Asking people who are
newly diagnosed with HIV or a sexually transmitted infection (STI) to recruit
contacts in their social network for HIV/STI screening is an effective way of
detecting previously undiagnosed infections, investigators report in the online
edition of the Journal of Acquired Immune
Deficiency Syndromes. The study was conducted in Malawi. Patients were
asked to recruit up to five individuals from their social or sexual network for
patients to recruit their social contacts was a feasible, effective and
efficient way of diagnosing new HIV cases in a generalized epidemic,” write the
authors. “To identify one new case of HIV infection only 8-10 contacts of
clinic seeds needed to be tested for HIV, much better efficacy than random
testing in the population.”
of adults in Malawi are HIV positive. But up to a third of HIV cases are
undiagnosed. Reducing the proportion of undiagnosed infections is a public
health priority. An international team of investigators wanted to see if social
network recruitment by people newly diagnosed with HIV/STIs was an efficient
and effective way of reaching people with previously undiagnosed infections.
designed a study involving two groups of patients – each numbering 45 individuals – who accessed care at the STI clinic at Kamuzu
Central Hospital in Lilongwe, Malawi between 2010 and 2012. The first group comprised people newly diagnosed with HIV; the second comprised people diagnosed with an STI
but not HIV. A control arm consisted of 45 individuals without HIV or an STI were
also recruited from the general, local population.
All the participants
were aged between 18 and 45 years. They were asked to recruit up to five
individuals in their social or sexual network for HIV/STI screening.
of participants were women and the mean age was 27 years.
The participants recruited
a total of 244 contacts. Over two-thirds (69%) of individuals recruited from
the community recruited at least one contact, compared to 53% of STI patients
and 47% of HIV-positive participants.
(62%) of contacts were friends or neighbours of the recruiting individual, 18%
were family members, 11% were sexual contacts (primarily spouses) and 8% had
Most of the
contacts (64%) were female and their mean age was 28 years.
HIV prevalence was
three times higher among the contacts of the HIV-positive patients than the
contacts of the community controls (31 vs 11%).
The contacts of
the HIV-positive patients and patients with STIs were more likely to have an STI
than the contacts of the community controls (29 vs 19 vs 9%).
A total of 20
patients were newly diagnosed with HIV through the study. Seven of these
individuals were recruited by patients with HIV, seven by STI patients and six
by community controls.
In order to
identify one new case of HIV it was necessary to screen eight contacts of the
HIV patients; ten contacts of the STI patients and 18 contacts of the community
To identify one
new STI, six contacts of patients with HIV, four contacts of STI patients and
eleven contacts of community controls required screening.
Identification of one
new case of HIV or a new STI required the screening of four contacts of patients
with HIV, three contacts of STI patients and seven contacts of the controls.
“High risk persons
tend to associate with other persons who engage in similar high risk
activities,” write the authors. “Even in the context of a generalized HIV
epidemic, STI and HIV risk was not evenly distributed, but rather, clustered in
believe their findings have implications for HIV screening and testing
strategies. “Our findings reflect a novel strategy for addressing a pressing
public health need: identifying undiagnosed, hard-to-reach cases of HIV
infection,” they conclude. “We demonstrated that asking STI patients to recruit
their social contacts was a feasible, effective, and efficient way of
identifying this population. These observations support social contact
recruitment extending the reach of the healthcare screening system. Such an
approach could become a powerful way of identifying HIV in hard-to-reach