Intestinal schistosomiasis in chimpanzees on Ngamba Island, Uganda: observations on liver fibrosis, schistosome genetic diversity and praziquantel treatment.

Despite treatment with praziquantel (PZQ) at 40 mg/kg in food, several chimpanzees on Ngamba Island Chimpanzee Sanctuary (NICS) continue to excrete eggs of Schistosoma mansoni. To monitor disease, 8 animals were closely examined under anaesthesia in March 2011 with portable ultrasonography and by rectal snip biopsy. Schistosome genetic diversity had been previously assayed within 4 of these chimpanzees, finding extensive diversity with 27 DNA barcodes encountered, although none was common to all animals. Calcified schistosome eggs were found in the rectal snips from 5 chimpanzees and liver fibrosis was clearly documented, indicative of progressive disease in 6 animals, the latter being surprisingly advanced in a younger chimpanzee. All 8 animals were treated under anaesthesia by oral gavage with PZQ at 60 mg/kg dosing that was well tolerated. These animals were again re-examined in June 2012 using stool and urine sampling. Only 1 chimpanzee appeared to be free from infection and active egg excretion was confirmed in 6 animals. If intestinal schistosomiasis is to be controlled within this setting, a long-term disease management plan is required which should combine active case-detection with an insistent treatment regime with praziquantel for these chimpanzees, exploring perhaps the performance of even higher dosing.

Rifampicin mono-resistant Mycobacterium tuberculosis in Bujumbura, Burundi: results of a drug resistance survey.

SETTING: Bujumbura, Burundi. OBJECTIVES: To determine resistance levels of Mycobacterium tuberculosis (TB) to the main anti-tuberculosis drugs after 11 years of a DOTS programme using a WHO-recommended partially intermittent 6-month rifampicin (RMP) first-line regimen and fixed-dose drug combinations (FDCs). DESIGN: Drug susceptibility testing of systematic samples of M. tuberculosis isolated from newly registered sputum smear-positive cases in the capital during a 15-month period (2002-2003). RESULTS: Of 496 strains from new cases, 16.1% showed resistance to any drug, 6.3% to isoniazid (INH), 2.0% to RMP (1.4% multidrug-resistant TB [MDR-TB]), 13.3% to streptomycin and 1.6% to ethambutol. Among 69 strains from previously treated cases, the prevalence of resistance was 30%, 19%, 15% (12% MDR-TB strains), 25% and 6%, respectively. CONCLUSION: Levels of drug resistance in Bujumbura are higher than average for Africa, despite long-term use of the DOTS strategy with FDCs and a ban on sales of TB drugs. Most worrying is the appearance of MDR-TB and RMP-resistant, INH-susceptible strains in new cases. Although a survey cannot prove that high HIV prevalence, elevated levels of resistance to some other drugs and irregular intake allowed acquisition of drug resistance, the effectiveness and safety of 6-month regimens with (partially) intermittent RMP throughout under such conditions should be investigated.