Bat-borne viruses in Africa: a critical review

In Africa, bat‐borne zoonoses emerged in the past few decades resulting in large outbreaks or just sporadic spillovers. In addition, hundreds of more viruses are described without any information on zoonotic potential. We discuss important characteristics of bats including bat biology, evolution, distribution and ecology that not only make them unique among most mammals but also contribute to their potential as viral reservoirs. The detection of a virus in bats does not imply that spillover will occur and several biological, ecological and anthropogenic factors play a role in such an event. We summarize and critically analyse the current knowledge on African bats as reservoirs for corona‐, filo‐, paramyxo‐ and lyssaviruses. We highlight that important information on epidemiology, bat biology and ecology is often not available to make informed decisions on zoonotic spillover potential. Even if knowledge gaps exist, it is still important to recognize the role of bats in zoonotic disease outbreaks and implement mitigation strategies to prevent exposure to infectious agents including working safely with bats. Equally important is the crucial role of bats in various ecosystem services. This necessitates a multidisciplinary One Health approach to close knowledge gaps and ensure the development of responsible mitigation strategies to not only minimize risk of infection but also ensure conservation of the species.

Screening for syphilis among men who have sex with men in various clinical settings

OBJECTIVES

To assess the prevalence of syphilis infections among men who have sex with men (MSM) accessing the Brisbane Sexual Health Clinic during the period 1997 up to May 2003, data were collated through three clinical programmes conducted by the service-a large inner city mainstream sexual health clinic and two small outreach sessional clinics conducted on the site of male sex on premises venues (SOPV). Data analysis also provided the opportunity to evaluate the effectiveness of the smaller outreach clinics to access populations of MSM less likely to attend or identify at the larger mainstream clinic, and therefore enhance the detection of previously undiagnosed sexually transmissible infections.

METHODS

Computerised records from 1997-2003 were collated for a statistical analysis of syphilis and other STI pathology results for all MSM accessing the mainstream clinic, and two outreach clinics.

RESULTS

A review of client charts showed that 16 new syphilis diagnoses were made over the previous 5 years, but only two of these infections (both through the mainstream clinic) were early syphilis and therefore transmissible. All other cases were latent infections. A higher proportion of bisexual men was identified with positive syphilis serology but this was just below significance (p=0.06). Significantly, almost a third of syphilis diagnoses (all latent) were made at SOPV outreach clinics, despite the much lower proportion of clients seen overall through the SOPV clinics. For other sexually transmissible infections, the mainstream clinic demonstrated greater efficiency at case detection.

CONCLUSION

Outreach clinics located in male saunas may serve an effective function in syphilis screening by facilitating access for a particular subpopulation of MSM (bisexual, married men). These outreach clinics may provide important outlets for education and opportunistic screening of asymptomatic MSM and foster a greater willingness for men to honestly self identify. However, larger, mainstream clinics serve a more anonymous venue for the testing of symptomatic men.

A cluster of tuberculosis associated with use of a marijuana water pipe

SETTING

New cases of pulmonary tuberculosis (TB) were noted in a cluster of young Caucasian males, an unusual ethnic group for this disease in Queensland, Australia. It was noted that marijuana water pipe ('bong') smoking was common amongst cases and contacts.

OBJECTIVE

To report this cluster of TB and to investigate whether shared use of a marijuana water pipe was associated with transmission of TB.

DESIGN

All contacts were identified and screened according to standard protocols. Cases were asked to list contacts with whom they had shared a marijuana water pipe.

RESULTS

Five cases of open pulmonary TB were identified clinically and on sputum culture, and all isolates of Mycobacterium tuberculosis were identical on typing. Of 149 contacts identified, 114 (77%) completed screening, and 57 (50%) had significant tuberculin skin test (TST) reactions on follow-up. Of 45 contacts who had shared a marijuana water pipe with a case, 29 (64%) had a significant TST reaction.

CONCLUSION

Sharing a marijuana water pipe with a case of pulmonary TB was associated with transmission of TB (OR 2.22, 95 % CI 0.96-5.17), although the most important risk factor for acquiring TB infection in this cluster was close household contact with a case (OR 4.91, 95% CI 1.13-20.70).

Detection of Chlamydia trachomatis in an Australian high school student population

OBJECTIVE

To assess the prevalence of Chlamydia trachomatis infections among an Australian high school adolescent population.

METHODS

Over a 4 year period, 14 high schools were selected in which an infertility prevention programme targeting C. trachomatis was delivered to senior student populations. Coded first catch urine specimens were analysed by Amplicor PCR and infected students treated. Data retrospectively obtained from chlamydia screening programmes conducted among disadvantaged young people detached from formal education were also collated for comparison.

RESULTS

Of a total student test population of 1174, 15 (1.3%; 95% CI 0.7% to 2.1%) were diagnosed with C. trachomatis. Of 516 females and 658 males, 12 (2.3%; 95% CI 1.1% to 4.1%) and 3 (0.5%; 95% CI 0.1% to 1.4%) were tested positive respectively. Data collated for three populations of disadvantaged youth returned at total of 89 C. trachomatis infections out of 560 people (15.9% 95%CI 13.0-19.2%).

CONCLUSION

The overall prevalence of C. trachomatis infection among this population of senior high school adolescents is low, and significantly differs from the higher chlamydia rates detected in disadvantaged adolescents detached from formal schooling (p<0.0001).