No 34a - 2011
Gonorrhoea 2010
2010 saw 484 reported gonorrhoea cases in 464 persons. A total of 367 (76%) were male and 117 (24%) female cases. The median age was 24 years for females (range: 15-65) and 32 years for males (range:15-72). In all, 348 (72%) of the cases were detected by culture and reported to the Laboratory Notification System (LNS) and to the Notification System for Infectious Diseases (NSID) at the Department of Epidemiology. A total of 22 cases were only reported to the LNS and 114 only to the NSID. Among the 114 cases only reported to the NSID, the diagnosis was made by DNA detection in 84 (74%) cases. Nearly all of these cases occurred in the city of Copenhagen. Geographical distribution is shown in Table 1.
Notified cases
A total of 462 cases were notified to the NSID, including 350 cases in 337 males and 112 cases in 110 females. A total of 404 (90%) were Danish-born, 32 (7%) were immigrants, seven (2%) second generation immigrants and six (1%) were tourists. In 13 cases, the country of origin was not stated.
Mode of transmission
Among males, 166 (47%) were infected by females, 149 (43%) by males, and in 35 (10%) cases the mode of infection was unknown, Figure 1. Considerable geographic variation was seen in the share of males notified as MSM (males who have sex with males), e.g. 13% of males from North Jutland stated that they had been infected by males, while the corresponding share for Copenhagen City was 67%. Among MSMs, 92% were infected in Denmark, while this number was 62% for heterosexually infected males. Among heterosexually infected males > 40 years, 65% were infected abroad; approx. half of these cases were infected in Thailand. In contrast, only 22% of the male cases < 40 years were infected abroad. Among females, 87% were infected in Denmark.
Resistance
In 2010, the Reference Laboratory received 370 gonococcus isolates from Danish clinical microbiology departments. The isolates were tested for sensitivity to penicillin, fluoroquinolone and ceftriaxone. Penicillin resistance was found in 55% (57% in 2009), and 26% had reduced sensitivity (29% in 2009). A total of 19% were penicillinase-producing (14% in 2009). Fluoroquinolone resistance was found in 68% (75% in 2009) and 3% had reduced sensitivity (2% in 2009). Resistance or reduced sensitivity to both penicillin and fluoroquinolone was detected in 69% of the isolates (76% in 2009). No cases of ceftriaxone resistance were found.
Transmission and resistance
Fluoroquinolone resistance was detected in 51% of the isolates from homosexual males while the corresponding share was 74% in heterosexual males and 71% in females. Resistance to penicillin and fluoroquinolones occurred most frequently among Danes and was more frequently acquired abroad than in Denmark, Table 2.
Specific anatomical localisations
Gonococci were found in the joints of two males aged 32 and 35 years, respectively.
Region North Jutland
2010 saw a decrease in the the occurrence in 15-24-year-old females and a stagnation in males. Consequently, the observed increase in culture-confirmed gonorrhoea among 15-24-year-old males in Region North Jutland in the 2007-2009 period, EPI-NEWS 36/10, seems to have ended.
Commentary
A considerable proportion of the males who are heterosexually infected acquire their infection in the East where resistant gonococci strains are common. This explains that the occurrence of resistance is higher among heterosexually infected males than among MSM. It seems reasonable to expect that more resistant gonococci may be imported to Denmark. In the East, highly ceftriaxone strains have been observed.
The increase in the number of gonorrhoea cases observed since the beginning of the present millennium, EPI-NEWS 36/10 has not continued in 2010, and the proportion of resistant strains decreased slightly. Thus, 29% of the strains were fully sensitive to fluoroquinolones. In these patients, e.g. ciprofloxacine may be used. To ensure effective treatment, it is essential that the development of resistance be monitored nationally via monitoring of the submitted isolates. If gonococci are diagnosed by DNA testing, culture should be performed subsequently with a view to resistance determination.
(B. Søborg, S. Cowan, Department of Epidemiology, S. Hoffmann, DBMP)
24 August 2011