equatorial Monsoon climatic subzone of Cameroon, close to the coast, raising questions as to whether cases were linked with development of environmental reservoirs. METHODS: In an investigation conducted by the Laboratory for Emerging Infectious Diseases, University of Buea, toxigenic V. cholerae O1 were isolated from diarrheal stool samples from 18 patients, with ages ranging from <3 to 70 years. Coordinates for clinical centers at which cases were identified were obtained using a handheld GPS, and were mapped using ArcGIS. Antibiotic susceptibility testing was performed using the Kirby 'Bauer agar disc diffusion method. The full genomes of these strains were sequenced with the Illumina MiSeq platform. De novo assembly of cholera genomes and multiple sequence alignment were carried out using the bioinformatics pipeline developed in the Emerging Pathogens Institute laboratory at the University of Florida. RESULTS/DISCUSSION: Genetic comparisons showed that isolates were closely related, with pairwise p-distances ranging from 2.25 to 14.52 10-5 nt substitutions per site, and no statistically significant correlation between the pairwise genetic distances and the geographic distances among sampling locations. Indeed, the phylogeny of the Cameroonian strains displays the typical star-like topology and intermixing of strains from different locations that are characteristic of an exponential outbreak localized around a relatively restricted area with occasional spillover to other parts of the country, likely mediated by direct human contact and human movement. Findings highlight the utility of whole genome sequencing and phylogenetic analysis in understanding transmission patterns at the local level.

Malaria infection and anaemia in HIV-infected children in Mutengene, Southwest Cameroon: a cross sectional study.

BACKGROUND: Malaria is one of the leading causes of morbidity and mortality in children and HIV infection as well as other factors may worsen the situation. This study was aimed at determining the factors influencing malaria parasite prevalence and density as well as anaemia in HIV-infected children in Mutengene, Cameroon from November, 2012 to April, 2013. METHODS: A semi-structured questionnaire was used to record information on socio-demographic factors and use of preventive measures by caregivers of HIV-infected children aged 1-15 years and of both sexes. Venous blood was collected; blood films were prepared and Giemsa-stained for parasite detection and speciation. Haemoglobin concentration was measured and the anaemic status determined. Data was analysed using Epi Info 7 software. RESULTS: A total of 234 children were studied. The overall malaria parasite prevalence was 24.8 % (58) and was significantly higher (31.9 %, P = 0 .004) in females, those who did not implement any preventive measure at all (66.7 %, P = 0.03) and children who used antiretroviral therapy (ART) (28.6 %, P = 0.02) when compared with their respective counterparts. Geometric mean parasite density (GMPD) was significantly higher (3098.4, P = 0.02) in children who presented with fever, had CD4 T cells ≥500 cells/µL (491.3, P = 0.003) and those with moderate anaemia (1658.8, P = 0.03) than their respective counterparts. Although there was no significant difference, GMPD was however higher in males (549.0); those not on ART (635.0) and highest in children <5 years old (633.0) than their respective counterparts. The overall prevalence of anaemia was 49.6 % (116). The value was significantly highest (58.3 %, P = 0.01) in the 11-15 years age group; those with CD4 T cell level 200-499 (72.7 %, P = 0.001) and children with fever (85.7 %, P = 0.01). CONCLUSION: Implementation of proper and integrated malaria preventive measures as well as frequent monitoring of anaemia on prescription of ART could likely improve the health conditions of HIV-infected children thus avoiding malaria-related morbidity and mortality.

Time for Option B+? Prevalence and characteristics of HIV infection among attendees of 2 antenatal clinics in Buea, Cameroon.

As countries consider a wider use of triple antiretroviral therapy (ART) in pregnancy, which in recent World Health Organization guidelines is called Option B+, this study sought to explore the potential implications of adopting Option B+ by characterizing HIV infection in pregnant women attending 2 semiurban antenatal clinics in Cameroon. In a descriptive cross-sectional study, consenting women were screened for HIV; positive samples were confirmed using an enzyme-linked immunosorbent assay test, and CD4 levels and HIV viral loads were determined using flow cytometry and reverse transcription-polymerase chain reaction, respectively. The seroprevalence of HIV in the 407 pregnant women screened was 8.4% (95% confidence interval: 5.9%-11.5%). The majority (82.4%) of HIV-positive women had CD4 counts >350 cells/mm(3). A quarter (25%) had undetectable viral levels (<80 copies/mL). Adopting Option B+ in this setting would result in a 5-fold increase in the number of HIV-infected pregnant women being placed on lifelong triple ART.

Genetic diversity of Ehrlichia ruminantium strains in Cameroon.

In order to investigate the extent of genetic diversity among Ehrlichia ruminantium strains in Cameroon, a partial fragment (800 bp) of the E. ruminantium map1 gene was amplified by nested polymerase chain reaction in 121 of 156 E. ruminantium pCS20-positive DNA samples extracted from ticks and cattle collected from two ranches. Deoxyribonucleic acid sequencing of the map1 gene products indicated the presence of at least 21 genotypes at the nucleotide level and 16 genotypes at the amino acid level circulating within the study sites. Some of the genotypes were identical to Antigua (U50830), Blaaukrans (AF368000) or UmBanein (U50835), whilst the others were new genotypes. Twenty-four representative sequences were deposited in GenBank and given accession numbers JX477663 - JX477674 (for sequences of tick origin) and JX486788 - JX486799 (for sequences of cattle origin). Knowledge of E. ruminantium strain diversity could be important in understanding the epidemiology of heartwater.

Malaria and haematologic parameters of pupils at different altitudes along the slope of Mount Cameroon: a cross-sectional study.

BACKGROUND: Haematologic abnormalities are features in Plasmodium falciparum infection, and anaemia is an inevitable outcome. This study examines the influence of malaria status and altitude on haematologic parameters in school-aged pupils. METHODS: A cross-sectional study was conducted among 728 school pupils aged between four and 15 years at three different altitudinal ranges along the slope of the Mount Cameroon region. The investigative methods included the use of questionnaire, clinical evaluation and laboratory investigations. Blood sample collected from each child was used for the preparation of blood films for detection of malaria parasites and assessment of malaria parasite density as well as full blood count determination using an automated haematology analyzer. RESULTS: The prevalence of malaria in the study population was 33.8% and 64.2% (158/246) of these were asymptomatic (AM). Pupils in lowlands had a significantly (P <0.05) prevalence (95% confidence interval, CI) of malaria (60.6%, CI = 54.6-65.9%) than those in middle belt (29.1%, CI = 23.9-34.8%) and highlands (7.7%, CI = 6.1-9.8%), while those in middle belt had significantly higher geometric mean parasite density (475) than those in lowlands (233) and highlands (388). The prevalence of malaria was significantly higher in children that presented with fever (40.4%, CI = 33.8-47.2%) when compared with afebrile subjects (31%, CI = 27-35.2%). Pupils with AM had a higher prevalence of leucopaenia (43.7%, CI = 35.8-51.8%), microcytosis (27.2%, CI = 20.5-34.9%), hypochromasia (27.8%, CI = 21-35.5%) and thrombocytopaenia (14.9%, CI = 8.9-22.8%) when compared with those with clinical malaria (CM). All mean haematological parameters were comparable in pupils with CM and AM, except for the mean white blood cell (WBC) counts. Pupils with AM had significantly lower (P = 0.02) mean WBC counts (5.1 ± 2.5 × 109/L) than those with CM (5.9 ± 2.3 × 109/L). Age, altitude and malaria parasitaemia was of significant influence on several haematological parameters. CONCLUSION: Altitude influenced the distribution and density of malaria parasites and was of confounding influence on the haematologic profiles. These results highlight the insidious effects of AM on the haematologic components.

Contributions of the Global Emerging Infections Surveillance and Response System Network to global health security in 2011.

In its 15th year, the Global Emerging Infections Surveillance and Response System (GEIS) continued to make significant contributions to global public health and emerging infectious disease surveillance worldwide. As a division of the US Department of Defense's Armed Forces Health Surveillance Center since 2008, GEIS coordinated a network of surveillance and response activities through collaborations with 33 partners in 76 countries. The GEIS was involved in 73 outbreak responses in fiscal year 2011. Significant laboratory capacity-building initiatives were undertaken with 53 foreign health, agriculture and/or defense ministries, as well as with other US government entities and international institutions, including support for numerous national influenza centers. Equally important, a variety of epidemiologic training endeavors reached over 4,500 individuals in 96 countries. Collectively, these activities enhanced the ability of partner countries and the US military to make decisions about biological threats and design programs to protect global public health as well as global health security.

Prevalence of Ehrlichia ruminantium in adult Amblyomma variegatum collected from cattle in Cameroon.

Ehrlichia ruminantium, the etiologic agent of the economically important disease heartwater, is an obligate intracellular bacterium transmitted by ticks of the genus Amblyomma, particularly A. hebraeum and A. variegatum. Although serologic and microscopic evidence of the presence of heartwater have been reported in ruminants in Cameroon, knowledge of E. ruminantium infection in the tick vector, A. variegatum, is lacking. In order to determine the infectivity of A. variegatum ticks by E. ruminantium, we analysed 500 un-engorged A. variegatum ticks collected by hand-picking from predilection sites from 182 cattle [115 ticks from 82 cattle at Société de Développement et d'Exploitation des Productions Animales (SODEPA) Dumbo ranch (SDR) and 385 ticks from 100 cattle at the Upper Farms ranch (UFR)] by amplification of the open reading frame (ORF) 2 of the pCS20 region of E. ruminantium. PCR amplification of the 279 bp fragment of the pCS20 region detected E. ruminantium DNA in 142 (28.4 %) of the 500 ticks with a higher infection rate (47/115; 40.9 %) observed in ticks from SDR and 24.7 % (95/385) of ticks collected from cattle at UFR. Twenty five randomly selected PCR products were sequenced and results indicated that some of the isolates shared homology with one another and to sequences of E. ruminantium in the GenBank. This report represents the first molecular evidence of E. ruminantium infection in A. variegatum ticks in Cameroon and suggests possible exposure of cattle to this pathogen in our environment.

Genetic analysis of hepatitis A virus variants circulating among children presenting with acute diarrhea in Cameroon.

Molecular investigation was undertaken of circulating hepatitis A virus (HAV) associated with cases of acute diarrhea among children under 5 years of age in Kumba-Cameroon. Reverse transcription PCR, sequencing, and phylogenetic analysis of a 371 bp segment of the VP1/P2A junction of six isolates obtained from stool samples showed the exclusive emergence of genetically related HAV subgenotype IA. All the isolates clustered within a unique lineage exhibiting a 99.5% nucleotide identity suggesting infection from a common source. The Cameroonian HAV isolates did not intermix or cluster with those from other regions of Africa and the rest of the world. Tajima's neutralization tests using the six sequences suggested HAV/IA population expansion (D = -1.37; P = 0.016). This is the first description of indigenous HAV genotypes circulating in Cameroon revealing a community-wide spread and predominance of HAV/1A infection in the Kumba area. These findings stress the need for routine molecular tracking of HAV infection as a contributory cause of acute diarrhea in Cameroonian children.

DNA sequence analysis of South African Helicobacter pylori Vacuolating Cytotoxin Gene (vacA).

Sequence diversity and population structures can vary widely among pathogenic bacteria species. In some species, all isolates are highly similar, whereas in others most of the isolates are distinguished easily. H. pylori is known for its wide genetic diversity amongst the various strains most especially in the genes involved in virulence. The aim of this study was to evaluate by PCR and sequence analysis, the genetic profile of H. pylori vacA gene (s1, s2, m1 and m2). We sequenced small DNA segments from 13 vacAs1, 10 vacAm2, 6 vacAm1 and 6 vacAs2 strains which were amplified with amplicon size of 259/286 bp, 290 bp and 352 bp for vacAs1/s2, m1 and m2 respectively. Based on similarities among our strains accession numbers were provided for seven vacAs1 (HQ709109-HQ709115), six vacAs2 (JN848463-JN848468), six vacAm1 (JN848469-JN848474) and six vacAm2 (HQ650801-HQ650806) strains. Amongst the strains studied, 98.07%, 98.58%, 97.38% and 95.41% of vacAs1, vacAs2, vacAm1 and vacAm2 of the strains were conserved respectively. Findings of this study underscores the importance of understanding the virulence composition and diversity of H. pylori in South Africa for enhanced clinico-epidemiological monitoring and pathophysiology of disease.

Risk factors for African tick-bite fever in rural central Africa.

African tick-bite fever is an emerging infectious disease caused by the spotted fever group Rickettsia, Rickettsia africae, and is transmitted by ticks of the genus Amblyomma. To determine the seroprevalence of exposure to R. africae and risk factors associated with infection, we conducted a cross-sectional study of persons in seven rural villages in distinct ecological habitats of Cameroon. We examined 903 plasma samples by using an indirect immunofluorescence assay for antibodies to R. africae and analyzed demographic and occupational data collected from questionnaires. Of the 903 persons tested, 243 (26.9%) had IgG/IgM/IgA reactive with R. africae. Persons from four of the seven village sites were significantly more likely to be seropositive (P < 0.05), and lowland forest sites tended to have higher seroprevalences. These results suggest that African tick-bite fever is common in adults in rural areas of Cameroon and that ecological factors may play a role in the acquisition of R. africae infection.

Capacity-building efforts by the AFHSC-GEIS program.

Capacity-building initiatives related to public health are defined as developing laboratory infrastructure, strengthening host-country disease surveillance initiatives, transferring technical expertise and training personnel. These initiatives represented a major piece of the Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) contributions to worldwide emerging infectious disease (EID) surveillance and response. Capacity-building initiatives were undertaken with over 80 local and regional Ministries of Health, Agriculture and Defense, as well as other government entities and institutions worldwide. The efforts supported at least 52 national influenza centers and other country-specific influenza, regional and U.S.-based EID reference laboratories (44 civilian, eight military) in 46 countries worldwide. Equally important, reference testing, laboratory infrastructure and equipment support was provided to over 500 field sites in 74 countries worldwide from October 2008 to September 2009. These activities allowed countries to better meet the milestones of implementation of the 2005 International Health Regulations and complemented many initiatives undertaken by other U.S. government agencies, such as the U.S. Department of Health and Human Services, the U.S. Agency for International Development and the U.S. Department of State.

Ehrlichia species, probable emerging human pathogens in sub-Saharan Africa: environmental exacerbation.

Ehrlichiae are obligate intracellular Gram-negative tick-borne bacteria that are responsible for life-threatening emerging human zoonoses and diseases of veterinary importance worldwide, collectively called ehrlichioses. The genus Ehrlichia consists of five recognized species, including E. canis, E. chaffeensis, E. ewingii, E. muris, and E. ruminantium. The recent discoveries of Ehrlichia species in new areas and of tick species that were previously thought to be uninfected by these agents have suggested that these agents may have wider distribution than originally thought. Environmental factors like temperature, migration, control failure, and host population have been known to exacerbate the spread of Ehrlichia species. Human cases of moderate to severe disease caused by E. chaffeensis have been reported mainly in North America. In this article, we present an overview of ehrlichiae as emerging pathogens in sub-Saharan Africa, where E. ruminantium, the causative agent of heartwater, a disease of domestic and wild ruminants, is most established. Molecular evidence indicates that E. ruminantium may be an emerging pathogen of a life-threatening human disease. Ehrlichia ruminantium is considered an agricultural biothreat, with several strains reported throughout sub-Saharan Africa, where the infection is considered endemic. Understanding the diversity of E. ruminantium and other Ehrlichia species from all geographically distinct areas of sub-Saharan Africa may enhance our knowledge of the pathogenesis and epidemiology of these pathogens.

Prevalence of Helicobacter pylori vacA, cagA and iceA genotypes in South African patients with upper gastrointestinal diseases.

Clinical response to Helicobacter pylori infection may be determined by specific virulence-associated genotypes which varies geographically. The aim of this study was to investigate the diversity of putative virulence markers of H. pylori; cagA, vacA and iceA in the Eastern Cape Province of South Africa. One hundred H. pylori strains obtained from dyspeptic patients were used. Gastric biopsies were obtained from 254 dyspeptic patients. H. pylori was cultured and strains were studied. Bacterial genotypes cagA, vacA (s and m subtypes) and iceA were analysed by PCR using specific primers. CagA was identified in 90% of the strains investigated. Fifty-eight of the 100 strains had the vacA signal sequence genotype s1 and 26 had subtype s2. Combined vacA s1/s2 was detected in 16 of the strains. VacA middle region analysis showed that 8 (8%) strains were m1 while 50 were m2. Combined vacA m1/m2 was detected in 36 of the strains. s1m2 (20%) and s2m2 (20%) genotypes were the most common allelic combinations of the vacA gene among the strains. Multiple vacA genotypes were detected in this study. Twenty-six percent of the strains identified had both iceA1 and iceA2. All our strains tested positive for the ureC (glmM) gene. This study reveals a high prevalence of vacA, cagA and iceA2.