Pneumocystis jirovecii colonisation in HIV-positive and HIV-negative subjects in Cameroon.

OBJECTIVE: To determine the prevalence of Pneumocystis pneumonia (PCP), a major opportunistic infection in AIDS patients in Europe and the USA, in Cameroon. MATERIALS AND METHODS: Induced sputum samples from 237 patients without pulmonary symptoms (126 HIV-positive and 111 HIV-negative outpatients) treated at a regional hospital in Cameroon were examined for the prevalence of Pneumocystis jirovecii by specific nested polymerase chain reaction (nPCR) and staining methods. CD4 counts and the history of antiretroviral therapy of the subjects were obtained through the ESOPE database system. RESULTS AND CONCLUSION: Seventy-five of 237 study participants (31.6%) were colonised with Pneumocystis, but none showed active PCP. The Pneumocystis colonisation rate in HIV-positive subjects was more than double that of HIV-negative subjects (42.9% vs. 18.9%, P < 0.001). In the HIV-positive group, the colonisation rate corresponds to the reduction in the CD4 lymphocyte counts. Subjects with CD4 counts >500 cells/µl were colonised at a rate of 20.0%, subjects with CD4 counts between 200 and 500 cells/µl of 42.5%, and subjects with CD4 counts <200 cells/µl of 57.1%. Colonisation with Pneumocystis in Cameroon seems to be comparable to rates found in Western Europe. Prophylactic and therapeutic measures against Pneumocystis should be taken into account in HIV care in western Africa.

Hepatitis B and C: neglected diseases among health care workers in Cameroon.

BACKGROUND: Healthcare workers (HCW) are at risk of acquiring blood-borne viral infections, particularly hepatitis B (HBV), hepatitis C (HCV), and HIV, especially in high endemic regions such as sub-Saharan Africa. METHODS: Sera from 237 hospital workers in Southwest Cameroon were tested for anti-hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg), anti-hepatitis B surface antigen (anti-HBs), anti-HCV and (on a voluntary basis) for anti-HIV. Information on pre-study testing for HBV, HCV and HIV and pre-study HBV vaccination status was collected from these individuals. RESULTS: The pre-study testing rate among participating hospital staff for HBV was 23.6% (56/237), for HCV 16% (38/237), and for HIV 91.6% (217/237). The pre-study HBV vaccination rate was 12.3% (29/237). Analysis of anti-HBc revealed that 73.4% (174/237) of the hospital staff had been infected by HBV. Active HBV infection (HBsAg positivity) was detected in 15 participants. Anti-HCV was found in four of 237 participants, HIV antibodies were detected in four of 200 participants tested. CONCLUSION: HBV and HCV are neglected diseases among HCW in sub-Saharan Africa. The vaccination rate against HBV was very low at 12.3%, and therefore anti-HBc testing should be mandatory to identify HCW requiring HBV vaccination. Testing for HBV and routine HBV vaccination for HBV-negative HCW should be strongly enforced in Cameroon.

Pneumocystis species in Brown Leghorn laying hens--a hint for an extra-mammalian reservoir.

The fungus Pneumocystis spp. causes Pneumocystis pneumonia in immunocompromised mammals including humans, whereas healthy individuals are often colonized and can transmit it to others. There is little evidence that Pneumocystis spp. is also present outside mammalian species. We describe the first detection of Pneumocystis DNA from the lungs and air sacs of laying hens from deep litter and floor husbandry systems. The DNA from chickens' lungs and air sacs was amplified with a Pneumocystis-specific mtLSU rRNA gene nested PCR and sequenced. Pneumocystis DNA was detected in 20 of 111 (18.0%) hens. The DNA sequences showed specific differences to all known Pneumocystis mtLSU sequences. In induced sputum samples of 2 of 7 farm workers at this poultry farm, human Pneumocystis jirovecii strains without these mutations were detected; therefore, a transmission between chickens and farm workers appears implausible.

High prevalence of Pneumocystis jirovecii colonization among patients with autoimmune inflammatory diseases and corticosteroid therapy.

BACKGROUND: Patients with autoimmune inflammatory diseases (AID) account for 13-36% of Pneumocystis pneumonia (PCP) cases in human immunodeficiency virus (HIV)-negative patients. Up to 88% of PCP cases in HIV-negative patients are associated with prior steroid treatment. Pulmonary colonization with Pneumocystis in HIV-negative patients is associated with corticosteroid therapy in up to 75% of cases. The aim of this study was to detect the prevalence and risk factors of pulmonary colonization with Pneumocystis jirovecii in patients with AID receiving corticosteroid therapy in comparison with healthy control persons. METHODS: We investigated induced sputa of 102 patients with AID on current corticosteroid treatment and of 117 healthy controls for the presence of P. jirovecii using polymerase chain reaction (PCR). RESULTS: Twenty-nine patients (28.5%) with AID were colonized with P. jirovecii compared to three healthy controls (2.6%) [p < 0.001, odds ratio (OR) 15.10, 95% confidence interval (CI) 4.43-51.38]. In patients with AID, age over 60 years was significantly associated with colonization (p = 0.015, OR 3.19, 95% CI 1.27-7.94). Multivariate analysis showed age to be independently associated with the colonization of P. jirovecii (95% CI 1.002-1.092). Neither duration nor dose of corticosteroid therapy nor immunosuppressive co-medication had a significant influence on P. jirovecii colonization. CONCLUSION: Patients with AID, especially those over 60 years of age, display a high prevalence of colonization with P. jirovecii. Clinicians should be aware of this and ensure that they consider the possibility of PCP when pulmonary symptoms arise in these patients.

Schistosoma mansoni: schistosomicidal effect of mefloquine and primaquine in vitro.

We investigated the effects of the anti-malarials mefloquine and primaquine against the juvenile and adult life stages of Schistosoma mansoniin vitro. Cercariae were incubated with 0.5 µg/ml, 1 µg/ml and 2 µg/ml mefloquine or primaquine and with 1 µg/ml praziquantel for 12h. Schistosomula, pre-adults and adults were incubated with 0.5 µg/ml, 1 µg/ml and 2 µg/ml mefloquine or primaquine and with 1 µg/ml praziquantel for 7 days. The viability status was classified as viable, damaged or dead and was checked every 3h for cercariae and every 12h for schistosomula, pre-adults and adults. Both, mefloquine and primaquine show time and dose-dependent schistosomicidal effects on the four life stages of S. mansoni. The promising in vitro effects on all stages of the blood fluke S. mansoni warrants further evaluation of both anti-malarials and their derivatives for their prophylactic and therapeutic values in early and late schistosomiasis in field trials.

Safety and immunogenicity of a trivalent single dose seasonal influenza vaccine containing pandemic A(H1N1) antigen in younger and elderly subjects: a phase III open-label single-arm study.

BACKGROUND: During the pandemic of the 2009 A(H1N1) influenza virus strain, 20-40% of the population in some areas were infected. Infection with A(H1N1) may be mild, with an average case fatality rate below 0.25%, but severe disease is not limited to patients with underlying medical conditions. Since A(H1N1) is expected to continue to circulate it is included in the seasonal influenza vaccines for the 2010-2011 winter season. We investigated the immunogenicity and safety of a preservative-free non-adjuvanted seasonal trivalent influenza vaccine. METHODS: We conducted a single center single-arm study involving 142 subjects (77 adults of 18-60 years and 65 subjects 61 years and above) to test the immunogenicity, safety, and tolerability of a trivalent split influenza vaccine. The vaccine contained 15µg of hemagglutinin of each of the virus strains recommended for the 2010-2011 northern hemisphere winter season (A/California/7/2009 (H1N1)-like strain; A/Perth/16/2009 (H3N2)-like strain; B/Brisbane/60/2008-like strain) in a non-adjuvanted preservative-free formulation. Antibody response to each antigen was measured by hemagglutination inhibition (HI) 21 days after immunization. Subject diary cards and additional telephone interviews were used to assess the safety profile. RESULTS: By day 21 after the vaccination, seroconversion, or a 4-fold antibody increase in HI antibody titers, was detectable against A(H1N1) in 84% and 75% of younger and older adults, against A(H3N2) in 80% and 57%, and against the B influenza strain in 61% and 33%. HI antibody titers of 40 or more were observed against A(H1N1) in 99% and 90% of younger and older adults, against A(H3N2) in 100% and 90%, and against the B influenza strain in 91% and 78%. Pre-vaccination antibody titers were protective against A(H1N1), A(H3N2), and B in 26%, 44% and 33%, respectively of the adults below 61 years and in 27%, 54% and 44% of the subjects of 61 years and above. Local and systemic reactions were more common in younger than in older subjects and the most frequently reported reactions were pain at the injection site (36%), myalgia (24%), and fatigue (15%). Five percent elderly subjects and 1% of younger subjects had mild or moderate unsolicited adverse events such as prolonged ecchymosis or night sweats that resolved within 7 days after vaccination. CONCLUSIONS: This single dose trivalent seasonal influenza vaccine generated protective antibodies to all three viral strains and had an acceptable safety profile in both younger and older adults (ClinicalTrials.gov identifier: NCT01147081).

[Tick-borne encephalitis virus in humans and ticks in Northeastern Germany]. / Frühsommer-Meningoenzephalitis-Virus bei Menschen und Zecken in Mecklenburg-Vorpommern.

Tick-borne encephalitis (TBE) was known to have occurred in humans in the area of Mecklenburg-Western Pomerania in Germany, until 1985. Between 1992 and 2004 more than 16,000 ticks were tested and found to be negative for TBE virus in that area of Germany, wich was therefore thought to be free of TBE. But after 19 years three autochthonous cases of human TBE-infections were identified between 2004 and 2006. We subsequently collected ticks from the three areas where the infection had been acquired and tested them for the presence of TBE-virus RNA with a nested reverse transcription polymerase chain reaction (RT-PCR). Since there is evidence that a blood-meal leads to an increase of FSME-RNA in ticks, we tested both, unfed ticks and ticks after a blood-meal. Three unfed and one fed nymph from the area around Lake Woblitz and one unfed and one fed nymph from Thiessow were positive for TBE-virus RNA. A total of six of 250 (2.4%) ticks tested positive for TBE-virus. The emerging of human TBE infections in three regions in Mecklenburg-Western Pomerania shows that the activity of natural TBE virus foci does not cease even after decades, or that TBE-infected ticks could have recolonized these regions.

Schistosomula, pre-adults and adults of Schistosoma mansoni ingest fluorescence-labelled albumin in vitro and in vivo: implication for a drug-targeting model.

SUMMARY OBJECTIVE: Bilharziosis is one of the most important helminthal infections in humans and is caused by blood flukes of the genus Schistosoma. Three different life stages of the parasite occur within the mammalian host: schistosomula located in the skin, pre-adults located in the lung and adult worms located in the portal venous system. Erythrocytes are a major source of nutrient supply for adults. However, sources of nutrition for the developing stages are still unclear. METHODS: To investigate whether schistosomula, pre-adults and adults of Schistosoma mansoni ingest human serum albumin (HSA) in vitro, these life stages were incubated with aminofluorescein-labelled human serum albumin (Afl-HSA) for 5 h. To test the uptake of albumin in vivo, the albumin conjugate was given intravenously to S. mansoni infected NMRI mice 24 h before harvesting the 3 life stages. RESULTS: In comparison to the control group schistosomula, pre-adults, and adults showed an accumulation of Afl-HSA within the oesophagus and intestinal caecum in vitro and in vivo. CONCLUSION: Our findings suggest that albumin seems to be a major source of energy supply for the early schistosomal life stages and an additive energy support for adult worms. Since albumin has been used successfully as a drug carrier for chemotherapeutic substances against malignant disorders, further studies will focus on albumin as a carrier for anthelminthics in a drug-targeting model.